PRESS RELEASE: Dick Eussen Tropical Australia Media - 27/07/2016
MANGROVE DIE-OFF
By Dick Eussen
A report by the ABC in Julyof a massive mangrove die-off in the Gulf of Carpentaria between Karumba and the Roper River went largely unnoticed.The report was based on a fly-over by Professor Norm Duke of the James Cook University, a research fellow and climate change theorist, who predictable – and perhaps favorable to both theQLD and NT Governments -blamed the die-offon climate change as it coincided with a mass coral bleaching event on the Great Barrier Reefduring the same period.
Professor Duke did not land to confirm his findings even though the die-off has decimated some 7000ha of mangroves along a 700km stretch of the coast and estuaries from Karumba to the Roper River. According to July 2016 newspaper reports inthe Cairns Post and the North Queensland Register and on the Web, Professor Duke reported that because the mangrove kill had occurred in just over a month it suggested a link with climate change. Butaccording to Karumba-based commercial fishermen, mangrove die-back has been ongoing since 2014.
“We have seen smaller instances of this kind of moisture stress before, but what is so unusual now is the extent and that it occurred across the whole southern Gulf in a single month,” Professor Duke said.“What we are seeing is a natural process, but nature usually does this incrementally. Not with this severity. We have never seen that before.”
He stated that high temperatures and an extended dry season had done great damage and that some mangroves would recover, others not. He said that it did not bode well for species such as dugong and for Australia’s northern fisheries with mangroves being vital breeding grounds for prawns, crabs, and fish, including barramundi.
But the “bush-telegraph” is rife withrumours that are streaming back from visiting fishermen who have fished the McArthur and Limmen Bight River systems and the adjacent coast which suggest that the die-off is something very different and more ominous.
I have mates who have fished the N.T Gulf country andsaw the disaster first hand. The following is based on what they saw and fromother un-confirmed rumours, but rumours have foundationsand theseare based ona huge marine-life kill on the shores of the Limmen Bight and theinshore sea grass meadows. They spoke to me on a condition of anonymity for fear of reprisals, while fishing camp owners and managers would not comment, possible in fear of losing clients. A Borroloola mine worker and rec-fisher put it more bluntly, “I live here mate, don’t use my name or bad things may happen.”
“We saw 1000’s of dead long-bum shellfish on the sandy beaches about the Limmen Bight,” said a close fishing mate, a keen angler anda former commercial fisherman who spent 10 weeks camping and fishing the Limmen Bight River and the Limmen Bight this dry season.“There were other shellfish scattered amongst them. Some were still alive, but didn’t look too well. The stink was horrible, things were dying everywherein a matter of days, almost in front of our eyes. I have fished the Gulf from Karumba to the Roper for 50 years,but I have never seen anything like it. It was like being in a dead zone.”
He said that there werenofish or bait in the lower estuaries of the river, no crabs and that a few prawns caught in a bait net were abnormally tiny and appeared deformed.Few shore birds were seenorbirds of prey. Several small tidal inlets they visited east from the Limmen Bight River all had dying or dead mangroves while the beaches and tidal flats were littered with a myriad dead shellfish. He also said that a chemical-like smell was present.
The word is out amongst the fishing community, which means that the income derived from visiting anglers who utilize several fishing camps will be severely impacted due to the persistent rumours that the shores of the Gulf are polluted.All levels of Government need to act now to find the realfacts –climate change or pollution - to set our minds at rest.
There are also rumours of a new species of shellfish; “something like a tiny limpet snail that clings to the mangroves,” has appeared in the Limmen Bight. “No one has ever seen it before, including the Indigenous saltwater people of the Gulf country. It appears to bedoing better than the native snails,” said the mate.
Another fisher whofishes the Bight on a regular basissaid the same thing. He told me that Land and Sea Rangers had taken authorities out and that samples of both dead and surviving marine life had being collected, butnothing has been heard.
Only in the last week has the NT Government acted and I believe that a scientific team is currently in the Limmen Bight doing the research that should have been done weeks ago when this disaster was first reported. A person from the NT Department of Land Resources Management said that the mangrove die-off was due to poor wet season, but he was unaware of the decimation of shellfish in the Limmen Bight and would look into it. He also stated that his department and NT Parks and Wildlife and the JCU were working on the problem but he provided no details if teams were in the area or where.
