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Grey mackerel sustainably fished!???

by David Cook Wonga Beach

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These are the final words in the chapter on fishing for grey mackerel in Ralph De Lacey’s book ‘The North Queensland Fishing Eldorado’ published in 2005. The author spent years as a commercial gillnet fisherman in North Queensland. The book is factual and well worth a read. De Lacey describes the grey mackerel gillnetting fiasco that occurred from 1969 to 1971 out of Bowen. He records the legacy of unmanaged gillnet fishing of grey mackerel to serve as a stern warning to anyone with an interest in our coastal fisheries. Those chilling words, “The Greys never returned” instantly sprung to my mind when I learned our Fisheries Minister, John McVeigh, announced last month that he had changed the declared status of the east coast fishery for grey mackerel from ‘undefined’ to ‘sustainably fished.’ There is a very strong political incentive for all species in our fisheries to be, at least on paper, certified as ‘sustainably fished’. This is because for an export permit to be issued for any Australian fishery, the law requires that fishery to be ‘managed in an ecologically sustainable way’. There may well be a big difference in meaning between the two terms, depending on the definition of ‘sustainably fished’. You can imagine a fishery under nil management and with huge resources. If only a few people are fishing it, under the most basic of definitions, it may well be declared ‘sustainably fished’ even if the fishers are breaking all the guidelines that our federal government has set for the ecologically sustainable management of fisheries. I am concerned that something similar is happening in the modern day grey mackerel fishery. But first, let’s see what we can learn from the Bowen experience of 40 years ago. Collapse of the Bowen grey mackerel De Lacey records that a huge school of grey mackerel used to gather at Rayward’s Reef, near Bowen, every year between mid June and early September. By 1968 numbers of boats trolling for the greys had reached over 20. He recalls that the “fish caught when they first arrived had partially formed roe and when they departed (in early September) this roe was fully matured.” People were uncertain whether the fish spawned locally or moved off to spawn nearby. De Lacey says up to and including 1968 the line trollers could catch all they could handle and many up-graded their catching, handling and freezing facilities. In 1969 one fisherman started using gillnets. De Lacey writes (then) “... We all acquired nets and bigger freezers... The shift from line fishing to net fishing ... created many problems for the Bowen fishermen. ... it was possible to catch a tonne or more fish in an hour... the biggest problem was not catching them, it was filleting and freezing them.” Apparently by early September 1969 the fish were almost ready to spawn, “and as usual they all disappeared at once, as if on cue.” When the greys arrived back on 16 June 1970 they were met by even more mackerel gillnetters than previously. He states “By early August there were miles of nets permanently anchored across this small reef” catching huge amounts of greys. Then, from mid-August 1970, for the first time ever, no more mackerel were caught for the rest of the season. In June 1971 when greys arrived back on Rayward’s Reef, De Lacey records there were so many gillnetters waiting for them that he jokes “every piece of net in NQ was set across Rayward’s reef”. The fishing lasted just 20 days before catches fell to zero and “The greys never returned.” Apparently no large schools of greys returned for the next 30 years or more. De Lacey concluded that the greys had simply learned to avoid the area. Recent findings by a fish research team, led by fish biologist, David Welch, indicate a far less obvious explanation is actually more likely. Welch and team have debunked, once and for all, the claim that a single population of grey mackerel migrates up and down the entire Queensland coast. The team found that there are significant differences in the chemical composition of the otoliths (ear bones) and also the species of body parasites between grey mackerel caught around Townsville and those caught around Mackay. This indicates there are at least two separate, non mixing populations of greys on the east coast, each returning to their own home ground to spawn. This is a common, though often overlooked feature of many fisheries, known as philopatry. Fisheries managers who overlook this feature place entire local populations of certain species at risk of long-term or permanent depletion, much to the disadvantage of local communities. Allan Petersen of Home Hill, as a 20 year old back in the 1960’s, was shown how to rig his mackerel lines by Ralph De Lacey. He has fished the area ever since. Allan provided me with a signed statement recording his fishing for mackerel in the area. He confirms greys were virtually absent from the Bowen area after the collapse until 1983 when he began to get one or two in several days