Canadian Journal of Fisheries and Aquatic Sciences, Ahead of Print.
To understand the effects of widespread urbanization and agricultural impacts on recovery of Salish sucker (Catostomus sp. cf. catostomus), a federally threatened catostomid endemic to the lower Fraser Valley of British Columbia, we assessed (i) the current extent and effects of hypoxia on the distribution of Salish sucker and juvenile salmonids, (ii) potential drivers of hypoxia, and (iii) management options for hypoxia mitigation. Over 40% of sucker critical habitat experiences hypoxia (dissolved oxygen (DO) < 4 mg·L–1) by late summer, indicating widespread noncompliance with water quality guidelines. The strong positive relationship between seasonal hypoxia and temperature (R2 = 0.53) and negative relationship with streamflow (R2 = 0.78) indicates that hypoxia is driven by a synergy among low summer flows, elevated temperatures, and high primary production associated with nutrient enrichment (eutrophication). Sucker show strong selection against high water temperatures and weaker negative selection against low DO; juvenile salmonids show very strong selection against both high temperatures and low DO. Climate projections for declining summer flows and elevated temperatures indicate worsening trends in DO without intensive watershed-scale management to reduce nutrient loads, maintain or increase flows, and riparian restoration to lower stream temperatures, control primary production, and inhibit growth of invasive reed canary grass (Phalaris arundinacea).

中文翻译：

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景观尺度缺氧对 Salish 吸盘和鲑鱼栖息地关联的影响：对濒危物种恢复和管理的影响

加拿大渔业和水产科学杂志，提前印刷。
为了了解广泛的城市化和农业影响对 Salish 吸盘（Catostomus sp. cf. catostomus）恢复的影响，这是一种在不列颠哥伦比亚省菲沙河谷地区流行的受联邦威胁的 catostomid，我们评估了 (i) 目前缺氧的程度和影响关于 Salish 吸盘和幼鲑鱼的分布，(ii) 缺氧的潜在驱动因素，以及 (iii) 缓解缺氧的管理方案。到夏末，超过 40% 的吸盘临界栖息地经历缺氧（溶解氧 (DO) < 4 mg·L–1），表明普遍不遵守水质准则。季节性缺氧与温度 (R2 = 0.53) 之间的强正相关和与流量的负相关 (R2 = 0.78) 表明缺氧是由夏季低流量、升高的温度、与营养丰富（富营养化）相关的初级生产力高。吸盘对高水温表现出强选择，对低溶解氧表现出较弱的负选择；幼鲑鱼对高温和低溶解氧表现出很强的选择能力。夏季流量下降和温度升高的气候预测表明 DO 的趋势恶化，而没有集约化的流域规模管理来减少养分负荷，维持或增加流量，以及河岸恢复到较低的溪流温度，控制初级生产，并抑制侵入性芦苇的生长(Phalaris arundinacea)。幼鲑鱼对高温和低溶解氧表现出很强的选择能力。夏季流量下降和温度升高的气候预测表明 DO 的趋势恶化，而没有集约化的流域规模管理来减少养分负荷，维持或增加流量，以及河岸恢复到较低的溪流温度，控制初级生产，并抑制侵入性芦苇的生长(Phalaris arundinacea)。幼鲑鱼对高温和低溶解氧表现出很强的选择能力。夏季流量下降和温度升高的气候预测表明 DO 的趋势恶化，而没有集约化的流域规模管理来减少养分负荷，维持或增加流量，以及河岸恢复到较低的溪流温度，控制初级生产，并抑制侵入性芦苇的生长(Phalaris arundinacea)。