Inter-Research > MEPS > v414 > p223-235  
MEPS
Marine Ecology Progress Series

via Mailchimp

MEPS 414:223-235 (2010)  -  DOI: https://doi.org/10.3354/meps08731

Influence of predation risk and food supply on nocturnal fish foraging distributions along a mangrove–seagrass ecotone

Neil Hammerschlag1,2,*, Michael R. Heithaus3, Joseph E. Serafy1,4

1Rosenstiel School of Marine and Atmospheric Science, University of Miami, 4600 Rickenbacker Causeway, Miami, Florida 33149, USA
2RJ Dunlap Marine Conservation Program, University of Miami, 4600 Rickenbacker Causeway, Miami, Florida 33149, USA
3Department of Biological Sciences, Florida International University, 3000 NE 151 St., North Miami, Florida 33181, USA
4National Oceanic and Atmospheric Administration, National Marine Fisheries Service, Southeast Fisheries Science Center, 75 Virginia Beach Drive, Miami, Florida 33149, USA

ABSTRACT: Diverse taxa from many systems must make tradeoffs between food and safety. However, few studies have examined the response of multiple fish species to food and predation risk at night across their foraging landscape. In Biscayne Bay, Florida (USA), we investigated the influences of food and predation risk on nocturnal habitat use of gray snapper, bluestriped grunt and seabream along a distance gradient spanning from the mangrove–seagrass ecotone to 120 m offshore. Seine and submerged vegetation sampling were used to determine the distribution of fishes and their food resources. Tethering experiments were used to explore gradients in predator encounter rates. We used these data to test the following a priori predictions of fish distributions relative to food and risk as generated from foraging theory: (1) fishes will be distributed in proportion to their food supply (i.e. ideal free distribution, IFD); or (2) fishes will avoid high-risk areas such that their abundances will be lower than predicted by food resources in high-risk habitats (i.e. food–risk tradeoff). Results indicated that none of the fishes were distributed according to IFD. Seabream and gray snapper avoided foraging close to shore, where their food was abundant, but risk was highest. Bluestriped grunt responses to spatial variation in food supply and risk were less clear; they appeared to forage randomly across the distance gradient. Our results suggest that fish generally avoid the risky mangrove–seagrass ecotone, but responses to variation in food and risk are species-specific and may be dependent on specific anti-predator tactics or influenced by factors we did not measure.


KEY WORDS: Predators · Edge effects · Proximity gradient · Shark · Snapper · Porgy · Grunt


Full text in pdf format 
Cite this article as: Hammerschlag N, Heithaus MR, Serafy JE (2010) Influence of predation risk and food supply on nocturnal fish foraging distributions along a mangrove–seagrass ecotone. Mar Ecol Prog Ser 414:223-235. https://doi.org/10.3354/meps08731

Export citation
Mail this link - Contents Mailing Lists - RSS
Facebook - - linkedIn