The NSW Environment Protection Authority (EPA) has ruled out pesticide as causing the recent deaths of beach worms at beaches on the NSW Mid North Coast.
Commercial fisherman reported dead beach worms on Yagon Beach, near Seal Rocks, on 3 June 2021.
Laboratory testing of beach worms, pipis, sea water and sand from this location has found no evidence of pesticide or algal toxins.
The Department of Primary Industries laboratory has also ruled out disease as a cause of the deaths.
The EPA was informed that National Parks and Wildlife Service had sprayed bitou bush at Yagon Beach with pesticides in May and June, however a review of tidal conditions, groundwater and beach recession has led the EPA to conclude that the beach worm mortality was caused by natural events.
Executive Director Regulatory Operations Carmen Dwyer said the EPA found that the loss of two metres in sand depth and 20 metres of beach front after large storms lowered the habitat area for the beach worms.
"Groundwater levels were closer to the beach after significant rain in March 2021 and then prior to the beach worm mortality event," Ms Dwyer said.
"The EPA found evidence that low tides and calm seas at the time of the deaths did not allow the marine water to mix with the fresh groundwater egress on the beach face. Beach worms cannot handle these drastic changes in salinity and subsequently died."
The NSW Food Authority lifted the precautionary closure of commercially harvested shellfish from Yagon Beach on Friday 18 June.
The EPA's Environment Line handles general inquiries about environmental issues and takes reports of pollution for which the EPA has regulatory responsibilities. The Environment Line is open 24/7 on 131 555.
