Gladstone Fish Health Investigation 2011 - 2012 - Western Basin ...

fish health, it is unlikely that they were associated with the fish health issues in GladstoneHarbour. Overall, there is no strong evidence of a link between observed fish health at thetime of sampling and tissue residue concentrations.Mud crabsThe monitoring program collected information on catch composition (size and sex), presenceand severity of observed shell damage and abnormalities, as well as commercial catchinformation supplied by crabbers via commercial logbooks. This information was comparedwith historical data sets when possible to provide perspective.Sampling sites for mud crabs during Phase 1 included the Narrows, Port Development Area,Calliope River, South Trees Inlet (joins the lower reaches of the Boyne River), Rodds Bayand the Fitzroy River (reference site).Sampling sites for mud crabs during Phase 2 included the Narrows, Port Development Area,Hamilton Point, Calliope River, Rodds Bay, as well as the Fitzroy River and Bundaberg(reference sites).Commercial catchThe commercial catch of mud crabs in the Gladstone region between 2000 and 2012hasvaried, with the highest catch recorded in 2003 (163.11 t) and the lowest catch in 2012(67.65 t). In 2011, 112.66 t was landed, the fourth highest catch in the period (Figure 15).Weight (tonnes)180160140120100806040200Commercial mud crab catch for the Gladstone region2000 - 20122000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012YearFigure 15. The annual catch of mud crabs from the Gladstone region (CFish grid S30), as reported incommercial fisher logbooks (calendar years 2000 – 2012).Commercial fishing effort for mud crab in the Gladstone region (days fished with mud crabcatch recorded) closely follows the trend in catch, with peaks in catch corresponding withpeaks in fishing effort (Figure 16). Logbook data supplied by commercial fishers for 2012showseffort and catch has reduced from 2010 to a level similar to the period 2006 to 2008.37