A report from the Australian Institute of Marine Science has claimed around half of the Great Barrier Reef's coral has been destroyed by cyclones, crown-of-thorns starfish, and bleaching in the last 27 years.

CEO Australian Institute of Marine Science John Gunn said the degradation is a significant blow to the $5 billion a year tourism industry, and predicts that as little as 6 per cent of the reef's coral could be left by 2020.

We spoke with expert observers Peter Wright from Poseidon Outer Reef Cruises and Ben Cropp, underwater film maker who has dived the reef for 60 years, for their thoughts.

The Newsport: What is your take on the Australian Institute of Marine Science report?

Peter Wright: In a way it's a good thing that it has alerted the public to the risk, but it is also a bad thing in that it has been a bit over-blown. Somebody in California that's planning to come here on a holiday is going to read that and think 'I won't bother coming to Australia as the reef is stuffed', and it isn't.

Ben Cropp: I found the report very misleading. The outer reef in this area is in very good condition. It's only the inshore and coastal reefs that are suffering and this is due to pollution, not crown-of-thorns starfish or cyclones.

The Newsport: The report raises some major concerns about the health of the Great Barrier Reef. How are our local reefs faring?

PW: At the moment our reefs are pretty clear. We very occasionally find a juvenile crown-of-thorns, which is part of the normal eco-system.

The Agincourt coral is in particularly good condition. There was a little bit of damage from Cyclone Yasi in some of the more exposed sections, but very limited. It was only the fast growing stag horn coral and the occasional plate coral that were damaged, and they replace themselves within a couple of years.

I've heard anecdotally there were quite a few crown-of-thorns around Lizard Island, but we are certainly not seeing anything like an infestation.

We are lucky in Port. We do have the Agincourts there which are really superb reefs that get daily flushing from the open ocean.

TN: What is the biggest threat to coral reefs?

BC: Pollution has been and will continue to be the biggest killer of coral reefs, and is the major destructor of coral reefs around the world, along with over-development and over-fishing.

The worst pollution is sewerage, the second is land runoff of soils and fertilisers that smother and kill the corals and allows algae to take over. Most inshore coral reefs around the world and here are mostly dead because of this.

Our saving grace for the Great Barrier Reef is it is well offshore and very little pollution reaches it and it is still in good condition. However, massive dredging at Gladstone and soon at Cairns does destroy the corals of the inner reef and turbidity can reach up to more than 30 miles offshore and spoil the viewing of the reef by divers.

This has happened at Heron Island where back in the 80’s the water clarity dropped to half because of the Gladstone harbour dredging. Most underwater photographers used to go to Heron Island but when the vis (visibility) dropped they started to come up here to Cairns and Port Douglas. Now this problem may happen here.

A good example of pollution here, similar to around the world, is at Low Isle. I’ve been visiting Low for 40 years and witnessed the decline in hard corals in the lagoon anchoring area.

This has been caused by sewerage from boats and septic sewerage from the three houses there that leached through the porous limestone onto the corals. While both have stopped now, the damage remains.

Also the runoff from the Daintree River floods has deposited nutrients over the corals and helped to kill them. Today, 70 per cent of these lagoon corals are dead and covered by soft corals, I have witnessed this slow decline over 40 years. Fortunately the seaward corals are healthy, washed by clean currents, but the tourists rarely swim there.

PICTURED BELOW: The Daintree River flows into the Coral Sea.



TN: What is being done in response to reef degradation?

PW: The positive side of a report like this is that it encourages the Government to fund protective measures.

They have given us $1.4 million and there is a big charter vessel called 'Hero' and it's going up and down the reef wherever there are concentrations of crown-of-thorns and they're trying to protect dive sites because you can't protect the entire reef.

Cyclones you can't do anything about, crown-of-thorns you can do a little bit about. Water quality is something we can something about, reducing runoff from the land, reducing waste such as fertilisers particularly as fertilisers stimulate the growth of juvenile crown-of-thorns. They're prolific, one mature female will lay billions of eggs.

BC: Please, let's put the money and research into the pollution problem. Another big problem may exist is the breakdown of the huge plastic rubbish floating out there, and when it finally breaks down into minute particles it could be eaten by the plankton and even the coral polyps and would kill them. Research is needed for this one as it could be major and effect the whole food chain.

Personally, I would like to see all plastic bottles banned. We don’t need to buy drinking water when we have good water from the tap, unlike in Asian countries. If people saw the huge piles of plastic bottles along our northern beaches they would be horrified, and 90 per cent comes from our mainland, not foreign vessels.
 
TN: What's the relationship like between reef trip companies and cane growers these days, especially with the adoption of the Reef Rescue program?

PW: We've got good communications with the farmers. Certainly a lot of the ones I know personally are doing all they can to reduce runoff. They don't want to see the reef destroyed.

If we can improve the water quality or stop it detonating then the reef has a very good chance of recovering from major events like localised cyclone damage and any future crown-of-thorns outbreak.

If the water is full of nutrients it makes it that much harder for the coral to recover.

In the early days there was a lot of ignorance in both camps. We now realise we're all living up here for the same reason, to make a living and enjoy the environment. Once you see the reef you want to do everything you can to preserve it.

It's up to Council's up and down the coast to prevent any developments on the foreshore that are going to cause runoff because that can almost be as bad as farm runoff.

BC: I think it's good (the relationship with cane growers) because in the past it was bad and places like Low Isles suffered from the runoff. It's not just getting rid of the pesticides, it's getting rid of the erosion.

TN: It has been reported that the coral that remains will be drastically reduced over the next decade. Do you agree?

BC: If you take the reef as a whole, maybe that's true, maybe. It sounds exaggerated. If you take the outer reef where the tourists are mainly taken that's far from true.

PICTURED BELOW: Cane growers have drastically improved their practices in reducing nutrient runoff.