Seafood Watch Seafood Report
Florida Pompano (Trachinotus carolinus)
© Diane Rome Peebles
Florida Original report published: September 23, 2005 Stock update: September 15, 2011
Marianne Cufone, Esq. Maggie Ostdahl
Seafood Watch® US Florida Pompano Report
September 15, 2011
About Seafood Watch® and the Seafood Reports Monterey Bay Aquarium’s Seafood Watch® program evaluates the ecological sustainability of wild-caught and farmed seafood commonly found in the United States marketplace. Seafood Watch® defines sustainable seafood as originating from sources, whether wild-caught or farmed, which can maintain or increase production in the long-term without jeopardizing the structure or function of affected ecosystems. Seafood Watch® makes its science-based recommendations available to the public in the form of regional pocket guides that can be downloaded from www.seafoodwatch.org. The program’s goals are to raise awareness of important ocean conservation issues and empower seafood consumers and businesses to make choices for healthy oceans. Each sustainability recommendation on the regional pocket guides is supported by a Seafood Report. Each report synthesizes and analyzes the most current ecological, fisheries and ecosystem science on a species, then evaluates this information against the program’s conservation ethic to arrive at a recommendation of “Best Choices”, “Good Alternatives” or “Avoid”. The detailed evaluation methodology is available upon request. In producing the Seafood Reports, Seafood Watch® seeks out research published in academic, peer-reviewed journals whenever possible. Other sources of information include government technical publications, fishery management plans and supporting documents, and other scientific reviews of ecological sustainability. Seafood Watch® Research Analysts also communicate regularly with ecologists, fisheries and aquaculture scientists, and members of industry and conservation organizations when evaluating fisheries and aquaculture practices. Capture fisheries and aquaculture practices are highly dynamic; as the scientific information on each species changes, Seafood Watch®’s sustainability recommendations and the underlying Seafood Reports will be updated to reflect these changes. Parties interested in capture fisheries, aquaculture practices and the sustainability of ocean ecosystems are welcome to use Seafood Reports in any way they find useful. For more information about Seafood Watch® and Seafood Reports, please contact the Seafood Watch® program at Monterey Bay Aquarium by calling 1-877-229-9990. Disclaimer Seafood Watch® strives to have all Seafood Reports reviewed for accuracy and completeness by external scientists with expertise in ecology, fisheries science and aquaculture. Scientific review, however, does not constitute an endorsement of the Seafood Watch® program or its recommendations on the part of the reviewing scientists. Seafood Watch® is solely responsible for the conclusions reached in this report. Seafood Watch® and Seafood Reports are made possible through a grant from the David and Lucile Packard Foundation.
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Seafood Watch® US Florida Pompano Report
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Table of Contents I. Executive Summary…...……………………………………………………………..4 II. Introduction………………………………………………………………..…………6 III. Analysis of Seafood Watch® Sustainability Criteria for Wild-caught Species…...11 Criterion 1: Inherent Vulnerability to Fishing Pressure…………………………………….11 Criterion 2: Status of Wild Stocks…………………………………………………....…….13 Criterion 3: Nature and Extent of Bycatch…………...………………………….…….….17 Criterion 4: Effect of Fishing Practices on Habitats and Ecosystems………..…..…..…...19 Criterion 5: Effectiveness of the Management Regime……………………………….….23 IV. Overall Evaluation and Seafood Recommendation……………………………...27 V. References……………………………………………………………………..........31 VI. Appendices………………………………………………………..…….…….…….33
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Seafood Watch® US Florida Pompano Report
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I. Executive Summary Florida pompano is commonly referred to simply as “pompano” and is popular with both commercial and recreational fishing sectors. Florida pompano can be found in western Atlantic coastal waters from Cape Cod, Massachusetts to southeastern Brazil (including in the Gulf of Mexico). They are found year-round in waters off Florida, but appear to move north and south based on seasonal temperature change in nearshore waters (Berry and Iverson 1967). This report covers the Florida commercial fishery. Florida pompano are fast-growing and early-maturing with a life span of approximately 7 years (Florida Fish and Wildlife Conservation Commission, November 2003). All Florida pompano are mature by 14 inches in length, and some are mature as small as 10 inches and as young as one year of age (Guindon, Powell, and Barbieri 2002, unpublished data); it is believed that all males are mature by one year of age (Muller et. al. 2002). Peak spawning activity occurs during spring and fall (Finucane 1969a; 1969b), and spawning is believed to occur in offshore waters (Fields 1962). Their life history characteristics make pompano inherently resilient to fishing pressure. According to information from the Florida Fish and Wildlife Conservation Commission (FWC), the main agency with management authority for Florida pompano, the current status for the species is rebuilding, with overfishing likely occurring along the state’s Atlantic coast, although significant uncertainty around fishing mortality estimates exists. Stocks of Florida pompano on the Gulf of Mexico coast of Florida are considered a moderate concern, while stocks on the Atlantic coast of Florida are in poor condition. Fishing practices for Florida pompano differ somewhat between the Atlantic and Gulf coasts of Florida (Muller et al. 2002). Prior to the 1995 Florida Net Ban, which eliminated gillnet fishing for a variety of finfish, gillnets were the primary gear used to catch pompano (Richard Van Muenster, September 2004, Personal Communication, former Florida gillnet fisherman). There is still a gillnet fishery for Florida pompano in the federal waters of the Gulf of Mexico, but after 1995 cast nets and seine nets became popular for capturing Florida pompano along the Gulf Coast. On the Atlantic coast, Florida pompano are primarily caught with hook-and-line gears, including bandit gear (power rod and reel), rod and reel gear, and hand lines (Muller et al. 2002). Hook and line gears are also used to catch pompano along the Gulf Coast. Sport fishermen also catch pompano with cast and seine nets and hook and line gears; recreational landings dominate commercial landings of pompano on Florida’s Atlantic coast (Murphy et. al. 2008). Hook and line gear and cast and seine nets are selective and result in little bycatch or habitat impacts, while gillnets have a moderate impact on the seafloor and result in a moderate level of bycatch. The catch of fish in Florida has been managed by the state since 1861. Regulations specific to Florida pompano began in 1881 when it was deemed unlawful to catch them exclusively for the purpose of making oil, fertilizer, or compost (FWC, November 2003). Since then, size limits, bag limits, slot sizes, gear restrictions, and other rules have been created and implemented for Florida pompano. The most recent regulatory changes went into effect in late summer 2011. Effectiveness of the new management towards continued rebuilding of the Florida pompano stock cannot yet be determined, but overall management effectiveness is considered moderate.
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Seafood Watch® US Florida Pompano Report
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Florida pompano from both the Atlantic and Gulf of Mexico coasts of Florida is considered a Good Alternative, due to high inherent resilience of the species, moderate bycatch and habitat concerns, moderate to poor stock status, and moderately effective management.
Table of Sustainability Ranks Sustainability Criteria
Conservation Concern Moderate High
Low
Critical
√
Inherent Vulnerability Status of Stocks
√
√
Gulf Coast of Florida
Atlantic Coast of Florida
√ Nature of Bycatch
Hook and line, cast and seine nets
Habitat & Ecosystem Effects
Hook and line, cast and seine nets
√
√ Gillnets
√ Gillnets
√
Management Effectiveness
About the Overall Seafood Recommendation: • A seafood product is ranked Best Choice if three or more criteria are of Low Conservation Concern (green) and the remaining criteria are not of High or Critical Conservation Concern. • A seafood product is ranked Good Alternative if the five criteria “average” to yellow (Moderate Conservation Concern) OR if the “Status of Stocks” and “Management Effectiveness” criteria are both of Moderate Conservation Concern. • A seafood product is ranked Avoid if two or more criteria are of High Conservation Concern (red) OR if one or more criteria are of Critical Conservation Concern (black) in the table above.
Overall Seafood Recommendation: Gulf and Atlantic Coast of Florida : Best Choice
Good Alternative
5
Avoid
Seafood Watch® US Florida Pompano Report
September 15, 2011
II. Introduction Florida pompano is a member of the family Carangidae, which includes jacks and pompanos. Jacks and pompanos are often identified with their noticeable v-shaped tails. Coloration is usually a greenish gray on back, with shading to silvery sides. Those found in dark waters often show some gold on the throat, pelvic, and anal fins. Florida pompano have a deep, flattened body with a small mouth and no scutes. Soft dorsal rays usually number 22 to 27 with 20 to 23 soft anal rays. The origin of the anal fin is slightly behind the origin of the second dorsal fin (www.marinefisheries.org 2004). Florida pompano range from western Atlantic coastal waters by Massachusetts, down the U.S. East Coast, throughout the Gulf of Mexico, including along Central and South American coasts and through scattered West Indies localities (Smith 1997), and southward to Brazil and some say even Argentina (Bull Mar. Sci. 2000. 66(2): 399-403). They are absent from clear waters of the Bahamas and similar islands (www.fisbase.org 2004), but are found year-round in waters off Florida, though they move north and south based on water temperature changes (Berry and Iverson 1967). Adult pompano are generally found along sandy beaches, near inlets, and in brackish bays and estuaries (Berry and Smith-Vaniz 1977). They are also known to school in offshore waters over shoals and submerged structures. Florida pompano are frequently found in turbid water and may occur at depths up to 130 feet (www.marinefisheries.org 2004; FWC, November 2003). Along the Atlantic Seaboard of the U.S., adult Florida pompano are reported to move north in the summer (Fields 1962, Berry and Smith-Vaniz 1977); however, movement patterns and stock identification remain relatively unknown for pompano from both Atlantic and Gulf of Mexico waters (Bellinger and Avault, Jr. 1970). Though detailed dietary studies have not been completed for Florida pompano, it is generally believed that they feed on mollusks and crustaceans, especially sand fleas. Florida pompano grow rapidly and scientific estimates of maximum age are about 7 years. Florida pompano can mature as early as age one and are believed to spawn offshore, though this has not been observed. Recent evidence based on maturity stages of ovaries suggests that spawning habitats may be more inshore than previously suggested (Guindon, Powell, and Barbieri 2002, unpublished data). In the Gulf of Mexico, juvenile abundance indicates that peak spawning is during spring and fall (Finucane 1969a; 1969b). Off the Atlantic coast of Florida, juvenile abundance suggests that spawning occurs February to September with a peak in April to May (Fields 1962; Berry and Iverson 1967). Juveniles are found in the surf zone, as they prefer warmer (62 – 87º F), high salinity (> 32 ppt) waters (Finucane 1969a; 1969b). Most recruitment in the Gulf of Mexico is during April – May, followed by a smaller, secondary period of recruitment during August – September (Bellinger and Avault 1970; Modde 1980; Guindon, Powell, and Barbieri 2002, unpublished data). Along the Atlantic coast, most recruitment occurs during April – May in Florida and Georgia, June – July in North Carolina and South Carolina, and July – August in Delaware (Tagatz and Dudley 1961; Fields 1962; de Sylva, Kalber, and Shuster 1962; Cupka 1972; Anderson et al. 1977; Peters and Nelson 1987).
