Thermal treatment as a method to control transfers of invasive biofouling species via vessel sea chests.
This study examined the efficacy of heated seawater for the treatment and remediation of fouled vessel sea chest habitats. In laboratory trials, three temperature regimes (37.5°C for 60 min, 40°C for 30min and 42.5°C for 20 min) were tested on a range of temperate taxa commonly found in sea chests. Field validation trials further assessed the efficacy of heat treatment within a replica sea chest environment. During laboratory trials, 100% mortality was achieved across all three treatments for the majority of taxa; the exceptions being the barnacle Elminius modestus and the oyster Crassostrea gigas. Temperature tolerance limits observed in the laboratory were successfully replicated under simulated sea chest conditions; however, a failure to achieve even heat distribution was an obstacle to achieving uniform mortality. This study provides guidance on the temperature/exposure parameters required for vessels plying temperate latitudes, and demonstrates that heated seawater has potential for controlling biofouling in vessel sea chests.
Cawthron Institute, 98 Halifax Street East, Nelson 7042, New Zealand. richard.piola@dsto.defence.gov.au
Richard F
RF
Piola
Grant A
GA
Hopkins
D000818:Animals; D059001:Aquatic Organisms / Q000254:growth & development / Q000502:physiology; D057219:Biofouling / Q000517:prevention & control* / Q000706:statistics & numerical data; D006361:Heating / Q000379:methods*; D058865:Introduced Species / Q000706:statistics & numerical data*; D012623:Seawater / Q000737:chemistry*; D012767:Ships / Q000379:methods* / Q000706:statistics & numerical data