水产学报2018，Vol.42Issue(6)：881-888,8.DOI:10.11964/jfc.20171111040
东、黄海星康吉鳗生长、死亡和单位补充量渔获量
The growth, mortality and yield per recruitment of white-spotted conger ( Conger myriaster) in the Yellow Sea and the East China Sea
摘要
Abstract
The objective of this study was to provide biological reference points for the fisheries management of Conger myriaster in Yellow Sea and East China Sea. Specifically, we projected the yield per recruitment (YPR ) model for C. myriaster, and obtained the biological reference points, such as Fmax and F0.1, and the suggested length of first capture (L50). Through the scientific survey and the commercial fishery survey in the Yellow Sea and East China Sea in 2016 and 2017, 657 individuals of C. myriaster were collected and measured for the total length (cm) and weight (g), in which 256 samples were analyzed for their age according to the otoliths. Based on these 657 samples, the weight-length relationships were studied by a power law model. The condition factor a estimate was 4.5×10-4, indicating the slender eel-like body shape of C. myriaster, while the estimate of parameter b was 3.3, meaning that C. myriaster tends to become relatively fatter or have greater girth as it grows longer. The von Ber-talanffy growth model was used to analyze the length-age relationships based on those 256 samples with age data. The asymptotic length L∞ was estimated to be 102 cm, and the estimate for t0, the age at which weight and length were zero, was -0.19. The exponential rate K of approach to the asymptotic length was 0.21 per year, indicating the slow growth rate of this larger demersal carnivorous species. Five scientific bottom trawl surveys were conduc-ted in Haizhou Bay in March, May, July, September and December, 2011, in which 715 samples were collected and measured. In order to estimate the instantaneous total mortality rate Z, these samples were used to project the (length-converted) linearized catch curve to length-frequency data. This catch curve indicated that the estimate of Z was 3.36 and the length of first capture (L50) was 30 cm, meaning that the age of first capture is 1.47 years. The Pauly empirical formula evaluated the natural mortality M to be 0.33, according to the above growth parameters and the water temperature. Therefore, the fishing mortality F was 3.03, and the exploitation ratio was 90%. Based on all above estimates for the growth and mortality parameters, the yield per recruitment models were projected for C. myriaster. YPR increased to maximum, then decreased, when F kept increasing. Different M (0.23, 0.28, 0.33, 0.38 and 0.43) and different lengths of first capture (30 cm, 40 cm, 48 cm, 56 cm and 67 cm) were considered in the YPR model. When M increased, the estimates for Fmax and F0.1 would increase with smaller YPR, while the in-crease of L50 would result in greater Fmax, YPRmax, F0.1, and YPR0.1. The current YPR of C. myriaster was 27.14. When M=0.33, Fmax was 0.38, one eighth of the current F, while YPRmax was 52.89, nearly double of the current YPR. And when M=0.33, F0.1 was 0.255, 30% smaller than Fmax, while YPR0.1 was smaller than YPRmax by 5%. In conclusion, this fishery is undergoing heavy fishing pressure, with less length of first capture and extremely high fishing effort. Therefore, in order to keep this population health and the sustainable development of this fishery, we suggest to decrease the fishing effort largely and increase the length of first capture. For example, if F decreases from 3.03 to 2 and L50 increases from 30 to 40 cm, YPR would increase by 89%.关键词
星康吉鳗/生长/死亡/单位补充量渔获量/东海/黄海Key words
Conger myriaster/growth/mortality/yield per recruitment/East China Sea/Yellow Sea分类
农业科技引用本文复制引用
麻秋云,牟秀霞,任一平,孙远远..东、黄海星康吉鳗生长、死亡和单位补充量渔获量[J].水产学报,2018,42(6):881-888,8.基金项目
中央高校基本科研业务费专项(201612004) Fundamental Research Funds for the Central Universities (201612004) （201612004）