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Seafood Watch® US Florida Pompano Report
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Average catch size for Florida pompano is about 1 – 3 pounds (William Ward, October 25, 2004, Personal Communication, Owner, Captain’s Finest Seafood and Gulf of Mexico Commercial Fisherman). Female fish are believed to grow faster and reach larger sizes than males (Guindon, Powell, and Barbieri 2002, unpublished data). The most popular commercial catch size (and sale size) is 2 – 3 pounds (William Ward, October 13, 2004, Personal Communication, Owner, Captain’s Finest Seafood and Commercial Fisherman). The record recreational catch for Florida pompano on conventional gear is 8 lbs (pounds), 4 oz. (ounces) at Port St. Joe in 1999. The record for fly tackle is 6 lbs, 8 oz. at Cocoa Beach in 1978 (Mike Leech, November 3, 2004, Personal Communication, International Game Fish Association). Florida pompano is valuable to both commercial and recreational fishing sectors. Commercial fishermen target Florida pompano because it delivers very high prices in the market, often fetching from $3.00 – $5.00 per pound. The National Marine Fisheries Service (NMFS) tracks commercial fish landings and estimated value through its annual commercial landings statistics database (www.st.nmfs.gov, 2004) (see Table 5, in Appendix I, for detailed commercial landings information, including estimated catch values). High price in the market and resilience to salinity and temperature ranges make Florida pompano a good candidate for aquaculture. Aquaculture of Florida pompano and pompano-like species is common internationally, but not yet domestically. Some local science institutions are working on pilot projects to establish the feasibility of Florida pompano commercial production for food purposes (Dr. Daniel Benetti, November 2004, Personal Communication, Rosenstiel School of Marine and Atmospheric Science, University of Miami). Information on commercial catch is fairly good in Florida, as it is taken from the state “trip ticket” records. Commercial fishermen (without a wholesaler’s license) are required to sell their catch to wholesale fish dealers. The dealers must submit ‘trip tickets’ to the Florida Marine Research Institute (FMRI). Each trip ticket includes the fisherman’s Saltwater Products License number, the wholesale dealer license number, the date of sale, the gear used, trip duration, area fished, depth fished, number of traps or number of sets, where applicable, species landed, quantity landed, and price per pound (FWC, November 2003). Current information from the NMFS commercial landings database shows some fluctuation in the pompano catch, but an overall decrease in the commercial catch of Florida pompano in the Gulf of Mexico and the South Atlantic for 1990 – 2003. Sport-fishermen also enjoy targeting Florida pompano because they can be challenging to catch. Shore-based anglers fishing along beaches, piers, and jetties constitute most of the recreational Florida pompano fishery. Recreational landings are estimated through the NMFS Marine Recreational Fisheries Statistics Survey (MRFSS) (see Tables 6, 7, 8, 9, and 10, in Appendix I, for detailed recreational landings information). In Gulf of Mexico federal waters (waters in the U.S. exclusive economic zone, EEZ, 3 to 200 miles offshore) in recent years (2002 – 2004), Florida pompano recreational landings have declined, from an estimated 3,500 pounds to 1,947 pounds, with a low in 2003 of only 148 pounds. In the South Atlantic EEZ there have been little Florida pompano recreational landingsreported. From 1995 – 2004 only a total of 1,450 pounds were noted by NMFS. In Florida state waters combined (east and west coasts) recreational landings have fluctuated, but 7
Seafood Watch® US Florida Pompano Report
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have generally increased since 1995. More recent years (2000 – 2004) show a 10-year high in 2000, a dip in 2002, and a higher catch in 2003 (trends may differ some depending on whether weight or number of fish is used as the landings estimate). From both the NMFS MRFSS data and information from the state of Florida (Muller et al. 2002), it is clear that the majority of sport-fishing for Florida pompano occurs in Florida state waters (see Tables 7, 8, 9, and 10, in Appendix I). Still, the overall trend throughout state waters Gulfwide (except for catches in state waters off Florida’s west coast, which have generally decreased if reviewed independently from the Florida east coast catches) is increased Florida pompano landings in recent years (1995 – 2004) (see Table 10, in Appendix I). In South Atlantic state waters, landings in all states have fluctuated some, but there has been a general increase in Florida pompano recreational catch since 1995 (see Table 9, in Appendix I). Given that stocks of Florida pompano are rebuilding, and that recreational catch of pompano is a significant contributor to overall fishing mortality, continued increase in recreational catch of pompano is problematic. Pompano are managed by the Florida Fish and Wildlife Conservation Commission (FWC), a state constitutionally-created entity tasked with all wildlife management in the State of Florida. Though Florida pompano can be found (and are caught) in federal waters, the State of Florida still assumes primary responsibility for management of the species because Florida pompano traditionally was mostly a Florida state fishery. First regulations were put in place back in 1881. In 1925 the Florida Legislature established limitations for pompano. Following that, a number of other rules have been implemented, which have changed the minimum size for pompano, established bag limits, limited gear types, and more. The primary regulation, however, that has affected the catch of Florida pompano was the 1995 State Constitutional Amendment prohibiting the use of gillnets in state waters (Article X Section 16, “The Net Ban”). Currently, gears used to catch Florida pompano include seine and cast nets, bandit rigs (power rod and reel), and standard fishing poles (Muller et al. 2002; William Ward, October 25, 2004, Personal Communication, Owner, Captain’s Finest Seafood and Gulf of Mexico Commercial Fisherman). Additionally, there is still a gillnet fishery in federal waters, which is under strict management with licensing and special circumstances requirements. Despite the ban on gill nets in state waters, pompano landings with gill nets increased from 1996 – 2000, likely indicating an expansion of the federal gillnet fishery, rather than an increase in pompano abundance (Cody et al. 2000). Regulations enacted by the FWC in November 2001, including a Pompano Special Activity License and restrictions on having Florida pompano and gillnets on the same boat, should help minimize the offshore commercial pompano fishery (Muller et al. 2002). Though the FWC monitors stock status and tries to manage for maximum sustainable yield, regulations have not been as successful as hoped. Rumors of illegal gill-netting in state waters are notable, though purportedly decreasing. New regulations for pompano were implemented in 2003 and in 2011 to help rebuild the species. The minimum size limit has been increased, and gillnet trip limits along with the extension of state regulations into federal waters are being implemented. Future possible management measures for consideration include closed areas and seasons, trip limits for gill netters in federal waters, and changes in size and bag limits.
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Seafood Watch® US Florida Pompano Report
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Figure 1. Map including Florida pompano range: Massachusetts, U.S. – southeastern Brazil in Western Atlantic waters, including Gulf of Mexico and some areas of the West Indies .
Scope of the analysis and the ensuing recommendation: There are a number of fish identified and/or sold as “pompano” aside from Florida pompano, including African pompano (different size and market, but also identified as “pompano”), and silver pomfret and black pomfret; all these species are both wild-caught and cultured internationally. While the markets for each species may differ (Florida pompano verses African pompano, for example) based on quality and texture of product, all are seafood items found in the Southeast Region of the U.S. This report focuses on wild-caught Florida pompano, as it is the most popular of these species for the U.S. market. The recommendations in this report are thus specific to U.S. Florida pompano stocks and do not account for foreign-caught fish labeled as pompano or foreign-cultured pompano (as Florida pompano is not currently being cultured domestically for commercial food purposes). Some information is provided at the end of this report on African pompano, silver pomfret, and black pomfret for use in future seafood recommendations or general knowledge.
Availability of Science Florida pompano have been the subject of study in Florida for some time. Because Florida pompano are popular both commercially and recreationally in and near Florida, assessments are conducted periodically (five between 1994 – 2008) by the state marine wildlife management entity (FWC/Florida Marine Research Institute, FMRI) and regulations are implemented periodically to monitor and control the pompano stock (with first regulations in 1881 by the Florida Legislature). Assessments include some known life history information. Genetic analysis to identify potential independent stocks within the species range is not complete, so stocks are currently discussed by coast (east or west), rather than distinct genetic stocks.
