1st Panel Discussion
|Ron West, Alex Meehan, George Cotis
Question: I wanted to ask a question about seagrass. Is there any evidence that seagrass when you try to replant it will actually grow?
Alex Meehan: I did some transplant experiments for my PhD with posidonia australis in 5 sites in Port Hacking. It survived at 3 of the 5 sites and grew quite well at 2 of those sites. So that would be one of the first successful transplant experiments. They didn't take well in Gunnamatta Bay though. They grew quite well in Burraneer Bay and in a control site. At the Lilli Pilli Point site they died after about 10 months. So there is potential to transplant them to some of these areas, but obviously you need to do some trial transplanting.
Supplementary Question: And just another question about seagrass particularly in Botany Bay. There's a lot of heavy metals coming into the Bay from industrial sites. Is there any evidence that seagrass will take up heavy metals and that you could actually prune it and get rid of the heavy metals?
Alex Meehan: I honestly have no idea
Question: To Ron, your parting comments about reserve systems were that they needed to be comprehensive and representative. At the Southern Catchment Management Board meeting yesterday these two words caused a great deal of angst amongst certain people. Is there a definition that we might apply to that wording which might help us overcome that difficulty?
Ron West: I think that there are plenty of definitions actually if you look in the literature. The problem's not so much in the definition, as in actually applying any of those definitions in the real situation. When people talk about 'comprehensiveness', they really talk about delineating all the communities and then applying this 15% rule to them. So it's a very difficult question. But the problem we have now is not trying to be comprehensive and adequate in the totality of a reserve. The problem we have is that we just don't have any. It would be good to start with some reserves and then in the future - maybe in a decade or so - start looking at whether they are comprehensive and representative. It would be good to take that attitude right now, but I just think we're so far behind the eight ball in terms of the aquatic environment that we really need to start anyway.
Bruce Thom: I think the point's very relevant with respect to what the Minister said this morning about the $8.6m that the Government is investing in the Comprehensive Coastal Assessment because a direction from that is to come up with some answers with respect to those things that are outside the public protected areas or national park that should be protected. As it applies to the aquatic areas it's a very big question.
Ron West: Those four hectares that I indicated as being protected were actually protected I think mostly in the 70s. In the last 30 years we've had virtually no full protected areas put into place. Bruce is right, there needs to be some sort of assessment of the whole coast. But there are a lot of areas that really we can identify straight away and say well "That should be protected". Now people talk about Towra Point for example as being a protected area. Well it's protected in some aspects, but fishing is allowed. Well, then you could say that it's not a real reserve. There's only a very small proportion of that reserve that's really a reserve for fishes.
Question: I was wondering whether someone out there could give us some idea of just how extensive the caulerpa problems is in Port Hacking and perhaps also make some mention of how many of our estuaries and lakes along the coastline have problems with it.
Ron West: I can take a guess at it but Rob Williams is in the audience and can comment on it too. I think NSW Fisheries has done some mapping. It's difficult to say how extensive it is completely. Certainly it's in Port Hacking. Sydney Harbour was mentioned, along with Pittwater, Conjola, Burrill Lake on the south coast, (audience interjection: Towra Point) Towra Point is that right? Towra Point. So it's expanding certainly.
Rob Williams NSW Fisheries (in audience): I think Ron you have the essence of the distribution right. The main focus of NSW Fisheries' concern in the management of caulerpa is at Port Stephens so I can give the question a flick in that direction. My understanding is that the most current approach to control it is in terms of salt trials. The intention is to confront the organism with so much salt that in effect, it has a real trouble contending with the difference in the osmotic gradient. Those salt trials are being conducted at Lake Macquarie because Lake Macquarie is close to our office at Port Stephens. Now there are some elaborate experimental designs put in place to deal with these salt trials that in effect involve about five bags of pool salt per square metre. That's a lot of salt and implies a huge handling problem. The salt manufacturers are going to be pleased if this works unlike the conveyor belt individuals who thought they might have a use for some of their old conveyor belts. You may recall that in the media there were some suggestions some months ago, that conveyor belts could block out sunlight and therefore could help resolve the caulerpa problem. It's not that easy and indeed, like any of the alien species, whether it be foxes or rabbits, we have a real problem on our hands. So the question is well justified. The answer is one that is still problematic. Are we able to control this thing or has the horse bolted? I'm not sure. But I can say that there's some very intense activity aimed at trying to figure out whether salt is going to be a useful and reasonable answer to resolve the issue.
Bruce Thom: Thank you very much Rob. Recently we've heard that caulerpa is now in Adelaide as well, so it's starting to spread around parts of Australia and is really being seen nationally as the 'bitou bush of our estuaries'.
Question: It's a question for Ron West. I think it's a very good point about the threatened area of saltmarsh and the fact that most of it is in the private hands. I think there has been suggestions recently that saltmarsh should be considered a threatened habitat because of that. How realistic do you think that suggestion is and are there any other solutions?
Ron West: That's a loaded question because you probably know that I'm on the Threatened Species Committee of NSW. We have looked at it a number of times. But the problem exists in that, to some extent, there is still quite a bit there. It also depends on what you consider a 'threatened species'. 'Threatened species' is one which is threatened with extinction and certainly there are problems in how you might go about actually declaring it as an endangered species and I don't want to get into it in too much detail because it's something we deal with at committees and so on. But it certainly is a threatened community. Whether it's actually threatened with extinction as a community, or as a population or as individual species, is a little bit hard to determine scientifically. But on the other hand, yes, it is under tremendous pressure. How we deal with that doesn't have to be just through say for example, declaring it as a threatened species or threatened community, it's really a matter of better planning as well. None are in protection areas at present.
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