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Caulerpa now in BOI


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2 hours ago, CarpeDiem said:

The bottom line is it's here. How it got here and where it came from is academic. 

MPI have spent 100's of thousands officially reaching the conclusion, that with the technology available today, NZ can't get rid of it and we're now in containment mode.

It's known to be easily spread on boat anchors, chains and fishing gear. This is also how it was spread in the Med. 

 

this is the nub of it for me.

Apochrophal miscreant aquarium owners notwithstanding, the problem is now one of post-hoc management.

Anchoring bans are simply a part of that management.

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2 hours ago, CarpeDiem said:

I am not the one claiming that these strains are only in Singapore therefore the conclusion is that a yacht could never have bought it here.

 

No one has claimed these strains are only in Singapore, you have made that up. Same as the moderator making sh*t up.

I relayed that the expert said they are native to Singapore. You have decided to add in 'only' native to Singapore.

The basic problem here, is that when confronted with facts that don't confirm with what ever narrative you've all been indoctrinated in, you getting your undies tied in a knot. MPI have put out the narrative that boaties are the problem. When presented with actual facts, instead of an indoctrination, you really don't like it. There is a viable alternative vector to boaties, but MPI wont mention is publicly. Why is that?

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1 hour ago, waikiore said:

I wonder what its like in a stir fry ? Bit of Tamari organic soy ......

There are potential positives to Caulerpa:

We have a problem with kina barrens right? If kina eat this stuff they go sterile. So, it may well create suitable habitat for nursery fish, and, tadaa, re-balance the Hauraki Gulf. Providing the caulerpa doesn't smother other food sources, this could work really well. The photos I've seen show the eclonia still growning, with the caulerpa around the base. Could just work.

The other thing is the carbon sequestered growing this stuff. Carbon sequestered in the oceans is enough to reverse climate change. There are many projects underway to grow kelp for carbon sequestration. It is incredibly fast growing. So all we need to do is include Caulerpa in the emissions trading scheme, export all the carbon credits, and we will be as wealthy as Saudi Arabia. Genius. Sure, we may not be able to eat the snapper, but if we can't eat beef or lamb due to pine trees, what's the problem? Carbon credits are at about $50/ tonne at the moment aren't they?

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3 hours ago, K4309 said:

No one has claimed these strains are only in Singapore, you have made that up. Same as the moderator making sh*t up.

I relayed that the expert said they are native to Singapore. You have decided to add in 'only' native to Singapore.

Err you were the one who stated that the weed originates in Singapore and therefore how very unlikely it would be for a boat to sail directly from Singapore.  You neglected to mention our other nearby neighbors.  Whether it was your intention or not, your statement supported your unnamed gagged experts opinion that it was most likely a rampant disgruntled local aquarium owner with a grudge against the occupants of Great Barrier rather than looking at it critically and sharing that it could of come from an island far closer.

3 hours ago, K4309 said:

The basic problem here, is that when confronted with facts that don't confirm with what ever narrative you've all been indoctrinated in, you getting your undies tied in a knot. MPI have put out the narrative that boaties are the problem. When presented with actual facts, instead of an indoctrination, you really don't like it. There is a viable alternative vector to boaties, but MPI wont mention is publicly. Why is that?

I am not sure what facts you have presented?

Boats are the only 100% certain vector for spread that we have.  That it can be transported in a boats anchor well, on fishing gear, or in the bilge of a boat, is the only fact we actually know.  If you pull up your anchor and it has green weed on it then you can actually see it with your own eyes.  It's not a theory it is a confirmed and actual means of spread.

Riding on a long necked turtles back, arriving in a plastic bag via the postage system, flowing with the currents from the indo-pacific, being distributed by a disgruntled aquarium owner, set on destroying the way of life of the barrier people, arriving on a tanker out of Singapore that empties it's bilge in the Whangarei harbor are all unsubstantiated theories that cannot be proved and thus are not facts.

We can each argue on which theories are most likely.

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2 hours ago, Black Panther said:

How did they spread before we invented boats?

Your question suggests that it has?

It sinks and it doesn't survive at depth. The world's currents take around 500years to do a full circle of the planet so it's had 23 million years to get to our coast.  In that time it hasn't made it across vast distances. 

New Zealand isn't special in this regard, it also hasn't made it (naturally) to West or East Coast of the Americas which are a sh*t load longer than NZs coast.  As we've read in this thread it also hasn't made it naturally into the Med. 

I suspect that the warm surface currents of the tropics only carry it so far before it gets pushed to depths that it cannot survive and turns back into ocean nutrients.

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Once introduced it can certainly be carried on coastal currents.

According to MPI the theory is that as it can't survive below 40m so it won't spread to the rest of the gulf anytime soon.

I guess we have to wait and see. 

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It could probably survive a trip down the drain from east coast road to the nearest beach ?  How would you empty 100+ litre saltwater aquarium ? 
 

it could be well established in a corner of some murky harbour were no one dives and it doesn’t get enough wave movement to get washed up 

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4 hours ago, CarpeDiem said:

Your question suggests that it has?

It sinks and it doesn't survive at depth. The world's currents take around 500years to do a full circle of the planet so it's had 23 million years to get to our coast.  In that time it hasn't made it across vast distances. 

New Zealand isn't special in this regard, it also hasn't made it (naturally) to West or East Coast of the Americas which are a sh*t load longer than NZs coast.  As we've read in this thread it also hasn't made it naturally into the Med. 

I suspect that the warm surface currents of the tropics only carry it so far before it gets pushed to depths that it cannot survive and turns back into ocean nutrients.

Erm, so how did the NZ native species of Caulerpa get here?

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Apparently I'm not the only one that thinks MPI / Biosecurity NZ is doing a sh*t job.