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Seafood Watch® US Florida Pompano Report
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Only a small number of tagged Florida pompano have been returned during conducted tagging studies, apparently none of which migrated from one coast of Florida to the other. The FWC indicated that additional tagging studies could be done to estimate the extent of Florida pompano movement and migration and to determine the stock range. Tagging studies could also be used to verify estimates of fishing mortality derived from the stock assessment (Muller et. al. 2002; FWC, November 2003). The Muller et al. (2002) pompano stock assessment update used a 15% release mortality rate. This rate is based on bluefish, and not directly estimated for Florida pompano. Additional studies should be conducted to determine true release mortality rates for Florida pompano. Continued work on the life history of Florida pompano is needed to validate ages and develop guidelines for reading pompano otoliths (ear bones). Other areas that require additional research relative to pompano reproductive biology are: maturity schedules (what percent of pompano spawn at various ages?); spawning events and habitat; and fecundity (how many eggs do various sizes or ages of female pompano produce?) (FWC, November 2003). According to the FWC, the major impediment to a full assessment of fishing impacts on the Florida pompano stock is a lack of adequate age composition data for all sectors in the fishery. The overlap of ages at any given size necessitates sampling of landings directly for age. This will require collecting age-length data for several years (7 – 10 years) before an age-structured stock assessment analysis can be used to evaluate the impacts of different sectors in the fishery (FWC, November 2003).
Market Availability Common/Market Names Florida pompano is also known simply as pompano. Seasonal Availability Florida pompano can be found year-round near and off Florida’s east and west coasts, but natural, small stock size and difficult catchability make it scarce on menus when compared with other locally popular fishes, like snappers and groupers. The commercial fishery for pompano is not at all stable, with variance seasonally, suggesting either a strong annual migration of the fish or a change in availability with season. Along the Gulf coast, the Florida pompano fishery is year-round and progresses northward during the summer. Along the Atlantic coast, the fishery operates from late fall through early spring. Product Forms Given their small average size (about 1 – 3 pounds), Florida pompano are usually sold whole, with head and tail on or off at about $3 – $3.95 per pound (some fish houses even report up to $5.00 per pound). It is often served stuffed with a crab or shrimp mixture and cooked “en papille,” in parchment paper. Florida pompano are most often a special menu item at high-end seafood or Hispanic restaurants. Product Sources In the U.S. Southeast region, especially Florida, often the Florida pompano served are from local
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Seafood Watch® US Florida Pompano Report
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catches. There are also, however, a number of wild pompano and pompano-like imports (see Supplemental Information on Related Species, at the end of this report) and also aquacultured products that come to the U.S. from India, Indonesia, Japan, and other locales with avid aquaculture programs.
III. Analysis of Seafood Watch® Sustainability Criteria for Wild-caught Species Criterion 1: Inherent Vulnerability to Fishing Pressure There is not a great amount of data available on Florida pompano life history characteristics. Generally speaking, these fish are fast-growing and early-maturing, able to reproduce at a very young age (50% of females mature by 1 year of age; 100% of females mature by 2 – 3 years; 100% males mature by 1 year). While natural stock size is thought to be small when compared to virgin biomass of other popular food fish (thus making pompano more easily susceptible to overfishing), this natural fast-growing, early-reproducing pattern makes it more likely that the species can rebuild rapidly after being subject to significant fishing pressure (Peter Hood, Personal Communication, December 17, 2004, National Marine Fisheries Service). Catching Florida pompano is a challenging task. They have no special characteristics that make them easy targets. Florida pompano tend to move locally based on tides and regionally based on temperature, so they are not always present in certain locations. They are not as easily found and landed as other popular species. (Several local fishermen repeatedly indicated that if there were more Florida pompano to be had, they would catch them, as the species fetches a high market price and is a popular high-end seafood choice.) Research is still being conducted to ascertain the existence of multiple pompano stocks within its range and whether there are regional size, behavioral, and reproductive differences. If there are numerous stocks throughout the range of Florida pompano, some more vulnerable than others, this may influence Florida pompano vulnerability to overfishing. Currently while Florida pompano habitat areas have been harmed by a number of outside influences (water pollution, debris, etc.) there is still significant habitat available to support the species throughout its range.
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Seafood Watch® US Florida Pompano Report
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Table 1. Life history information summary. Intrinsic Von Growth Age at rate of Bertalanffy Rate/Max. Size Maturity increase (r) Growth Coefficient (k) High Atlantic: Rapid growth Females: 0.08 0.8 – 1.2 50% 1yr; Gulf: 0.06 inches/month 100% 2 – 3 Up to 11 inch yrs. yr 1 Males: Max rpt: 25 100% 1 yr. inch 8 lbs
Longevity Fecundity
Up to 7 yrs; Uncertain 3 – 4 years most common
Species Range
Massachusetts through southeastern Brazil, including Gulf of Mexico and West Indies
References
Fields 1962 Finucane 1969a,b,c Froese & Pauly 2002 FWC, Nov. 2003 Hood et al., in review Iverson & Berry 1969 Muller et al. 2002
Synthesis Florida pompano have a relatively low age (and size) at maturity. The small natural stock size makes Florida pompano arguably more susceptible to depletion, but also allows for rapid recovery to normal levels. In general, stock size can be viewed as a wash with respect to vulnerability. Florida pompano have no known special behaviors that increase ease of capture or population consequences of capture, and habitat areas are still able to support the species. Florida pompano therefore, are characterized as being inherently resilient to fishing pressure. Inherent Vulnerability Rank: Resilient
Moderately Vulnerable
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Vulnerable
Seafood Watch® US Florida Pompano Report
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Criterion 2: Status of Wild Stocks Management Classification Status: Recovering from overfished on Atlantic and Gulf coasts Prior to the most recent stock assessment, Florida pompano were considered overfished, and overfishing was occurring. The Florida Marine Research Institute (FMRI), the science division of the FWC, has completed five stock assessments of Florida pompano – in 1994, 1996, 2001 (a preliminary assessment), 2002, and 2006. The methods used in each of these stock assessments have varied; the most recent 2006 assessment contains fisheries-dependent and independent data through 2005 (commercial and recreational catch and effort, changes in relative abundance, and growth and reproduction) to assess condition of the stock. The 2006 assessment employed a suite of fishery models, where the two models deemed to have the most robust data were the non-equilibrium surplus production model (describes biomass over time); and a new stochastic stock reduction analysis (reconstructs the historical fishery and estimates uncertainty around population parameters of most interest to managers, e.g. MSY). This most recent pompano stock assessment is subdivided into Gulf and Atlantic coasts of Florida due to differing exploitation levels and possible differences in pompano life history (Murphy et. al. 2008). The 2006 assessment showed that population biomass estimates on both Atlantic and Gulf coasts of Florida generally exceeded minimum stock size thresholds, so it is unlikely that pompano stocks are still overfished (Murphy et. al. 2008). Current population abundance relative to BMSY: Atlantic – Moderately below BMSY Gulf – Above BMSY Florida’s FWC has not defined a control rule for determination of overfished/overfishing status. However, the stock assessment models used do allow for MSY-based estimates. Biomass associated with MSY was estimated to be 1.5 million pounds on the Atlantic coast; and 0.9-2.3 million pounds on the Gulf coast (Murphy et. al 2008). Based on conventional guidance for minimum stock size threshold, pompano would be overfished in the Atlantic at 0.9 million pounds and in the Gulf at 0.5-1.4 million pounds. Depending on the different models, abundance estimates of pompano for 2005 range from 0.8-1.5 million pounds in the Atlantic. The stock reduction analysis model estimates that pompano biomass is at the high end of this range, and just above Bmsy, while the surplus production model generates estimates of biomass that are generally above a minimum stock size threshold but below estimated BMSY. Erring on the side of caution, we consider that stock biomass is likely moderately below Bmsy. Pompano population abundance in the Gulf is more stable with estimates of biomass around 3.8 million pounds (above estimated BMSY) (Murphy et. al. 2008). Figure 2 below illustrates recent pompano abundance estimates.
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Seafood Watch® US Florida Pompano Report
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Figure 2. Estimated ratios of annual estimated average vulnerable stock biomass to the biomass associated with maximum sustainable yield for the surplus production model (filled circles) and stock reduction model (open circles) for Florida pompano on the Atlantic and gulf coasts of Florida during 1981-2005. The biomass-at-MSY ratio is given by the dashed horizontal line at 1.0 and the minimum stock size threshold (defined as [1-M]BMSY) by the solid horizontal line at 0.6. Figure from (Murphy et. al. 2008).
Occurrence of overfishing: Atlantic – Overfishing occurring Gulf – Overfishing not occurring The two models deemed most reliable in the most recent stock assessment (surplus production and stochastic stock reduction) differ as to analysis of whether overfishing is occurring on the Atlantic coast, leading to a great deal of uncertainty surrounding fishing mortality estimates. The surplus production model used in the recent stock assessment estimates FMSY to be around 0.38 on both coasts of Florida. The stock reduction analysis model generates higher estimates of Fmsy, around 1.19 on the Atlantic coast and 2.0 on the Gulf coast. While the stock reduction model only indicated overfishing during the period of 1998-2000 on the Atlantic coast, and yielded an estimated F/Fmsy ratio of 0.44; the surplus production models generally indicated overfishing since 1998, with current estimates of F at 0.684, yielding an estimated F/Fmsy ratio of 1.82. Erring on the side of caution, we rank this stock as likely experiencing overfishing on the Atlantic coast of Florida. There is much less uncertainty when it comes to the Gulf coast; neither model’s estimates indicated overfishing since 1981 (Murphy et. al. 1998). Figure 3 below shows estimates of F.
