Ecosystem monitoring inside and outside proposed sanctuary zones within the Encounter Marine Park- 2005 baseline surveys.

Abstract

Densities of fishes, macroinvertebrates and plants on subtidal rocky reefs within the Encounter Marine Park (EMP) were surveyed at 32 sites in March 2005. At the time of survey, a draft zoning plan for the EMP had just been released for consultation. Data obtained during 2005 thus represents baseline conditions, although the zones in which the surveyed sites are situated may change following public consultation. Any such change in boundaries is expected to be relatively minor, with little effect on the overall distribution of sites inside and outside Sanctuary zones. Monitoring surveys utilised the same underwater visual census techniques as used in monitoring programmes operating concurrently in Tasmania, New South Wales, Victoria and Western Australia, as well as previously in South Australia (Investigator Strait in 2004), forming part of a continental-scale study of the effectiveness of marine protected areas (MPAs). Because a wide range of species have been examined, ecosystem shifts as well as changes in the abundance of targeted fishery species will be detectable following the protection of areas from fishing. The selection of 16 sites within each management zone type provides sufficient replication to detect biologically meaningful change for common species and species richness indicators. Once fishing restrictions pertaining to different management zones are adequately enforced, surveys should be repeated on an annual basis until differences between zones stabilise. Such a monitoring scheme would not only provide time-series information on trends in the abundance of species of interest in different zones, but also information on indirect impacts of rock lobster, abalone fishing and general recreational and commercial fishing on ecosystems; and regional change associated with such factors as climate change. If insufficient funding is available for annual monitoring, then we recommend that surveys be undertaken every two years.