Editing Lake Superior (section)

==Ecology==
[[File:Lake Superior at Neys Provincial Park Ontario.jpg|thumb|Bedrock shoreline, [[Neys Provincial Park]], Ontario]]
[[File:Miners Castle, Pictured Rocks National Lakeshore.jpg|thumb|[[Pictured Rocks National Lakeshore]], Michigan]]

More than 80 species of fish have been found in Lake Superior. Species native to the lake include [[banded killifish]], [[Coregonus hoyi|bloater]], [[brook trout]], [[burbot]], [[Coregonus artedi|cisco]], [[lake sturgeon]], [[lake trout]], [[lake whitefish]], [[longnose sucker]], [[muskellunge]], [[northern pike]], [[pumpkinseed]], [[rock bass]], [[round whitefish]], [[smallmouth bass]], [[walleye]], [[white sucker]] and [[yellow perch]]. In addition, many fish species have been either intentionally or accidentally introduced to Lake Superior: [[Atlantic salmon]], [[brown trout]], [[carp]], [[chinook salmon]], [[coho salmon]], [[freshwater drum]], [[pink salmon]], [[rainbow smelt]], [[rainbow trout]], [[round goby]], [[ruffe]], [[sea lamprey]] and [[white perch]].<ref name=mnsea2>{{cite web |url = http://www.seagrant.umn.edu/fisheries/superior_fish_species |title = Lake Superior Fish Species |author = Minnesota Sea Grant |publisher = University of Minnesota |access-date = June 3, 2009 }}</ref><ref>{{cite book |title = Minnesota 2009 fishing regulations |page = 23 }}{{full citation needed|date=February 2020}}</ref>

Lake Superior has fewer dissolved nutrients relative to its water volume than the other Great Lakes and so is less productive in terms of fish populations and is an [[Trophic state index|oligotrophic lake]]. This is a result of the underdeveloped soils found in its relatively small watershed.<ref name=mnsea>{{cite web |url = http://www.seagrant.umn.edu/superior/overview |title = Lake Superior |author = Minnesota Sea Grant |publisher = University of Minnesota |access-date = August 9, 2007 |archive-date = February 20, 2007 |archive-url = https://web.archive.org/web/20070220053912/http://www.seagrant.umn.edu/superior/overview |url-status = dead }}</ref> It is also a reflection of relatively small human population and small amount of agriculture in its watershed. However, [[nitrate]] concentrations in the lake have been continuously rising for more than a century. They are still much lower than levels considered dangerous to human health; but this steady, long-term rise is an unusual record of environmental nitrogen buildup. It may relate to anthropogenic alternations to the regional [[nitrogen cycle]], but researchers are still unsure of the causes of this change to the lake's ecology.<ref>{{cite magazine |last1 = Sterner |first1 = Robert W. |last2 = Anagnostou |first2 = Eleni |last3 = Brovold |first3 = Sandra |last4 = Bullerjahn |first4 = George S. |author-link4=George S. Bullerjahn|last5 = Finlay |first5 = Jacques C. |last6 = Kumar |first6 = Sanjeev |last7 = McKay |first7 = R. Michael L. |last8 = Sherrell |first8 = Robert M. |title = Increasing Stoichiometric Imbalance in North America's Largest Lake: Nitrification in Lake Superior |magazine = Geophysical Research Letters |volume = 34 |pages = L10406 |year = 2007 |doi = 10.1029/2006GL028861 |bibcode = 2007GeoRL..3410406S |issue = 10 |url = https://eprints.soton.ac.uk/339953/1/Sterner_et_al._2007_GRL_LS_NO3.pdf |doi-access = free }}</ref>

As for other Great Lakes fish, populations have also been affected by the accidental or intentional introduction of foreign species such as the sea lamprey and [[Ruffe|Eurasian ruffe]]. Accidental introductions have occurred in part by the removal of natural barriers to navigation between the Great Lakes. Overfishing has also been a factor in the decline of fish populations.<ref name=pursuit/>