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Sea Urchin Population Issues in California Kelp Forests. Andy Ostrowski Bio 457- Fall 2004. Sea Urchins Of Southern Ca. Purple ( Strongylocentrotus purpuratus ) and Red Sea Urchins ( S. franciscanus ) Subtidal foraging Omnivores that prefer kelp
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Sea Urchin Population Issues in California Kelp Forests Andy Ostrowski Bio 457- Fall 2004
Sea Urchins Of Southern Ca. • Purple (Strongylocentrotus purpuratus) and Red Sea Urchins (S. franciscanus) • Subtidal foraging Omnivores that prefer kelp • Enchinoderms: sea stars, sea cucumbers, brittle stars. • Hardy, Long lasting • Use Tube feet for locomotion
Their Affects on Kelp Forests • Eat base stronghold of Kelp, disabling it • Floats to the surface and dies • Abundant urchin populations create “Barrons” • Eat on floating algae and don’t allow kelp recruitments
Why a Problem? • Natural Predators are lacking • California Sea Otters are endangered • Sheepshead are being fished • Creates different population dynamics in system
Population Control • Increased fishing of Red Sea Urchin for Export to Japan • One of California’s most valuable fisheries • Declining rapidly • Protection of the Sea Otter population by numerous agencies • Regulation of size of urchin allowed to catch • Regulation of Sheepshead Fishing • Increased areas of kelp growth to avoid “barrons”