Document Type
Article
Publication Title
PLoS ONE
Abstract
Understanding how animals alter habitat use in response to changing abiotic conditions is important for effective conservation management. For bull sharks (Carcharhinus leucas), habitat use has been widely examined in the eastern and western Gulf of Mexico; however, knowledge of their movements and the factors influencing them is lacking for populations in the more temperate north-central Gulf of Mexico. To examine how changes in hydrographic conditions affected the presence of young bull sharks in Mobile Bay, Alabama, thirty-five sharks were fitted with internal acoustic transmitters and monitored with an acoustic monitoring array consisting of thirty-three receivers between June 2009 and December 2010. Tagged sharks ranged in size from 60 to 114 cm fork length and were detected between the upper and lower portions of Mobile Bay. Despite a variety of freshwater sources associated with this highly productive estuary, sharks were most consistently detected at the largest input to the system – the Mobile and Tensaw Rivers. Our findings suggest a combination of hydrographic factors interact to influence the distribution of juvenile bull sharks in Mobile Bay. The factors affecting the probability of detecting at least one bull shark varied both temporally (2009 vs 2010) and spatially (upper vs lower bay). Electivity analysis demonstrated that bull sharks showed highest affinity for warm water (29–32°C), moderate salinities (10–11 psu) and normoxic waters (5–7 mg/l), although these patterns were not consistent between regions or across years. We suggest future studies coupling telemetry and hydrographic variables should, when possible, consider the interactions of multiple environmental parameters when defining the dynamic factors explaining the spatial distribution of coastal sharks.
First Page
e97124
DOI
https://doi.org/10.1371/journal.pone.0097124
Publication Date
5-19-2014
Department
Marine and Environmental Sciences
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.
Recommended Citation
Publisher required citation: Drymon JM, Ajemian MJ, Powers SP (2014) Distribution and Dynamic Habitat Use of Young Bull Sharks Carcharhinus leucas in a Highly Stratified Northern Gulf of Mexico Estuary. PLoS ONE 9(5): e97124. https://doi.org/10.1371/journal.pone.0097124
Included in
Aquaculture and Fisheries Commons, Ecology and Evolutionary Biology Commons, Marine Biology Commons
Comments
Must use original publisher's citation to cite this work.
Copyright: 2014 Drymon et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Funding: This work was funded through a grant from the Shelby Center for Ecosystem Based Fishery Management. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Competing Interests: The authors have declared that no competing interests exist.