Industry and scientists conflict over Reef weed

by Jeni Bone on 21 Jan 2010 The Australian Research Council says a new report shows half of the inshore reef has been overrun by marine algae, but tourism operators have accused scientists of scaremongering to lock out boats and visitors and add more fish to the list of no-take species.

The new study indicates seaweed has overwhelmed large parts of the Great Barrier Reef, which could threaten fragile ecosystems. While tourism proponents is usually supportive of researchers’ efforts to protect the health of the famous stretch of coral that extends 2,000km down the continent’s tropical north-east coastline, on this occasion, organisations such as the Association of Marine Park Tourism Operators is not convinced.

The Australian Research Council, an independent body that advises the government, has reported that half of the inshore reef system has been overrun by marine algae, known as sargassum seaweed.

'You can go to some locations and as far as the eye can see is like open fields of weed,' said David Bellwood of the Australian Research Council, who is also a professor in marine biology at Queensland’s James Cook University. 'The real problem is that weeds are often regarded as a sign of degradation. If it starts to spread, we’ve got to be very concerned.'

He continues: 'The problem is it can stop the young coral settling and it will slowly strangle the reef. That’s the worrying side. The good news is we know what we can do to help prevent seaweed spreading and that is to protect herbivorous fish. That is one of the main things we can do immediately to try and help the future of the reef.'

These plant-eating fish species – among them parrot, surgeon, rabbit and bat fish – are referred to as 'nature’s guardians and gardeners' because their grazing stops seaweed from colonising the coral beds.

Col McKenzie, executive director of the Association of Marine Park Tourism Operators, a trade organisation that represents businesses on the Great Barrier Reef, says biologists are sensationalising the extent of the seaweed infestation. He insists the council’s results were not indicative of the entire Great Barrier Reef, where tourism enterprises employ more than 63,000 people.

'The problem is relatively isolated and what people forget is that as coral moves from events such as heat stressing or bleaching it goes through a cycle where the algae grows and then dies off, when the coral comes back. So I’m not too concerned about the scientists finding the algae on those reef areas. I do get concerned, however, when I continually hear stories saying the Barrier Reef is going to die,' McKenzie says.

'In a lot of cases it is the researchers trying to push their own barrow hoping to get more money,' he continues. 'We have to be really careful that we don’t overplay the negative card and not simply from the point of view that it could hurt tourism. I don’t want to get to the stage where the politicians think this is so badly gone that we can’t do anything about it. The government won’t keep putting money in if it doesn’t think there’s any hope of a successful outcome.'

The Reef has also suffered from a series of bleaching episodes, chemical runoff from farmland and rising ocean temperatures, which it has proven resilient to over the 200 or so years of colonisation of the east coast. Researchers surmise the spread of seaweed is an sign that phosphates and soil flowing into the ocean from farms have triggered this recent bloom.

As Bellwood explains: 'The problem is when you have this accumulation of different assaults, each of them adding one upon the other, you get to the point where we may be weakening the capacity for regeneration.'

The Reef contains an abundance of marine life and comprises of over 3000 individual reef systems and coral cays and literally hundreds of picturesque tropical islands. The Great Barrier Reef is one of the seven wonders of the natural world. It is larger than the Great Wall of China and the only living thing on earth visible from space.

The marine park stretches over 3000km (1800 miles) almost parallel to the Queensland coast, from near the coastal town of Bundaberg, up past the tip of Cape York, and is between 15km and 150km off shore and around 65km wide in some parts.