Abstract
<p> <p id="x-x-sp0035"> Predator outbreaks have increased in the past two decades in many ecosystems and are predicted to become more common with climate change. During these outbreaks, predator densities increase rapidly, and can cause large reductions in prey populations or shifts in <a href="https://www.sciencedirect.com/topics/earth-and-planetary-sciences/prey-size" title="Learn more about Prey Size from ScienceDirect's AI-generated Topic Pages"> prey size </a> structure. However, unexpected interactions may occur at high predator densities, necessitating a mechanistic understanding of how increased predator density affects predator-prey dynamics. In the northern <a href="https://www.sciencedirect.com/topics/earth-and-planetary-sciences/gulf-of-mexico" title="Learn more about Gulf of Mexico from ScienceDirect's AI-generated Topic Pages"> Gulf of Mexico </a> , outbreaks of southern oyster drill, <em> Stramonita haemastoma </em> (Linnaeus, 1767), occur during high salinity events, and can greatly reduce <a href="https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/eastern-oyster" title="Learn more about Eastern Oyster from ScienceDirect's AI-generated Topic Pages"> eastern oyster </a> , <em> Crassostrea virginica </em> (Gmelin, 1791), populations. A large outbreak of drills occurred from 2013 to 2015 in Apalachicola Bay, FL which corresponded with an oyster fishery collapse in that bay. To improve our mechanistic understanding of predation during such a high-density outbreak, laboratory experiments based on field observations were used to quantify the <a href="https://www.sciencedirect.com/topics/earth-and-planetary-sciences/prey-size" title="Learn more about Prey Size from ScienceDirect's AI-generated Topic Pages"> prey size </a> selection by drills and the drill functional response, as a function of drill abundance. Drills fed on medium-sized oysters (50–75 mm) more often than small and larger-sized oysters, and often formed aggregations during feeding events. However, despite this aggregative response, there was a negative relationship between per capita feeding rates and drill abundance. Indeed, the Crowley-Martin <a href="https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/functional-response-models" title="Learn more about Functional Response Models from ScienceDirect's AI-generated Topic Pages"> functional response model </a> had the most parsimonious fit to the data, suggesting that predator-predator inhibition reduced attack rates and increased handling times. Due to an increase in regional drought conditions and water usage in the southeastern United States, drill outbreaks will likely increase in frequency and duration. A greater understanding of how predation rates change with predator densities during outbreaks will improve predictions of oyster mortality, and strengthen the scientific framework for oyster fishery decisions. </p></p>
Original language | American English |
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Journal | Journal of Experimental Marine Biology and Ecology |
Volume | 501 |
DOIs | |
State | Published - Jan 1 2018 |
Disciplines
- Life Sciences