It's funny how good scientific research often provides insights into issues that were not the original subject of study.

A case in point is the research that has been carried out in and around the Maria Island marine reserve since it was declared in 1992. This research was primarily aimed at determining the effectiveness of marine reserves. The last issue of this newsletter reported on this research, and pointed out that fish numbers have dramatically increased in the section of the reserve that is protected from human fishing activities (Edgar & Barrett, 1999).

Now for something completely different.

It seems to me that every couple of years some angry fishermen gets up and blames poor fish catches on the Australian fur seal. Claims of a population explosion of seals are usually thrown in, and demands for a cull or other extreme measures usually follow, along with a series of letters to the editor.

The lack of evidence for any population explosion, despite rigorous scientific surveys, has meant that claims of seals reducing fish populations have been met with justifiable scepticism. Unfortunately, it has always been difficult to separate the impacts of humans and seals on local fish populations, and disprove the assertion that seals are to blame for declining numbers of fish. And one thing everyone agrees on is that fish numbers are falling.

Luckily, the creation of a marine protected area at Maria Island and research associated this reserve has provided a new source of evidence that can be used to answer this question once and for all.

Research based around the Maria Island marine reserve clearly indicates that blaming the seals for poor catches is totally unwarranted.

The huge increase in fish numbers within the Maria Island marine reserve is a definite indicator that human fishing activities are to blame for reduced fish numbers, and not the normal hunting activities of seals.

After all, seals don't use maps and are not excluded from the reserve. Their fishing activities continue on as normal, while human activities are largely excluded. Despite the hunting activities of seals continuing in the Maria Island Marine Reserve, the stocks of fish have increased enormously.

So we can't use seals as a scapegoat any longer. The management of Tasmanian fish stocks is purely a human responsibility.

Jon Bryan
jonbryan@southcom.com.au

Reference
Edgar, G. J. & N. S. Barrett. 1999. Effects of the declaration of marine reserves on Tasmanian reef fishes, invertebrates and plants. Journal of Experimental Marine Biology and Ecology 242: 107-144.