GREAT BARRIER REEF: by Peter WestmoreNews Weekly
Science and the shutdown of our tropical fisheries
, April 30, 2011
Why are state and federal governments closing down substantial areas of Australian waters to commercial and recreational fishing, forcing consumers to rely increasingly on imported seafood from over-fished areas of the world?
The largest single protected area is the Great Barrier Reef, which is administered by the Great Barrier Reef Marine Park Authority.
The GBRMPA argues that fishing on the reef must be curtailed in order to preserve biodiversity and prevent damage to the reef. A number of academic studies have been produced to support these claims, which are also backed by environmental organisations such as the World Wildlife Fund and the Australian Conservation Foundation.
Last year, these claims were supported by 21 researchers from the Centre for Excellence in Coral Reef Studies at James Cook University, Townsville.
Their report claimed that since the expansion of no-take zones on the Great Barrier Reef in 2004, there had been “major, rapid benefits … for targeted fish and sharks”. It said, “Monitoring has documented very fast and sustained recovery, with up to two-fold increases in both numbers (of coral trout) and size of fish on many no-take reefs”.
Professor Walter Starck, a world expert on tropical fisheries, examined the report in detail, and found that its claims were unjustified. He said the detailed information in the report showed that only one of the eight reefs featured in the report showed a two-fold increase in coral trout numbers, and this reef had the lowest number to begin with, and the lowest difference between fished and unfished reefs.
He also pointed out that the 21 marine scientists who contributed to the report were all engaged professionally by the Great Barrier Reef Marine Park Authority and were recipients of “generous funding” from the authority. Hence they could not claim to be undertaking independent research.
None of the authors disclosed their link with the GBRMPA in publishing their research.
Professor Starck said that the 2010 study also contradicted earlier, comprehensive studies of the effect of excluding fishing from the Great Barrier Reef.
A 1997 study by Dr Tony Ayling, a marine biologist from north Queensland, examined long-term trends in reef fish abundance in the Great Barrier Reef World Heritage Area. It covered a period of about 11 years. He asked, “Is the protection that has been afforded some reefs by Marine Park zoning preventing overall coral trout numbers from declining in the face of continuing fishing pressure?”
Dr Ayling concluded, “Counts that have been made on protected and fished reefs since 1986 suggest that this is not the case.”
Professor Starck also cited a study by Dr Russ Babcock, published last year in the prestigious Proceedings of the National Academy of Science, which examined areas subject to much greater fishing pressure than that on the Great Barrier Reef. He concluded that the effects of marine protected areas were “decidedly less large, rapid, extensive and uniformly positive” than those reported for the Great Barrier Reef.
Another recent report in the New Scientist magazine by Wendy Zukerman, claimed that “carbon dioxide has pillaged the Great Barrier Reef of a compound that corals and many sea creatures need to grow.” (New Scientist, April 16, 2011)
Zukerman stated, “The finding, from the first survey of ocean acidification around one of the world’s greatest natural landmarks, supports fears that the ecosystem is on its last legs.”
She claimed that “oceans become acidic when they absorb CO2 from the atmosphere”.
In fact, sea water has a pH of over 8, meaning that it is alkaline and would require a net 10-fold increase in its acid content to make it chemically neutral.
Even more importantly, sea water is a complex “buffered solution”, meaning that its chemical composition automatically resists changing its acid-base balance.
Therefore, increasing levels of CO2 in the atmosphere — which dissolves in water to form carbonic acid (H2CO3), a weak acid — will have little or no measurable effect on the alkalinity of the ocean.
Further, she claimed, “Once dissolved [in sea water], the gas [CO2] reacts with carbonate to form bicarbonate.”
In fact, CO2 dissolves in water to become carbonic acid, which then dissociates to form hydrogen ions (H+) and bicarbonate ions (HCO3-), without any involvement of carbonates at any point.
Zukerman’s lack of scientific knowledge was shown in her conclusion: “Bizarrely, the reef doesn’t appear to be suffering from the effects of ocean acidification just yet.”
Because the ocean is a mildly alkaline, buffered solution, it is not in the least surprising that the Great Barrier Reef “doesn’t appear to be suffering from the effects of ocean acidification”.