Abstract:
Schizoporella errata is an encrusting colonial bryozoan of the family Schizoporellidae. Although
its invasive potential is well recognised globally, their presence in Sri Lankan marine
environment was noted for the first time in 2014 and has since been observed abundantly
throughout the port environment. The present study provides the potential impact of S. errata on
native communities settling on test panels in Colombo Port, which is the main commercial port
in Sri Lanka. Community succession was observed in six sampling locations for 24 months. The
panels were placed in four depths at 1, 2, 3 and 4 m. In order to study the community
development and percentage cover, plates were taken monthly by retrieving the collector out of
the water, ensuring minimal exposure to direct sunlight and photographs of the plates were
taken. In the laboratory, these photographs were analyzed using PhotoQuad software. During the
study, a maximum of 99.25% of covering percentage was observed among the S. errata colonies
of different successional stages outcompeting and inhibiting the growth of other fouling
organisms, including native bryozoans (i.e. Arbopercula bengalensis and Hippoporina indica).
Their ability to invade all the successional stages of a fouling community, including the climax
community, indicates the potential threats caused by S. errata to the structure and dynamic of the
native fouling community. Furthermore, S. errata seem to act as a secondary substrate for the
settlement of other fouling organisms such as tunicates (i.e, Didemnum sp.). Since experimental
panels are well known method to study the fouling community, the invasive behavior of S. errata
in experimental panels ratifies its potential ecological impacts to the natural environment as a
competitor for native fouling species and its ability to provide favorable living space for nonnative
species.
