当前位置: X-MOL 学术Can. J. Fish. Aquat. Sci. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Warmer water increases early body growth of northern pike (Esox lucius), but mortality has larger impact on decreasing body sizes
Canadian Journal of Fisheries and Aquatic Sciences ( IF 2.4 ) Pub Date : 2021-10-15 , DOI: 10.1139/cjfas-2020-0386
Terese Berggren 1, 2 , Ulf Bergström 3 , Göran Sundblad 4 , Örjan Östman 5, 6
Affiliation  

Canadian Journal of Fisheries and Aquatic Sciences, Ahead of Print.
Large fish species often display truncated size distributions related to harvest. In addition, temperature, food availability and density dependence affect body growth and together with natural mortality influence population size structure. Here we study changes in body growth, size distributions and mortality in both harvested and nonharvested populations of northern pike (Esox lucius) over 50 years along the Baltic Sea coast and in Lake Mälaren, Sweden. For coastal pike, body growth has increased coincidentally with increasing water temperatures, yet in the last two decades there has been a decrease of larger individuals. In Lake Mälaren, in contrast, size distributions and body growth were stationary despite similar increases in water temperature. A dominance of slow-growing individuals in older age classes was evident in all studied populations, also in the no-take zone, suggesting other factors than fishing contribute to the mortality pattern. We propose that increasing temperatures have favoured body growth in coastal areas, but this has been counteracted by increased mortality, causing pike sizes to decline. To regain larger coastal pike, managers need to consider multiple measures that reduce mortality.


中文翻译:

温暖的水增加了北梭子鱼(Esox lucius)的早期身体生长,但死亡率对减少体型的影响更大

加拿大渔业和水生科学杂志,印刷前。
大型鱼类通常表现出与收获相关的截断尺寸分布。此外,温度、食物供应和密度依赖性会影响身体生长,并与自然死亡率一起影响种群规模结构。在这里,我们研究了波罗的海沿岸和瑞典梅拉伦湖 50 多年来收获和未收获的北梭子鱼 (Esox lucius) 种群的身体生长、大小分布和死亡率的变化。对于沿海梭子鱼来说,随着水温的升高,身体的生长同时增加,但在过去的二十年中,大型个体的数量有所减少。相比之下,在梅拉伦湖,尽管水温有类似的升高,但大小分布和身体生长是稳定的。在所有研究的人群中,在高龄人群中,生长缓慢的个体占主导地位,在禁捕区也是如此,这表明除了捕鱼以外的其他因素也导致了死亡率模式。我们提出温度升高有利于沿海地区的身体生长,但这已被死亡率增加所抵消,导致梭子鱼大小下降。为了重新获得更大的沿海梭鱼,管理人员需要考虑降低死亡率的多种措施。
更新日期:2021-10-15
down
wechat
bug