Hull fouling on domestic vessels as a vector for secondary spread of marine nonindigenous species

MELONI MARCO; CORREA, NANCY; PITOMBO FABIO; BOLTOVSKOY, DEMETRIO; SYLVESTER, FRANCISCO

Niagara Falls

Congreso; ICAIS 2013 (18th International Conference on Aquatic Invasive Species); 2013

ICAIS

Vessel hull fouling is a well recognized vector for the introduction of nonindigenous species (NIS), although its role in regional species dispersal has received less attention. We assessed hull fouling communities attached to an oceanographic vessel serving routes from Brazil to Antarctica. We sampled both in the water using divers and in dry-dock in the Argentine port of Mar del Plata. Video and 20x20 cm quadrat samples were obtained from exterior surfaces of the bow thruster, bulbous bow, dry-dock support strips, propeller, rope guard, rudder, bilge keel, waterline, and main hull. Bryozoans, hydroids, and nematodes accounted for >80% of total invertebrates in the samples. Other taxa found, in order of decreasing abundance, included tunicates, copepods, amphipods, polychaetes, and bivalves. Comparatively rare barnacles accounted for a large percentage of the biomass and likely provided habitat for mobile invertebrates. A few crabs, isopods, sea spiders, cladocerans, hirudineans, cumaceans, and ascidean larvae were also sampled. Preliminary taxonomic identifications revealed the presence of a few species not reported for the Southern Atlantic such as the isopods Paracerceis sculpta and Dynamene sp. Established NIS such as Gonothyraea loveni (Hydrozoa) and Hydroides elegans (Polychaeta) were also transported in hull-fouling assemblages. A significantly larger number of invertebrates were obtained from quadrats sampled in dry-dock than in the water. While total richness might be properly estimated using either sample set, rare species may be overlooked during in-water sampling of hull-fouling communities. Overall, our results suggest that hull fouling on domestic vessels can accelerate NIS regional dispersal using ports as pickup locations. Faster dispersal rates than those attained naturally through water currents can be important for the colonization of remote habitats such as Antarctica. With international legislation regulating ballast water discharges, hull fouling should be the focus of future research.