Size structure of Antarctic krill inferred from samples of Pygoscelid penguin diets and those collected by the commercial krill fishery
Size structure of Antarctic krill inferred from samples of Pygoscelid penguin diets and those collected by the commercial krill fishery
复制标题
DOI：
10.1007/s00227-021-03831-0
复制
发表时间：
2021-02
期刊：
影响因子：
2.4
通讯作者：
Mariana A. Juáres;M. Grech;R. Casaux;J. Negrete;Jazmín Fógel;N. Coria;Mercedes M. Santos
中科院分区：
文献类型：
--
作者：
Mariana A. Juáres;M. Grech;R. Casaux;J. Negrete;Jazmín Fógel;N. Coria;Mercedes M. Santos
在南极半岛，在育雏期，阿德利企鹅 (Pygoscelis adeliae) 和巴布亚企鹅 (P. papua) 主要以南极磷虾 (EuphausiaSuperba) 为食，该磷虾也被商业渔业所利用。对南设得兰群岛陌生角捕食者捕食的磷虾长度和幼磷虾比例（2007/2008 年至 2015/2016 年）与马德拉弗洛塔/布兰斯菲尔德海峡磷虾渔业（2009/2010 年至 2015/2016 年）收集的磷虾长度和幼磷虾比例进行比较，以评估每个数据源作为磷虾变化指标的潜力。磷虾种群的大小构成等人口结构。总体而言，巴布亚企鹅摄入的磷虾平均尺寸大于阿德利企鹅，后者消耗的幼年磷虾（≤ 35 毫米）和一岁磷虾（≤ 25 毫米）比例更高。尽管渔业捕获的磷虾大小在统计上与两种企鹅捕获的磷虾大小相似，但三个数据库之间磷虾大小的频率分布存在差异。此外，当仅考虑成年磷虾（> 35毫米）时，磷虾数据的三个来源显示出成年磷虾群体可用性的类似年际变化。我们的研究结果表明，这里分析的每个数据库都可能提供有关磷虾大小组成的不同信息（尽管是互补的）。此外，较小规格磷虾的年际波动可能反映了它们补充的第一年，因此可以用作当地磷虾供应量变化的指标。
In the Antarctic Peninsula, during the chick-rearing period Adélie (Pygoscelis adeliae) and gentoo (P. papua) penguins feed primarily on Antarctic krill (Euphausia superba), which is also exploited by the commercial fishery. Krill length and proportion of juvenile krill consumed by these predators that breed at Stranger Point, South Shetland Islands (from 2007/2008 to 2015/2016), and those collected by the krill fishery in the Mar de la Flota/Bransfield Strait (from 2009/2010 to 2015/2016) were compared to evaluate the potential of each data source as an indicator of changes in the size composition and so, in the demographic structure of the krill population. Overall, the mean krill size taken by gentoo penguins was larger than that ingested by Adélie penguins, which consumed higher proportions of juvenile (≤ 35 mm) and one-year-old (≤ 25 mm) krill. Although the krill size caught by the fishery was statistically similar to that taken by both penguin species, there were differences in the frequency distributions of krill size among the three databases. Furthermore, when only adult krill (> 35 mm) was considered, the three sources of krill data showed a similar inter-annual variation in the availability of adult krill cohorts. Our findings suggest that each database analysed here can potentially provide different information (although complementary) about krill size composition. In addition, inter-annual fluctuations in the smaller size classes of krill likely reflect their first year of recruitment and, therefore, may be used as an indicator of shifts in local krill availability.