编辑“︁鮭魚”︁（章节）

===與河狸的關係===
[[File:Beaver Dam Steep Creek 584.jpg|thumb|河狸筑坝形成的水塘可以为鲑鱼提供非常理想的产卵区域]]
[[河狸]]亦在當地扮演著「生態系的工程師」的角色。牠們在啃伐树木建造[[水壩]]的時候大幅改變了周边的生態系統，為鮭魚幼體提供了重要的[[栖息地]]<ref>{{cite web | url=http://rocky.ess.washington.edu/grg/publications/pdfs/Pollock.pdf | format=PDF | title=The Importance of Beaver Ponds to Coho Salmon Production in the Stillaguamish River Basin, Washington, USA | author=Pollock, M. M. | author2=Pess, G. R. | author3=Beechie, T. J. | last-author-amp=yes | accessdate=2007-12-21 | archive-date=2008-02-16 | archive-url=https://web.archive.org/web/20080216100912/http://rocky.ess.washington.edu/grg/publications/pdfs/Pollock.pdf | dead-url=no }}</ref>。

河狸修建的水坝可以对成长期的鲑鱼产生如下影响<ref>{{cite web | url = http://www.nwcouncil.org/history/Extinction.asp | title = Extinction | publisher = Northwest Power and Conservation Council | access-date = 21 December 2007 | archive-url = https://web.archive.org/web/20180101173222/https://www.nwcouncil.org/history/Extinction | archive-date = 1 January 2018 | url-status = live}}</ref><ref>{{cite journal | title=Sockeye salmon (''Oncorhynchus nerka'') nursery lake fertilization: Review and summary of results |journal=Environmental Reviews|volume=12|issue=3|pages=133–162|doi=10.1139/a04-008|year=2004|last1=Hyatt|first1=K D|last2=McQueen|first2=D J|last3=Shortreed|first3=K S|last4=Rankin|first4=D P|s2cid=12930576| url=http://pdfs.semanticscholar.org/0cfb/39999bce91178a1091a58a6f8f9d090570cb.pdf | archive-url=https://web.archive.org/web/20200807012439/http://pdfs.semanticscholar.org/0cfb/39999bce91178a1091a58a6f8f9d090570cb.pdf | url-status=dead | archive-date=2020-08-07 }}</ref><ref>{{cite web | url = http://rocky.ess.washington.edu/grg/publications/pdfs/Pollock.pdf | title = The Importance of Beaver Ponds to Coho Salmon Production in the Stillaguamish River Basin, Washington, USA | last1 = Pollock | first1 = M. M. | last2 = Pess | first2 = G. R. | last3 = Beechie | first3 = T. J. | access-date = 21 December 2007 | archive-url = https://web.archive.org/web/20060901185801/http://rocky.ess.washington.edu/grg/publications/pdfs/Pollock.pdf | archive-date = 1 September 2006 | url-status = live}}</ref>：
* 延缓水中养分被冲刷的速度，使得之前产卵死亡的成年鲑鱼尸体所释放的营养可以被下一代的幼鲑所用；
* 增加水体的局部水深，可以为幼鲑提供躲避水鸟捕食的栖息地；
* 增加[[光合作用]]对水体氧气的补充效果和[[碎屑]]中[[纤维素]]分解可以赋予的养分浓度；
* 建造缓水环境让幼鲑可以把更多摄入的养分用于成长，而不是耗费体力去克服水流；
* 提供能够帮助幼鲑藏身的水下结构。

河狸坝甚至可以在[[河口湾]]的[[潮汐]][[盐碱滩]]之中产生可以供养幼鲑、[[盐分]][[百万分比]]小于10的[[淡水]][[水塘]]。河狸通常会建造低于{{convert|2|ft|sigfig=1|order=flip}}的小水坝，这些矮坝在涨潮时会没漫过，但低潮时可以蓄水，因此可以被洄游的鲑鱼轻易越过并且可以保护孵化的幼鲑不受大河中掠食者的威胁<ref>{{cite web | last1 = Hood | first1 = W Gregory  | title = AN OVERLOOKED ECOLOGICAL WEB | url = http://www.skagitwatershed.org/rpapers_overlooked.html | archive-url = https://web.archive.org/web/20080724000846/http://www.skagitwatershed.org/rpapers_overlooked.html | archive-date = 24 July 2008 | url-status = dead }}</ref>。

在[[1818年条约]]后，[[英国政府]]与[[美国政府]]达成协议允许美国公民进入[[哥伦比亚河]]流域，[[哈德逊湾公司]]曾通知其下属的[[猎手]]尽可能的捕杀毛皮动物来让美国[[皮草贸易|皮草贸易商]]无利可图，而当时对河狸故意的大举捕猎使得当地水域内的[[鲑鱼洄游]]几乎消失。