1. Quantifying habitat associations and threats to the persistence of imperilled species is a fundamental step for initiating species recovery efforts, but the traits associated with species imperillment (e.g. rarity and vulnerability to stressors) also limit the ability to empirically inform recovery strategies. Novel sampling designs and modelling approaches are therefore needed to quantitatively assess habitat associations and the threats to species persistence.
2. To improve the understanding of habitat associations and threats for one of the rarest endangered freshwater fish species in Canada, northern madtom (Noturus stigmosus), two‐species occupancy models were developed with two invasive gobies: round goby (Neogobius melanostomus) and tubenose goby (Proterorhinus marmoratus). Models were parameterized with data from a multi‐year benthic trawling survey of two large Great Lakes tributaries in southern Ontario, Canada, and subsequently used to evaluate the need for reducing measurement error with future sampling efforts.
3. The probability of detecting northern madtom in the St. Clair (0.163) and Thames (0.194) rivers was low compared with round goby (St. Clair, 0.827; Thames, 0.833) and tubenose goby (St. Clair, 0.297). The best occupancy models indicated a negative association between northern madtom and round goby in the St. Clair River and the importance of gravel substrate for northern madtom.
4. Up to 16 repeated non‐detections using benthic trawls are needed to be 95% confident that northern madtom is absent at a site, indicating that current sampling approaches are likely inadequate.
5. Despite low detection probabilities, intensive trawling surveys combined with the two‐species occupancy modelling framework provided vital information for describing habitat associations for northern madtom and identified a significant negative association with round goby. Nonetheless, alternative sampling methods to improve the detection probability of northern madtom would allow a more robust evaluation of habitat associations and would provide more information on the negative association with round goby.

中文翻译：

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圆环虾虎鱼新黑猩猩和结节虾虎鱼Proterorhinus marmoratus与加拿大濒临灭绝的北疯子Noturus stigmosus之间的非生物和生物联系

1. 量化栖息地关联和对受威胁物种的持久性的威胁是启动物种恢复工作的基本步骤，但与物种障碍相关的特征（例如稀有性和对压力源的脆弱性）也限制了以经验为依据的恢复策略的能力。因此，需要新颖的采样设计和建模方法来定量评估栖息地关联和对物种持久性的威胁。
2. 为了更好地了解加拿大最稀有的濒危淡水鱼之一北部马多姆（Noturus stigmosus）的栖息地协会和威胁，开发了两种带有两种侵入性虾虎鱼的种群模型：圆形虾虎鱼（Neogobius melanostomus）和块头虾虎鱼（Nogos melanostomus）。Proterorhinus marmoratus）。使用来自加拿大安大略省南部两个大湖支流的多年底栖拖网调查数据对模型进行参数化，随后将其用于评估减少未来抽样工作的测量误差的需求。
3. 与圆形go鱼（St. Clair，0.827; Thames，0.833）和块头go鱼（St. Clair，0.297）相比，在圣克莱尔（0.163）和泰晤士河（0.194）河流中检测到北部狂风的可能性较低。最佳入住率模型表明，北部的madtom和圣克莱尔河的圆虾虎鱼之间的负相关性以及砾石基质对北部的madtom的重要性。
4. 需要多达16次使用底栖拖网的重复未检测，才能有95％的信心确定某个地点不存在北部madtom，这表明当前的采样方法可能不充分。
5. 尽管检测概率较低，但密集的拖网调查与两种物种的占用模型框架相结合，为描述北马多姆地区的栖息地关联提供了重要信息，并确定了与轮渡的显着负相关。但是，可以通过其他采样方法来提高对北部斑痣的检测概率，从而可以对生境关联性进行更可靠的评估，并且可以提供有关轮生虾虎鱼的负面关联性的更多信息。