ECOLOGICAL DATA
Distribution: rocky areas throughout exposed and
protected coastal waters.
Habitat: rocky substrates, especially ledges and crevices; locate near or in
giant or bull kelp beds and other brown algae in areas of moderate to swift currents;
larvae drift and feed in plankton; juveniles settle near kelp beds, often associate with
aggregations of adults, remain under adult spines until they reach 40 mm.
Tidal elevation: extreme low tide to 100 m subtidal depth; most concentrated
abundance just below the upper limit of range, usually 5-10 m subtidal.
Food: herbivore; grazes on attached marine plants and drifting kelp fragments;
primary food is kelp and may limit kelp distribution.
Predators: sea stars, sea otter, octopus, crabs, wolf eels; numerous predators
on larvae.
GROWTH RATE
Slow, very dependent on food (i.e. kelp) supply;
sexually mature at 50 mm test diameter reached at 2 yr; reaches commercial size, 100 mm at
4-5 yr; may reach 190-200 mm test diameter.
FISHERY
Small commercial diving fishery; minimum size limit 100 mm;
1986 commercial catch was 2,067 t valued at $1 million.
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REFERENCES
Bernard, F.R. 1977. Fishery and reproductive cycle of the red
sea urchin, Strongylocentrotus franciscanus, in British Columbia. J. Fish. Res.
Board Can. 34: 604-610.
Breen, P.A. 1984. Sea urchins: suitability of the present minimum size limit, p.
25-51. In G.S. Jamieson [ed.] 1982 shellfish management advice, Pacific Region.
Can. MS Rep. Fish. Aquat. Sci. 1774.
Jamieson, G.S., and K. Francis. 1986. Sea urchins, p. 8-12. In G.S. Jamieson
and K. Francis [ed.] Invertebrate and marine plant fishery resources of British Columbia.
Can. Spec. Publ. Fish. Aquat. Sci. 91. Kato, S., and S.C. Schroeter. 1985. Biology of the
red sea urchin, Strongylocentrotus franciscanus, and its fishery in California.
Mar. Fish. Rev. 47: 1-20.
Mottet, M.G. 1976. The fishery biology of sea urchins in the Family
Strongylocentrotidae. Wash. Dep. Fish. Tech. Rep. 20: 66 p.
Sloan, N.A. 1986. World jellyfish and tunicate fisheries, and the Northeast Pacific
echinoderm fishery, p. 23-33. In G.S. Jamieson and N. Bourne [ed.] North Pacific
workshop on stock assessment and management of invertebrates. Can. Spec. Publ. Fish.
Aquat. Sci. 92.
Sloan, N.A. 1986. Red sea urchin. Underwater World, Fish. Oceans Can., Ottawa: 4 p.
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