Power of monitoring programmes to detect decline and recovery of rare and vulnerable fish
Power of monitoring programmes to detect decline and recovery of rare and vulnerable fish
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DOI：
10.1111/j.1365-2664.2005.01000.x
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发表时间：
2005-02-01
影响因子：
5.7
通讯作者：
Jennings, S
中科院分区：
文献类型：
--
作者：
Maxwell, D;Jennings, S
1.在确定保护优先事项时，异常趋势提供了关键的指导，无论是表明人口下降，稳定还是恢复。了解调查在发现趋势方面的作用至关重要，因为没有发现真实的趋势的后果可能是深远的。不幸的是，一些调查已经建立，没有评估的权力，和其他人被用来研究物种，而不是他们原来的重点。后一种情况在海洋环境中很常见，在海洋环境中，稀有鱼类的监测是利用针对更丰富的商业捕捞物种进行的调查的渔获量数据。我们计算了一个大规模的年度监测调查（英国北海底拖网调查）的力量，以检测易受捕捞的物种的下降和恢复。由于渔业开发总是在科学调查之前，调查是在许多脆弱物种已经枯竭之后开始的。该调查发现脆弱物种丰度在小于10年的时间尺度上下降的能力很低，而且该调查往往未能发现可导致列入自然保护联盟A1红色名录标准的下降。因此，仅基于调查数据的保护优先级可能无法识别处于区域灭绝风险的物种。如果保护措施有效，脆弱种群以最大的潜在速度恢复，通常需要5-10年的监测才能发现恢复。通过制定一个反映若干脆弱物种丰度趋势的综合指标，提高了探测丰度趋势的能力。这一指标提供了其养护状况的概览。合成与应用。根据预防原则，在电力不足是历史性枯竭的结果时，养护的优先次序和管理行动不应取决于最近丰度趋势的统计意义。如果珍稀和/或脆弱物种的保护优先级和管理必须基于显著下降的证据，那么较高的第1类错误率（错误地检测到下降）应该是可以接受的。这是因为第一类错误的成本低于第二类错误（未能检测到真实的下降）。
1. Abundance trends provide key guidance when setting conservation priorities, whether indicating population decline, stability or recovery. Knowledge of the power of surveys to detect trends is essential, as the consequences of not detecting a real trend can be profound.2. Unfortunately, some surveys have been established with no assessment of power, and others are used to study species that were not their original focus. The latter is common in the marine environment, where rare fish are monitored using catch data from surveys that target more abundant commercially fished species.3. We calculated the power of a large-scale annual monitoring survey (the English North Sea bottom trawl survey) to detect decline and recovery of species that are vulnerable to fishing. As fisheries exploitation invariably precedes scientific investigation, the survey began after many vulnerable species had already been depleted.4. The power of the survey to detect declines in the abundance of vulnerable species on time scales of < 10 years was low and the survey often failed to detect declines that would lead to listings under the IUCN A1 Red List criteria. Thus conservation prioritization based solely on survey data may fail to identify species at risk of regional extinction.5. If conservation measures were effective, and vulnerable populations recovered at the maximum potential rate, 5-10 years of monitoring would often be required to detect recovery.6. Power to detect trends in abundance was increased by developing a composite indicator that reflected trends in abundance of several vulnerable species. This indicator provided an overview of their conservation status.7. Synthesis and applications. Consistent with the precautionary principle, conservation prioritization and management action should not depend on the statistical significance of recent abundance trends when low power is a consequence of historical depletion. If the conservation prioritization and management of rare and/or vulnerable species have to be predicated on evidence of significant declines, then higher type 1 error rates (falsely detecting a decline) should be acceptable. This is because the costs of type 1 errors are lower than those of type 2 (failure to detect a real decline).