Abstract:
Introduction of non-indigenous aquatic organisms to the new environments through ships
biofouling has been identified as a major threat to world oceans and for the conservation
of biodiversity. As an island nation with intensive shipping activities, there is a high
possibility to introduce invasive species into Sri Lanka through ships biofouling. It is
imperative to identify and assess the fouling related invasions in Sri Lankan waters to
adopt necessary control measures. This study examined the biofouling related invasion in
Colombo port with a view of adopting control measures. The study was undertaken
between October 2019 to January 2020 in Colombo port. The hard substrate samples were
collected monthly basis from eight sampling locations. The artificial settlement plates
were deployed to collect benthic fouling samples. Samples were collected from the ship’s
hull which arrived at the Colombo port from various regions of the world. 93 biofouling
creatures were identified up to their family level and 83 up to their species level. 51%
nonindigenous, 35% native, and 4% cryptogenic fouling species were detected. 33 native
fouling organisms were detected from all samples. Relative abundance, diversity indices,
species richness, and evenness were calculated. Mean relative abundance varied with
0.0169 to 0.0579. Amphibalanus amptrite the most abundant species on ship’s hull
while Saccostrea cucullata was the most common species at harbour sites. The exotic
species of Chathamalus montagui was recorded for the first time in Colombo harbour.
The five globally known invasive alien species introduced through ships were recorded.
Results imply that some invasive biofouling species had already settled in the harbour
basin area and ships arrive in Colombo port poses a risk of introducing invasive species
into Sri Lanka waters. This study suggests that it is exigent to adopt relevant international
guidelines to mitigate the threat of introducing invasive species through ship biofouling.
Keywords: Invasive alien species, Biofouling, Colombo port, Ship's hull, Introducing
