Marine Reserves: Spreading the idea

Forest and Bird, Volume 20, Issue 4, 1 November 1989, Page 13

Marine Reserves: Spreading the idea

by

Russell Joyce

ae UNIVERSITY marine biologist Dr Bill Ballantine likes to tell a story about the Leigh Marine Reserve where he lives and works, 100km north of Auckland. The heavy concentration of marine life which has chosen the five square kilometre reserve as home attracts thousands of people a year. Occasionally some of those visitors ask him how the university can afford all the bright buoys which mark the reserve’s perimeter. Dr Ballantine is happy to explain: the buoys are proof that the 10-year-old marine reserve works. In fact they are tied to crayfish pots carefully placed around the boundary by commercial fishers who know that the Leigh reserve holds the greatest concentration of crayfish anywhere in the area. It's not that the coastline habitat is anything special, he says. Its just that nobody has been allowed to catch or kill anything there for ten years. It now reflects what the rest of our coastline could be like without human interference.

Startling Results

An Auckland University student recently spent a year diving at Leigh, studying crayfish and comparing their numbers with those outside. The startling results showed crayfish

numbers to be 20 times greater than in similar surrounding shorelines. "That's not twenty percent more, that’s 2000 percent more," Dr Ballantine emphasises. The numbers are still rising and the weights are greater than elsewhere. "Nobody had predicted this when Leigh was set up. In fact if we had made a prediction it would have been that the reserve would have made no difference to crayfish numbers. "What we knew about crayfish was that they hatch into larvae and drift off in currents for up to 18 months. They're extremely unlikely to end up where they started. "What we found at Leigh was that the adult crayfish don’t migrate. They stay and, because nobody is touching them, they build up in numbers. And that’s fairly shattering because it suggests that what we've been doing in the rest of the country is not very sensible and the programmes our fisheries management are based on are not even true. "You would think the crayfish at Leigh might be overcrowded — they aren’t. You might think that they are short of food and slower growing, but they aren't. And it's not only the crayfish which have benefitted from the reserve, Dr Ballantine says. Snapper abound in great numbers while

the red moki population is estimated to be about 250 percent greater than elsewhere.

Reserve Advocate

Dr Ballantine does not hide the fact that he is pro-reserves. His aim is to see ten percent of New Zealand's coastline turned into protected marine areas. "I’m pushing for more reserves. I live next to one and I think its pretty good. The question is do we just want one — like you have one set of crown jewels — or is there some point in spreading the idea elsewhere?" Presently the Department of Conservation (DOC) is contemplating setting up such reserves around the country. The Royal Forest and Bird Protection Society has embarked on a campaign to see Bill Ballantine's dream come to fruition. Already it has proposed a reserve for Waitemata Harbour’s Pollen Island -a feature of the marine reserves legislation is that organisations other than the Department of Conservation can nominate areas for reserve. These days Dr Ballantine is often called on to speak at public meetings and disarm the often angry commercial and recreational fishers with his arguments and proof. Part of that argument revolves around those crayfish pot buoys. It would be hard, if

not impossible, to find a commercial fisher around Leigh who objected to the reserve now, he says. Many claim fishing has actually improved since it was set up. Dr Ballantine sees the reserves as potential nurseries and "stud farms" for future commercial harvests. Snapper serve as his example. "In Leigh reserve large snapper are now common. These big fish are home ranging and they don’t move round much, so they don’t waste energy that way. They don’t grow very fast at this stage and they've got big heads and jaws so they can easily munch up high protein foods like kina — so where does all this high grade energy go to? Into reproduction. "This relatively small number of large fish, putting all their energy into reproduction, will be producing a disproportionately large number of the next generation — at least they would if they were allowed to exist. "But these fish, because they are close to shore and home ranging, are the easiest to catch and the first to go," he says. In a country internationally renowned for its first class land reserves, Dr Ballantine finds

it hard to understand why this can happen, why it has taken so long to extend the reserves concept to our coastal waters. "Our birds are protected, including the marine birds, when they come in to shore. We have legislation to protect their nests but we don’t move to provide them with food. In the sea they take their chances along with everyone else. "We have totally protected our marine mammals — but only against deliberate killing. Hector’s dolphin, which schools off Banks Penninsula amongst other places, was last year estimated to have a population of about 600 in that region. In the past four years 200 have been accidently caught and drowned in set nets — they don’t breed as fast as that," he says.

Strict Limitations

On the land we have strict limitations on hunting and killing but in our coastal waters people are free to do as they like. Only at Leigh has this full protection been extended below the high tide mark. At the Poor Knights Islands, New Zealand’s second marine reserve, big game fishing has been allowed to

continue. Recreational spearfishing gives a good example of the impact the slightest human activity can have, he says. "One relatively inexperienced spearfisher, fishing inshore for home ranging territorial reef fish, can have an effect in half an hour which can last for 10 years." In the 1950s Leigh was an example of this. Close to Auckland, the coast became a favourite weekend spearfishing spot which quickly saw the area gutted of fish, crayfish and shellfish. Since the reserve was created, fishing of any sort has stopped. "Today we can see what happens if we stop all the killing; things change back to what is presumably more natural," Dr Ballantine says. "Most people would like to eat crayfish that are at Leigh. Most people would like to eat the snapper, or sell them. But we have decided, collectively, that we won't because there are other benefits which outweigh that — fun, recreation, education for students, but most importantly of all the protection of fish stocks.

"| think insurance is important — most sensible people spend money on it. We're still very ignorant of the way the sea works. This is a complicated system which we know so little about. So perhaps it would be better to keep some parts untouched, as insurance, until we find out what effects we're having. "I think it would be quite nice to keep some places pristine and natural so we can tell what effect we're having on others. Are we going to have more disasters like the Chatham Island crayfish industry, the Firth of Thames mussels, the Golden Bay scallops, fur seals, snapper nearly everywhere — or are we learning? "Symbolically you can ask — is Leigh a sunrise of a new idea which will actually provide a benefit and do some good? Or is it a sunset in which we will preserve a sort of museum of how things used to be? "Leigh is a place where fish can breed undisturbed. It’s a place where large fish can provide lots of eggs and continue to live. Dispersal of fish out of the reserve supports people who wish to fish for fun, food or money.

"It seems to me this situation is increasingly required if we're to have fishing rights in the future — who wants rights to something that doesn’t exist? Would you like rights to catch moa? It’s hardly worth bothering about," he concludes. #& Russell Joyce is a Department of Conservation journalist from the Waikato region.