Rock Lobsters in Peril

The Tasmanian Government’s failure to act on longstanding problems associated with the rock lobster fishery not only threatens its sustainability and export accreditation, but also jeopardises the abalone fishery and the marine environment.

Tasmania’s iconic rock lobster fishery has been plagued by serious problems for many years and the Tasmanian Government is doing nothing about it. Localised overfishing, inshore fishing pressure and expanding Centrostephanus urchin barrens are longstanding problems. Since 2008, recruitment failure, that is the failure of juvenile rock lobsters to grow and survive to become part of the legal sized fishery stock, has amplified the other problems.

Centrostephanus barrens arguably pose the greatest threat. These occur because fishing removes the large rock lobster that can prey upon Centrostephanus urchins, so urchin numbers explode and their grazing clears the large marine plants that are vital to this habitat. The resulting urchin barrens do not support significant numbers of either rock lobster or abalone, so both these important fisheries are excluded. The environmental impact is devastating, as once productive reefs areconverted into underwater wastelands.

As a regular diver along Tasmania’s east coast, I have observed that urchin barrens are rapidly expanding and we are running out of time to deal with this problem. The last five years has seen a great expansion in the numbers of incipient barrens, which are likely to multiply and become full-blown barrens in the near future. We do not have five or ten years to manage this problem. If urchin barrens continue to develop at this rate and something is not done right away, we can say goodbye to very large areas of reef along the east and south-east coasts during the next five years.

Suggestions by the fishing industry that culling or a commercial market for Centrostephanus urchins are solutions have so far failed to withstand scrutiny. The size of the potential market and time/cost contraints appear to make this impractical. An even more difficult barrier is created by the practical difficulty for divers operating in depths greater than 15m to 20m. At best, culling and a commercial market may be useful in certain limited areas, but will not have a significant effect on the east and south-east coast under current circumstances.

The real key to solving this problem is increasing numbers of large rock lobster to somewhere in the order of 0.1/100m2. While this is much lower than normal densities of large rock lobster (densities in the Maria Island Marine Protected Area are approximately 1.0/100m2), experimental work indicates that this density is likely to protect reefs from further encroachment by urchin barrens and gives them a chance of recovery.

It is interesting to note that a recent scientific (IMAS) report indicated that the only single management option that would achieve densities of large rock lobster greater than the required 0.1/100m2 on the east coast is a complete closure of the east-coast fishery for somewhere between five and 10 years. The TCT believes that a more targeted approach would be better, but if nothing is done soon then this may be the only viable option.

Reducing the total allowable catch (TAC), introducing maximum size limits (to protect the large rock lobster that are able to prey on Centrostephanus urchins), temporary area closures to allow reefs to recover, directing fishing activities to reduce pressure on critical areas and the introduction of area management for the fishery are all options that could be part of the solution. These should have been considered as part of the just-completed statutory five- year review of the rock lobster fishery. Instead, some essentially meaningless reductions in TAC and recreational bag limits have been introduced and other options have been put off for consideration at some indefinite point in the future.

A reduction in commercial TAC and recreational bag limits might seem like a good idea, but the cuts proposed so far will barely, if at all, reduce the catch to below the amount that would be caught if there were no limits at all. A basic fisheries management principle is that a catch limit is only a useful management tool if it actually limits catch. If it doesn’t, it is analogous to starting out with a speed limit on the Midland Highway of 500kph, then reducing it to 250kph in an effort to reduce the road toll. The constraint is meaningless as no cars can reach either limit.

In Tasmania's rock lobster fishery, the catch over the years has clearly led to serious problems, such as urchin barrens. The actual commercial catch in every season since 2008–09 has been significantly below the limit imposed by the TAC and has therefore not been constraining. Changes to recreational bag limits have also simply reflected the normal catches taken by average recreational fishers, so once again management tools are not limiting catches to a level below that which can be caught and which has clearly led to problems.

This year, for the first time since 2008, there is a chance that the greatly reduced TAC may put a limit on the actual commercial catch, but it will be a close-run thing, and if it does reduce the catch it will not be by much. The limit will certainly not be enough to address problems such as inshore fishing pressure or Centrostephanus barrens.

What all this means is that, since 2008, the Tasmanian Government has, in effect, made no management decisions that would lead to an actual reduction in catch or deal with any of the major problems associated with this fishery.

This would be bad enough if the only thing to suffer were the rock lobster and its associated commercial and recreational fisheries. Unfortunately, the marine environment is also severely damaged and the abalone fishery is excluded along with rock lobster from areas where urchin barrens become established.

Just to be clear, the Tasmanian Government has allowed, and continues to allow, the rock lobster fishery to operate at a level that not only destroys the environment upon which it depends, but turns once productive reef into wasteland and threatens Tasmania's valuable abalone fishery.

This is a truly bizarre situation. It seems that the process of fishery management has been paralysed by the enormity of the problems. So far, it seems that the management response has been ‘let’s do nothing and see if that works’.

Complicit with the Tasmanian Government is the commercial rock lobster fishery. I am sure that there are many commercial fishers who are as concerned as I am, but there is no doubt that many have lobbied hard to prevent meaningful changes being made. Representatives have repeatedly rejected the introduction of area management at a scale that would assist in dealing with the main problems, and the peak body, the Tasmanian Rock Lobster Fishermen's Association, recently voted to support a one-year moratorium on any further reduction in the commercial catch.

A possible circuit breaker to all this is the need for the commercial fishery to get export approval under the Environment Protection and Biodiversity Conservation (EPBC) Act. As almost all (90%) of the Tasmanian rock lobster catch is sold into China (mainly via illegal imports, but that is another story), a failure to get EPBC export approval would be devastating. EPBC export approval requires a reviewevery five years to ensure that the fishery is managed in an ecologically sustainable way.

It is clear that the Tasmanian rock lobster fishery is not currently being managed in a sustainable way. Current management not only threatens this fishery itself, but also he marine ecosystem and Tasmanian abalone fishery.

There is currently a Commonwealth review of this fishery, with public submissions closing on 7 December 2011. It is to be hoped that critical Commonwealth Government scrutiny of the rock lobster fishery, together with the threat of halting exports, will motivate the Tasmanian Government to take meaningful action to protect the fishery from itself as well as the abalone fishery and Tasmania's marine environment.

Doing nothing for another five years is not an option if we wantviable rock lobster and abalone fisheries along the east and southeast coasts, and a marine environment in that region that is not devastated by urchin barrens.

Jon Bryan
Tasmanian Conservation Trust