Decadal Trends in Age Structure and Recruitment Patterns of Ocean Quahogs Arctica islandica from the Mid-atlantic Bight in Relation to Water Temperature
Decadal Trends in Age Structure and Recruitment Patterns of Ocean Quahogs Arctica islandica from the Mid-atlantic Bight in Relation to Water Temperature
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大西洋中湾北极圆蛤年龄结构和补充模式与水温的十年趋势
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发表时间：
2008
期刊：
影响因子：
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通讯作者：
R. Mann
中科院分区：
文献类型：
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作者：
J. Harding;Sarah E. King;E. Powell;R. Mann
海洋双壳类动物是一种长寿的双壳类动物。北美东岸大西洋中湾（MAB）海洋quohog的分布模式和生物学特性与底水温有直接关系。我们研究了跨时间（年代际）和空间（纬度、水深）尺度的海洋圆头鲸的长期招募模式，使用了一个空间定义的（长岛海峡到切萨皮克湾口）种群，包括尚未被商业渔业招募的大尺寸（年龄）范围的动物[<80毫米壳长（SL）]。使用幂函数描述了小于80mm SL的夸猪的年龄-长度关系。夸hog年龄与深度或区域之间没有显著差异，年龄和长度与深度或区域之间也没有显著的相互作用项。开发了一种年龄长度键，用于海洋quhogs生成每个站点的年龄频率。主成分分析（PCA）对得到的每tow标准化的年龄-频率分布进行了主成分分析，从而可以为由PCA因子得分确定的类似站点构建特征年龄-频率分布。这些特征性的年龄-频率分布确定了与1948-1950、1954-1959、1972-1980和1978-1983时间段招募的模态年龄相对应的quahog队列。观察到的MAB海洋quohog的招募模式与底部水温模式密切相关。水温平均为6°C至10°C的月份数比水温低于6°C的月份数至少多两个月的年份，也是对人口年龄-频率分布的模态年类别有重大影响的年份。一般来说，1月、2月和3月底水温高于平均水平的年份往往会产生年龄-频率分布与MAB类圆蛤种群不同的年份。所观察到的白牡蛎捕捞时间序列与种群调查和大多数渔业动态估计的时间尺度不同。底栖动物招养牡蛎和渔业招养牡蛎之间50 - 60年的时间差对渔业预测提出了挑战，因为成体生物量的变化及其对种群招养关系的影响只有在这个时间尺度上才会变得明显。
Abstract Ocean quahogs (Arctica Islandica) are long-lived bivalves. Distribution patterns and biology of ocean quahogs in the Mid-Atlantic Bight (MAB) off the east coast of North America are directly related to bottom water temperatures. We examined long term recruitment patterns for ocean quahogs across temporal (decadal) and spatial (latitudinal, bathymetric) scales using a spatially defined (Long Island Sound to Chesapeake Bay mouth) population encompassing a broad size (age) range of animals that had not yet recruited to the commercial fishery [<80 mm shell length (SL)]. An age-at-length relationship for quahogs less than 80 mm SL is described using a power function. Quahog age did not vary significantly with depth or region, nor were any interaction terms between age and length with depth or region significant. An age-length key was developed for ocean quahogs to generate age frequencies for each station. Principal components analysis (PCA) on the resulting age-frequency distributions standardized per tow enabled construction of characteristic age-frequency distributions for similar stations identified by the PCA factor scores. These characteristic age-frequency distributions identified quahog cohorts with modal ages corresponding to recruitment during the 1948–1950, 1954–1959, 1972–1980, and 1978–1983 time periods. Observed recruitment patterns in MAB ocean quahogs are strongly related to bottom water temperature patterns. Years in which the number of months with water temperatures averaging 6°C to 10°C exceeds the number of months with water temperatures less than 6°C by at least two months are also years that contribute strongly to the modal year classes in the population age-frequency distributions. In general, years with above average bottom water temperatures during January, February, and March tend to produce year classes that are distinct in the age-frequency distributions from the MAB quahog populations. The observed time series of quahog recruitment operates at a different time scale than stock surveys and most estimates of fishery dynamics. The 50–60-y lag between quahog recruitment to the benthos and recruitment to the fishery presents challenges for fishery forecasting in that changes in adult biomass and subsequent effects on stock-recruit relationships will only become evident on this time scale.