By David Cook, Wonga Beach
They live in what should be one of our richest and most productive ecosystems, but their numbers are heavily depleted and their plight is too often ignored.
It suddenly dawned on me just recently, they are in trouble mainly because they are not visible to us when they are in their natural ecosystem. They are out of sight and out of mind but they are still very much at risk.
Yes, we are talking about the only wildlife we still intensively hunt to eat, namely fish: in this case our iconic inshore and estuary species.
Unlike the well-known fish of our coral reefs, these species live in muddy waters so we cannot photograph or video them in ‘real life’. Out of sight, they are out of mind and largely ignored by the general public. There are no Nemo equivalents in Trinity Inlet!
Highly efficient but relatively unselective gillnets are set at night, quite legally, even in ridiculously small waterways such as Cairns’ Thomatis Creek and Packer’s Creek in Port Douglas. The netters target breeding aggregations or ‘runs’ of several species that spawn outside the barramundi closure. This is something that is widely regarded by authorities elsewhere as a ‘high risk’ activity – not to the netters, but to the survival of species!
Gillnets in inshore waters can also pose a risk to other large iconic marine wildlife including our dugong and endemic snub fin dolphin, a dolphin with a penchant for estuaries and shallow, muddy inshore waters.
I am all for fishing, both recreational and commercial, but it must be done sustainably. By law, under the EPBC Act, all fisheries from which product is exported must be “managed in an ecologically sustainable way”.
Government has even produced the ‘Guidelines for the Ecologically Sustainable Management of Fisheries’ to help determine whether given fisheries should be certified as sustainably managed.
A few of us have reviewed Queensland’s gillnet fishery against these guidelines. We consider it fails to meet the requirements of all 17 guidelines (see our “Review of Concerns …” on the Fishers for Conservation website, www.ffc.org.au/Grey_Mackerel.html).
I look forward to continuing to work with community and local organisations to address the very real risk of loss of uniquely adapted populations of large iconic species of inshore fish and the possible local extinction of our few remaining dugong and inshore dolphins.
A 96 cm female grey mackerel, one of several inshore species having philopatric (remain near or return to their birthplace) populations at risk from under-regulated gillnetting of spawning aggregations in the inshore GBRMP
Our large inshore fish species:
- Key species reach over a metre in length and include king threadfin, queenfish, jewfish, barramundi and grey mackerel.
- Populations may have been genetically isolated for thousands of years so natural selection has ensured each is uniquely adapted to its own home range. Locally impacted populations are not replenished by individuals travelling from other areas.
- Many species have well defined and predictable communal migrations to traditional breeding grounds. People who are licensed to harvest these animals can use intimate knowledge of the seasonal spawning migrations of these species to overfish these populations.
- Making matters more complex from a management perspective, some species have a rather unusual life history. Individuals first mature and live as males for several years, growing all the while until, in at least two species, they reach a size of almost a metre. Should they survive long enough then they change sex and live out the rest of their lives as females.
- These protandrous hermaphrodites (males become females) are the species most at risk from what many consider to be the under-regulated gillnet overfishing of Queensland’s inshore estuary and associated turbid water ecosystems.