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Seafood Watch® US Florida Pompano Report
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Figure 3. Annual estimates of the ratio of fishing mortality (F) to the fishing mortality at maximum sustainable yield for the surplus production model (filled circles) and the stock reduction model (open circles) for Florida pompano on the Atlantic and gulf coasts of Florida during 1981-2005. Figure from (Murphy et. al. 2008).
Overall degree of uncertainty in status of stock – Medium for both Atlantic and Gulf The extension of data time-series and changes to the stock assessment models and analyses are considered improvements to the understanding of pompano stock status, but uncertainty as to abundance and fishing mortality still exists on both coasts, if to a somewhat lesser extent on the Gulf coast. The two preferred models from the most recent stock assessment differ substantially on estimates of fishing mortality for the Atlantic coast. Additionally, there have been large changes to input data from recreational effort, which is significant for pompano. There is also minimal age-composition data, so the 2006 assessment acknowledges difficulty in analyzing yield-per-recruit or spawning stock biomass (Murphy et. al. 2008). Trends (relative to species’ generation time) in population abundance as measured by either fishery-independent (stock assessment) or fishery-dependent (standardized CPUE) measures Long term trend: Atlantic – variable Gulf – up Short-term trend: variable or flat for both Atlantic and Gulf coasts
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As shown in Figure X above, population abundance of pompano trends upward over the longterm in the Gulf, and is variable in the Atlantic. Over the shorter term, pompano population abundance appears stable in the Gulf, and remains variable in the Atlantic. Current age, size or sex distribution of the stock relative to natural condition: unknown for both Atlantic and Gulf coasts Stock distribution parameters of pompano are generally unknown; there is little age-composition data to evaluate. Similarly unclear is whether size distribution of the stock is at all skewed, although a recent analysis of minimum size limits indicates tentatively positive impacts to the spawning stock biomass if minimum size were to be increased again, from 11 to 12 inches (FWC 2011). Table 2. Summary of stock status (data from Murphy et. Al. 2008).
Stock
Classification F2005/FMSY Status Atlantic*
B2005/BMSY Atlantic*
F2005/FMSY Gulf*
B2005/BMSY Gulf*
Abundance Trends
Florida pompano
Rebuilding; overfishing probable in Atlantic
0.53 – 0.87**
0.12 – 0.30**
4.22 – 1.65**
Stable after increase in Gulf; variable in Atlantic
0.44 – 1.82**
*Information taken from Murphy et. Al. 2008. **When biomass ratio is < 1, the stock is overfished and when fishing mortality is >1, the stock is experiencing overfishing.
Synthesis Pompano stocks on both the Atlantic and Gulf coasts of Florida appear to be recovering from being overfished, although there is a moderate degree of uncertainty in both cases. Stock distribution parameters are unknown; and short-term population abundance trends are variable or steady in both cases. On the Atlantic side, long-term population abundance is also variable; and while there is a high degree of uncertainty as to fishing mortality, overfishing is likely occurring. Whereas on the Gulf coast long-term population abundance trends upwards and overfishing is likely not occurring. Therefore, pompano stocks along the Atlantic are now considered in poor health; while stocks along the Gulf coast of Florida are of moderate concern. Status of Wild Stocks Rank Atlantic Coast: Healthy
Moderate/Rebuilding
Poor
Critical
Moderate/Rebuilding
Poor
Critical
Gulf Coast: Healthy
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Seafood Watch® US Florida Pompano Report
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Criterion 3: Nature of Bycatch Seafood Watch® defines sustainable wild-caught seafood as marine life captured using fishing techniques that successfully minimize the catch of unwanted and/or unmarketable species (i.e., bycatch). Bycatch is defined as species that are caught but subsequently discarded (injured or dead) for any reason. Bycatch does not include incidental catch (non-targeted catch) if it is utilized, accounted for and managed in some way. According to Muller et al. (2002), there is no bycatch information available for the current Florida pompano fishery. According to the FWC (November 2003), incidental catch and bycatch information were derived from the Marine Fisheries Information System (MFIS) and on-board observer trips that targeted Florida pompano in federal waters. The most common species taken incidentally, as noted by commercial fishermen who also reported catching Florida pompano, are: Spanish mackerel, jack crevalle, king mackerel, striped mullet, bluefish, permit, and various sharks. During onboard observer trips, the most common species caught in conjunction with Florida pompano were: Spanish mackerel, jack crevalle, bluefish, cownose rays, blue runner, and undersized Florida pompano (less than 10”) (Cody et al. 2000). Though bycatch data are limited, the primary gear types used for catching Florida pompano are also employed in various other fisheries. Therefore, typical occurrences of bycatch for those gears during common usage can impute some conclusions with respect to their impact on ecology when used to catch Florida pompano. Gill nets Gill nets are known to have frequent interactions with marine mammals, sharks, and other nontarget species. They function by entangling, often fatally, marine life that comes in contact with the gill nets. The indiscriminate manner in which gill nets operate prompted a ban on their use in Florida waters in 1995. Gill nets are still permitted for catching Florida pompano in federal waters, with special permits and conditions and anecdotal information indicates that bycatch has been minimal, though there is real potential for more significant impacts if gill nets are left to soak for long periods, abandoned, or lost. However, pompano are targeted with small mesh gillnets (≤ 5 inches) (FMRI 2003), which have been shown to have less marine mammal bycatch than medium and large mesh gillnets (Palka and Rossman 2001). In addition, gillnet strikes on a school of pompano result in the majority of the catch being pompano, and other species caught such as Spanish mackerel and bluefish are landed (FMRI 2003). Hook-and-line gear Other gears used to target Florida pompano are collectively known as hook-and-line gear. This includes bandit reels (power rod and reel) and standard fishing poles (rod and reel). Bandit gear and standard rod and reel gear bring up one or several fish at a time (depending on rigging). These gears are constantly attended, meaning someone is present by the gear when the catch is landed, providing ample opportunity for live release and rehabilitation of bycatch. In terms of environmental impacts, discarded line (monofilament) is possibly more harmful than the actual fishing using hook-and-line methods. Discarded line can become entangled on coral, fish, seabirds, marine mammals, and sea turtles, often proving fatal. All gears in the hook-and line category have similar configurations and functions, though with some apparent differences.
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Seafood Watch® US Florida Pompano Report
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Rod-and-reel gear Probably the most recognized fishing gear type, rod-and-reel gear consists of a pole with line running its length and a hook on the end of the line. The line is lowered into the water using a spool-like device known as a reel and remains near or on the ocean bottom, often held there by a weight or “sinker.” Usually such gear is constantly attended (sometimes fishing poles are placed in slots on boats and dragged through the water or “trolled” to catch fish, but ultimately someone needs to reel in the catch). Because rod-and-reel gear catch one fish at a time and are powered only by human strength, they provide a good opportunity for any unwanted catch to be immediately released. Therefore, while there is still some bycatch (those fishing with rod-andreel gear cannot see their target and may catch species different than those intended), there is usually less mortality of that bycatch. Bandit gear Bandit gear is similar to rod and reel gear with two notable modifications: 1) the line is reeled in electronically; and 2) often more than one hook is present on each line. Anywhere from 2 – 8 hooks are standard per bandit rig. Because bandit gear can retrieve a catch more quickly from the water under electric power than can standard rod-and-reel gear under human power, and can also catch more than one fish at a time, it might have a higher bycatch rate and mortality than rod-and-reel gear, depending on the resilience of the fish caught and the skill of those fishing. However, most bandit rigs are constantly attended, so unwanted catch still may have good chance of being properly rehabilitated and returned to the water with limited harm. Cast or seine nets Both cast and seine nets are set around a particular catch, in this instance a school of Florida pompano. While there might be a few other creatures inside the netted school, most of the catch will be the targeted Florida pompano. For this reason, there is little bycatch associated with these gears when they are attended. Similar to concerns with gill nets, cast and seine nets can cause problems when lost or abandoned. These nets can ensnare and kill a wide array of marine life when floating freely through ocean waters. Synthesis Generally speaking, most of the gears used to target Florida pompano have little bycatch, though bycatch is often associated with them in other fisheries. Gill nets can entangle a wide variety of species that contact fishing gear. Abandoned, lost, or long-soaking gill nets in particular can cause severe harm to wildlife and habitat. While gill nets used to catch Florida pompano are fished differently that traditional gill nets, the potential for significant bycatch if the gear is lost, abandoned, or over-soaked is factored into the ranking. Similarly, lost or discarded monofilament and lost or abandoned cast or seine nets all have bycatch potential. Though there is no noted bycatch data for the current pompano fishery, based on results in other fisheries with similar gears, bycatch for Florida pompano caught with hook-and-line gear or cast and seine nets is a low conservation concern. Bycatch for Florida pompano caught with gill nets is a moderate conservation concern.
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Seafood Watch® US Florida Pompano Report
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Nature of Bycatch Rank: Hook and line, cast and seine net: Low
Moderate
High
Critical
Moderate
High
Critical
Gillnet: Low
Criterion 4: Effect of Fishing Practices on Habitats and Ecosystems Habitat Effects As discussed above, the primary fishing gears used to capture Florida pompano are: gill nets, seine or cast nets, bandit rigs (power rod and reel), and standard rod-and-reel gear. Prior to the constitutional prohibition on entangling nets in state waters in 1995, gill nets were the primary gear used to catch Florida pompano (accounting for 83% of Florida pompano landings). After 1995, only seines, cast nets, or hook-and-line gear could be used by commercial fishermen to catch Florida pompano in state waters. This motivated a shift in effort from inshore state waters to offshore federal waters. Landings reported from federal waters, where the use of gill nets was, and is, still legal, rapidly increased. From 1996 to 2000, 59% of the commercial Florida pompano harvest was by gill or trammel nets. This rapid increase in the federal waters net fishery inevitably resulted in the FWC establishing regulations and licensing requirements for commercial fishermen to legally possess Florida pompano caught with gill nets in federal waters (FWC, November 2003). On the Atlantic coast, the majority of Florida pompano landed in 2000 were caught using hookand-line gear (60%), gill nets (28%), and cast nets (11%); the percentage of Florida pompano landed in 2000 from the Atlantic coast using gill nets was a decrease from the percentage caught in 1992 – 1994 using gill nets. On the Gulf coast in 2000, the majority of the landings continued to be caught using gill nets (54%) but fishermen also used other gears to catch Florida pompano, such as cast nets (31%), and hook-and-line gear (7%) (Muller et. al. 2002).
