Charlie McKillop ABC News 10 Oct 16;
One of Australia's largest trawler operators is questioning why more is not being done to explain a mass mangrove dieback event in the Gulf of Carpentaria.
Austral Fisheries chief executive officer David Carter has welcomed a Senate inquiry into the impact of climate change on Australia's fisheries and marine biodiversity.
But Mr Carter, whose company owns 10 of the 52 boats in the $100 million northern prawn fishery, said there was mounting concern about the apparent lack of urgency being directed at the problem.
"I've been disturbed by the lack of interest in the impact of those mangrove deaths," he said.
"We've had nobody on the ground to look at what the possible cause was. We can speculate about climate change but it might be a disease event or a contamination or something, but we just don't know.
"These are really questions for the various governments to be thinking about, certainly for the industry to be watching."
International mangrove expert Dr Norm Duke — who described the scene as the most "dramatic, pronounced extreme level of dieback" he'd ever seen — admitted a lack of funding had prevented him from returning to the site since he surveyed more than 7,500 hectares of dead mangroves in June.
Preliminary findings indicated the most likely cause was a combination of low moisture due to extended lack of rainfall, rising ocean temperatures, and a drop in sea level but researchers had "reached a limit" with what could be achieved using available climate records and satellite imagery to measure impacts.
Dr Duke said mangrove dieback was a natural phenomena but had not occurred anywhere in the world on the scale or as rapidly as witnessed in the Gulf of Carpentaria.
"Imagine if that happened on the east coast of Australia, the distance from Melbourne to Sydney or Sydney to Brisbane, if we lost 10 to 25 per cent of mangroves along that coast in one month. What would be the reaction?"
"Is remote Australia somehow not as important?" Dr Duke said.
The James Cook University-based scientist was hoping a scientific paper he had written would soon be published to further amplify the case for urgent action.
"We'd like to be able to survey the entire shoreline and we'd like to look at the water quality in the estuaries to ascertain as to why there were differences in different river catchments," he said.
"What we discovered in the mapping was a considerable variation in the degree of, or severity of, the dieback in some rivers but not others across that 1,000 kilometres.
"It would make sense to look at why, of if there was any correlation with that pattern of dieback."
Senate inquiry to examine impact of climate change on fisheries
Mr Carter said the Senate inquiry initiated by the Greens into the impact of climate change on Australia's marine biodiversity would help the government to focus on what was at stake for the industry.
"The fishing industry, and I think agribusiness generally, is really at the forefront of those changes and really needing to adapt, one way or the other," Mr Carter said.
"You marry our mangrove dieback experience with the coral bleaching events, disappearance of kelp beds along hundreds of kilometres of the West Australian coastline, migration of warmer water species down the east coast further south in response to warming temperatures and you've got quite a lot of changes that are going on that are indicators really of climate change in action."
But Dr Duke said the issues were "bigger than fisheries" and it was disappointing the intense media attention sparked by initial reporting of the mangrove dieback had not translated to specific funding commitments.
"I mean where else has this sort of dieback happened?" he said.
"If it wasn't for people like fishermen on the ground who had reported it to us, then we probably still wouldn't know.
"That's not really the way to be doing shoreline monitoring if you're talking about these things."
