Tag: fish kill

South West anglers gutted at fish deaths

UPDATE: 21/02/19

Readers may recall the deaths of brown trout in Big Brook Dam during January, believed to be a result of rapidly lowering water levels in the dam to undertake excavation and repair work on the embankment and pipes by the Water Corporation. Neither Recfishwest, or our Freshwater Fishing Reference Group, were advised of this repair work.

Photo credit: Kelvin Ty

Thanks to the quick thinking of some keen anglers a number of these prized fish were able to be saved, however, many fish needlessly perished.

At the time of this event, Recfishwest reported that we would work with relevant agencies to ensure the risk of fish kills were reduced in the future.

We are pleased to report that Recfishwest recently met with Water Corporation staff to determine how best we can work together to prevent future fish kills during remedial works on our dams.

These fish are a valuable asset that has been paid for by recreational fishers (through licence fees) and when work on our dams is likely to threaten our assets it is only reasonable we are consulted about it.

Photo credit: Kelvin Tyj

Better consultation and early knowledge of planned work on our dams allows us to take action to significantly reduce the risk of fish deaths.

Water Corporation have committed to working in partnership with Recfishwest to ensure early communication of works on our dams, as well as strategies to reduce impacts on fish and fish habitat.

Recfishwest is pleased at the timeliness of this commitment and look forward to working together to ensure that quality fishing experiences remain throughout our Southwest.

Water Corporation have now committed to an increased level of monitoring of Big Brook Dam whilst the water level remains low and will implement actions such as water aeration should this be necessary to maintain water quality.

Recfishwest will continue to monitor the situation and keep our community updated.

 

 

 

Water Corporation statement:

Fishers’ happy with plans to prevent further fish deaths

Water Corporation is installing water aeration pumps to improve oxygen concentrations at Big Brook Dam in Pemberton while it completes essential safety maintenance.

A range of mitigation strategies were discussed at a recent meeting with Recfishwest to look at options that would help reduce the impact on fish stocks at the dam when water levels are temporarily lowered.

Water Corporation South West Regional Manager, John Janssen said about 30 fish located in feeder creeks had sadly died recently when water levels were lowered to allow maintenance to go ahead.

“We are working closely with Recfishwest to help manage any further unforeseen impacts on recreational fishing activity at the dam,” Mr Janssen said.

“We will continue to closely monitor the introduced fish stocks in the Big Brook Dam while this maintenance work is carried out.

“The work we are doing at the dam is to ensure the dam will remain a safe and fantastic place to fish and recreate for many years to come.”

Matthew Gillett, Fishing Development Officer at Recfishwest said it was important to understand that trout would naturally swim upstream and struggle in the warmer weather.

“It is a rare event for more than one hundred more mature Brown Trout to be introduced at Big Brook Dam and fishers were looking forward to catching these. So we will work with Water Corporation to make sure the dam maintenance work can be completed, along with allowing fishing enthusiasts to still enjoy a good catch.” Mr Gillett said.

For more information about the Big Brook Dam Maintenance Work project please visit:
https://www.watercorporation.com.au/water-supply/ongoing-works/big-brook-dam-maintenance-work

 

Read the previous updates below.

Continue reading “South West anglers gutted at fish deaths” →

10,000+ Murray Cod Perish in Murray-Darling River

Photo credit: Department of Primary Industries and Regional Development

There’s nothing that angers fishers more than a fish kill. As passionate West Aussie fishers, we have not been immune to fish kills that have resulted in losing large numbers of important recreational species in recent memory.

The most recent kill though, is outside of WA, but should act as a reminder to everyone that appropriate management is required for all of our waterways if we are to avoid what is currently taking place in the Murray-Darling system in Victoria and New South Wales.

Thousands of iconic Murray cod have perished as water levels have dropped to critical levels following water extraction for many uses throughout the system.

Management that provides a balance between competing uses is critical to ensuring environmental flows that sustain our pastime. Although we don’t have river systems as large as the Murray-Darling in WA, the same principle applies to protect our trout, marron and redfin fisheries, which attract tens of thousands of fishers to the south-west region each year.

To learn more about the Murray-Darling fish kill see the following links:

https://www.mdba.gov.au/managing-water/drought-murray-darling-basin/fish-death-events-lower-darling

https://www.abc.net.au/news/2018-12-20/ten-thousand-fish-dead-as-darling-river-water-quality-worsens/10635730

https://www.abc.net.au/news/2019-01-21/murray-darling-fish-kill-independent-report/10730774

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.

WATCH: 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.

A spawning school of pinkies in the Sound!

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…

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.

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

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.

Cockburn Sound Fish Kill Update

Recfishwest Update
Please find below the Department of Fisheries Media Release regarding the latest on the Cockburn Sound fish kill.

Department of Fisheries Media Release 8 December, 2015 – Breakthrough in cause of Cockburn Sound fish deaths

The Department of Fisheries investigations have confirmed that November’s Cockburn Sound fish deaths were likely caused by a bloom of microscopic algae.  Supervising Scientist Dr Michael Snow said exhaustive testing had isolated a spike of a group of algal diatom species called Chaetoceros spp. which have spines made of silica and are known to causes gill irritation in fish that can lead to mucous accumulation and respiratory failure.

“Similar diatoms have been implicated in fish death events in other parts of Australia and also internationally,” Dr Snow said.

“This bloom may also have been associated with low dissolved oxygen conditions which are known to periodically occur in southern section of Cockburn Sound placing extra stress on the fish. We know from experience that fish death events often involve multiple contributory factors that make cases difficult to solve.

“We appreciate the patience of the WA community as the multidisciplinary investigative team have methodically eliminated many other causes. We cannot afford to jump to conclusions in these cases which must be based on solid scientific evidence. Investigations have included screening for a wide range of over 120 algal toxins and industrial contaminants including heavy metals, fertilisers, pesticides and hydrocarbons.

“Other Government agencies have also pursued and eliminated a number of other possibilities.

Dr Snow said results received late yesterday – and confirmed earlier today – indicate that the algal diatom is the most likely cause. He said satellite data also showed an increase in surface water temperature at the same time, which may have contributed to the bloom event

“The diatom is 10-50 microns in size, which is similar to the diameter of a human hair,” he said. “Diatoms naturally occur in all marine and estuarine environments. They are not harmful to humans. The Department of Health has confirmed the Sound is safe for fishing and swimming.”

Dr Snow said the Department of Fisheries would continue to monitor fish stocks to assess the long term implications of the fish deaths event.

“Seasonal restrictions on pink snapper fishing remain in place (due to spawning), as does a ban on crab fishing due to stock declines in recent years and Cockburn Sound is also subject to the annual West Coast demersal finfish closure,” he said.

Dr Snow said the Department of Fisheries would release a public report on its findings and provide it to other departments with a management role in Cockburn Sound, as well as the Cockburn Sound Management Council.