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Seafood Watch® US Florida Pompano Report
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Figure 4: Breakdown of gear types used on the Atlantic coast to catch Florida pompano. Data taken from Muller et al. 2002.
Figure 5: Breakdown of gear types used on the Gulf coast to catch Florida pompano. Data taken from Muller et al. 2002.
Gill nets Of all the gears employed for catching pompano, only gill nets are usually set on the ocean floor. However, when used for catching Florida pompano, gill nets are most often set around a school of fish and pulled almost immediately, rather than being placed as a wall with weights on the bottom of the net and allowed to soak until fish are entangled. The degree of actual habitat impact is determined by many factors, most notably: 1) the weight of gear used; 2) the resilience of the seabed; and 3) the amount and frequency of the disturbance. Gill net disturbance of the seabed is largely dependant on bottom type (e.g., rock and sand verses coral and seagrass). Some sediment types (and their associated ecosystems) are more resilient to certain disturbances. As entangling nets can be set on the ocean bottom, using lead weights, some bottom disturbance is likely during setting and retrieving. Additionally, if gill nets are lost,
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Seafood Watch® US Florida Pompano Report
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abandoned, or over-soaked, they might sweep across the ocean bottom for long periods of time with tidal action, more severely harming the environment. When used carefully, gill nets are not intentionally dragged for long expanses across the ocean floor and therefore, habitat impacts are likely to be much less severe than with other gears, like trawls. Hook-and-line gear (rod-and-reel and bandit gear) Bandit and rod-and-reel gears do not usually contact the ocean bottom, but rather hang in the water column. Significant habitat damage is thus not typically associated with these gears. Primary habitat impacts do occur, however, from discarded or lost fishing line and sinkers from these gears. Monofilament line is very durable and does not easily decompose in ocean waters, and lines can become entangled on important habitat, like coral forms, ultimately causing die-off of corals. Correct disposal of fishing line can help prevent habitat impacts from these gears. Sinkers are small lead weights used on fishing line to submerge and retain the fishing line under water. It is not regular practice to discard these weights by cutting the line as constantly replacing them can be expensive; however, some sinkers do end up on the ocean bottom when lines break or are cut. Though the weights are usually small, many are still crafted from lead and can do damage to fragile habitat. Cast and seine nets Both cast and seine nets are set in the water column to catch schools of fish and do not frequently cause habitat damage. As with gill nets, however, lost or abandoned gear can be a problem. In addition to entangling marine life, unattended cast or seine nets can tangle around bottom habitat. Eventually, increased algal growth on and around such tangled nets can suffocate fragile systems like corals and seagrasses. Ecosystem effects Though all fishing arguably has an impact on ecosystems, some is more harmful than others. The Southeast Atlantic and Gulf of Mexico regions are well known for fishing activities and are home to some of the most popular local food fishes (shrimp, groupers, snappers, and pelagics like mahi-mahi and various sharks). Despite the use of gill nets in federal waters, Florida pompano is a very small fishery and thus is not a substantial source of ecological disturbance in the South Atlantic and Gulf of Mexico regions. Synthesis Most gear types used to target Florida pompano do not have substantial habitat or ecological impacts (other than the fact that they remove fish from the ecosystem). Gill nets are known to have some impact on benthic habitat and thus the surrounding ecology, as they are set on the ocean floor; however, the common practice for gill-netting Florida pompano involves setting the gear around a school of fish, rather than placing the gear on the ocean bottom and waiting for fish to become entangled. Standard employment and retrieval time of gill nets in the pompano fishery is also thought to be minimal. Other gears also have limited habitat impacts, except when inappropriately discarded, lost, or abandoned. The effects of fishing practices on habitats and ecosystems are therefore considered a low conservation concern for hook-and-line gear and cast and seine nets and a moderate conservation concern for gill nets in the Florida pompano fishery.
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Seafood Watch® US Florida Pompano Report
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Effect of Fishing Practices Rank: Hook and line, Cast and Seine net: Benign
Moderate
Severe
Critical
Moderate
Severe
Critical
Gillnet: Benign
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Seafood Watch® US Florida Pompano Report
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Criterion 5: Effectiveness of the Management Regime Florida pompano has an extensive history of management. The following history is modified from information contained in FWC, November 2003, unless otherwise indicated. History of management timeline: 1881: It is made unlawful to catch Florida pompano exclusively for the purpose of making oil, fertilizer, or compost. 1925: The Florida Legislature enacted Ch. 10123, Acts 1925, s. 1, Laws of Florida, establishing a nine inch minimum size limit: any person, firm or corporation could not take or possess, buy, sell, or offer for sale at any time, or unnecessarily destroy any pompano of less than nine inches from the tip of the nose to the fork of the tail. 1953: The Florida Legislature passed Ch. 28145, Laws of Florida, increasing the minimum size limit for pompano to ten inches from the tip of the nose to the fork of the tail. The State Board of Conservation (created in 1933) was made responsible for saltwater fishing laws). 1969: The Florida Legislature adopted Chapter 70-96, Laws of Florida. This reduced the pompano minimum size limit to nine and one-half inches from the tip of the nose to the fork of the tail. This action coincided with a major governmental reorganization that abolished the State Board of Conservation and created a new Department of Natural Resources (DNR), which became responsible for managing saltwater fishing laws. 1971: The Florida Legislature amended the 1969 provision to establish proper pompano measurement as being from the tip of the nose to the tip of the tail (Chapter 71-154, Laws of Florida). 1973: The Florida Legislature changed the legal way to measure a fish as from the tip of the nose to the rear center edge of the tail. 1980: The Florida Legislature created the Saltwater Fisheries Study and Advisory Council to review the status and management of Florida’s marine species, and to develop future management recommendations. In its review of marine species, the Council recommended that no change to existing law (i.e., the minimum size limit) was needed to manage pompano. The Council also pointed out that very little was known about pompano, including spawning locations, length of life, size or age at onset of maturity, or first spawning. 1983: The Florida Legislature created the Marine Fisheries Commission (MFC). This body would make recommendations about all marine wildlife management in Florida. Commission rulemaking proposals were subject to final approval by Florida’s Governor and Cabinet. MFC rule proposals could only be accepted or rejected, and not amended, by the Governor and Cabinet.
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Seafood Watch® US Florida Pompano Report
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1988: The MFC collected information on pompano in January 1988. Staff collected and presented data throughout 1988 to the MFC. Staff developed a draft rule to establish a minimum size limit of 10 inches fork length (FL) (measured from the tip of the nose to the fork of the tail) or 12 inches total length (TL) (measured from the tip of the nose to the tip of the tail), and a maximum size limit of 20 inches fork length or 22 inches total length for pompano, and to prohibit the sale of pompano over 20 inches fork length. 1989: The MFC concluded that pompano was susceptible to over-harvest, and approved a rule that established a minimum size limit of 10 inches fork length. The MFC was concerned that reports of decreased landings might indicate that growth or recruitment overfishing could occur, and increasing the minimum size limit would raise the age of recruitment into the fishery, thereby increasing overall yield to the fishery. The rule also prohibited the purchase, sale or exchange of pompano with a fork length greater than 20 inches. Florida Marine Patrol reports indicated that large pompano-like fish were being marketed in Florida as “Mexican pompano”; however, these fish were later identified as being permit. Permit demanded a lower market price than pompano. Since pompano larger than 20 inches were considered to be rare, the MFC decided to eliminate this issue by establishing a maximum size limit. This also would enable the Marine Patrol to quickly identify pompano, and ensure the public that fish marketed as pompano were, indeed, pompano. In addition, the rule also included prohibitions on snatch hooking and the use of multiple hooks with natural bait (in order to reduce release mortality of undersized fish), and a requirement that pompano be landed in whole condition (to aid enforcement). March 28, 1989: The Florida Governor and Cabinet approved the new pompano rule (Ch. 4635, F.A.C.). The rule took effect on July 1, 1989. February 1995: Article X, Section 16, of the Florida Constitution prohibited the use of entangling (gill) nets within 9 miles of the Gulf coast and 3 miles of the Atlantic coast. January 1996: The MFC implemented a recreational 10-fish aggregate bag limit for pompano and permit (Trachinotus falcatus), with the allowance of only one fish over 20 inches. November 1998: Florida voters approved an amendment to the state’s Constitution that merged the Marine Fisheries Commission (MFC), the Game and Fresh Water Fish Commission, and the Department of Environmental Protection’s marine science and law enforcement programs into a new agency given the authority to manage Florida’s wildlife and saltwater and freshwater fish. The Fish and Wildlife Conservation Commission (FWC) became effective July 1, 1999, and has full and final rulemaking authority over Florida’s marine species. November 2001: The FWC permitted only qualified fishermen to catch pompano with gill nets in specified federal waters adjacent to state waters under certain conditions. These conditions included: a pompano endorsement or special activity license; a specific vessel length; a net specification; and landings requirements to limit the expanding offshore fishery. This regulation allows eligible fishermen to possess a gill net and pompano in specified state and adjacent federal waters; provides that commercial fishermen who do not possess a pompano endorsement or special activity license will be subject to existing gear limitations, as well as a daily harvest, possession and sale limit of 250 fish caught per vessel in state waters; and allows bycatch of 100 pompano in legal nets targeting other legal species in federal waters (Muller et. al. 2002).
