Seagrasses are marine flowering plants that form extensive meadows in the sheltered bays around Kangaroo Island. While these meadows may be comprised of only a few species of seagrass plants, they are home to a huge diversity of animals and provide critical nursery habitats and refuge for a range of fish species including economically important ones such as King George whiting and garfish.
Seagrasses also play a vital role in carbon sequestration, nutrient recycling and help stabilise the sea bed. Seagrass loss commonly results in an increase in wave height and intensity, and associated erosion of the foreshore.
Above: Common critters found in seagrass meadows on Kangaroo Island.
One of the biggest threats to seagrasses is reduced water quality entering the marine environment from the land. Urban and rural development can lead to high levels of nutrients and sediments entering the sea via terrestrial runoff. This runoff increases water turbidity and can promote excessive algal growth, both of which reduce the amount of light available for seagrass and, if conditions are bad enough, this may lead to their eventual loss.
Natural Resources Kangaroi Island's Coast and Marine program undertakes regular monitoring of the major seagrass meadows on KI. An underwater video camera is towed beneath our vessel to record footage that is later viewed in the lab to assess the cover and condition of the seagrass.
Above: Map showing the monitoring sites and characteristics of associated seagrass meadows. Click to enlage.
The seagrass monitoring program is part of a larger Catchment to Coast project that aims to improve water quality in the Cygnet River and Nepean Bay Basin. The information collected on seagrass health will be used to assist land managers to implement and evaluate the effectiveness of on-ground works in the Cygnet River catchment. This project is funded through Caring for our Country, an initiative of the Australian Government.
Click here to download the Seagrass Biodiversity on Kangaroo Island 2006-2007 Report. 673.01 KB