Port of Karumba long term seagrass monitoring: October 2008

Abstract

Seagrass habitats are valuable fisheries resources that provide critical ecological functions within the coastal zone. The wide distribution of seagrasses in Queensland and their capacity to show measurable, short-term responses to changes in water quality, make them ideal candidates for monitoring the health of marine and coastal environments.\ud \ud A network of long term seagrass monitoring sites has been established at various port locations throughout Queensland to assist port managers in the planning and development of port operations to achieve minimal impacts on the marine environment and fish habitats. The programs are also used as an indicator of the overall marine environmental health of ports and are an example of international best practice in the management of port environments.\ud \ud This report details the latest findings of the Port of Karumba long-term seagrass monitoring program incorporating data from the most recent survey conducted in October 2008. The Karumba monitoring program aims to ensure port activities have a minimal impact on seagrasses. It is also used to provide a measure of the marine environmental health of the port.\ud \ud Results of the 2008 monitoring find seagrass in Karumba to be in a healthy state, supporting dugong populations and providing a fisheries resource. Inter-annual variation in seagrass meadow area and density (i.e. biomass) continues to be large. Here we report strong evidence to suggest that throughout 15 years of monitoring seagrass variability has not been caused by local anthropogenic factors. Inter-tidal seagrass meadows in Karumba are thought to be principally driven by atmospheric temperature, tidal exposure and catchment rainfall.\ud \ud In conclusion, this survey indicates that human activities in Karumba, including dredging and other port and urban activities were unlikely to have had a significant impact on seagrasses in the area, and that the marine environment of the port was in a healthy condition