Skip to Main Content
 

Global Search Box

 
 
 
 

Files

File List


HarrisonSusanna_MastersThesis_2021.pdf (1.54 MB)

ETD Abstract Container

Abstract Header

Effects of light pollution on fish feeding behavior and assemblage structure in reservoirs

Harrison, Susanna
http://orcid.org/0000-0003-0212-9687
http://rave.ohiolink.edu/etdc/view?acc_num=osu1638379317556167

Abstract Details

2021, Master of Science, Ohio State University, Environment and Natural Resources.
Artificial light at night (ALAN) is one of the most pervasive and rapidly expanding sources of anthropogenic pollution. A growing body of research suggests that ALAN poses a significant threat to ecological communities and global biodiversity. As important sources of biodiversity, aquatic ecosystems may be especially vulnerable to the effects of ALAN, particularly in urban and suburban areas. However, research on the environmental effects of light pollution is scattered and tends to focus on individual taxa and terrestrial systems. Thus, as the human population grows and the influence of ALAN expands, there is an urgent need to improve our understanding of the impacts of light pollution on aquatic ecosystems. Here, my two main objectives were to 1) experimentally determine the extent to which nighttime exposure to different intensities of artificial lighting alters foraging efficiency in Bluegill (Lepomis macrochirus), a common North American freshwater fish, and, 2) identify differences in freshwater fish assemblages and Bluegill diet composition along the lighting gradients created by artificially lit bridges. I predicted that Bluegill foraging efficiency would increase to a point under low to moderate ALAN intensities but decrease at higher intensities. I also predicted that fish assemblages would vary with light intensity because forage fish will take advantage of increased feeding opportunities in brightly lit areas, while predators hunt those forage fish at the edges of the light. Additionally, I expected that the diet of wild-caught Bluegill diet would vary with artificial light intensity as the abundance and type of prey available changed. I used a combination of mesocosm experiments and field sampling to test these predictions. Using an array of outdoor mesocosm tanks, I separated juvenile hatchery-reared Bluegill into five treatment groups, each of which was exposed to a different intensity of ALAN over the course of six weeks. I conducted weekly nighttime feeding trials on each mesocosm tank to assess the foraging efficiency of the fish housed under the various lighting treatments. Results of these mesocosm experiments suggest that high-intensity light pollution allowed fish to locate and strike at prey more quickly. Additionally, flashing high intensity lights (intended to mimic the effect of passing car headlights on a busy highway) appeared to inhibit the ability of fish to successfully capture prey. To assess changes in fish assemblages in response to ALAN, I conducted nighttime electrofishing and light surveys at six bridge crossings over reservoirs in central Ohio. Surveys were conducted along transects parallel to the bridge at each site, including two transects within areas with the greatest exposure to the bridge lights and two transects in areas beyond the reach of the bridge lights. Finally, to evaluate differences in Bluegill diet between fish in lit and unlit areas, I analyzed the stomach contents of Bluegill captured during electrofishing. The diet of wild-caught Bluegill did not differ appreciably between fish captured in lit and unlit areas. However, the fish assemblage data collected from the electrofishing surveys indicate that light pollution has a subtle, but significant negative effect on species evenness and diversity. Overall, these results suggest that light pollution has the potential to alter fish behavior at the individual level and contribute to shifts in freshwater fish diversity at the community level.
Suzanne Gray (Advisor)
Lauren Pintor (Committee Member)
Mažeika Sullivan (Committee Member)
73 p.
Ecology
ALAN; light pollution; freshwater fish; Lepomis macrochirus

Recommended Citations

Citations

  • Harrison, S. (2021). Effects of light pollution on fish feeding behavior and assemblage structure in reservoirs [Master's thesis, Ohio State University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=osu1638379317556167

    APA Style (7th edition)

  • Harrison, Susanna. Effects of light pollution on fish feeding behavior and assemblage structure in reservoirs. 2021. Ohio State University, Master's thesis. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=osu1638379317556167.

    MLA Style (8th edition)

  • Harrison, Susanna. "Effects of light pollution on fish feeding behavior and assemblage structure in reservoirs." Master's thesis, Ohio State University, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=osu1638379317556167

    Chicago Manual of Style (17th edition)

osu1638379317556167
162
© 2021, all rights reserved.
This open access ETD is published by The Ohio State University and OhioLINK.