Department of Oceanography and Coastal Sciences, Louisiana State University, Baton Rouge, Louisiana, United States of America.
Department of Marine Biology, Texas A&M University (Galveston Campus), Galveston, Texas, United States of America.
PLoS One. 2019 Mar 14;14(3):e0213506. doi: 10.1371/journal.pone.0213506. eCollection 2019.
Habitat shifts that occur during the life cycles of marine fishes influence population connectivity and structure. A generalized additive modeling approach was used to characterize relationships between environmental variables and the relative abundance of red snapper Lutjanus campechanus over unconsolidated substrate on the continental shelf (<150 m) of the U.S. Gulf of Mexico (GoM) at three different life stages: juvenile (age-0, <125 mm FL), sub-adult (age-1-2, 125-300 mm FL), and adult (age-2+, >300 mm FL). Fisheries independent data (2008-2014) were used to develop separate models for both the eastern and western GoM, and final models were used to predict the relative availability of suitable habitat for each life stage across the two regions. Predictor variables included in final models varied by age class and region, with depth, dissolved oxygen, longitude, and distance to artificial structure common to most models. Depth was among the most influential variables in all models, and preferred depth increased with increasing size/age. Regional differences in fish-habitat relationships were also observed, as relative abundance of larger red snapper over unconsolidated substrates was more closely linked to artificial structure in the eastern GoM. The location of predicted high quality habitat for juvenile red snapper was greatest on the inner Texas shelf and a smaller area east of the Mississippi River Delta, suggesting these two areas may represent important nursery grounds for the respective regions. Clear ontogenetic shifts in the spatial distribution of predicted high quality habitat were evident in both the eastern (expansion from west to east with age) and western (shift from inshore to offshore) GoM. Given the unique population dynamics between the eastern and western GoM, improving our understanding of spatial and temporal variability in habitat quality may be important to maintaining connectivity between juvenile and adult habitats, and may enhance recovery and management of red snapper stocks in the GoM.
鱼类生活史中的生境变化会影响种群的连通性和结构。本研究采用广义加性模型方法，描述了美国墨西哥湾（GoM）大陆架（<150 米）上未固结基质上的红鲷鱼（Lutjanus campechanus）相对丰度与环境变量之间的关系，该关系存在于三个不同的生命阶段：幼鱼（年龄 0，<125mm 全长）、亚成鱼（年龄 1-2，125-300mm 全长）和成鱼（年龄 2+，>300mm 全长）。本研究使用独立的渔业数据（2008-2014 年）分别为 GoM 东部和西部开发了模型，最终模型用于预测两个区域每个生命阶段的适宜生境的相对可用性。最终模型中包含的预测变量因年龄组和区域而异，深度、溶解氧、经度和到人工结构的距离是大多数模型共有的。在所有模型中，深度都是最具影响力的变量之一，随着体型/年龄的增加，适宜深度也随之增加。还观察到了鱼类-生境关系的区域差异，因为在未固结基质上较大的红鲷鱼的相对丰度与 GoM 东部的人工结构更为密切相关。幼鱼红鲷鱼高优质生境的预测位置主要在德克萨斯州内大陆架和密西西比河三角洲东部的较小区域，这表明这两个区域可能是各自区域的重要育苗场。在 GoM 东部（随年龄从西向东扩展）和西部（从近岸向近海转移），预测的高优质生境的空间分布都出现了明显的发育阶段变化。考虑到 GoM 东部和西部之间独特的种群动态，了解生境质量的时空变化可能对维持幼鱼和成鱼生境之间的连通性很重要，并且可能增强 GoM 红鲷鱼种群的恢复和管理。
