Codend selectivity in the East China Sea of a trawl net with the legal minimum mesh size
Codend selectivity in the East China Sea of a trawl net with the legal minimum mesh size
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DOI：
10.1007/s12562-018-1270-x
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发表时间：
2019-01-01
影响因子：
1.9
通讯作者：
Yoda, Mari
中科院分区：
文献类型：
--
作者：
Tokai, Tadashi;Shiode, Daisuke;Yoda, Mari
根据东海2001年至2011年的资源评估研究数据，使用附着在拖网（Seikai国立水产研究所SS-RI型拖网）的网囊上的覆盖网，获得了22种鱼类和鱿鱼的选择性曲线。拖网囊由菱形网眼网制成，其具有法律的最小网眼尺寸为54 mm（网眼长度为66 mm）。将具有18 mm（或10.3mm，取决于研究年份）网孔的覆盖网附接到囊体。对于每一个20种鱼类和两种鱿鱼，我们汇集了数据的拖运，其中身体大小为整个捕获量进行测量，而不进行二次抽样，以获得的身体大小组成的鱼类捕获的囊和覆盖网。进行最大似然法估计代表密码子选择曲线的逻辑曲线方程中的参数。对18种鱼类（不包括带鱼和海鳗）的选择参数[50%保留长度（l（50））和选择范围（SR）（=l（75）-l（25））]与鱼体形状的关系进行了研究。我们证明，在具有较小的身体高度/宽度与身体大小之比的鱼类中（即，此外，通过比较各鱼种的l（50）与成熟时最小体长等繁殖参数，考察了基于最小网目尺寸规定的资源可持续性。
Selectivity curves were obtained for 22 species of fish and squid from stock assessment research data for the East China Sea between 2001 and 2011, conducted using a cover net attached to the codend of a trawl net (Seikai National Fisheries Research Institute SS-RI-type trawl net). The trawl net codend was made of diamond mesh net with a legal minimum mesh opening size of 54mm (mesh length of 66mm). A cover net with a mesh opening of 18mm (or 10.3mm depending on the research year) was attached to the codend. For each of the 20 fish species and two squid species, we pooled data of hauls where body size for the whole catch was measured without subsampling to obtain the body size compositions of fish caught in both the codend and the cover net. The maximum likelihood method was performed for estimation of parameters in the logistic curve equation representing the codend selection curve. For 18 fish species (excluding Trichiurus japonicus and Muraenesox cinereus), we examined the relationship of the obtained selection parameters [length at 50% retention (l(50)) and selection range (SR) (=l(75)-l(25))] to fish body shape. We demonstrated that, in fish species with a smaller ratio of body height/width to body size (i.e., more slender body type), there was a tendency for larger l(50) and SR. Furthermore, by comparing the l(50) of each fish species with reproductive parameters such as minimum length at maturity, we examined the sustainability of the resources based on the minimum mesh size regulation.