On Friday 21 July 2023, I attended Cooloola Coastcare’s barbecue at Crab Creek Park at Tin Can Bay. I reflected on all the issues we discussed over the barbecue such as the long slow decline of seagrass in Tin Can Bay and Cooloola Inlet. 

As with many of us who are now active in the environment movement, most of the people at the barbecue have relocated to the Great Sandy in the last couple of decades.  I only moved to Maryborough in 2002 and can only imagine how good the environment was decades ago.  However, at least one person was able to recall their observations of K’gari and Cooloola from several decades ago. 

Decades ago, there were no golf courses around Cooloola, leaching fertilisers and herbicides into the groundwater and running out to the inshore waters.  Decades ago, there was no stench of sewage treatment at Inskip Point, and no sewage treatment plants also discharging nutrients into the waters.  Decades ago, there were still bêche-de-mer, sea cucumbers, that had not yet been strip-harvested by commercial fishery licence holders.

I expect seagrass meadows benefit from the presence of sea cucumbers, which harvest nutrients from the sediment and beneficially bioturbate the sediment as they dig through it.  As any gardener who turns over their compost heap knows, bioturbation is a great boon for soil health.  In fact, it is thought that complex life only really started to progress after the Cambrian Period, when plants developed roots and animals became large enough to start digging through and thus turning over the mud.

Bêche-de-mer strip-harvesting occurred around the same time that a commercial fishery licence holder attached a brigalow-clearing metal ball and chain to a couple of tugs and flattened the corals of Hervey Bay so that he could strip-harvest the fish without snagging his trawl nets.  Since then, Hervey Bay corals and fish have been decades recovering to their present state, where their further recovery is limited by being smothered under sediment exported from the deforested Mary Basin during flood events.

Maintenance of sea cucumbers in adequate numbers could be of potential benefit to Great Sandy ecosystems, as would Hervey Bay corals, and oyster and mussel beds throughout.  If, however, nutrient runoff from golf courses and residential gardens, sewage treatment plants and municipal garbage tips are too high then ecosystem restoration will be constrained. 

At the barbecue, it was also proposed that funding for water sampling and chemical analysis would help inform decision-makers.  As with sand disturbance by vehicles on K’gari and possibly in Cooloola, one wonders if our decision-makers want to be informed?

Article contributed by David Arthur, Wide Bay Burnett Environment Council

Bêche-de-mer Fishery Information
The commercial sea cucumber (Bêche-de-mer) fishery area consists of all tidal waters east of longitude 142°31’49″E between latitude 10°41’S and latitude 26°S (parallel to the southern limit of Tin Can Bay). In practice, however, waters south of the Great Barrier Reef are rarely fished. The fishery operates under the fishery symbol B1.
Major commercially harvested sea cucumber species include:
·       black teatfish (Holothuria whitmaei)
·       white teatfish (Holothuria fuscogilva)
·       burrowing blackfish (Actinopyga spinea)
·       various other sea cucumber species.
 Sea cucumbers are harvested mainly by divers breathing surface-supplied air from hookah equipment and, to a lesser extent, by free-diving from dinghies or by hand collection along reefs at low tide.
The fishery imposes species-based catch limits and due to their potential vulnerability to depletion, black teatfish (Holothuria whitmaei) has a quota of zero on all licences. White teatfish catch is limited by condition of licence. Collecting sandfish is prohibited in Hervey Bay.
Fisheries Queensland monitors other species in this fishery by performance measurement systems.