The decline of Estuary Cobbler (Cnidoglanis macrocephalus) stocks in south-western Australia since European settlement of the region in 1829 is described, based on evidence from historical documents, fishery statistics and scientific surveys. Estuary cobbler is a relatively large, long-lived, benthic carnivore that was once abundant in the three largest west coast estuaries, where it was a major component of fishery catches for decades. The breeding stock in each estuary declined dramatically between 1960 and 2000, after which time exploitation effectively ceased. Two stocks appear to have largely disappeared, while the third still persists at a relatively low level. In each estuary historical overfishing coincided with a period of severe habitat degradation including flow modification, eutrophication, benthic habitat loss and hypoxia. Hence there is no obvious, primary driver of decline for these stocks. Exploitation probably acted synergistically with environmental impacts to cause each stock decline. In degraded environments, fisheries management should be highly precautionary to reflect the elevated risk to exploited species posed by multiple simultaneous stressors. A risk-based ‘weight-of-evidence’ approach that can accommodate both quantitative and qualitative lines of evidence, including fishing and non-fishing impacts, is recommended to assess the status of exploited species in such environments.

河口皮匠（Cnidoglanis macrocephalus）的衰退基于历史文献，渔业统计数据和科学调查的证据，描述了自1829年欧洲在该地区定居以来澳大利亚西南部的种群。河口补鞋匠是一个相对较大，寿命较长的底栖食肉动物，曾在西海岸三个最大的河口盛产，数十年来一直是渔业捕捞的主要组成部分。在1960年至2000年之间，每个河口的繁殖种群急剧下降，此后有效地停止了开采。两只股票似乎已基本消失，而第三只股票仍处于相对较低的水平。在每个河口，历史上的过度捕捞时期都伴随着严重的栖息地退化，包括流量变化，富营养化，底栖生境丧失和缺氧。因此，没有明显的 这些股票下跌的主要驱动力。开发可能与环境影响协同作用，导致每只种群下降。在退化的环境中，渔业管理应高度预防，以反映多个同时存在的压力源对被捕捞物种造成的风险增加。建议采用基于风险的“证据权重”方法来评估定量和定性证据，包括捕捞和非捕捞影响，以评估此类环境中被开发物种的状况。