Supplementation of adult Atlantic salmon (Salmo salar) restores biofilm biomass and benthic metabolism

IF 2.3 2区农林科学 Q2 FISHERIES

Fisheries Research Pub Date : 2025-10-18 DOI:10.1016/j.fishres.2025.107556

Kurt M. Samways

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引用次数: 0

Abstract

Restoration of adult Atlantic salmon (Salmo salar) populations can restore key ecological functions in nutrient-limited freshwater ecosystems. This study assessed the effects of marine-derived nutrients (MDNs) from spawning salmon on biofilm biomass and benthic metabolism in two adjacent watersheds, the Upper Salmon River (USR) and Point Wolfe River (PWR), located in and around Fundy National Park, New Brunswick, Canada. Using a Before-After-Control-Impact (BACI) design, between 2015–2017 we monitored changes in biofilm growth, metabolism, and stable isotope signatures across upstream (reference) and downstream (treatment) sites in both rivers. Significant increases in biofilm biomass (up to 0.099 μg chlorophyll m⁻²) and net daily metabolism (up to 13.1 mg O₂ m⁻² d⁻¹) were observed at treatment sites in the USR where adult salmon were released. In contrast, no such increases occurred in reference sites, or the non-supplemented PWR. Stable isotope analysis confirmed MDN assimilation in biofilm and linked enriched δ¹ ³C and δ¹ ⁵N values to the presence of adult salmon. A mass balance nutrient model demonstrated that adult salmon, unlike juvenile stocking, deliver net nutrient gains to streams. This study provides the first empirical evidence for functional ecosystem recovery in Atlantic salmon rivers via adult supplementation, emphasizing the role of salmon as a keystone species and supporting their use in both demographic and ecological restoration efforts in the endangered inner Bay of Fundy population range.

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补充成年大西洋鲑鱼（Salmo salar）可恢复生物膜生物量和底栖生物代谢

恢复大西洋鲑鱼（Salmo salar）成年种群可以恢复营养有限的淡水生态系统中的关键生态功能。在加拿大新不伦瑞克省芬迪国家公园及其周边的两个相邻流域，上鲑鱼河（USR）和沃尔夫角河（PWR），本研究评估了产卵鲑鱼的海洋营养物（mdn）对生物膜生物量和底栖生物代谢的影响。利用控制后影响（BACI）设计，在2015-2017年期间，我们监测了两条河流上游（参考）和下游（处理）站点的生物膜生长、代谢和稳定同位素特征的变化。在美国释放成年鲑鱼的治疗地点，观察到生物膜生物量（高达0.099 μg叶绿素m−2）和净日代谢（高达13.1 mg O₂m⁻²d⁻¹）的显著增加。相比之下，在参考站点或未补充的压水堆中没有出现这种增加。稳定同位素分析证实了MDN在生物膜中的同化作用，并将δ¹ ³C和δ¹ 5 N值的富集与成年鲑鱼的存在联系起来。质量平衡营养模型表明，成年鲑鱼与幼年放养不同，可以为溪流带来净营养收益。本研究为大西洋鲑鱼河流通过补充成鱼恢复功能生态系统提供了第一个经验证据，强调了鲑鱼作为关键物种的作用，并支持了它们在濒危的芬迪内湾种群范围内的人口和生态恢复工作中的应用。

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来源期刊

Fisheries Research 农林科学-渔业

CiteScore

4.50

自引率

16.70%

发文量

294

审稿时长

15 weeks

期刊介绍： This journal provides an international forum for the publication of papers in the areas of fisheries science, fishing technology, fisheries management and relevant socio-economics. The scope covers fisheries in salt, brackish and freshwater systems, and all aspects of associated ecology, environmental aspects of fisheries, and economics. Both theoretical and practical papers are acceptable, including laboratory and field experimental studies relevant to fisheries. Papers on the conservation of exploitable living resources are welcome. Review and Viewpoint articles are also published. As the specified areas inevitably impinge on and interrelate with each other, the approach of the journal is multidisciplinary, and authors are encouraged to emphasise the relevance of their own work to that of other disciplines. The journal is intended for fisheries scientists, biological oceanographers, gear technologists, economists, managers, administrators, policy makers and legislators.