mackerel fishing each season. Prior to the collapse he used to catch around 10 greys in just two hours trolling. Much has been written about serial depletions of fisheries around the world involving philopatric populations. Experience suggests it is quite likely that the local grey mackerel population of the Bowen area was simply wiped out by the unrelenting pressure of too much gillnetting. In recent years, I am informed, some sizeable catches of greys have been made out of Bowen. Were these from Reywards Reef? I do not know, would anyone familiar with the fishery please let us know? There are concerns from other areas that netting has been responsible for local depletions of grey mackerel, e.g. Keppel Bay from 1987 and more recently in Llewellyn Bay near Sarina, and Douglas Region, both 2006 – 2007. For the whole story on the near collapse of the Douglas fishery see www.ffc.org.au. Anyone aware of any other similar collapse, please let me know. GBRMPA Vulnerability Assessment Love them or hate them and their Green Zones, some people in GBRMPA are doing some great work. On their website you can find what they call a ‘Vulnerability Assessment’ (VA) of grey mackerel stocks in the GBRMP. Their Grey Mackerel VA notes that fishing of spawning aggregations as a high-risk activity and recommends the potential impacts of targeted fishing of grey mackerel aggregations be considered in any stock assessment of the species. Their VA notes there are further indications there may also be other smaller local populations at the “embayment scale”. It recommends the possible existence of other local populations should be considered when undertaking stock assessments and the risk of localised stock depletions be taken into account. It also recommends the continued development of fishery management processes that engage stakeholders at a local or regional scale: spot on! The VA recommends regional management of fishery stocks to address “the separate and distinct stocks of grey mackerel that are becoming apparent”. GBRMPA summarises that grey mackerel on the east coast are “highly exposed and highly sensitive to commercial fishing having a high residual vulnerability when spawning aggregations are fished commercially.” Fancy language aside, GBRMPA are spot on with this assessment! How can our Fisheries Minister ignore these crucial findings? Poseidon ARM Scoping study A scoping study of the Douglas Shire grey mackerel fishery was undertaken in 2008 by independent international fisheries consultant, Richard Banks, Director, Poseidon Aquatic Resource Management Pty. Ltd. This is available at www.consult-poseidon.com/fishery reports. The study concludes that “the management authorities ... are required by Law ... at the very least to undertake a participatory risk analysis evaluation ... it would point to significant concerns in respect to commercial gill netting in the Douglas Shire area, and damage to economic well being of the local economy if left unchecked. There is therefore no reason to wait for scientific evidence to demonstrate that a management problem exists ...” NSF Review of Concerns In 2010 co-ordinators of the Network for Sustainable Fishing compared the performance of gillnet fisheries in the GBRMP against the 17 ‘Guidelines for the Ecologically Sustainable Management of Fisheries’ published by the Federal Government. The fishery fails all 17 guidelines! This report is also available at www.ffc.org.au. The greatest risks are posed by the big offshore gillnet boats and other roaming netters that travel up and down the coast looking for aggregating schools of pre-spawning species like grey mackerel, threadfin and fingermark. The sustainable alternative is to stay on their local patch and carefully match their catching efficiency to the productivity of local resources. Request to Minister McVeigh I wrote to Minister McVeigh and Fisheries Queensland on 22 July in far more detail than space allows here, regarding the minister’s recent statement on the grey mackerel fishery. So far I have not received any explanation. Given the overwhelming evidence to the contrary, Minister McVeigh, would you please explain to us all why your advisers consider the grey mackerel fishery to be ‘managed in an ecologically sustainably way’. We also wish to be informed as to who provided the advice and whether they have any formal qualifications in fish stock assessment or fisheries management? And, never to miss a good opportunity, may I also ask, with respect, if you have been advised about Queensland’s pressing need for regional management of our inshore commercial fishing industry and the need to halt roaming and part-time commercial fishing? David Cook: davecook@bigpond.com 13 August 2013

 

Photo 1: Grey mackerel have proportionally larger tail, anal and dorsal fins and a deeper more tapering profile than other mackerel caught in North Queensland; note also the slightly concave forehead.

Photo 2: Daughter Tanya with a fine Douglas Region grey. Small local populations of greys are a valuable community resource and should not be at risk from boom and bust gillnetting. “The Greys never returned”.