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2003: The FWC approved new regulations to reduce pompano catch. The new rules increased the minimum size limit from 10 to 11 inches FL and reduced the recreational bag limit from 10 to 6 pompano and permit per day. The State of Florida is currently reviewing and editing a Draft Strategic Fisheries Plan for Florida pompano and might enact further regulations in the near future for this species. 2011: In June 2011, FWC amended rules for permit and Florida and African pompano to create separate management strategies specific to each species. See the FWC website for more information on permit and African pompano. Effective August 31, 2011, in addition to existing permit, gear and mesh size regulations, the Florida pompano recreational bag limit of 6 fish applies not only to state but also federal waters. Commercial limits have been similarly extended into federal waters, and there is now an incidental gillnet bycatch limit in federal waters (for vessels not directly targeting pomano) of 100 fish. Management effectiveness While managers have acknowledged the need to regulate fishing for Florida pompano since 1881, unfortunately stock status remains apparently below a healthy threshold. The various actions taken by the Florida Legislature and other bodies with authority through the years have maintained Florida pompano at a status that does not require a threatened or endangered designation; however, the amount of Florida pompano fishing is apparently still too high to rebuild and maintain the species at a long-term sustainable level. Though compliance with size limits and bag limits is generally believed to be high, there have been some notable problems with violations of Florida pompano regulations, including illegal poaching and gill-netting. After the Florida Net Ban in 1995, some fishermen continued to employ the prohibited gear. Catch from illegal gear, when added to landings projected through other means, raised the total catch higher than the stock could support at that time. Furthermore, because Florida pompano is such a valuable fish in the market, some fishermen find that the risk of being caught in illegal activities is worth the potential economic gains. Better enforcement and education efforts, along with the acceptance of a gill net fishery for Florida pompano in federal waters (with certain restrictions) supposedly has helped diminish illegal activities, though there are still regular reports of intercepted poachers. Newer regulations in 2003 and regular stock status monitoring and review are contributing to better management for Florida pompano, though the species is still overfished with overfishing occurring.
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Table 3: Summary of management regulations for Florida pompano. Jurisdiction Hard Size Commercial Trip Gear and Agencies TAC* Limit Limits Restrictions FWC primary for state and federal waters off Florida.
No
11” – 20” Fork length
Direct harvest 250 pompano trip limit; state and federal waters. Incidental bycatch with gillnets federal waters 100 pompano
Yes. No gill nets in state waters; special circumstances for gill nets in federal waters. Mesh size standards.
Recreation Restrictions Yes. 11” fork length minimum size. 6 pompano bag limit in state and federal waters. Allowable gears are hook-line, cast net, beach or haul seine
Closed Seasons/ Areas No
* TAC= Total Allowable Catch
Synthesis The state of Florida has a long track record of some active management of Florida pompano since 1881, with increasing focus and regulations in recent years. Multiple stock assessments have been performed for the species, with each assessment improving the information available; the most recent assessment was completed in 2006. It is unclear when the next assessment of Florida pompano is scheduled to be completed or released. FWC and its research arm, the Florida Fish and Wildlife Research Institute, collect fishery-dependent and independent data, although more data – particularly age-specific and stock distribution characteristics – are needed to evaluate the health of the stock. Managers have implemented regulations to minimize bycatch and habitat impacts. Incidental catch limits are too new to evaluate success, but statewide regulations such as the Florida Net Ban which eliminated gillnets from state waters have contributed to improvements in the stock of pompano and other finfish. Though compliance with size limits and bag limits is generally believed to be high, there have been some notable problems with violations of Florida pompano regulations, including illegal poaching and gill-netting. After the Florida Net Ban in 1995, some fishermen continued to employ the prohibited gear. Catch from illegal gear, when added to landings projected through other means, raised the total catch higher than the stock could support at one time. Furthermore, because Florida pompano is such a valuable fish in the market, some fishermen find that the risk of being caught in illegal activities is worth the potential economic gains. Better enforcement and education efforts, along with the acceptance of a gill net fishery for Florida pompano in federal waters (with certain restrictions) supposedly has helped diminish illegal activities, though there are still regular reports of intercepted poachers. Newer regulations and regular stock status monitoring and review are contributing to better management for Florida pompano, though the species is still recovering from being overfished, and fishing levels are likely higher than sustainable along the Atlantic Coast of Florida. Therefore, Seafood Watch © considers management of Florida pompano to be moderately effective. Effectiveness of Management Rank: Highly Effective
Moderately Effective
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Ineffective
Critical
Seafood Watch® US Florida Pompano Report
IV.
September 15, 2011
Overall Evaluation and Seafood Recommendation
Florida pompano are fast-growing and early-maturing (50% of females are mature at 1 year), and are thus thought to be relatively resistant to fishing pressure. The stock status for Florida pompano depends on which coast of Florida it is landed. Florida pompano along the Gulf of Mexico are rebuilding with no overfishing occurring and thus of moderate conservation concern; while pompano in the Atlantic are still likely experiencing overfishing, and therefore stocks are still considered poor. Predominant methods for capture of Florida pompano include gill nets (in federal waters), seine and cast nets, bandit gear (power rod and reel), and hook-and-line gear (e.g., standard fishing polls, troll gear, etc.). Of the usual gears, only gill nets have a significant potential to harm bottom habitat and generate bycatch (especially if abandoned or lost). By nature, gill nets are indiscriminate in terms of species caught, and, along with targeted catch, gill nets can take unmarketable or undersized species that are fatally discarded. Also, when gill nets are set on the ocean bottom, lead weights are used, which can damage bottom habitat. Dependant on the type of benthic habitat (especially mud or sand verses coral or seagrass) and bottom resiliency, gill nets may be considered detrimental to habitats and ecosystems. The standard practice for catching Florida pompano using gill nets, however, is to set the gear to catch a school of fish, with little soak time and more precise deployment and retrieval. This practice keeps bycatch lower than it is with gill nets in other fisheries; bycatch for gill nets in the pompano fishery is ranked a moderate conservation concern. Similarly, habitat impact from gill nets in the pompano fishery is ranked a moderate conservation concern. Contrary to gill nets, hook-and-line gear and cast and seine nets have little bycatch and minimal contact with bottom habitat and thus bycatch and habitat impacts for these gears are ranked low conservation concerns. A number of regulations have been implemented to help Florida pompano stocks rebuild, and managers actively observe stock abundance patterns and have implemented several regulations over the years in an attempt to maintain stock productivity. However, it remains to be seen whether new regulations can fully rebuild the stock; and there is still some concern over poaching and illegal gill netting occurring in the recent past. Therefore, the current management regime is considered moderately effective. Stocks of Florida pompano in the Gulf of Mexico are considered a moderate concern, while Atlantic stocks are in poor condition. Bycatch and habitat impacts are of low to moderate concern depending on the gear type; the management regime is moderately effective; and pompano life history is inherently resilient to fishing pressure. Florida pompano from both the Atlantic and Gulf of Mexico is considered a Good Alternative, due to high inherent resilience of the species, moderate bycatch and habitat concerns, moderate to poor stock status, and moderately effective management.
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Table of Sustainability Ranks
Sustainability Criteria Inherent Vulnerability
Conservation Concern Moderate High
Low
Critical
√
Status of Stocks
√
√
Gulf Coast of Florida
Atlantic Coast of Florida
√ Nature of Bycatch
Hook and line, cast and seine nets
Habitat & Ecosystem Effects
Hook and line, cast and seine nets
√ Gillnets
√
√ Gillnets
√
Management Effectiveness
About the Overall Seafood Recommendation: • A seafood product is ranked Best Choice if three or more criteria are of Low Conservation Concern (green) and the remaining criteria are not of High or Critical Conservation Concern. • A seafood product is ranked Good Alternative if the five criteria “average” to yellow (Moderate Conservation Concern) OR if the “Status of Stocks” and “Management Effectiveness” criteria are both of Moderate Conservation Concern. • A seafood product is ranked Avoid if two or more criteria are of High Conservation Concern (red) OR if one or more criteria are of Critical Conservation Concern (black) in the table above.
