长江口脊尾白虾繁殖生物学及资源评估
发布时间:2018-06-26 23:07
本文选题:长江口 + 脊尾白虾 ; 参考:《上海海洋大学》2017年硕士论文
【摘要】:白虾(脊尾白虾、安氏白虾)历史上是长江口“五大渔汛”之一,是长江口重要的渔业捕捞对象,同时在长江口水生生态系统中也占据重要地位。然而,由于过度捕捞和环境污染等的影响,长江口生态系统全面衰退,脊尾白虾资源和种群数量受到严重影响。2015年对长江口水域脊尾白虾进行了调查,研究了脊尾白虾的时空分布及其与环境因子之间的关系、繁殖生物学、资源量进行了研究。旨在丰富、更新和储备长江口脊尾白虾的研究资料,为长江口脊尾白虾资源的可持续利用提供理论依据和实际指导。1.长江口白虾的分布及其与环境因子的关系采用2015年2月(冬季)、5月(春季)、8月(夏季)和11月(秋季)长江口水域渔业资源调查资料,结合该水域的水文情况,研究长江口白虾的季节资源丰度、平面分布及与环境因子之间的关系。结果显示:脊尾白虾和安氏白虾丰度存在明显的季节差异,均表现为秋季最高,冬季最低。脊尾白虾主要分布在北支水域,安氏白虾主要分布于南支水域;通过对两种白虾丰度分布与环境因子的RDA分析表明,脊尾白虾和安氏白虾的分布主要受盐度、水温、溶解氧和pH等影响。2.长江口脊尾白虾繁殖生物学研究通过周年逐月采样,对长江口脊尾白虾繁殖生物学进行了研究。结果表明:长江口脊尾白虾体长范围为25~75 mm,优势体长范围为35~55 mm,平均体长(48.32±9.07)mm;周年间月性比变化介于0.89~1.63,年平均性比为1.12±0.22,雌雄数量差异不显著(P0.05);长江口脊尾白虾繁殖期在3~10月,繁殖高峰期在5~8月,其中5~6月繁殖群体以越年虾为主,7月繁殖群体以当年虾为主;个体绝对生殖力(F)在660~8000egg,与体长(L)呈直线相关,F=68.86L-2072(R2=0.498);个体绝对生殖力与体重(W)也呈直线相关,F=318.5W+267.0(R2=0.504)。个体体长相对生殖力(FL)为2.97~154.35egg/mm,个体体重相对生殖力(FW)为107.87~1964.66egg/g。F、FL与各生物学指标间的相关系数均达到极显著水平(P0.01);FW仅与空壳重、成熟系数之间的相关系数达到极显著水平(P0.01)。F、FL与体长、体重、空壳重、成熟系数呈幂函数相关,与卵巢重呈线性相关;FW与卵巢重呈幂函数相关,与成熟系数呈线性相关。多元逐步回归分析表明,F与卵巢重密切相关。3.长江口脊尾白虾生长参数及持续渔获量分析运用FiSAT II软件对脊尾白虾的生长参数以及种群补充模式进行了分析。结果表明:雌虾的体长组成范围为27~74mm,其中35~50mm的个体占绝对优势;生长系数(K)和极限体长(L∞)分别为1.01和79.8mm,种群总死亡系数(Z)、自然死亡系数(M)和捕捞死亡系数(F)分别为4.81、1.9和2.87。当前长江口近岸水域脊尾白虾的资源开发率(E)为0.597,大于Fopt(0.5)。利用长度结构的VPA方法估算的年平均资源量为2.234×109ind,463.54t。通过对单位补充量产量、资源量、渔获产量分析表明,该群体利用合理,开捕体长亦处最佳位置,同时建议在7~8月实休渔期。
[Abstract]:White Shrimp (White Shrimp, White Shrimp) is one of the "five major fishing floods" in the Yangtze Estuary in history. It is an important fishing object in the Changjiang Estuary, and also occupies an important position in the aquatic ecosystem of the Yangtze River Estuary. However, due to the effects of overfishing and environmental pollution, the ecosystem of the Yangtze River Estuary has completely declined, and the resources and population of the white shrimp have been seriously affected. A survey was carried out on the white shrimp in the Yangtze River Estuary in 2015. The temporal and spatial distribution of white shrimp and its relationship with environmental factors, reproductive biology and resources were studied. The aim of this paper is to enrich, renew and store the research data of white shrimps in the Changjiang Estuary, and to provide theoretical basis and practical guidance for the sustainable utilization of the resources of white shrimps in the Yangtze River Estuary. Distribution of White Shrimp in the Changjiang Estuary and its relationship with Environmental factors the survey data of fishery resources in the Yangtze Estuary waters in February (winter), May (spring), August (summer) and November (autumn) were used. The seasonal abundance, plane distribution and relationship with environmental factors of white shrimps in the Yangtze River Estuary were studied. The results showed that there were significant seasonal differences in the abundance of white shrimps and white shrimps, which were the highest in autumn and the lowest in winter. The abundance distribution and environmental factors of two species of white shrimp were analyzed by RDA. The distribution of white shrimp and white shrimp were mainly influenced by salinity and water temperature, the distribution of white shrimp was mainly distributed in the waters of the northern branch, and the distribution of the two species of white shrimps was mainly affected by salinity and water temperature, according to the RDA analysis of the abundance distribution and environmental factors of the two species of white shrimp. Effects of dissolved oxygen and pH. Reproductive Biology of White Shrimp in the Yangtze River Estuary the annual monthly sampling was carried out to study the reproductive biology of White Shrimp in the Yangtze River Estuary. The results showed that the range of body length was 2575 mm, the dominant length was 35 ~ 55 mm, the average length was (48.32 卤9.07) mm, the monthly sex ratio was 0.891.63, the annual sex ratio was 1.12 卤0.22, there was no significant difference between male and female (P0.05), the breeding period of white shrimp was from March to October, and the average sex ratio was 1.12 卤0.22 (P0.05), and the average length was (48.32 卤9.07) mm. The peak period of reproduction was from May to August, in which the main breeding population in May ~ June was old shrimp, and in July, shrimp was dominant; the absolute fecundity of individual (F) was 660,8000 eggs. there was a linear correlation between individual absolute fecundity (F) and body length (L), and there was a linear correlation between individual absolute fecundity and body weight (W). There was a linear correlation between individual absolute fecundity and body weight (R _ 2O _ (0.504), and there was also a linear correlation between individual absolute reproductive power and body weight (R _ (2) ~ (0.504). The relative fecundity (FL) of individual body length was 2.97 / 154.35 eggs.The relative fecundity (FW) of individual body weight was 107.87 / 66.64.66 / g 路FFL and the correlation coefficient between FW and each biological index was extremely significant (P0.01), and the correlation coefficient between maturity coefficient and body length was very significant (P0.01). Body weight, empty shell weight, maturation coefficient were power function correlation, ovarian weight was linear correlation with ovarian weight and ovarian weight was power function, and maturation coefficient was linear correlation. Multiple stepwise regression analysis showed that F was closely related to ovarian weight. Growth parameters and continuous catch Analysis of White Shrimp in the Yangtze Estuary the growth parameters and population replenishment model of the white shrimp were analyzed by FiSAT II software. The results showed that the body length composition of female shrimp was 274mm, the individual of 35~50mm was dominant, the growth coefficient (K) and limiting body length (L 鈭,
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