An analysis of temporal variability in abundance, diversity and growth rates within the coastal ichthyoplankton assemblage of South Georgia (sub-Antarctic)
An analysis of temporal variability in abundance, diversity and growth rates within the coastal ichthyoplankton assemblage of South Georgia (sub-Antarctic)
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DOI：
10.1007/s00300-013-1321-9
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发表时间：
2013-07-01
期刊：
影响因子：
1.7
通讯作者：
Lawson, Jennifer
中科院分区：
文献类型：
--
作者：
Belchier, Mark;Lawson, Jennifer
研究浮游鱼类（鱼卵和仔鱼）的时空分布和多样性，可以提供与鱼类无关的海洋鱼类种群动态和补充过程的信息。迄今为止，南大洋的鱼类浮游生物研究主要限于夏季。我们分析了鱼类浮游生物的数据，从一年四季，长期（2002 - 2008年），浮游生物拖网采样计划在一个大型峡湾系统（坎伯兰湾）在南格鲁吉亚，亚南极（54.25度，36.5度W），以评估幼鱼多样性和丰度的时间变化。幼虫的22种，代表9个家庭，被确定，虽然三个，Krefftichthys andersoni（Myctophidae），Lamponotothen nudifrons/Trematomus hansoni（Nototheniidae）和Champsocephalus gunnari（Champsocephalus gunnari），占主导地位的丰度在所有年份。多变量分析显示，显着的季节和年际差异的仔鱼组合。估计幼虫生长提供了五个丰富的物种。相当大的种间差异的相对幼虫生长速率的记录，但种内的年际变化很小。然而，在商业上重要的C。gunnari，多个幼虫群体，代表了一个漫长的产卵季节，观察到以不同的速度增长，这可能与温度和/或食物供应。与南格鲁吉亚历史增长数据的比较表明，在过去三十年中，主要物种的增长率几乎没有变化。
The study of spatial and temporal distribution and diversity of ichthyoplankton (fish eggs and larvae) can provide fisheries-independent information on the population dynamics and recruitment processes of marine fish species. Ichthyoplankton studies in the Southern Ocean have to date been largely constrained to the summer months. We analysed ichthyoplankton data collected from a year round, long term (2002-2008), plankton trawl sampling programme in a large fjord system (Cumberland Bay) at South Georgia, sub-Antarctic (54.25 degrees S, 36.5 degrees W) to assess temporal changes in larval fish diversity and abundance. Larvae of 22 species, representing nine families, were identified although three, Krefftichthys anderssoni (Myctophidae), Lepidonotothen nudifrons/Trematomus hansoni (Nototheniidae) and Champsocephalus gunnari (Channichthyidae), dominated abundance in all years. Significant seasonal and interannual differences in the larval fish assemblage were revealed by multivariate analyses. Estimates of larval growth are provided for five abundant species. Considerable inter-specific differences in relative larval growth rate were recorded but interannual variability within species was small. However, in the commercially important C. gunnari, multiple larval cohorts, representing a protracted spawning season, were observed to grow at different rates, and this may be related to temperature and/or food availability. A comparison with historical growth data from South Georgia suggests there has been little change in growth rate for the main species over the last three decades.