There are a few small seagrass beds in the bays and coves of the middle and lower Derwent estuary, but the largest areas are found in the region between Cadburys Point and the Granton/Bridgewater area. The Habitat Atlas indicates that there are 6.6 square kilometres of brackish seagrass beds (macrophtyes) and 0.2 square kilometres of marine seagrasses remaining in the Derwent estuary. In some areas, where nutrient levels are high, seagrass beds may become overgrown by thick mats of slimy, green algae.
Did you know?
- You can often see hundreds of black swans and native ducks feeding on seagrass on both sides of the Bridgewater Causeway, particularly during dry summer months.
- Seagrasses can be seen from the air and monitoring seagrass in the Derwent estuary involved collecting aerial imagery. See report for more details.
Things to explore
Learn more about seagrass at Seagrass Watch and consider how seagrasses in Tasmania may differ from tropical areas.
- Estuarine Habitat Mapping in the Derwent – Integrating Science and Management, 2001
- Spatial imagery for management of Submerged Aquatic Vegetation in the River Derwent estuary, 2011
- Estuarine Habitat Mapping in the Derwent – A Resurvey of Marine Habitats by SeaMap Tasmania, 2007