10/30/2012
POLLUTION AND BIOACCUMULATION
What is Pollution? Pollution: the introduction of contaminants into the environment (air, water, or soil) • A contaminant is not always a toxic chemical or poison – it can be
something naturally occurring (such as Nitrogen or Phosphorus) that disrupts ecological processes when introduced into a certain area
Pollution • Major forms of pollution: • Light (cars, boats, buildings, street lights, etc.) • Noise (cars, factories, human voices, music, sonar, aircraft) • Solid Waste (e.g. plastics, other garbage) • Chemicals (fuel burning byproducts, pesticides, fertilizer, etc.)
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10/30/2012
Light Pollution
Light at night from artificial sources (and its effects)
Light Pollution
Some types of light pollution: • Sky glow • Overillumination • Light trespass
Light Pollution:
effects on wildlife
• Navigation, orientation • Disorientation in sea turtles, migrating birds
• Reproductive behavior • Decreased mating under night lighting
• Development • Delayed metamorphosis in frogs
• Foraging behavior • Altered timing and duration of foraging
• Communication • Impacts on coyote howling
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Light Pollution: migrating birds • Over 450 bird species migrate at night across N. America
(incl. threatened or endangered species - cerulean warbler and Henslow's sparrow) • Use the moon and stars for navigation
Light Pollution: migrating birds •
Disoriented by artificial lights
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Fly into windows, collide with each other
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Reluctant to leave a light source once it has been entered
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Fly around until they are exhausted
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Drop to the ground – vulnerable to predation/injury
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Estimated 100 million to 1 billion birds killed by collisions with glass/buildings in US per year. Photo: Jay Smooth
Light Pollution: mitigation •
Selectively turning off lights – building in Chicago turned off lights in half the building and reduced bird strikes by over 80% (field museum in Chicago)
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Different types of lights (eliminate stray light)
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Different color lights - Nocturnally migrating birds less disoriented by blue and green light Poot et al. (2008) Ecology and Society
PBS documentary on light pollution http://www.youtube.com/watch?v=zGyFsMCsQNE
FAU Astronomical Observatory
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Noise Pollution
Unwanted noise that may interfere with natural processes, adversely affect wildlife or humans, or cause damage (e.g. to structures)
Noise Pollution: effects on wildlife Communication: Altered bird singing activity • Male nightingales (Luscinia megarhynchos) sing songs
• Songs are used to mark territory and to attract mates
Brumm (2004) Journal of Animal Ecology • Birds sang louder in areas with more urban noise (e.g. traffic) • Birds sang louder on weekday mornings than on weekends • Birds did not differ significantly in size between noisier or quieter areas Male nightingale
What costs may be associated with singing louder songs?
Noise Pollution: effects on wildlife Communication • Female grey tree frogs (Hyla chrysoscelis)
take longer to locate and find calling males when exposed to the sounds of passing traffic • Several species of marine mammal stop
vocalizing or experience difficulty in locating mates (air guns, sonar, boat noise)
Hyla chrysoscelis
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Noise Pollution – effects on wildlife • Navigation and Foraging Behavior • Altered foraging behavior to avoid noise (bats, marine mammals) • Disorientation • More vigilant foraging behavior
• Direct Injury • Hemorrhaging of tissues • Hearing loss (marine mammals)
Noise Pollution Case study: the greater mouse-eared bat, Myotis myotis Schaub et al. (2008) Journal of Experimental Biology
• Hunt at night • Rely on listening for prey rustling sounds to find food (gleaning bat) • Prey on ground-running arthropods (beetles, crickets, etc.)
Myotis myotis
Noise Pollution Case study: the greater mouse-eared bat, Myotis myotis Schaub et al. (2008) Journal of Experimental Biology
A “choice experiment”: Bats were given the choice of foraging in a compartment where sounds were being played from a speaker or one without sounds being played
Fig. 1. Schematic representation of the flight room and the experimental setup (not to scale). Each of the two foraging compartments was equipped with a loudspeaker and six landing platforms, two of which contained live mealworms. The room and the division between the compartments were lined with sound-absorbing acoustic foam. A video camera and infrared illumination served to document the batsʼ behaviour.
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Noise Pollution Case study: Foraging bats avoid noise Schaub et al. (2008) Journal of Experimental Biology
(A) Percentage of the flight time in the stimulus compartment.
(B) Percentage of flights into the stimulus compartment. Fig. 4. Influence of noise treatments on foraging behaviour of the mouse eared bats. Results from repeated-measures ANOVAs for the factors noise treatment and stimulus compartment position are given in the text. As the latter did not have a significant effect on any of the behavioural measures, we combined the behavioural data from both compartments for this graphic representation (averaged within each individual; error bars give the standard error, N=7 bats). Asterisks show significant differences revealed in post hoc paired t-tests for these combined data sets (sequential Bonferroni correction to account for multiple testing). ***P
