Behind the Scenes: Snapper Guardians Egg Collection

Recfishwest recently joined the team from the Australian Centre for Applied Aquaculture and Research (ACAAR) on their mission to collect fertilised snapper eggs for this summer’s Snapper Guardian’s project.

Recfishwest habitat officer Michael Tropiano joined ACAAR where they successfully collected enough fertilised eggs to once again stock Cockburn Sound with one of WA’s most important recreational fishing species.

Check out the video below to see some of the action as it happened.

Pink Snapper are found throughout the world, however, in the West Coast bioregion of Western Australia, there are a few particularly special locations that we rely on every year to ensure the future of the wild stock for this species. Cockburn and Warnbro sounds are the largest and most important spawning grounds for Pink Snapper in the entire West Coast bioregion and the health of these systems has a close linkage to the ongoing health of the wild stock of this species. 

While all spawning in the same location makes for simple protection of spawning snapper (the closure in the sounds protects spawning snapper from 1 October – 31 January), for these fish, releasing all their eggs in one location does have the potential to be a risky strategy.

For any fish egg to hatch, and survive all the way to adulthood is a struggle against the forces of nature. For Pink Snapper, in particular, it’s the first few months when the eggs are most vulnerable. Whether a Snapper egg hatches and survives these first few perilous months is almost completely dependent upon the environmental conditions. Most years, unfortunately, the environmental conditions aren’t quite right and only a small number of snapper actually hatch and survive. Luckily there are a few times every decade when the perfect conditions line up with spawning time and there is a boom year with a huge number of snapper hatching and surviving.

Image: Bongo nets skimming the surface collecting snapper eggs.

The strategy to spawn all in the one location and the huge natural variations in their spawning success, coupled with the fact that the Pink Snapper stock is still in a recovery phase, means these snapper are literally putting all their eggs in the one basket…

Image: School of spawning Pink Snapper spotted on the sounder.

Given the importance of Pink Snapper to Western Australian fishers and knowing the risks associated with their spawning strategy, there was an investment in 2015 into a trial project to see if it was possible to create a Pink Snapper insurance policy. The idea behind the trial was to test if it was possible to collect a very small number of eggs from the wild (the amount spawned by only two or three snapper) and grow them large enough to potentially release, plus test the genetics to ensure they would reflect that of the natural population.

If this trial was successful (as it was), then it would provide an insurance policy in case something happened or the conditions turned out to be unfavourable for their survival in the sound year after year. The idea was that once these insurance snapper were to reach a size where they were no longer dependent on favourable environmental conditions to survive, they could then be released back into the wild to support the natural recovery of this species.  As with all insurance policies, you hope you never have to use them, however in 2015 there was a large fish kill in Cockburn Sound and the insurance policy was called upon in its first year.

The trial project proved to be a success and is now known as Snapper Guardians and has been running for three years. Over the last few weeks, the staff from ACAAR have been out working into the late hours of the night to try and to collect just enough eggs to create this year’s supply of insurance snapper. The good news is, it looks like they have been able to collect enough eggs to again begin running Snapper Guardians. The latest news is that snapper eggs have just hatched and are being carefully reared at their hatchery in Fremantle.

The plan this year is to again release the snapper back into the wild once they are big enough to survive on their own. Stay tuned for more details on how you can lend a hand in the community release day early next year.

Read WA Today’s coverage of our story, here.

Fact file
• The Snapper Guardians program has already released 100,000 baby Pink Snapper back into the wild.
• The original trial project was funded through the Recreational Fishing Initiatives fund and was run by ACAAR with support from the Department of Primary Industries and Regional Development and Recfishwest.
• In 2016 the WA State Government committed funds to continue the program running for two years.

Fisheries Fact Sheet: Pink Snapper Government of Western Australia, Department of Fisheries. 2011.

Reference
Fisheries Fact Sheet: Pink Snapper. Government of Western Australia, Department of Fisheries. 2011.Sourced:http://www.fish.wa.gov.au/Documents/recreational_fishing/fact_sheets/fact_sheet_pink_snapper.pdf

Prawning Back to the Future

West Australians will once again have reason to celebrate as an additional 400,000 Western School Prawns were released in the Swan and Canning rivers last week bringing the total number of prawns released since 2013 to four million.

Although the prawns released now are only small (3 mm), they will grow and breed by around Christmas this year and help in the future sustainability of the population.  Recreational fishing for the iconic Western School Prawn had all but disappeared as prawn numbers had fallen to record low levels. Then a three-year project partly funded using recreational fishing licence money through the Recreational Fishing Initiative Fund led to the development of world first spawning techniques and the stocking of 2.5 million prawns.

Last year an addition investment of recreational fishing licence money capitalised on the great work from the original project and resulted in an additional 1.5 million prawns being stocked in the Swan and Canning rivers this summer.

Recfishwest CEO Dr Andrew Rowland said the Swan and Canning rivers are popular recreational fishing sites and perfect for families.

“We want people to reconnect with the Swan and Canning rivers which are arguably the most important estuary systems for recreational fishing in WA and we are excited to see recreational fishing licence money being invested to produce tangible benefits for the community” Dr Rowland said.

Murdoch University’s Dr James Tweedley was ecstatic with the results of the project including the positive response from the community, who now can be seen prawning on the river most nights during summer.

“During this project our research team have put in over 3,000 hours on the rivers monitoring prawn numbers monthly across 36 sites, determining when and where they breed but also looking which predators eat the newly released prawns to help maximise survival rates,” Dr Tweedley said.

“Our findings suggest that, contrary to popular belief, the dreaded Blowfish is not a significant predator of the juvenile school prawns, but rather the little known, but aptly named, ‘Gobble Guts’ seems to find the prawns particularly tasty.

“Last weeks’ midday release in the Canning River was selected as Gobble Guts are less abundant here and also less active during daylight. We are trying to use good science and research to maximise the survival of these prawns” Dr Tweedley said.

This recent release is the result of a joint project between Recfishwest, the Department of Parks and Wildlife, the WA Fish Foundation, Murdoch University, the Australian Centre for Applied Aquaculture Research the Fisheries Research and Development Corporation and the Department of Fisheries. This project was partly funded through the Recreational Fishing Initiatives Fund.
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FACT FILE:
• Between May 2013 and March 2015, 2.5 million juvenile prawns were released into the rivers. Another 1.1 million prawns were released in December 2015 and today’s release brings the total number to an impressive 4 million prawns released.
• Every year 25 per cent of recreational fishing licence fees are placed in the Recreational Fishing Initiatives Fund (RFIF) to enable projects and research aligned with enhancing recreational fishing in WA – and this prawn restocking project is a great example where the community can see the benefits of the RFIF.
• The prawn restocking project is an excellent example of the recreational fishing licence fees working towards managing and improving recreational fishing experiences. Since its inception in 2011 more than 30 projects valued at over $8 million have been funded.