Influence of latitudinal variation in environmental gradients and population structure on the demography of a widespread pelagic fish, Arripis trutta (Forster, 1801)

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• 作者：Julian M. Hughes ; John Stewart ; Jeremy M. Lyle…
• 关键词：Arripidae ; Age structure ; Size composition ; East Australian Current ; Growth ; Age validation
• 刊名：Environmental Biology of Fishes
• 出版年：2017
• 出版时间：February 2017
• 年：2017
• 卷：100
• 期：2
• 页码：121-135
• 全文大小：
• 刊物类别：Earth and Environmental Science
• 刊物主题：Freshwater & Marine Ecology; Zoology; Animal Systematics/Taxonomy/ Biogeography; Environment, general; Nature Conservation;
• 出版者：Springer Netherlands
• ISSN：1573-5133
• 卷排序：100

文摘

Knowledge of the influence of both spatial and temporal environmental gradients on life history traits and population demographics is a critical requirement in the management of exploited fish populations. This study examined variation in the demographics of Arripis trutta, an economically-important pelagic fish species with a broad latitudinal distribution in the waters of coastal south-eastern (SE) Australia, a region dominated by the influence of the East Australian Current (EAC). A validated ageing protocol was first developed using sectioned sagittal otoliths, which in turn permitted examination of latitudinal variation in A. trutta growth, size compositions and age compositions. The von Bertalanffy growth function parameters for A. trutta in SE Australia were estimated to be L_∞ = 63.20 ± 0.37 cm fork length (FL), k = 0.26 ± 0.01 yr−1 and t_o = −0.14 ± 0.03 yr, with a maximum estimated age of 12.7 years. Growth was shown to be faster with decreasing latitude likely due to a simple relationship with the latitudinal gradient in water temperature; fastest growth occurring in northern NSW and slowest growth occurring in Tasmania. Latitudinal patterns in growth were remarkably similar to those previously reported for this species, despite age being estimated using scale readings some 40 years ago. This consistency in latitudinal growth patterns of a temperate fish can be attributed to the life history-related movements undertaken by A. trutta in this region. This temporally-consistent movement pattern is supported by the spatial gradient in the size and age composition of A. trutta sampled from different latitudes in both the current and historical research, whereby numbers of large and old fish increase progressively from Tasmania to northern NSW. These results highlight the need to consider the potential for spatial size- or age-structuring in the development of sampling designs and interpretation of results for any study examining spatial or temporal variation in demographic parameters of exploited fish populations.