GPC: Seagrass is Flourishing in Gladstone Harbour (Australia)
Despite a major dredging project in the Gladstone harbour, an independent seagrass study conducted by James Cook University has found the Gladstone harbour is one of the few locations along the developed Queensland coast where seagrasses have shown recovery since the 2010/11 floods.
Gladstone Ports Corporation (GPC) CEO Leo Zussino said the results from the November 2012 survey found the total area of seagrass mapped in the Gladstone Port had increased since November 2011 and was the broadest distribution mapped since November 2009.
“Despite over 14 million cubic meters of dredging taking place in the Gladstone Port between November 2011 and November 2012, this independent scientific study confirms our impact on the environment in the Gladstone harbour has been minimal.
“The Western Basin Dredging and Disposal Project was required by the Australian and Queensland Government to minimize impact on seagrasses which are the major food source for turtles and dugongs. This was achieved through detailed environmental monitoring and engagement of world leading dredging equipment which cost the project an additional $250 million.
“The report states that not only have dugong feeding trails been found in areas previously not thought to be used by dugongs, but there has also been an overall increase of approximately 718 hectares of seagrass meadows in the Gladstone harbour.
“The strategy has worked and verifies that sustainable port development can continue in the Gladstone harbour,” Mr Zussino said. The report by James Cook University’s Centre for Tropical Water and Aquatic Ecosystem Research details the findings of the November 2012 seagrass monitoring survey of Port Curtis and Rodds Bay.
The survey incorporated the established annual seagrass monitoring program for Port Curtis as well as additional seasonal mapping of seagrasses within the entire Western Basin region of the Gladstone Port. Additional mapping has been conducted bi-annually since 2009 as a part of increased monitoring for harbour expansion and dredging programs.
The report states: ‘large scale declines in seagrass distribution and abundance have been reported throughout the north eastern coast of Queensland over the past several years. Declines in Cairns, Mourilyan, Townsville and Abbot Point as well as in Gladstone have been principally attributed to regional, rather than local drivers of change including heavy rainfall and severe flooding events.’
“This report by James Cook University backs up the evidence from the most respected scientific body in Australia, the CSIRO, who stated in 2012 and again in 2013, that the Gladstone harbour is a healthy harbour compared to most industrialised harbours around the world,” Mr Zussino added.
Key Findings of the report:
• Seagrass meadows in the Gladstone Western Basin showed signs of recovery with increases in area and density of meadows following several consecutive years of reduced distribution and abundance;
• Mean biomass of seagrass had increased in each of the six regions from 2011 to 2012 with significant increases in five of the fifteen monitoring meadows;
• Dugong and their feeding trails were observed in the Western Basin region in areas where they have historically been present, as well as for the first time in the South Trees Region providing positive signs of recovery;
• Gladstone is one of the few locations along the developed east coast of Queensland where seagrasses have shown recovery in 2012;
• Despite these positive signs of recovery, several consecutive years of decline have likely left seagrasses with a reduced resilience to further impacts and it may take some time for meadows to reach pre-flood (2009) levels.
Press Release, July 5, 2013