Lead pollution in the McArthur River has been well recorded.Not long ago some 400 head of cattle were shot because of high lead levels. An independent review suggested that lead levels in the river did not pose a “serious” health risk to people eating fish, but local people wereadvised “to limit their intake.”
But is there something else? Ship ballasts tanks are purged with poisons to kill all foreign marine life. Massive ore carrier discharge “foreign” water when they enter our territorial waters and “our” sea water is pumped in as replacement ballast. The tanks are cleaned on a regular basis with toxic chemicals, which under right tidal conditions may wash ashore. Decks are also washed directly into the sea after loading to get rid of ore dust. The question is did an orecarrier discharge such poisons into the Limmen Bight while taking on orefrom the Bing Bong facility?
There are reports from fishers and pilots in the area that speak of filthy cloudy water plumes tailing out from ore carriers waiting offshore to take on product from the Bing Bong ore transfer ship. Fishermen also said that a big ship was moored off Bing Bong some days before shellfish started to die. Was it the cause of the rapid decline of marine life and the mangroves kill? Surely any discharge would have been seen by a patrolling Coastguard plane and reported?
Perhaps the “new” shellfish has originated froma ballast water discharge.It isbelieved to be a South China Sea species.Should we also be concerned about the health of the Sir Edward Pellew Islands marine life…?
History
The Gulf of Carpentaria has been subjected to pollution from mining, farming, harbour dredging and industry, since the 1880s. Mass land clearing continues in QLD with soil run-off in the wet season being rampart. Only since the 1970s have there being restrictionsto stop this, but accidents continue to happen. Karumba had a mangrove-die back some years ago, but the cause was reported to be from lead fuel used in outboards by recreational fishers and the lack of a proper wet season...
Robert Pender, a Karumba-based commercial fisherman and chairman of the QLD Fishermens Portal Inc, which represents commercial fishers in the State, has a different view on the die-back and in an email on the 24/07/2016 he stated:
“I noticed the early stages of the dieback in 2014 in the lower Gulf. This has corresponded with light wet seasons. I have noticed there is no die-back in tidal waterways. If there was contamination from ballast as you mention here then we would see the evidence farther inland.
We have observed no loss of life or impacts other than dieback. And there is evidence that the mangroves are generating this year. Taxpayers could spend millions of dollars looking for a unicorn. As you know the wets have been poor for consecutive years but the cycle is predicted to return to normal.
My view is that we also see the mangroves return to normal and that by the next year the issue will just be a record. Hopefully it will not result in a windfall for people with hidden agendas in the meantime.”
Regards, Robert Pender
In the past there have been contaminated spills in the Gulf country, but even though the Gulf is one of our most important sources ofsea-food - prawns, crabs and fish - successive governments at all levelshavea poor record in preventing suchenvironmental disasters until after the fact.
Die-back of mangrove communities and marine-life kills have occurred before, with smaller kills going unnoticedunless reported by commercial and recreational fishermen, but the current kill is unprecedented.
The Limmen Bightmarine kill is too huge to ignore whilethe climate change theoryis open to question because the kill was too rapid and selective, something that Professor Duke noted when he said that nature does not kill so quickly or with such severity.
The Gulf is relatively shallow and its currents are akin to a washbowl splashed back and forward by its unique 24-hour tides. This means that drifting pollutants are washed into estuaries and onto beaches for a continuous 12-hour period before the tide turns.
Other factors are that healthy stands of mangroves still prevail in the kill zone, mostly above the high tide mark and upstream in large estuaries. If climate changeis toblamewhy are they not dead - nor does it explain the sudden high decimation of marine life on open beaches and tidal flats fringing the Limmen Bight….
Federal, QLD and NT Governments must show responsibility and send independent ground teams in to sample the water and soils instead of standing back andusing the climate change bogeyman as a handy excuse - or waituntil an early wet washes any evidence out to sea.Our food from both land and sea depends on it…
Dick Eussen is an author and freelance fishing and outdoor writer/photographer who contributes to national and international magazines. He is one of the founders of the NT Fishermens Association.