Friday 18 May, 2012

The invasive Northern Pacific Seastars (Asterias amurensis) were discovered yesterday at Tidal River within the Wilsons Promontory National Park for the first time.

Northern Pacific Seastars at Tidal River

The seastars were sighted from the Tidal River footbridge, and were confirmed by Parks Victoria staff as being Northern Pacific Seastars.
Parks Victoria promptly deployed an incident control team to monitor the spread considering the high value of the marine environment surrounding Wilsons Promontory National Park.
Incident Controller Mr Matthew Hoskins said the Northern Pacific Seastar is a large seastar with five distinct arms that taper to pointed, upturned tips.
“Northern Pacific Seastars feed on a wide range of native animals and can have a major effect on the marine food chain,” said Mr Hoskins. “The species exists primarily in areas where wave action is low. It is not dangerous or harmful to humans. “
Ninety seven specimens have now been collected from Tidal River and confirmed as Northern Pacific Seastars.
Mr Hoskins said the team acted swiftly to ensure a rapid response with teams focusing comprehensive search efforts in Tidal River, Norman Bay, Squeaky Beach, Oberon Bay, Picnic Beach, Whisky Beach and Sealers Cove.
“So far, the searches have only uncovered the Northern Pacific Seastars within Tidal River itself. We are hoping it may be an isolated event, though we are not taking any chances”, said Mr Hoskins.
The full-scale search involving scuba-diving, snorkelling and rockpool inspections will continue across the weekend.
Mr Hoskins said that it would be difficult to pin-point exactly how the seastars arrived at this location.
“Our focus now is to ensure the removal of all Northern Pacific Seastars and how we can prevent any further spreading of these marine pests into other areas of the park.
“Boats can easily spread these pests so it is important that anyone using boats ensures their boat is kept clean and all marine life clinging to the surface are removed,” he said.
Parks Victoria is encouraging all boat owners to be especially vigilant in keeping their boats clean when travelling around the waters surrounding Wilsons Promontory National Park.
Additionally, Parks Victoria is encouraging the public to report sightings of the 5 armed starfish which match the description of Northern Pacific Seastars in all locations outside of Port Phillip Bay and Tidal River.
For more information about the Northern Pacific Seastar or aquatic pests in general, go to: www.dse.vic.gov.au/marinepests

Tidal River Northern Pacific Seastars update

Monday 4 June, 2012

Divers have now removed 129 Northern Pacific Seastars from the Tidal River Estuary. Parks Victoria Incident Controller Matt Hoskins said extensive searches in nearby estuaries, beaches, inlets, and in offshore areas have found no sign of the spread of Northern Pacific Seastars.
“The precautionary limitations on swimming and fishing have been lifted, however the use of all water vessels including kayaks and canoes in Tidal River remains strictly prohibited until further notice,” said Mr Hoskins. “Operations will focus on Tidal River for the foreseeable future. We’re treating this infestation as seriously as we would a fire or flood emergency. It is very important for people who love the Prom and its surrounding waterways.”
Mr Hoskins said Northern Pacific Seastar females can produce from 10-25 million eggs per year.
“From July-October larvae remain in the water column for up to 120 days providing a huge opportunity for spread to new areas through the water movements along the coast,” said Mr Hoskins. “It is a voracious predator feeding on a wide range of native animals and can have a major effect on the native, and commercially important, shellfish populations that form part of the marine food chain. They directly compete with many fish, including snapper, which use native shellfish as a source of food.”
Mr Hoskins said the team would work through management options while manual removal of the Northern Pacific Seastars continued with professional diving teams.
“We’re washing and drying all equipment as we enter the river,” said Mr Hoskins. “This is vital in containing the spread. We would encourage all users of tidal river to take this precautionary approach.”

• Marine pests including the Northern Pacific Seastar are easily spread from one part of the coast to another by
people.
• Boats, kayaks and canoes, wetsuits, fishing gear, and other equipment that remain wet can spread fertilised eggs, larvae, or small animals or plants, to new locations.
• All equipment used in marine areas should be washed in freshwater after use then thoroughly dried to reduce the
risk of spreading marine pests.
• This is particularly important for people moving any equipment used in areas like Port Phillip Bay to other areas
such as the Prom.

Mr Hoskins said the response and awareness of the severity of the Northern Pacific Seastar infestation has been overwhelming.
“We thank everyone for their support on this important issue.”
Sightings of suspected Northern Pacific Seastars outside of Wilsons Promontory National Park or Port Phillip Bay can be reported to the Department of Sustainability and Environment (DSE) customer service centre on 136 186. DSE recommends taking a photo of the suspected seastar as well as the specific location where it was observed would assist in any investigation.