Somenos Lake is a small shallow water body located in the Municipality of North Cowichan on Southeast

Vancouver Island Vancouver Island is an island in the northeastern Pacific Ocean and part of the Canadian Provinces and territories of Canada, province of British Columbia. The island is in length, in width at its widest point, and in total area, while are o ...

. Somenos Lake has a maximum area of approximately 247 ac, 100 ha at above geodetic datum. The Lake is relatively shallow with a maximum depth of . Somenos Lake is fed by three major tributary streams: Richards Creek from the North and Northeast, Averill Creek from the Northwest and Bings Creek from the West. The lake is drained near its southern extremity by Somenos Creek which flows southeast approximately to the

Cowichan River The Cowichan River is a Canadian Heritage River on Vancouver Island, in British Columbia, Canada. Its headwater is Cowichan Lake. The river flows east over Skutz Falls and through Marie Canyon towards its mouth at Cowichan Bay. The river's d ...

. Somenos Lake and its tributary streams support resident populations of

Rainbow Trout The rainbow trout (''Oncorhynchus mykiss'') is a species of trout native to cold-water tributaries of the Pacific Ocean in Asia and North America. The steelhead (sometimes called "steelhead trout") is an anadromous (sea-run) form of the coasta ...

(''Oncorhynchus mykiss'') and

Cutthroat Trout The cutthroat trout is a fish species of the family Salmonidae native to cold-water tributaries of the Pacific Ocean, Rocky Mountains, and Great Basin in North America. As a member of the genus '' Oncorhynchus'', it is one of the Pacific tro ...

(''O. clarkii'').

Anadromous Fish migration is mass relocation by fish from one area or body of water to another. Many types of fish migrate on a regular basis, on time scales ranging from daily to annually or longer, and over distances ranging from a few metres to thousan ...

populations of

Coho Salmon The coho salmon (''Oncorhynchus kisutch;'' Karuk: achvuun) is a species of anadromous fish in the salmon family and one of the five Pacific salmon species. Coho salmon are also known as silver salmon or "silvers". The scientific species name i ...

(''O. kisutch'') and

Chum Salmon The chum salmon (''Oncorhynchus keta''), also known as dog salmon or keta salmon, is a species of anadromous salmonid fish from the genus '' Oncorhynchus'' (Pacific salmon) native to the coastal rivers of the North Pacific and the Beringian A ...

(''O. keta'') spawn in the tributary streams. The Lake also contains populations of native

Brown Bullhead The brown bullhead (''Ameiurus nebulosus'') is a fish of the family Ictaluridae that is widely distributed in North America. It is a species of bullhead catfish and is similar to the black bullhead (''Ameiurus melas'') and yellow bullhead (''Ame ...

(''Ameiurus nebulosus''), Three-Spined Stickleback (''Gasterosteus aculeatus''), and

Peamouth Chub ''Mylocheilus caurinus'', the peamouth, peamouth chub, redmouth sucker or northwestern dace, is a species of freshwater ray-finned fish from the family Cyprinidae, the carps and minnows, that is found in western North America. It is the only sp ...

(''Mylocheilus caurinus''). The Invasive species Pumpkinseed (''Lepomis gibbosus'') has been in the lake since the 1970s. and is now the most abundant fish species. In addition to these fish species, Somenos Lake and associated marsh habitats are an important winter refuge for numerous species of ducks, geese and swans. Of particular interest to conservation is the large number of Trumpeter Swans (''Cygnus buccinator'') that arrive at Somenos Lake in October and remain until early April. During the past two decades Somenos Lake has been subject to persistent

cyanobacteria Cyanobacteria (), also known as Cyanophyta, are a phylum of gram-negative bacteria that obtain energy via photosynthesis. The name ''cyanobacteria'' refers to their color (), which similarly forms the basis of cyanobacteria's common name, blu ...

blooms during the summers. These blooms render the lake unsuitable for human uses like swimming,

canoeing Canoeing is an activity which involves paddling a canoe with a single-bladed paddle. Common meanings of the term are limited to when the canoeing is the central purpose of the activity. Broader meanings include when it is combined with other acti ...

and

birding Birdwatching, or birding, is the observing of birds, either as a recreational activity or as a form of citizen science. A birdwatcher may observe by using their naked eye, by using a visual enhancement device like binoculars or a telescope, by ...

. The decay of the highly productive cyanobacteria also generates

anoxic The term anoxia means a total depletion in the level of oxygen, an extreme form of hypoxia or "low oxygen". The terms anoxia and hypoxia are used in various contexts: * Anoxic waters, sea water, fresh water or groundwater that are depleted of diss ...

conditions in the water column which severely limits habitat for trout and salmon. These blooms are the result of excessive

phosphorus Phosphorus is a chemical element with the symbol P and atomic number 15. Elemental phosphorus exists in two major forms, white phosphorus and red phosphorus, but because it is highly reactive, phosphorus is never found as a free element on Ear ...

in the lake due to

deforestation Deforestation or forest clearance is the removal of a forest or stand of trees from land that is then converted to non-forest use. Deforestation can involve conversion of forest land to farms, ranches, or urban use. The most concentrated d ...

and excessive use of phosphate

fertilizer A fertilizer (American English) or fertiliser (British English; see spelling differences) is any material of natural or synthetic origin that is applied to soil or to plant tissues to supply plant nutrients. Fertilizers may be distinct from ...

s in surrounding agricultural and urban lands.

Management

Somenos Lake and its surrounding marsh and wetland habitats are managed by the Somenos Management Committee. This organisation promotes stewardship and habitat restoration in the Lake and surrounding environs. Membership of the committee includes

Cowichan Tribes Cowichan Tribes ( hur, Quw’utsun) is the band government of the Cowichan, a group of Coast Salish peoples who live in the Cowichan Valley region on Vancouver Island. With over 3,800 registered members, it is the single largest First Nations ban ...

, North Cowichan,

Ducks Unlimited Canada Ducks Unlimited Canada (DUC) is a Canadian non-profit organization that works to conserve, restore and manage Canadian wetlands in order to preserve habitat for North American waterfowl, wildlife and people. They work with industry leaders, govern ...

, and the Somenos Marsh Wildlife Society.

References

{{authority control Lakes of Vancouver Island Lakes of British Columbia Somenos Land District

Management

See also

References