Blackmans Bay beach has reopened after more tests showed a significant improvement in the River Derwent’s water quality, but the southern end of the beach remains closed.
Earlier, the main beach was closed after tests found elevated faecal contamination.
This week water tests conducted by the Derwent Estuary Program revealed beaches across the river were unsafe for swimming and needed retesting due to extremely high results.
Chief Executive Officer of the Derwent Estuary Program Ursula Taylor says beaches including Bellerive, Howrah, Hinsby, Nutgrove and Kingston were retested today along with Blackmans Bay.
Ms Taylor says despite the high test results, there are other beaches around Hobart swimmers can use.
"Places like little Sandy Bay, parts of Howrah beach and Kingston middle. There are lots of options in Hobart to still take a swim despite some of the high readings this week," she says.
Ms Taylor says it's not yet known what caused the elevated contamination. Investigations are continuing.