Exposing environmental myths about the Great Barrier Reef.

• Author: Starck, Walter
• Position: 151441498
• Pages: 46(13)

Over the past four decades, hardly a year has passed without some dire threat to the Great Barrier Reef being proclaimed. Crown-of-thorns starfish, over-fishing, tourism, anchor damage, pesticides, fertilizer, cattle, cane, oil shale, coastal development, roads, marinas, shipping, global warming and sundry other menaces have repeatedly been declared to threaten the reef, and "experts" cited in support. None of these things has ever been dealt with in any effective manner, yet the reef remains much as it has always been. Credibility, however, never seems lacking for another threat nor for more expert opinions.

Although reefs in many other parts of the world have indeed been damaged by human activities, the Great Barrier Reef is among the most pristine of reef areas. Distance, weather and a relatively small population mean most of the reef is rarely ever visited.

Of the 2,900 reefs in the complex, only a few dozen are regularly used for tourism and the total annual fish harvest per [km.sup.2] is less than one per cent of what reefs elsewhere commonly sustain. Solutions appropriate to the problems of heavily-impacted reefs are uncalled for and may even have undesirable consequences here.

No-take areas, limited licences, quotas, closed seasons, size limits, gear restrictions and other such limitations have proven effective where fishing pressure is high and stocks over-fished. However, they are of no utility where fishing pressure is well below sustainable limits and substantial breeding stock is widespread as on the Great Barrier Reef. The benefit from such measures here is unneeded, undemonstrated and unlikely, yet all these and more are being imposed without even any plan to monitor and evaluate their effect. In other words, we will be stuck forever with a multitude of restrictions which we don't know are either needed or effective, and have made no effort to find out. Calling this "precaution" defies common sense. It is indeed just the opposite. It amounts to wholesale environmental meddling for no good reason, with no idea of the consequences, and no intention of ever determining them.

The Great Barrier Reef commercial fishing harvest is now limited to an annual quota of 3,061 tonnes. Averaged over the 347,000 [km.sup.2] of reef and lagoon area in the Great Barrier Reef, this comes to just under 9 kg/[km.sup.2]/ year. The average harvest over a broad range of reef areas elsewhere in the Pacific is 7,700 kg/[km.sup.2]/year, and even the conservation NGO World Resource Institute cites 4,000 kg/[km.sup.2]/ year as being a sustainable level for coral reef fisheries.

Coral trout are the most heavily fished species on the Great Barrier Reef. For over two decades, the Great Barrier Reef Marine Park Authority has funded extensive underwater surveys of coral trout populations, but has never published the results. As to what the surveys actually show, you don't have to take my word for it. Dr Tony Ayling has conducted most of the trout surveys and, about two years ago, there was a most interesting summary by him on the Internet. It was removed shortly after I had called attention to it in public debate regarding the expanded green zones. It was entitled: "Where are all the coral trout? Or are coral trout numbers on the Great Barrier Reef being reduced by current levels of fishing?"

Here are a few salient quotes from this document:

* "... it is obvious that coral trout numbers have not increased on reefs that have been closed to fishing."

* "All these figures suggest that far from decreasing in numbers there has been a marked increase in the numbers of coral trout on the GBR [Great Barrier Reef] over the past 10 years."

* "The Marine Park Authority and DPI [Department of Primary Industries] have made recent estimates of the total annual catch of coral trout from the GBR of about 2 million kilograms, including both the recreational and commercial catch. Given the average size of coral trout, this equates to about 3 million fish or only about 10 per cent of the available stock."

* "... the annual input of young coral trout is equivalent to about 40 per cent of the available stock, far higher than the annual catch of 10 per cent of available stock."

* "... it seems unlikely that the present exploitation levels of coral trout on the GBR are any threat to coral trout numbers."

After discussing the popular perception of declining trout numbers and the effect of frequent fishing on catchability, as opposed to the actual numbers of fish present on a reef, he concluded with the statement: "Just remember: the number of fish that are caught does not relate to the number of fish that are there, but to how easy they are to catch."

In addition to the trout surveys, the Great Barrier Reed Marine Park Authority (GBRMPA) has funded a largescale, long-term study of the effects of line-fishing on the Great Barrier Reef. During the Green Zones debate, the authority repeatedly claimed that this study provided proof of the need to further restrict fishing. Unfortunately, the formal report of this decade-long study was not published until just after the expanded zones were finally decided. The actual conclusions of the study present a quite different picture than GBRMPA had claimed.

Here are four key points from the final conclusions of this report that I have translated from techno-speak into English:

* Coral trout populations were predicted to remain "robust" under all the future projections that were considered.

* The likely effect of additional area closures would be poorer fishing.

* No evidence was found that fishing had any detrimental effect on the reef community.

* Closing more areas to fishing could be expected to increase the impact of fishing in areas left open.

Although the GBRMPA has claimed there has been a decline in trout, there is simply no evidence for this. DPI catch statistics show that both the total harvest and "catch per unit of effort" for recent years are near an all-time high. There is no evidence of decline.

In a current GBRMPA-sponsored public opinion survey on "Threats to the condition of the GBR", it is stated that commercial fishing has doubled since 1995. This is also untrue. On the contrary, it has actually decreased. The commercial harvest in 1995 was 3,183 tonnes. It is now limited by quota to 3,061 tonnes.

Figured over the entire reef and lagoon area, the boats participating in the Great Barrier Reef commercial line fishery enjoy an average density of over 500 [km.sup.2] per boat. The average number of days fished per boat however is only about 50 per year, thus the mean fishing-boat density comes to over 4,000 [km.sup.2] per boat on any particular day. For all practical purposes, commercial fishing pressure on the Great...