Overall Seafood Recommendation: Florida Pompano: Best Choice
Good Alternative
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Avoid
Seafood Watch® US Florida Pompano Report
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Supplemental Information on Related Species There are a number of species often sold and served as or in place of Florida pompano. Species to be aware of include: • Black pomfret • African pompano • Silver pomfret Black pomfret Black pomfret is found in India, Indonesia, Japan, and other areas of the Indio-Pacific region. It is marketed in the U.S. often as simply pompano, as well as black pompano, sweep, or false butterfish (http://vm.cfsan.fda.gov/%20~frf/rfe2pm.html). Like Florida pompano, black pomfret is of the family Carangidae. The maximum size for black pomfret is about 75 cm TL, and the fish are colored brown above and silvery-white below. The anterior parts of the dorsal and anal fins are colored bluish-gray, and the other fins are yellowishcolored. Black pomfret are associated with reef habitats, and are often found in brackish and marine waters in depths from 15 – 105 meters. The regular habitat for black pomfret is in coastal areas with muddy substrate, and the fish can be found near the ocean bottom during the daytime and near the surface at night. Black pomfret often frequent estuaries as well as more open waters. Black pomfret swim on their sides near the surface, normally form large schools, and feed on zooplankton. Black pomfret are popular food fish and are marketed fresh, dried, or salted (www.fishbase.org, 2004). African pompano African pompano appear notably different than Florida pompano, though they share the pompano name and both can be caught in waters off Florida. Like Florida pompano, African pompano is of the family Carangidae. The fish’s maximum size is about 150 cm TL, and the fish’s maximum published weight is 22.9 kg. African pompano are associated with reefs and are found at depths ranging from 60 – 100 meters. The species is not as fast-growing and earlymaturing as Florida pompano, and has a known low fecundity. African pompano have weaklydeveloped scutes, which makes them appear naked. African pompano are the only fish in the family Carangidae that does not have dorsal fin spines throughout life; juveniles have long trailing filaments. The diet of African pompano includes sedentary or slow-moving crustaceans and occasionally small crabs and fishes. African pompano can be found worldwide in tropical areas, including: the western Atlantic— Massachusetts, U.S.A., and Bermuda to Santos, Brazil; the Caribbean Sea and the Gulf of Mexico (Ref. 9626); the eastern Atlantic—Senegal to Congo; the western Indian Ocean—Red Sea to Algoa Bay, South Africa, and to Sri Lanka; the western Pacific—Fiji and Tuvalu; and the eastern Pacific—Mexico to Peru. Physically, African pompano is silvery with a light metallic bluish tinge dorsally; the fish has a small diffuse dark spot on its opercle. Generally, its habitat is pelagic in neritic and oceanic waters; they can also sometimes be found near the ocean bottom. Small juvenile African pompano may be found near the shore; adults may be near the ocean bottom to depths of 60 meters.
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There is a limited commercial fishery for African pompano, but they are popular game fish and are also caught for commercial aquarium display. Juveniles, especially, are attractive aquarium fish, but do not do well in captivity. African pompano are used as a food fish and are marketed fresh, dried, or salted (www.fishbase.org, 2004). Silver pomfret Silver pomfret, in Indonesia known as bawal putih, is a favorite fish for Chinese cuisine and medicine (http://www.pacific.net.id/~ybudih/39.html). It is often imported from Indonesia and India. In the U.S., silver pomfret may be sold as a pompano—and is called “pompano” in Spanish (see: http://www.saletseafoods.com/products/pomfrets.htm)—but is also known by the USDA as butterfish (http://vm.cfsan.fda.gov/~frf/prnomgen.html). As with black pomfret and African pompano, silver pomfret is a member of the family Carangidae. The maximum size for silver pomfret is about 60 cm standard length (SL), and its body color is gray above, grading to silvery white towards the belly, with small black dots all over. The fins are faintly yellow and the vertical fins have dark edges. The diet of silver pomfret includes ctenophores, salps, medusae, and other zooplankton groups. Western populations of silver pomfret spawn from late winter through the summer with peaks from April to June. Silver pomfret can be found at depths of 5 – 110 meters in the Indo-West Pacific—the Persian Gulf to Indonesia, north to Hokkaido, Japan. Extralimital captures have been made from the Adriatic and off Hawaii, but there are no records of silver pomfret from Australasia. Silver pomfret is an inshore species, which is usually found in schools over muddy bottoms and associated with fish species like Nemipterus and Leiognathus. Silver pomfret is a highly commercialized fish and is often sold fresh in local markets or shipped frozen to urban centers. It is also used in Chinese medicine.
Acknowledgements The Seafood Watch® Program thanks Andrew Strelcheck and Peter Hood of the National Marine Fisheries Service, Southeast Regional Office, and Jessica R. McCawley from The Florida Fish and Wildlife Conservation Commission, for reviewing this document. Scientific review does not constitute an endorsement of the Seafood Watch® program on the part of the reviewing scientists or its seafood recommendations. Seafood Watch® is solely responsible for the conclusions reached in this report and the ensuing seafood recommendations.
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V. References Anderson, W. D., J. K. Dias, R. K. Dias, D. M. Cupka, and N. A. Chamberlain. 1977. The macrofauna of the surf zone off Folly Beach, South Carolina. NOAA Tech. Rept. NMFS SSRF704:i-iv+1-23. Bellinger, J. W. and J. W. Avault, Jr. 1970. Seasonal occurrence, growth, and length-weight relationship of juvenile pompano, Trachinotus carolinus, in Louisiana. Trans. Amer. Fish. Soc. 99:353-358. Berry, F. H. and E. S. Iverson. 1967. Pompano: biology, fisheries, and farming potential. Proc. 19th Annual Session Gulf and Carib. Fish. Inst. 116-128. Berry, F. H. and W. S. Smith-Vaniz. 1977. Carangidae. FAO species identifications sheets for fishery purposes. Western Central Atlantic (Fishing Area 31), Vol. 2. W. Fischer, ed. Food and Agriculture Organization of the United Nations, Rome. Cody, R. P., J. R. O’Hop, S. Brown, and L. A. Hallock. Final report on at-sea observations of pompano netting. Florida Fish and Wildlife Conservation Commission. Florida Marine Research Institute. St. Petersburg, Fl. 6 August 2000. Cufone, M. 2005. Florida pompano, Trachinotus carolinus. Seafood Watch Seafood Report. Monterey, CA. 53p. Cupka, D. M. 1972. A survey of the ichthyofauna of the surf zone in South Carolina. South Carolina Wildl. Mar. Res. Dept., Tech. Rep. No. 4. 19 pp. de Sylva, D. P., F. A. Kalber, and F. A. Shuster. 1962. Fishes and ecological conditions in the shore zone of the Delaware River estuary, with notes on other species collected in deeper water. Univ. Delaware Mar. Lab. Information Ser., Publ. #5. 164 pp. Finucane, J. H. 1969a. Faunal Production Project. In Report of the Bureau of Commercial Fisheries Biological Laboratory, St. Petersburg Beach, FL, Fiscal Year 1968. pp. 11- 15. Finucane, J. H. 1969b. Faunal Production Project (Life History of Pompano). In Report of the Bureau of Commercial Fisheries Biological Laboratory, St. Petersburg Beach, FL, Fiscal Year 1968. pp. 11-15. Fields, H. M. 1962. Pompano (Trachinotus spp.) of south Atlantic coast of the United States. Fish. Bull. 62:189-222. Florida Fish and Wildlife Conservation Commission (FWC). November 2003. Draft Fisheries Strategic Plan for Florida pompano, Permit and African pompano. Tallahassee, Florida. FMRI. 2003. Proposed gill net minimum mesh size to target 11-inch Florida pompano (Trachinotus carolinus). Report prepared by the Florida Fish and Wildlife Conservation Commission, Florida Marine Research Institute.
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Froese, R. and D. Pauly. Editors. 2002. FishBase. World Wide Web electronic publication. www.fishbase.org. FWRI 2011. Evaluation of a 12-inch minimum size limit on the Florida pompano populations and fisheries in Florida. Fish and Wildlife Research Institute, Florida Fish and Wildlife Conservation Commission. St. Petersburg, Florida. 20p. Guindon, Kathryn Y., C. Powell, and L.R. Barbieri. 2002. A re-assessment of the age and size structure, growth, and reproduction of pompano (Trachinotus carolinus) stocks in Florida. Internal Report for the Sport Fish Restoration Program. Fish and Wildlife Conservation Commission, Florida Fish and Wildlife Research Institute. Modde, T. 1980. Growth and residency of juvenile fishes within a surf zone habitat in the Gulf of Mexico. Gulf Res. Rep. 6:377-385. Muller, R.G., K. Tisdel, and M.D. Murphy. 2002. The 2002 update of the stock assessment of Florida pompano (Trachinotus carolinus). Florida Marine Research Institute, St. Petersburg, FL. Murphy, M. D., R. G. Muller, and P. H. Hood. 1996. A stock assessment of Florida pompano, Trachinotus carolinus. Florida Department of Environmental Protection. Florida Marine Research Institute. St. Petersburg, FL. Revised 20 June 1996. Murphy, M.D., R.G. Muller, and K. Guindon. 2008. A stock assessment for pompano, Trachinotus carolinus, in Florida waters through 2005. Fish and Wildlife Research Institute, Florida Fish and Wildlife Conservation Commission. St. Petersburg, Florida. 113p. Palka, D. L., and M. C. Rossman. 2001. Bycatch estimates of coastal bottlenose dolphin (Tursiops truncatus) in U.S. Mid-Atlantic gillnet fisheries for 1996 to 2000. Northeast Fisheries Science Center Reference Document 01-15. Peters, D. J. and W. G. Nelson. 1987. The seasonality and spatial patterns of juvenile surf zone fishes of the Florida east coast. Flor. Sci. 50:85-99. Rosenberg, A. A., G. P. Kirkwood, J. A. Crombie, and J. R. Beddington. 1990. The assessment of stocks of annual squid species. Fisheries Research, 8: 335-350. Ruple, D. L. 1984. Occurrence of larval fishes in the surf zone of a northern Gulf of Mexico barrier island. Est. Coast. Shelf Sci. 18:191-208. Smith, C. L., 1997 National Audubon Society field guide to tropical marine fishes of the Caribbean, the Gulf of Mexico, Florida, the Bahamas, and Bermuda. Alfred A. Knopf, Inc., New York. 720 p. Tagatz, M. E., and D. L. Dudley. 1961. Seasonal occurrence of marine fishes in four shore habitats near Beaufort, N. C., 1957-60. U. S. Dept. Interior, Fish and Wildl. Ser., Spec. Sci. Rept.-Fisheries No. 390, 19 pp.
