Byron Shire Council say that staff, in consultation with NSW Government agencies including NPWS, NSW DPI Fisheries and the Marine Park Authority are continuing to investigate the recent fish kill at Tallow Creek to improve entrance opening protocols to try to minimise the chances of it happening again.
Tallow and Belongil Creeks are Intermittently Closed and Open Lakes and Lagoons (ICOLLs).
Council’s Coastal Biodiversity Coordinator Chloe Dowsett said no one wants to see a repeat of the fish kill that happened in June, and while Council and agencies improve protocols relating to the future opening of Tallow Creek, the community should be aware that the mouth of the creek has closed. ‘Water levels behind the sandbank at the creek mouth are starting to rise, and are currently sitting at two metres,’ said Ms Dowsett.
‘At the meeting on 27 June 2019 Council resolved that its preference is that no further openings of the Tallow Creek ICOLL be undertaken unless there is agreement of Arakwal Corporation, NPWS, and Cape Byron Marine Park, and that there is a low probability of a fish kill at the proposed opening time.
Local conservationist, Dailan Pugh, is demanding NSW Fisheries prosecute Byron Shire Council for knowingly and cruelly killing hundreds of thousands of fish when they opened Tallow Creek estuary in June, given reports obtained under freedom of information prove Council were repeatedly warned of a fish kill and they refused to take recommended mitigation actions.
‘The reports by Council’s own consultants Australian Wetland Consulting (AWC) clearly identify in three monitoring reports since 2017 (when there was another massive fish kill), that the principal cause of these fish kills is the decanting of oxygenated surface waters when the estuary is opened leaving deoxygenated subsurface waters behind,’ says Pugh.
Saving fish or saving property
Ms Dowsett without the openings the water will rise and some properties will be affected by flooding and the public walkway to the beach will not be accessible.
‘Naturally this has an impact on people’s ability to enjoy their yards, but there are also environmental considerations that need to be taken into account, with the avoidance of a fish kill being the primary consideration,’ she said.
‘This issue is very complicated with sections of the community having very different ideas about what should and shouldn’t be done with respect to the management of the Tallow Creek ICOLL.
‘Council and NSW Government agencies are now exploring strategies to improve the future management of the creek and whilst this is happening we are asking for people’s patience and understanding because the ultimate aim is trying to avoid fish kills whilst balancing the expectations and needs of the community,’ said Ms Dowsett.
Pugh says that on April 2019 AWC advised Council that: Artificial opening of the creek system should not be undertaken without thorough consideration of potential consequences (ie fish kills).
In the past, an opening during/after a rainfall event reduces the likelihood of a fish kill.
‘Stratification generally puts the poorer quality water at depth (anoxic), without the pushing and stirring action of the catchment runoff during a rainfall event, the better quality water is decanted from the top of the water body, leaving the poorer anoxic water potentially resulting in a fish kill,’ says Pugh.
Pugh says the AWC repeatedly recommended that before an artificial opening event Council assess dissolved oxygen levels at a number of depths to identify the risk of a fish kill, and to only open it during a significant rainfall event, or if there is no rainfall, to install an aerator to reduce the potential fish kill. ‘Council decided to ignore these recommendations.’
The AWC recommendations
The AWC recommended to Council if it is necessary to undertake an artificial opening of the estuary, the following is recommended:
1. Undertake an assessment of the water quality, particularly DO, at a number of depths through the system to determine the potential risk to aquatic life as a result of estuary opening.
2. The creek should only be opened when there is a rainfall event forecast exceeding 20-40mm or as discussed with key stakeholders. This will ensure there is the potential for water to enter the estuary for upstream that contains sufficient DO to sustain the aquatic life within the system.
3. If the creek needs to be opened and there is no rainfall forecast, BSC should investigate if an aerator can be installed on a temporary basis to reduce the potential fish kill as a result of low DO values.
Pugh says that Council was also aware that its openings of the Belongil estuary in February and March 2019 had resulted in fish kills.
‘Council chose to open Tallow Creek on 14 June 2019 in a dry period without attempting any mitigation measures, and against expert advice, in the full knowledge that it would most likely result in a significant fish kill,’ says Pugh. ‘This was a reckless and callous act. They then left the scene.
‘The next morning hundreds of thousands of fish were dying, some of which were rescued by residents. Council was forced to return that afternoon to take 12.4 tonnes of dead fish to the tip, leaving behind the many thousands of dead fry and fingerlings, and the many tonnes of dead fish that had been washed out to sea.
‘Council’s only rationale was that they were being pressured by upstream landholders suffering nuisance flooding of their yards to act as soon as they could, even though they knew waiting for rain could have mitigated the risk of a fish kill.
‘A week later there was a major rainfall event that may have naturally opened the estuary without a fish kill.
‘What the fish kills this year clearly illustrate is that for years Byron Shire Council’s management of estuary openings has been disastrous for marine life and is degrading two Special Purpose Zones specifically protected for rehabilitation in the Cape Byron Marine Park.
‘These deaths also show an abject failure by the NSW Government agencies responsible for fish and marine parks to intervene to stop this.
‘As NSW Fisheries give on the spot fines of $500 to a person for taking a single fish, then surely they must throw the book at Byron Shire Council for knowingly and cruelly killing hundreds of thousands of fish in a marine park. This was not an innocent act and must be stopped.
‘Suffocation is a horrible, slow and cruel death as fish are unable to breathe in the water and gasp for air on the surface or pull themselves out of the water onto the shore in desperate, but futile, attempts to survive.’