Principal source: NIMPIS, 2002 Leathery sea squirt : Styela clava
JNCC, 1997 Styela clava
Compiler: National Biological Information Infrastructure (NBII) & IUCN/SSC Invasive Species Specialist Group (ISSG)
Review: Expert review underway: \ Andrew N. Cohen \ San Francisco Estuary Institute Oakland California USA
Publication date: 2006-03-23
Recommended citation: Global Invasive Species Database (2024) Species profile: Styela clava. Downloaded from http://www.iucngisd.org/gisd/species.php?sc=951 on 07-10-2024.
It can also occur as fouling on vessels, aquaculture and fishing equipment and other artificial structures. Dense fouling on fishing equipment, moorings, ropes, etc. can be time consuming to remove and can result in tangling of fishing gear. Hull fouling increases drag on vessels, requires an increase in the frequency of hull cleaning, and increases fuel costs. In Japan it has been known to impact human health causing an asthmatic condition in oyster shuckers when hammering open Styela fouled oysters in poorly ventilated areas (NIMPIS, 2002).
NIMPIS (2002) states that, \"In some power plants, raw water systems, reservoirs, locked marinas and impoundments, water levels can be lowered (drawn-down) to expose fouling infestations to the air. Subsequent freezing or desiccation due to ambient temperatures may kill a large proportion of the exposed population.\" The authors go on to state that this method has been successful in controlling S. clava. Various combinations of salinity, temperature and exposure to air have proved successful in killing S. clava fouled on oysters without harming the oysters (NIMPIS, 2002).
The dipping of dredged oysters, and associated species, in saturated or strong salt solutions is extremely effective in killing ascidians without harming the oysters. Brine dipping of oysters fouled with Sargassum muticum, Codium fragile ssp. tomentosoides and S. clava was found to be an effective control. Brine dipping infested oysters is considered the cheapest, safest and most effective method of control of fouling species, however, this requires collection of all the fouled oysters to place them in a bath as it is not possible to implement in the open environment (NIMPIS, 2002).