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VI. Appendices Appendix I. Additional Tables and Figures Table 4: Annual Commercial trips and landings for pompano by coast and area fished (Muller et al. 2002, Table 1),
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Table 5: On-line NMFS Commercial Landings Query Results (http://www.st.nmfs.gov/st1/commercial/landings/annual_landings.html) • • •
Year Species State
Year
: From: 1950 To: 2003 : POMPANO, FLORIDA : Atlantic And Gulf
Species
Metric Tons
Pounds
$
1950
POMPANO, FLORIDA
383.5
845,400
458,962
1951
POMPANO, FLORIDA
446.3
984,000
489,273
1952
POMPANO, FLORIDA
458.3 1,010,300
586,842
1953
POMPANO, FLORIDA
284.9
628,200
336,157
1954
POMPANO, FLORIDA
295.7
651,900
422,222
1955
POMPANO, FLORIDA
211.1
465,500
356,667
1956
POMPANO, FLORIDA
238.3
525,300
466,314
1957
POMPANO, FLORIDA
349.7
771,000
603,546
1958
POMPANO, FLORIDA
360.2
794,100
372,955
1959
POMPANO, FLORIDA
267.8
590,500
322,958
1960
POMPANO, FLORIDA
324.9
716,200
456,326
1961
POMPANO, FLORIDA
345.8
762,400
517,514
1962
POMPANO, FLORIDA
398.1
877,700
654,824
1963
POMPANO, FLORIDA
417.6
920,700
589,931
1964
POMPANO, FLORIDA
370.8
817,400
505,972
1965
POMPANO, FLORIDA
402.3
886,900
563,375
1966
POMPANO, FLORIDA
517.6 1,141,200
780,660
1967
POMPANO, FLORIDA
605.2 1,334,200
809,992
1968
POMPANO, FLORIDA
626.5 1,381,200
945,203
1969
POMPANO, FLORIDA
454.6 1,002,200
960,377
1970
POMPANO, FLORIDA
523.6 1,154,400 1,303,432
1971
POMPANO, FLORIDA
447.4
1972
POMPANO, FLORIDA
586.2 1,292,400 1,664,949
1973
POMPANO, FLORIDA
588.0 1,296,400 1,513,133
1974
POMPANO, FLORIDA
673.8 1,485,500 1,837,270
1975
POMPANO, FLORIDA
634.2 1,398,100 1,555,772
1976
POMPANO, FLORIDA
653.8 1,441,300 1,932,755
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986,300 1,232,254
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1977
POMPANO, FLORIDA
629.0 1,386,800 2,096,317
1978
POMPANO, FLORIDA
411.6
907,351 1,810,305
1979
POMPANO, FLORIDA
376.5
830,111 2,056,878
1980
POMPANO, FLORIDA
390.5
860,881 2,243,066
1981
POMPANO, FLORIDA
407.3
897,967 2,266,236
1982
POMPANO, FLORIDA
421.3
928,757 2,251,325
1983
POMPANO, FLORIDA
366.2
807,375 2,227,286
1984
POMPANO, FLORIDA
302.5
666,792 1,967,611
1985
POMPANO, FLORIDA
327.7
722,409 2,300,871
1986
POMPANO, FLORIDA
345.7
762,054 2,231,181
1987
POMPANO, FLORIDA
385.3
849,456 2,534,081
1988
POMPANO, FLORIDA
366.5
807,991 2,285,146
1989
POMPANO, FLORIDA
381.6
841,188 2,560,965
1990
POMPANO, FLORIDA
493.5 1,087,919 3,041,552
1991
POMPANO, FLORIDA
336.5
741,788 2,044,429
1992
POMPANO, FLORIDA
305.8
674,064 2,018,835
1993
POMPANO, FLORIDA
290.7
640,849 1,994,458
1994
POMPANO, FLORIDA
343.0
756,205 2,344,898
1995
POMPANO, FLORIDA
232.1
511,726 1,679,999
1996
POMPANO, FLORIDA
171.0
376,890 1,158,531
1997
POMPANO, FLORIDA
361.1
795,984 2,054,788
1998
POMPANO, FLORIDA
375.1
826,971 2,178,373
1999
POMPANO, FLORIDA
244.9
539,811 1,598,901
2000
POMPANO, FLORIDA
266.7
587,981 1,848,208
2001
POMPANO, FLORIDA
208.2
458,917 1,449,939
2002
POMPANO, FLORIDA
183.5
404,459 1,363,497
2003
POMPANO, FLORIDA
178.1
392,655 1,348,650
GRAND TOTALS:
-
20,968.0 46,226,051 77,195,961
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Figure 14. Historical commerical landings and trips for pompano; inshore, offshore, and total landings by coast. (Muller et al. 2002, Figure 3).
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Table 6: On-line MFRSS results (http://www.st.nmfs.gov/st1/recreational/queries/catch/time_series.html) for: • South Atlantic and Gulf coasts • All areas combined (inland, state, and EEZ) • All modes combined (private/rental, shore, charter, and headboats) • All catch combined (catch, observed catch, reported catch, and released alive)
Species: FLORIDA POMPANO Year TOTAL CATCH (TYPE A + B1 + B2) PSE 1981
1,021,641 29.4
1982
601,620 15.8
1983
486,515 16.3
1984
641,670 15.2
1985
801,343 16.7
1986
1,774,745
30
1987
348,099 15.3
1988
366,095 13.7
1989
360,061
1990
819,666 11.1
1991
698,190 25.1
1992
498,051 10.6
1993
641,102 9.4
1994
424,525 9.6
1995
660,773 9.9
1996
304,524 11.2
1997
744,480
1998
895,231 6.5
1999
758,518 6.8
2000
1,054,214 6.7
2001
1,252,691 7.9
2002
935,678 8.1
2003
1,925,794 7.9
13
9
*Note: A new method for estimating charter boat effort was implemented in the Gulf of Mexico region (Louisiana to West Florida) beginning in 2000. This change affects both the effort and catch estimates. The time series from 2000 and future years will not be completely comparable to earlier years.
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Appendix II. Explanation of Stock Assessment Models (Excerpted from Muller et al. 2002). Age-structured models Age-structured models use catch and age data and an estimate of natural mortality to reconstruct the population dynamics of exploited fish stocks. In Florida, catch data are attained from two sources: 1) the FWC’s Marine Fisheries Information System (MFIS), a mandatory reporting system for commercial fishermen, which provides information such as commercial landings and effort; and 2) the Marine Recreational Fishery Statistics Survey (MRFSS), which estimates recreational landings and effort based on angler interviews and telephone surveys. Age and length data, obtained from analysis of fish otoliths (ear bones) and angler intercepts, are then used to reconstruct the ages of the catch. Once the ages of the catch have been estimated and natural and release mortality rates are approximated, population sizes (either in terms of biomass or abundance), recruitment, and fishing mortality rates can be estimated. This model was not used in the most recent pompano stock assessment. Surplus-production models Surplus production models are more simplistic models than age-structured models. Surplus production models require only landings and fishing effort information (catch-rates, catchperunit-effort, etc.) to estimate fishing mortality and population biomass (or abundance), and do not require information about the age and growth of harvested fish. In general, these simple models rely heavily on the assumption that changes in catch rates (number of fish caught per angler or per trip) reflect changes in stock biomass or abundance. Thus, if catch rates are declining, the population is estimated to be declining, and when catch rates are increasing, the population is estimated to be increasing. These models do not require specific information regarding the age-structure of the population; however, because of their simplicity, they also cannot estimate age-specific assessment information, such as spawning potential ratios.
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Appendix III. Details from the non-equilibrium, surplus production model and the Delury Model (from Muller et al 2002) Surplus production model The surplus production model was based on the discussion presented in Hilborn and Walters (1992) and Prager (1994). There are two equations for the surplus production model: 1) The first model relates the biomass at time t + 1 as a function of the biomass at time t: Bt+1 = Bt + rBt * (1 – Bt / K) – Ct
(1)
In this equation, Bt is the biomass at time t, r is the net rate of growth in biomass, K is the carrying capacity of the environment, and Ct is the catch during time t. 2) The second model relates the catch to the biomass: Ct = q * Et * Bt
(2)
In this equation, q is the catchability coefficient which links effort by time and sector to biomass, and Et is the effort during time t. Because eliminating entangling nets possibly changed the effectiveness of a commercial trip, FWC used a different catchability coefficient after 1995 with the commercial sector but only one catchability coefficient with the recreational sector. DeLury model The FWC used a continuous recruitment model developed by Carl Walters of the University of British Columbia. Walters’s model stems from the simple idea that recruits increase the number of fish and mortality decreases it. dN/dt = R – ZN
(3)
In this equation, dN/dt is the change in numbers with time, R is the number of fish entering the exploited portion of the population, Z is the total, instantaneous mortality rate, and N is the number of fish in the population. Solving the differential equation (3) provides the number of fish at time t+1 from time t: Nt+1 = Rt / Zt + (Nt – Rt / Zt) exp(-Zt)
(4)
The predicted catch for a given sector or time is: Ct = q Et Nbart
(5)
In this equation, Nbart is the average number in the population at time, t, Rt is the recruitment in numbers at time, t, Nt is the number in the population at the beginning of time, t, M is the natural mortality rate, Ct is the catch during time, t, q is the catchability coefficient that relates the
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mortality expended by one unit of effort, and Et is the effort expended during time, t. With continuous recruitment, Nbart is also modified to: Nbart = (Rt + (Nt – Rt / Zt) * (1 – exp(-Zt)) / Zt
(6)
A natural mortality rate of 0.40 per year based on a maximum age for pompano of 7 years was used. The model varies the values of the initial population size and for each year’s recruitment until the smallest difference between the observed catches and the predicted catches is identified.
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