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首页> 外文期刊>Marine ecology progress series >Assessing the sampling effort required to estimate a species diversity in the groundfish assemblages of the North Sea
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Assessing the sampling effort required to estimate a species diversity in the groundfish assemblages of the North Sea

机译：评估估计北海底层鱼类种群物种多样性所需的抽样工作

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Conserving and restoring biodiversity are key objectives for an ecosystem approach to management in the North Sea, but ecological guality objectives for the groundfish community instead concentrate on restoring size structure. Species richness and diversity estimates are strongly influenced by sampling effort. Failure to account for this has led to the belief that species richness and diversity indices are not adequate indicators of 'state' for the groundfish community. However, adherence to a standard procedure that is robust within respect to sampling effort influence should allow these metrics to perform a state indicator role. The Arrhenius power and Gleason semi-log species-area relationships are examined to determine whether they can provide modelled estimates of species richness at the ICES (International Council for the Exploration of the Sea) rectangle scale. Of these, the Gleason semi-log appears most reliable, particularly when a randomised aggregation process is followed. Aggregation of at least 20 trawl samples is required to provide empirically derived index values that are representative of the communities sampled, and therefore sensitive to drivers of change in these communities. However, given current groundfish survey sampling levels, combining 20 half-hour trawl samples to provide single estimates of species richness and diversity will require considerable aggregation over time and/or space. This can lead to estimates of α or local richness/ diversity becoming inflated through the inclusion of elements of β or regional richness/diversity. For the North Sea groundfish assemblage, this occurs when the distance between the focal position and the location of the most distant sample exceeds 49 km.
机译：保护和恢复生物多样性是北海生态系统管理方法的主要目标，但是底层鱼类群落的生态质量目标却集中在恢复大小结构上。物种丰富度和多样性估计数受抽样工作的强烈影响。无法解释这一点导致人们相信物种丰富度和多样性指数不足以作为底层鱼类群落“状态”的指标。但是，遵守在抽样工作影响方面具有鲁棒性的标准程序应允许这些指标执行状态指示符的角色。检查了Arrhenius幂和格里森半对数物种-面积关系，以确定它们是否可以在ICES（国际海洋探索理事会）矩形比例尺上提供模型化的物种丰富度估计。其中，格里森半对数似乎最可靠，尤其是当遵循随机聚集过程时。需要汇总至少20个拖网样本，以提供经验得出的指数值，这些指数值代表了所采样的社区，因此对这些社区的变化动因敏感。但是，鉴于目前的底层鱼类调查抽样水平，结合20个半小时的拖网样本以提供物种丰富度和多样性的单一估计，将需要在时间和/或空间上进行大量汇总。这可能导致对α或局部富裕/多样性的估计通过包含β元素或区域富裕/多样性而被夸大。对于北海底栖鱼类，当焦点位置与最远样本位置之间的距离超过49 km时，就会发生这种情况。

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