Blue-Crab Population-Dynamics In Chesapeake Bay - Variation In Abundance (York River, 1972-1988) And Stock-Recruit Functions
Blue-Crab Population-Dynamics In Chesapeake Bay - Variation In Abundance (York River, 1972-1988) And Stock-Recruit Functions
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切萨皮克湾的蓝蟹种群动态 - 丰度变化（约克河，1972-1988 年）和种群招募功能
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发表时间：
1990
期刊：
影响因子：
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通讯作者：
W. A. V. Engel
中科院分区：
文献类型：
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作者：
R. Lipcius;W. A. V. Engel
对 1972 年至 1988 年期间通过底拖网采样的两个站点对弗吉尼亚州约克河蓝蟹丰度的年际、月度和空间变化进行了分析。各种种群招募和补充种群函数源自拖网丰度和商业渔业上岸统计数据。变化的关键组成部分是由于丰度的年际波动造成的，丰度在发生变化之前的两年或更长时间内一直保持在高位或低位，这表明存在内部种群反馈机制，例如同类相食或长期气候控制。此外，库存招募函数残差的显着循环模式进一步表明丰度存在长期变化。季节性丰度高峰和变化最低发生在六月至八月。显着的年×月交互效应是由于最高季节丰度的时间从高丰度年份的夏季转移到低丰度年份的夏末和秋季，这表明连续年份类别的差异优势。空间变化非常明显，除了 17 年中的 2 年之外，上游站的渔获量始终高于下游站。一个关键发现涉及拖网数据的显着且圆顶形的股票招募关系（Ricker 模型）。重新审视之前反对蓝蟹存在重要的股票招募关系的经验和概念论证表明它们是无效的。种群-招募关系中纳入了显着的替代效应，包括代表先前招募年份类别和产卵种群的组成部分，这可能通过食物供应、生长和生存的变化影响招募。补充种群函数很重要，表明幼体丰度与产卵种群大小之间存在相关性。与前面的模型相一致，其他补充种群函数表明切萨皮克湾蓝蟹种群不同部分之间存在各种具有生物学意义的相互关系。商业捕捞统计数据（Hurt 等人，1979 年；Tang，1985 年；Van Engel，1987 年）和研究调查（Hines 等人，1987 年）表明，切萨皮克湾的蓝蟹丰度波动很大。这种种群差异是由于众多的生物和环境来源造成的，如果没有长期的独立于渔业的数据集，就很难识别和量化这些来源，种群不同部分之间的功能关系也是如此。例如，关于蓝蟹产卵种群招募关系的存在（Applegate，1983；Tang，1985）或不存在（Pearson，1948；Sulkin 等，1983；Van Engel，1987）存在相互矛盾的观点。因此，尽管切萨皮克湾的蓝蟹具有生态和经济意义，但其种群动态仍然知之甚少，部分原因是缺乏对不包括商业捕捞量的长期丰度数据的记录分析。弗吉尼亚海洋科学研究所 (VIMS) 三十多年来一直在弗吉尼亚州约克河对蓝蟹丰度进行独立于渔业的拖网调查，并在弗吉尼亚州詹姆斯河和拉帕汉诺克河进行了较短的持续时间。该数据集是同类中最长的，包含多个时间和空间尺度上蓝蟹丰度的定量信息。对该数据集的彻底分析对于增进我们对切萨皮克湾蓝蟹种群动态的了解非常有用。在这份报告中
Blue crab abundance in the York River, Virginia was analyzed for interannual, monthly and spatial variation at two stations sampled by bottom trawl from 1972-1988. Various stock-recruitment and recruit-stock functions were derived from trawl abundance and commercial fishery landings statistics. The key component of variation was due to interannual fluctuations in abundance, which remained consistently high or low for two or more years before changing, suggesting internal population feedback mechanisms, such as cannibalism, or long-term climatic control. In addition, significant cyclic patterns in residuals from stockrecruitment functions further indicated the existence of long-term variability in abundance. Peak seasonal abundance and lowest variation occurred from June-August. A significant year x month interaction effect was due to shifts in the time of highest seasonal abundance from summer during high-abundance years to late summer and fall in low-abundance years, suggesting differential dominance of successive year classes. Spatial variation was appreciable such that an upriver station had consistently higher catches than a downriver station, except for 2 of 17 years. A key finding concerned the significant and dome-shaped stock-recruitment relationship (Ricker model) for the trawl data. Re-examination of previous empirical and conceptual arguments against the existence of a significant stock-recruitment relationship for the blue crab indicates their invalidity. Significant surrogate effects were incorporated into the stock-recruitment relationship, including components representing prior recruiting year classes and spawning stocks, which may impact recruitment through alterations in food availability, growth and survival. A recruit-stock function was significant and indicated a correlation between juvenile abundance and a measure of spawning stock size. In concert with the preceding models, other recruit-stock functions indicate various biologically meaningful inter-relationships between different segments of the blue crab population in Chesapeake Bay. Blue crab abundance in Chesapeake Bay fluctuates greatly, as indicated by commercial catch statistics (Hurt et al., 1979; Tang, 1985; Van Engel, 1987) and research surveys (Hines et al., 1987). Such population variation is due to numerous biotic and environmental sources, which are difficult to identify and quantify without long-term fishery-independent data sets, as are the functional relationships between different segments of a population. For instance, conflicting views exist regarding the existence (Applegate, 1983; Tang, 1985) or absence (Pearson, 1948; Sulkin et al., 1983; Van Engel, 1987) ofa spawning stock-recruitment relationship for the blue crab. Thus, despite the ecological and economic significance of the blue crab in Chesapeake Bay, its population dynamics remain poorly understood due in part to the lack of documented analyses of long-term abundance data exclusive of the commercial catch. The Virginia Institute of Marine Science (VIMS) has been conducting a fisheryindependent trawl survey of blue crab abundance for over three decades in the York River, Virginia, and for a shorter duration in the James and Rappahannock rivers, Virginia. The data set is the longest of its kind, and contains quantitative information on blue crab abundance over several temporal and spatial scales. A thorough analysis of this data set will be extremely useful in advancing our understanding of blue crab population dynamics in Chesapeake Bay. In this report