Environment Minister Donna Faragher has reassured the public about health concerns relating to the Swan and Canning rivers following a recent spate of dolphin deaths.

The State Government has been advised by fisheries and health agencies that there is no direct risk to the public by swimming in, or by consuming any fish caught in the Swan and Canning rivers.

Mrs Faragher said the Swan River Trust and Department of Environment and Conservation, in collaboration with two universities, would continue to monitor the dolphins living in the Swan Canning Riverpark to ensure their long-term health.

Following a meeting of researchers and government agencies on Thursday, which discussed the findings of six dolphins reported dead between June and October, the Minister reiterated the importance of programs launched by the State Government designed at continually improving the eco-system of the rivers.

“I am concerned by the number of dolphin deaths and determined to find out exactly why they are dying, which is why the Swan River Trust is co-ordinating further investigations in conjunction with Murdoch and Curtin universities, and government agencies including the departments of Environment and Conservation, Water and Fisheries,” she said.

Mrs Faragher said evidence indicated factors such as seasonal changes in water quality and the long-term exposure to contaminants, including high levels of dieldrin, as possible attributes in the deaths.

“Through the Liberal-National Government’s Natural Resource Management program, a number of projects which tackle water quality improvement and waterways restoration have been funded including $3.19million for the Swan and Canning rivers,” she said.

“These projects, which are designed to address pollution issues and our water quality, will have a positive outcome for the entire Swan Canning river system.”

The recent dolphin deaths share many of the same features observed in dolphins studied elsewhere in the world, including evidence of suppressed immune systems and bacterial, fungal and virus infection. 

International research has shown that dolphin deaths of this nature are not unique to the Swan Canning Estuary and have been observed in other locations in Australia and around the world.

The trust has been working with other government departments on a non-nutrients contamination program since 2006 and has released reports that show high levels of dieldrin and DDE in sediment in parts of the river. 

However, the study showed that on the whole the level of contaminants were typical of a modern city and that many of the contaminants were the result of historic use of now banned chemicals.

Discarded fishing line is also a contributing factor, with two dolphins dying as a result of an infection arising from entanglement.

The Minister encouraged members of the community interested in monitoring dolphins to join the trust’s River Guardians program and sign up to become a Dolphin Watch member.

“Efforts to protect the Swan River dolphins for the long-term will require a collaborative approach working across government agencies and research institutions and with significant community involvement,” she said.

Recreational fishers also have an important role to play, as they can reduce the risk of entanglement for dolphins by properly disposing of fishing line and using biodegradable fishing line.