Poor Knights Islands - A snapper update

The Poor Knights Island's Marine Reserve is an interesting experiment.

Some would call it a return of the islands to their natural state. It's not of course. Some apex predators do seem to have increased in abundance - mainly bronze whaler sharks - but there has also been a corresponding increase of bronze whaler sharks in unprotected areas on the coast as well. The fish populations currently present in the marine reserve represent the unnatural removal of the principal apex predator (namely humans) from one isolated and well-defined area. The result is a disparity in fish populations that wouldn't normally occur.

Most obvious are the huge hordes of snapper that now populate the reserve. Their numbers are at an all-time historical high. With few predators to make any real dent in their population, the total biomass of adult snapper within the reserve can only get larger and larger.

The competition for food amongst these big snapper will become intense. Already congregations of big snapper follow along behind tourist divers waiting for them to knock food items out of the kelp or accidentally turn over a rock (feeding fish is banned at the reserve).

Not satisfied with these meager pickings, the biggest snapper have turned predatory, killing and eating large reef fish that, in recent decades, have had few real enemies. One group of snapper was witnessed herding up a group of pink maomao, with one large pink maomao being 'taken out' by the largest snapper. The resulting piranha-like feeding frenzy was photographed underwater.

The implications are that big snapper will become the dominant apex predator of the reef environment at the Poor Knights, with roving gangs of big, knobbly-faced snapper hunting down cowering reef fish wherever they can. It will make quite a sight: a marine reserve full to overflowing with big snapper bullies. Anyone diving there in the future might be well advised to keep their fingers clenched into fists and their hands close by their sides.?

	This article is reproduced with permission of New Zealand Fishing News October 2008 - written by Craig Worthington RE-PUBLISHING ELSEWHERE IS PROHIBITED