SELECTIVITY OF TOWED-NET SAMPLERS
SELECTIVITY OF TOWED-NET SAMPLERS
复制标题
拖网采样器的选择性
DOI：
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发表时间：
1972
期刊：
影响因子：
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通讯作者：
R. Barkley
中科院分区：
文献类型：
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作者：
R. Barkley
浮游生物和Nekton的理想采样器是一种已知其选择性特征适用于任何给定问题的采样器，这样它就可以以已知的效率捕捉到合适的生物，并拒绝其他生物。本文从理论上定量分析了拖网采样器选择性的一个方面，即避免拖网采样器。用不同网速下的三组配对样本对该理论进行了评估，以提供对其有效性的绝对和相对检验。然后分析了一张网以一种速度拖曳所获得的单个样本，以说明该过程。该理论的最终评估有待对动物行为的研究，但该理论提供了对浮游生物和尼克顿渔获量数据的信息和合理解释，特别是对种群数量和网目损失的估计，即使动物的行为未知。一个理想的浮游生物和Nekton采样器必须至少满足两个要求，一个是定量的，一个是定量的：它必须收集或检测这些极其多样化的群落的某些成分，同时拒绝大多数其他成分；而且它必须以已知的有效性做到这一点。对于某些目的，采样器选择性的定性方面相对比定量方面更重要，反之亦然，但在采样装置的设计和选择中，两者都不能完全忽略。取样器的选择性通常是通过比较同一取样器在不同条件下获得的结果或通过相互比较不同的取样方法来进行经验评估的。墨菲和克拉特(1972)开发的浮游生物围网对于后一种目的似乎是近乎理想的。正如墨菲和克拉特所证明的那样，对于广泛的生物体类型和大小，它是相对非选择性的，这使其成为校准更具选择性的齿轮的“主要标准”。一个合理的取样器选择性理论对收集和分析经验数据具有很大的指导价值，但对这种理论的发展投入的努力相对较少(Tranter，1968)。我的建议是
ABSTRACf The ideal sampler for plankton and nekton is one whose selective characteristics are known to be appropriate to any given problem, so that it catches the right organisms, and rejects others, with known efficiency. This paper presents a quantitative theoretical analysis of one aspect of selectivity, avoidance of towed-net samplers. The theory is evaluated against three sets of paired samples obtained by different nets at different speeds to provide absolute and relative tests of its validity. A single sample obtained by one net towed at one speed is then analyzed to illustrate the procedure. Final eval uation of the theory awaits studies of animal behavior when confronted by a sampler, but the theory provides informative and· reasonable interpretations of plankton and nekton catch data, particularly estimates of population abundance and mesh losses, even when behavior of the animals is not known. An ideal sampler for plankton and nekton must meet,at least two requirements, one qual itative and the other quantitative: It must col lect or detect certain components of these ex tremely diverse communities, while rejecting most others; and it must do this with known effectiveness. For some purposes the qualitative aspects of sampler selectivity are relatively more important than the quantitative ones, or vice versa, but neither can ever be completely ignored in the design and selection of sampling gear. Sampler selectivity has usually been evaluated empirically, by comparing results obtained with one sampler under different conditions or by in tercomparing various sampling methods. The plankton purse seine developed by Murphy and Clutter (1972) appears to be nearly ideal for the latter purpose. It is relatively nonselective for a wide spectrum of organism types and sizes, making it useful as a "primary standard" for calibrating more selective gear, as Murphy and Clutter demonstrate. A sound theory of sampler selectivity would be of great value as a guide to the collection and analysis of empirical data, but relatively little effort has been devoted to the development of such theory (Tranter, 1968). What I propose