MEPS 466:145-153 (2012)  -  DOI: https://doi.org/10.3354/meps09986

Preference for feeding at habitat edges declines among juvenile blue crabs as oyster reef patchiness increases and predation risk grows

Peter I. Macreadie1,2,*, Nathan R. Geraldi1, Charles H. Peterson1

1Institute of Marine Science, University of North Carolina, Morehead City, 28557 North Carolina, USA
2Centre for Environmental Sustainability, School of the Environment, University of Technology, Sydney,
2007 New South Wales, Australia

ABSTRACT: Both habitat patchiness and behaviorally-mediated indirect effects (BMIEs; predator-induced changes in prey behavior that affect the prey’s resources) are important in many food webs, but the relationships between these 2 factors have yet to be investigated. To explore effects of habitat patchiness and variation in perceived risk of predation on food-web dynamics, we conducted a factorial experiment in a model aquatic food chain of predator−prey−resource using 2 contrasting predators (adult blue crab Callinectes sapidus and toad fish Opsanus tau), juvenile blue crab as prey, and mussel Geukensia demissa as resource. Both predator presence and habitat patchiness influenced the prey’s preference for consuming resources at patch edges instead of interiors. The preference of prey for consuming resources at habitat edges was 4 times stronger in continuous oyster reef habitat than in smaller habitat patches. This suggests that interior resources in continuous habitat experience a refuge from consumption, but this refuge is largely lost in patchy habitat. The mere presence of predators reduced the prey’s preference for consuming resources at habitat edges. This BMIE was significant for the ambush predator (toadfish) and the treatment containing both predators, but not for the actively hunting predator (adult blue crab). We conclude that habitat patchiness and predator presence can jointly affect resource distribution by inducing shifts in prey foraging behavior, revealing a need to incorporate BMIEs into habitat fragmentation studies. This conclusion has broad and growing relevance as anthropogenic factors increasingly modify predator abundances and fragment coastal habitats.


KEY WORDS: Habitat fragmentation · Edge effect · Hunting mode · Non-consumptive effect · Trait-mediated indirect effect · Oyster reef · Non-lethal effect · Trophic cascade


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Cite this article as: Macreadie PI, Geraldi NR, Peterson CH (2012) Preference for feeding at habitat edges declines among juvenile blue crabs as oyster reef patchiness increases and predation risk grows. Mar Ecol Prog Ser 466:145-153. https://doi.org/10.3354/meps09986

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