Editing Lake trout (section)

==Life history==
Lake trout inhabit cold, oxygen-rich waters. They are [[Pelagic fish|pelagic]] during the period of [[Lake stratification|summer stratification]] in [[dimictic lake]]s, often living at depths of {{convert|20|-|60|m|ft|abbr=on}}.

The lake trout is a slow-growing fish, typical of [[oligotroph]]ic waters. It is also very late to mature. Populations are extremely susceptible to [[overfishing]]. Many native lake trout populations have been severely damaged through the combined effects of [[Hatchery#Fish hatcheries|hatchery]] stocking (planting) and over harvest. Another threat to lake trout is [[Freshwater acidification|acidification]], which can have longterm effects on their populations through both direct harm and reduced prey populations (e.g. ''[[Mysis relicta]]'').<ref>{{Cite journal|last=Ogden|first=Lesley Evans|date=2018-11-01|title=Acid Rain: Researchers Addressing Its Lingering Effects|url=https://academic.oup.com/bioscience/article/68/11/928/5123903|journal=BioScience|language=en|volume=68|issue=11|pages=928|doi=10.1093/biosci/biy113|issn=0006-3568|doi-access=free}}</ref>
[[File:Lamprey.jpg|left|thumb|A lake trout being preyed upon by [[Lamprey|lampreys]]]]
There are three [[subspecies]] of lake trout. There is the common lake trout (''Salvelinus namaycush namaycush''), the siscowet lake trout (''Salvelinus namaycush siscowet''), and the less common rush lake trout (''Salvelinus namaycush huronicus''). Some lakes do not have [[pelagic zone|pelagic]] [[forage fish]] during the period of summer stratification.<ref>{{cite journal |last1=Rochard |first1=Eric |last2=Elie |first2=Pierre |date=1994 |title=La macrofaune aquatique de l'estuaire de la Gironde : contribution au livre blanc de l'Agence de l'eau Adour Garonne |url=https://hal.science/hal-02582433/ |journal=Etat des connaissances sur l'estuaire de la Gironde, Agence de l'Eau Adour Garonne |access-date=24 November 2023}}</ref>{{full citation needed|date=March 2025}} In these lakes, lake trout act as [[planktivore]]s. Lake trout in planktivorous populations are highly abundant, grow very slowly and [[Sexual maturity|mature]] at relatively small sizes. In those lakes that do contain deep-water forage, lake trout become [[Piscivore|piscivorous]]. Piscivorous lake trout grow much more quickly, mature at a larger size and are less abundant. Notwithstanding differences in abundance, the density of [[Biomass (ecology)|biomass]] of lake trout is fairly consistent in similar lakes, regardless of whether the lake trout populations they contain are planktivorous or piscivorous.{{citation needed|date=June 2016}}

[[Image:Lake trout fish in hands salvelinus namaycush.jpg|right|thumb|A lake trout in spawning dress.|267x267px]]

In [[Lake Superior]], common lake trout (''S. n. namaycush'') and siscowet lake trout (''S. n. siscowet'') live together. Common lake trout tend to stay in shallower waters, while siscowet lake trout stay in deeper water. Common lake trout (also called "lean" lake trout) are slimmer than the relatively fat siscowet. Siscowet numbers have become greatly depressed over the years due to a combination of the [[Local extinction|extirpation]] of some of the fish's deep water [[Coregoninae|coregonine]] prey and to [[overexploitation]]. Siscowet tend to grow extremely large and fat and attracted great commercial interest in the last century. Their populations have rebounded since 1970, with one estimate putting the number in Lake Superior at 100 million. Professor of Zoology at the [[University of Wisconsin-Madison]] James Kitchell credits effective constraint of commercial fisheries and persistent [[sea lamprey]] (''Petromyzon marinus'') control for the successful recovery of Lake Superior's lake trout. "Looking at what has happened in the lake and the results of computer simulations, it is clear that lamprey control needs to continue if Lake Superior is to keep its lake trout."<ref>{{cite web | url=http://www.seagrant.umn.edu/newsletter/2002/12/siscowet_trout_a_plague_of_riches.html| title=Siscowet Trout: A Plague of Riches| access-date=20 December 2007| last=Moen| first=Sharon|date=December 2002| publisher=Minnesota Sea Grant}}</ref>