The Blackman Rivulet Marine Conservation Area occupies approximately 263.1 hectares within Blackman Rivulet and Blackman Bay in the north of the Tasman Peninsula.
The reserve contains sheltered marine inlet sediment ecosystems and diverse seagrass and algal vegetation. The area features dense seagrass and seaweed beds which include Heterozostera and Ruppia macrophyte types. Seagrass is a relatively rare habitat within the Bruny bioregion and a large proportion of it is located in the Blackman Bay area. Therefore, this reserve is significant for conservation values and as a scientific reference area for seagrass habitats.
Seagrass ecosystems are known to be extremely productive, have a high biodiversity, support complex food webs and play an important role in a wide range of nutrient cycling processes and primary production. They also provide nursery habitat and refuge for a number of organisms including crustaceans, molluscs, fish, sharks and stingrays. Large rays are common in the reserve. The reserve also contains habitat for the rare brown algae (Cyptoseira trinodis)
The area was proclaimed a conservation area under the Nature Conservation Act 2002 on 9 December 2009. This reserve class provides for the protection and maintenance of the natural and cultural values of the area and the sustainable use of natural resources.
Fishing is permitted in the reserve. Rules and regulations relating to recreational fishing in Tasmania can be found in the Recreational Sea Fishing Guide.