Pond water quality and pond size Zachary Burriss1 ABSTRACT Vernal pool and pond size effects on dissolved oxygen (DO) levels and nutrient levels were studied in six Central New York ponds. Study sites included a vernal pool, four chain ponds, and one pond bordered, in part, by a bog. We collected water quality and nutrient data for each pool and pond. Previous DO and nutrient data for study sites are limited. Water quality and nutrient data were added to existing data sets. We tested samples for ammonia, nitrate + nitrite, total nitrogen, and total phosphorus. We used Microsoft Excel and Minitab to analyze the data collected. Nutrient and DO data had no relationship with pond size. Errors possibly introduced into the DO data are discussed and recommendations for future work are offered.

INTRODUCTION Our study was conducted on six ponds in Otsego County, Central New York. The six pond sites were in two locations. The first location included four chain ponds at the Thayer Farm in Springfield, NY. Pond surface areas on Thayer Farm sites ranged from 0.03 - 0.12ha (Payne and Butler 2007) (Figure 1). The second location included a vernal pool and a Cranberry Bog at the Greenwoods Conservancy in Burlington, NY (Figure 2). Surface areas were 0.04ha for the vernal pools and 28ha for the beaver pond. Study sites at Thayer Farm consist of four chain ponds that increase in size moving from CP3 - CP8 in the pond chain. Center depths, surface area, and volumes of ponds, as available, are provided in Table 1. Table 1. Depths, surface area, and volume of Central New York chain ponds, summer 2009 (after Payne and Butler 2007). Depth (m)

Surface area (ha)

Surface area (ac)

Volume (m3)

CP31

1

0.03

0.08

99

CP41

1.1

0.03

0.06

91

CP51

1.4

0.05

0.12

223

CP81

0.9

0.12

0.31

515

VP

0.04

0.10

BP

28

69

Pond

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 Undergraduate student, Environmental Sciences Program, SUNY Oneonta. 

Figure 1. Chain pond (CP) 3, 4, 5 and 8 site locations at the Thayer Farm.

Figure 2. Cranberry Bog (BP) and vernal pool location at Greenwoods Conservancy.

Ponds are identified by an abundance of aquatic macrovegetation and associated microflora attached to all surfaces (Wetzel 1983). One major component of a pond’s ability to support life is dissolved oxygen levels (Reid 2001). The purpose of this study was to collect dissolved oxygen and nutrients levels for ponds of various sizes. We analyzed dissolved oxygen (DO) and nutrients to ascertain relationships with pond size. Little is known about the effect of size on DO and nutrients. Our hypothesis was that pond size affects DO positively and that nutrient data would trend consistently by pond size. Vernal, or ephemeral, pools can be natural or man-made. Whether naturally formed, or manmade, vernal pools support endemic life (Heidelberg 1978). The pools contain water most of the year, but lack water at least some part of the year. Because the pools lack water for some time, they have no fish. The drying process of vernal pools is a key factor in protecting its insect and natal amphibian inhabitants. For some species, vernal pools are the only place they are able to live and breed (Bronark 1998). METHODS Sample sites and timing DO and nutrient data for CP3, CP4, CP5 & CP8 were sampled at randomly chosen. Those locations were consistently sampled throughout the study. Sample numbers varied by pond size. We sampled our two largest ponds, BP and CP8 in four places while we took two samples from other sites. Samples for BP and VP were taken in the late morning-early afternoon while CP3, CP4, CP5 & CP8 were sampled in mid-late afternoon. Dissolved Oxygen DO readings were taken at each pond study site. We used a YSI Model 55TM Dissolved Oxygen System with attached probe. On small ponds we measured at a meter off-shore from surface to available depths in 10cm increments. Care was taken, in all sampling, not to disturb sediments. Measurements for the BP were taken to depths of 50cm. Nutrient Analysis We obtained 100ml samples at a depth of 5cm. We used H2SO4 to preserve samples. Preservation and auto-analyzer methods, per parameter, are described in Table 2. We analyzed samples for levels of total phosphorus, total nitrogen, nitrite + nitrate, and ammonia using Lachat QuickChem FIA+®water auto-analyzer. Statistical Analysis We tested our hypothesis that pond size effects DO by running a regression for pond size with average DO. Likewise, each pond or pool nutrient data set was averaged separately and a regression was run with pond sizes. Our null hypothesis for the regressions was that there would be no straight line relationship between DO or nutrient levels with pond sizes. We ran regressions with DO and nutrient data as a response to pond size. All regressions and statistical analysis were run in Microsoft Office Excel® 2007 and Minitab® 15.1.0.0.

Table 2. Summary of laboratory methodologies used on water samples for nutrient data calculations for comparison of Central New York ponds, 2006 (after Payne and Butler 2007). Parameter Total Phosphorus- P

Preservation H2SO4