Sea Urchin Population Issues Sea Urchin Population Issues in California Kelp Forestsin California Kelp Forests

Andy OstrowskiAndy Ostrowski

Bio 457- Fall 2004Bio 457- Fall 2004

Sea Urchins Of Southern Ca.Sea Urchins Of Southern Ca.

Purple (Purple (Strongylocentrotus Strongylocentrotus purpuratuspurpuratus) and Red Sea ) and Red Sea Urchins (Urchins (S. franciscanusS. franciscanus))

Subtidal foraging Subtidal foraging Omnivores that prefer kelpOmnivores that prefer kelp

Enchinoderms: sea stars, Enchinoderms: sea stars, sea cucumbers, brittle sea cucumbers, brittle stars.stars.

Hardy, Long lastingHardy, Long lasting Use Tube feet for Use Tube feet for

locomotionlocomotion

Their Affects on Kelp ForestsTheir Affects on Kelp Forests

Eat base stronghold of Kelp, disabling itEat base stronghold of Kelp, disabling it Floats to the surface and diesFloats to the surface and dies Abundant urchin populations create Abundant urchin populations create

“Barrons” “Barrons” – Eat on floating algae and don’t allow kelp Eat on floating algae and don’t allow kelp

recruitmentsrecruitments

Why a Problem?Why a Problem?

Natural Predators are lackingNatural Predators are lacking– California Sea Otters are endangeredCalifornia Sea Otters are endangered– Sheepshead are being fishedSheepshead are being fished

Creates different population dynamics in systemCreates different population dynamics in system

Population ControlPopulation Control

Increased fishing of Red Sea Urchin for Export to Increased fishing of Red Sea Urchin for Export to JapanJapan– One of California’s most valuable fisheriesOne of California’s most valuable fisheries– Declining rapidlyDeclining rapidly

Protection of the Sea Otter population by Protection of the Sea Otter population by numerous agenciesnumerous agencies

Regulation of size of urchin allowed to catchRegulation of size of urchin allowed to catch Regulation of Sheepshead Fishing Regulation of Sheepshead Fishing Increased areas of kelp growth to avoid “barrons”Increased areas of kelp growth to avoid “barrons”