Wirgin Isaac, Maceda Lorraine, Stabile Joseph, Waldman John
Department of Environmental Medicine, NYU School of Medicine, 341 East 25 Street, New York, New York 10010.
Department of Biology, Iona College, 715 North Avenue, New Rochelle, New York 10801.
Fish Res. 2022 Jun;250. doi: 10.1016/j.fishres.2022.106270. Epub 2022 Feb 12.
Summer flounder supports one of the most valuable commercial and recreational fisheries along the Atlantic Coast of the U.S. However, in recent decades the management of this species has proven to be one of the most contentious for any exploited marine resource in the region. A coastwide catch quota is imposed annually for summer flounder of which 60% is allocated to the commercial fishery and 40% to the recreational fishery. The allocation is further divided among the individual coastal states from North Carolina to Massachusetts based on their landings in the 1980s. This process, based on political jurisdictions, does not consider the species' biological stock structure. Previous genetic studies (allozyme, mtDNA, and SNPs) provided contradictory results regarding the possible population structure of summer. To address this issue, we used DNA microsatellite analysis at 9 loci to define the coastwide population structure of summer flounder. In total, 1,182 specimens were analyzed from 18 collection sites. Most collections were from the continental shelf during the fall-winter spawning season. These were supplemented with additional samples from inshore waters from North Carolina to Florida, and inshore sites which support significant recreational fisheries at Nantucket Shoals, Massachusetts and Fire Island, New York. The overall level of genetic differentiation in pairwise comparison between collections was very low, mean = 0.001. There was no evidence of genetic differentiation between collections from north and south of Cape Hatteras. Our microsatellite results are consistent with an earlier SNP study which failed to find significant allelic heterogeneity among coastwide collections of summer flounder. However, a subset of pairwise comparisons between some collections proved statistically significant. Furthermore, in STRUCTURE analysis we found evidence of two genetic clusters within the species' northern landings area, however, this finding was not supported by DPAC analysis. We conclude that summer flounder most likely constitute a single population along their entire Atlantic Coast distribution.
夏季比目鱼支撑着美国大西洋沿岸最具价值的商业和休闲渔业之一。然而，近几十年来，该物种的管理已被证明是该地区任何被开发的海洋资源中最具争议性的管理之一。每年都会对夏季比目鱼设定一个全海岸捕捞配额，其中60%分配给商业渔业，40%分配给休闲渔业。该配额进一步根据北卡罗来纳州到马萨诸塞州各沿海州在20世纪80年代的上岸量在各州之间进行分配。这个基于政治管辖区域的过程没有考虑该物种的生物种群结构。先前的遗传学研究（等位酶、线粒体DNA和单核苷酸多态性）关于夏季比目鱼可能的种群结构给出了相互矛盾的结果。为了解决这个问题，我们使用9个位点的DNA微卫星分析来确定夏季比目鱼的全海岸种群结构。总共分析了来自18个采集地点的1182个样本。大多数样本采集于秋冬产卵季节的大陆架。此外，还补充了从北卡罗来纳州到佛罗里达州近岸水域的样本，以及马萨诸塞州楠塔基特浅滩和纽约火岛支持重要休闲渔业的近岸地点的样本。各采集样本之间成对比较的总体遗传分化水平非常低，平均值 = 0.001。没有证据表明哈特拉斯角以北和以南的采集样本之间存在遗传分化。我们微卫星分析的结果与早期一项单核苷酸多态性研究一致,该研究未能在全海岸夏季比目鱼采集样本中发现显著的等位基因异质性。然而，一些样本之间的成对比较子集证明具有统计学意义。此外，在结构分析中，我们在该物种北部上岸区域内发现了两个遗传簇的证据，然而，这一发现并未得到动态规划聚类分析（DPAC）的支持。我们得出结论，夏季比目鱼在其整个大西洋海岸分布范围内很可能构成一个单一的种群。
