Institute for Coastal Science and Policy, East Carolina University, Greenville, NC, United States of America.
Smithsonian Environmental Research Center, Edgewater, MD, United States of America.
PLoS One. 2018 Apr 12;13(4):e0195221. doi: 10.1371/journal.pone.0195221. eCollection 2018.
Estuaries function as important nursery and foraging habitats for many coastal species, including highly migratory sharks. Pamlico Sound, North Carolina, is one of the largest estuaries in the continental United States and provides a variety of potential habitats for sharks. In order to identify and spatially delineate shark habitats within Pamlico Sound, shark catch and environmental data were analyzed from the 2007-2014 North Carolina Division of Marine Fisheries (NCDMF) gillnet and longline surveys conducted within the estuary. Principal species were identified and environmental data recorded at survey sites (depth, temperature, salinity, dissolved oxygen, submerged aquatic vegetation (SAV) distance, and inlet distance) were interpolated across Pamlico Sound to create seasonal environmental grids with a 90-m2 cell size. Boosted Regression Tree (BRT) analysis was used to identify the most important environmental factors and ranges associated with presence of each principal species, and the resulting models were used to predict shark capture probability based on the environmental values within the grid cells. The Atlantic Sharpnose Shark (Rhizoprionodon terraenovae), Blacktip Shark (Carcharhinus limbatus), Bull Shark (Carcharhinus leucas), Sandbar Shark (Carcharhinus plumbeus), Smooth Dogfish (Mustelus canis), and Spiny Dogfish (Squalus acanthias) were the principal species in Pamlico Sound. Most species were associated with proximity to the inlet and/or high salinity, and warm temperatures, but the Bull Shark preferred greater inlet distances and the Spiny Dogfish preferred lower temperatures than the other species. Extensive Smooth Dogfish habitat overlap with seagrass beds suggests that seagrass may be a critical part of nursery habitat for this species. Spatial delineation of shark habitat within the estuary will allow for better protection of essential habitat and assessment of potential interactions with other species.
河口是许多沿海物种（包括高度洄游性鲨鱼）的重要育雏和觅食栖息地。北卡罗来纳州的帕姆利科湾是美国最大的河口之一，为鲨鱼提供了多种潜在的栖息地。为了确定并在空间上划定帕姆利科湾内鲨鱼的栖息地，分析了 2007 年至 2014 年期间在该河口进行的北卡罗来纳州海洋渔业部（NCDMF）刺网和延绳钓调查的鲨鱼捕捞和环境数据。在调查点确定主要物种，并对环境数据（深度、温度、盐度、溶解氧、淹没水生植被 (SAV) 距离和入口距离）进行插值，以便在帕姆利科湾内创建具有 90m2 单元格大小的季节性环境网格。使用提升回归树 (BRT) 分析确定与每种主要物种存在相关的最重要的环境因素和范围，并使用所得模型根据网格单元内的环境值预测鲨鱼捕捞概率。大西洋尖吻鲨（Rhizoprionodon terraenovae）、黑鳍鲨（Carcharhinus limbatus）、牛鲨（Carcharhinus leucas）、沙虎鲨（Carcharhinus plumbeus）、光滑星鲨（Mustelus canis）和尖吻鲛（Squalus acanthias）是帕姆利科湾的主要物种。大多数物种与靠近入口和/或高盐度和温暖的温度有关，但牛鲨更喜欢更大的入口距离，而尖吻鲛则比其他物种更喜欢更低的温度。广泛的光滑星鲨栖息地与海草床重叠表明，海草可能是该物种育雏栖息地的关键部分。在河口内划定鲨鱼栖息地的范围将有助于更好地保护重要的栖息地，并评估与其他物种的潜在相互作用。
