Kachemak Bay Research Reserve National Estuarine Research Reserve System Marine Invasives of Concern for Kachemak Bay KACHEMAK BAY RESEARCH RESERVEa unit of theNational Estuarine Research Reserve System Fostering stewardship through integrated research & education
GREEN CRAB Mature very quickly Female can lay 200,000 eggs. Aggressive Eat other crabs as large as themselves Voracious Eat young crab Very good at opening mussels and clams Can eat 40 ½” clams per day Broad ecological tolerances Wide range of salinities Wide range of temperatures
What is a tunicate? Tunicates named for their tunic, a tough fleshy shield that surrounds the barrel-shaped body of the animal. Closely related to vertebrates. This is evidenced by their larvae bilateral tadpole-like larvae w/ simple nerve cord. Larvae is free swimming with several vertebrate characteristics including; notochord, gill slits, dorsal nerve cord post anal tail Phylum chordata, subphylum Urochordata. Adult tunicates are sessile, larval tunicates float/swim in the water column.
Invasive Tunicates -Fouling organisms (tunicates) -many originate in Asia -Cause problems for marine infrastructure including boats and aquaculture -Out-compete native benthic organisms -Difficult to remove Botryllid Tunicates
But… Heavy shipping only began in AK began w/ start-up of Valdez terminal.
In Kachemak Bay… E. Gray G. Ashton Caprella mutica (2000, 2007) Botrylloides violaceus (2000)
What can we do? Top-down (prevention) Regulation -mid-ocean ballast exchange (currently coastwise, and tanker traffic exempt) -ballast treatment (engineering challenges) Bottom-up (response) - Monitoring aimed at early detection/rapid response
Regulation: mid-ocean exchange Exchange coastal water with open ocean water 200 miles off shore Coast wise traffic exempt Oil tankers exempt Safety exemption
Ballast water treatment Ship-based treatment Shore-based treatment
Tunicates/fouling organisms Settling plates PVC square, brick, line, tag Deploy/retrieve/re-deploy quarterly: 1m from surface
Take Home Message: 1) Ballast water is a major vector for marine invasives, Alaska receives large quantities of untreated ballast water 2) Community monitoring aimed at early detection and rapid response is a the most immediate and valuable tool we have for combating marine invasives.