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首页> 外文期刊>ICES Journal of Marine Science >Changes in weight-at-length and size-at-age of mature Northeast Atlantic mackerel (Scomber scombrus) from 1984 to 2013: effects of mackerel stock size and herring (Clupea harengus) stock size
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Changes in weight-at-length and size-at-age of mature Northeast Atlantic mackerel (Scomber scombrus) from 1984 to 2013: effects of mackerel stock size and herring (Clupea harengus) stock size

机译：1984年至2013年东北大西洋成熟鲭鱼（Scomber scombrus）的体重和成年体重的变化：鲭鱼种群规模和鲱鱼（Clupea harengus）种群规模的影响

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摘要

Weight-at-length and length-/weight-at-age were analysed for mature 3- to 8-year-old Northeast Atlantic mackerel (Scomber scombrus; n = 26 084) collected annually in autumn (September and October) at the end of the annual feeding season during 1984-2013 in the northern North Sea. The age range represented 92% of the mackerel stock size (age 3+). During the most recent decade, mackerel length-and weight-at-age continually declined. In 2013, the average mackerel was 3.7 cm shorter and weighed 175 g less than the average individual in 2002. Individual weight-at-length, demonstrating annual summer feeding success, continually declined during the most recent 5 years, whereas somatic growth of cohorts aged 3-8 continually declined for the last 11 of 25 cohorts investigated. Growth of the latest cohort was 34% of the maximum cohort growth recorded. Both weight-at-length and cohort growth were negatively affected by mackerel stock size and Norwegian spring-spawning herring (Clupea harengus) stock size (weight-at-length: r(2) = 0.89; growth (length): r(2) = 0.68; growth (weight): r(2) = 0.78), while temperature was not significant. Conspecific density-dependence was most likely mediated via intensified competition associated with greater mackerel density. Negative effects of herring were likely mediated by exploitative competition for shared food resources rather than direct competition due to limited spatio-temporal overlap between mackerel and herring during the feeding season. Herring begin their seasonal feeding migration at least a month before mackerel; therefore, herring consumption influences prey availability for the later-arriving mackerel. Record low mackerel growth and negative effects of mackerel and herring stock size suggest that the carrying capacity of the Norwegian Sea and adjacent areas for plankton-feeding fish stocks have been reached. However, compounding effects of a less productive Norwegian Sea during the 30-year period cannot be excluded.
机译：分析了每年秋季（9月和10月）结束时每年收集的成熟的3至8岁东北大西洋鲭鱼（Scomber scombrus； n = 26 084）的体长和体长/体重。 1984-2013年北海北部的年度取食季节的变化。年龄范围代表鲭鱼种群大小（3岁以上）的92％。在最近的十年中，鲭鱼的长度和成年体重不断下降。 2013年，平均鲭鱼比2002年的平均个体短3.7厘米，重175克。个体的体长比重，表明每年夏季进食成功，在最近5年中持续下降，而同龄人的体细胞增长年龄较大在接受调查的25个队列中的最后11个队列中，有3-8个继续下降。最新队列的增长是记录的最大队列增长的34％。鲭鱼种群规模和挪威春季产卵鲱鱼种群（种群纵向重量：r（2）= 0.89;生长（长度）：r（2） ）= 0.68;生长（重量）：r（2）= 0.78），而温度不显着。特定密度依赖性很可能是通过与更高的鲭鱼密度相关的竞争加剧而介导的。鲱鱼的负面影响很可能是由于对共享食物资源的剥削竞争而不是直接竞争，因为鲭鱼和鲱鱼在进食季节之间时空重叠有限。鲱鱼至少在鲭鱼开始前一个月就开始季节性进食。因此，鲱鱼的消费会影响后来到来的鲭鱼的猎物供应。鲭鱼的低增长记录以及鲭鱼和鲱鱼种群规模的负面影响表明，挪威海及邻近地区的浮游生物饲养鱼类种群已达到承载能力。但是，不能排除生产力较低的挪威海在30年期间的复合影响。

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