AUSTRALIA: Grey Mackerel

line fishery failed in World Heritage Waters of Far North Queensland

In 2006 this newsletter reported that a pre-spawning aggregation of grey or broad-barred mackerel (Scomberomorus semifasciatus) was being targeted by commercial offshore netters in sheltered, inshore World Heritage Area waters of the Great Barrier Reef Marine Park (GBRMP) in Far North Queensland (FNQ).

In 2007, the May issue reported calls by local commercial line and recreational fishers for an emergency closure of the netting on sustainability grounds because of an apparent sudden drop in size of schools and very poor catches. During the 2008 season, the use of echo sounders by the leading commercial line fisher failed to locate any schools of grey mackerel for the first time ever. Commercial line catches fell from 500 - 800 large fish per season prior to 2004 to under 40 fish per fisher. The net boats did not return that year and the lead fisher was forced out of the fishery and sold his mackerel fishing licence back to government. A documented case study is available on the website of Fishers For Conservation, http://www.ffc.org.au/Grey_Mackerel.html.

Local commercial line and charter fishers have also noted a big drop in catches of other large inshore species and consider that the big net boats, using up to 1.2 km of hydraulically hauled monofilament nets, are just too efficient for a coastline where the longest river in the area is only 120 km in length, the watershed of the coastal catchment often falls within 7 km of the coast and mangrove systems are relatively small. These fishers are concerned that other inshore species, which also do not have any spawning closures, are suffering a similar fate to the more visible grey mackerel schools.

The Federal Government carried out a review of Queensland’s fishery management, published online in November 2008, see: http://www.environment.gov.au/coasts/fisheries/qld/east-coast-finfish/index.html. This review notes: p 66, “A serious lack of validated and species-specific data on the fishery catch means there is very limited knowledge of the sustainable levels of catch for most species. ...... the Panel has concerns over the level of precaution being adopted ... and, p72: “depletions are not always obvious when fishery “assessments” are based on aggregate (species) data, as they have been ... Yet in schooling species with local residency and/or those that form seasonal spawning aggregations, the risk of localised depletion is high (e.g. grey mackerel ).

The international fishery consultancy company, Poseidon ARM Pty Ltd, undertook a scoping study last October of the processes for establishing management arrangements for the inshore grey mackerel fishery, using the best available evidence. Their report, available at www.consult-poseidon.com/reports.asp; (Report 13), notes that in this case, “management authorities ... are required by law to apply the Precautionary Principle ...”
In March 2009 the Queensland government introduced a series of measures “in order to take a sufficiently precautionary approach to this fishery”. These include a single total allowable catch for the entire east coast of Queensland, despite at least two separate stocks having been identified during 2008. A second measure is a minimum size limit of 60 cm, despite size at first breeding being 75 cm.

Local fishers in FNQ consider that the measures introduced will be ineffective in securing a precautionary approach and, based on their history of observations, have serious concerns for the sustainability of the fishery. They are calling authorities to commission an independent participatory risk analysis of inshore fishery of the World Heritage waters of the GBRMP as a lead-in to the adoption of further, more effective, precautionary measures.

For the full story on our campaign to save stocks of grey mackerel see: www.ffc.org.au/Grey_Mackerel.html

David C. Cook
Network for Sustainable Fishing in Far North Queensland, Mossman Boat and Fishing Club
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