Council seeks urgent Ministerial meeting over seaweed threat

15 May 2023, 9:15 AM

A ‘manifestly insufficient’ response by Biosecurity New Zealand to the threat posed to Taitokerau by invasive Caulerpa seaweed has prompted the Northland Regional Council to seek an urgent meeting with Biosecurity Minister Damien O’Connor.

In a letter to the Minister the council says the threat posed by the seaweed is of utmost urgency for Northland due to its presence at Great Barrier Island (Aotea), the speed at which it spreads and takes over ecosystems, and the lack of an appropriate response to date by Biosecurity New Zealand (BNZ).

Media releases - Northland Regional Council - Council seeks urgent Ministerial meeting over seaweed threat - Northland Regional Council (nrc.govt.nz)

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Note: The 2 exotic species of caulerpa present in New Zealand at Aotea Great Barrier Island and Ahuahu Great Mercury Island do not contain this toxin and do not create any food safety issue with consuming fish.

Aquarium Caulerpa | NZ Government (mpi.govt.nz)

So, brachypus and the other one is not toxic. Only the main fish tank variety is. Is this then not the solution to our kina barrens? 

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1 hour ago, Ex Machina said:

It could probably survive a trip down the drain from east coast road to the nearest beach ?  How would you empty 100+ litre saltwater aquarium ? 
 

it could be well established in a corner of some murky harbour were no one dives and it doesn’t get enough wave movement to get washed up 

Given the initial infestation in Bland Bay had clearly been there for some time, I think it is highly likely that there is more of it around that just hasn't been found or identified yet. There is nothing to suggest the Bland Bay / Barrier infestation was the first patch of growth in NZ.

The stuff at Bland Bay was only discovered because an ecologist was there on holiday, and decided to put a photo of the stuff on a citizen science page cause he didn't know what it was. How many of us bother to find out what genus and species the green sh*t is on the beach when we go for a walk?

Noting that the sample found at Rawhiti is only 20cm apparently. The photo NRC have is it on a scallop shell.

I'm fascinated by the assertion it can't get here on ocean currents and tides cause it sinks. What if its growing on a log? Or any other floating debris. The weather systems have changed markedly with La Nina for the last 3 years, far more north easterlies and the East Auckland current on steroids', hence all of the marine heatwaves. 

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1 hour ago, Ex Machina said:

It could probably survive a trip down the drain from east coast road to the nearest beach ?  How would you empty 100+ litre saltwater aquarium ? 
 

it could be well established in a corner of some murky harbour were no one dives and it doesn’t get enough wave movement to get washed up 

Yes. And this is/was one of MPIs working theories when it was first discovered at the Barrier. 

But time is ticking on and the elusive bay hasn't shown up. 

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1 hour ago, K4309 said:

Erm, so how did the NZ native species of Caulerpa get here?

Good question.  Our native Caulerpa are found only in Australia and New Zealand.  No where else in the world has them. 

I have very little idea and certainly no proof.  I know there's an awful lot of marine species that are native to both Australia and NZ only.  Science tells us that sea weed has been around for over 1 billion years and that the two countries were a super-continent 80 million years ago.

The more interesting question is how did it get to Gondwana in the first place and what wiped it out on it's evolutionary path from where it originated. 

 

 

 

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 Anywhere could’ve been the vector not just Auckland . If for example if it was off an anchor the boat could’ve have been heading north , stopped at mercs first then Barrier . That puts every harbour and domesticated inlet south and inshore of the mercs in the realm of possibility 

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1 hour ago, CarpeDiem said:

Good question.  Our native Caulerpa are found only in Australia and New Zealand.  No where else in the world has them. 

I have very little idea and certainly no proof.  I know there's an awful lot of marine species that are native to both Australia and NZ only.  Science tells us that sea weed has been around for over 1 billion years and that the two countries were a super-continent 80 million years ago.

The more interesting question is how did it get to Gondwana in the first place and what wiped it out on it's evolutionary path from where it originated. 

 

 

 

I'm actually quite interested in these native species of caulerpa, but haven't been able to find any information on them yet. Any google search for anything related gets buried in stories about the exotic species. To compare attributes to the exotic species, particularly range, habitat and growth rates.

I was under the impression that both exotic species were toxic, both from the expert at the boatshow and comments on here. So I was surprised to see that statement on the MPI site that they are not toxic, or at least they do not cause toxicity in edible fish. It is not actually clear from the statement, other they don't have the toxin the main aquarium species has.

IF they are not toxic, then the question is what is the main problem with them? Obviously they out-grow and smoother, esp over sand, but rocks and everything else. But for something to out-grow everything else, it needs to be better adapted to the specific environment than everything else. The same concerns applied to fan worm. In my view, fan worm is not that prolific. I see it occasionally on the beach and while free diving / spear fishing, but it certainly has not smoothered the entire sea floor.

One of the stated concerns from MPI on the caulerpa is that it will destroy the habitat for nursery fish. But nursery fish need weed to hide in. So which is correct?

The AC / boatshow expert did say that kina go sterile if they eat caulerpa (which didn't sound like a bad thing to me), but on reflection, its not entirely clear which species he was talking about. As far as I can tell, all current research is on the main aquarium variety. For natural control, snapper are carnivores, but Parore are herbivores. They are in plague proportions at my fav spear fishing spots, and incidentally are really good eating if you don't pierce the gut cavity (not as easy to prepare and fillet as snapper, but really easy to shoot).

There is a native sea slug (nubibranch) that eats it...

It would be good if the ecosystem adapts to caulerpa, and it turns out to not be a major issue. Certainly NRC are making big noise about it, but that is also very closely related to them demanding more funding, which can also be construed as empire building.

So far it appears fan worm is good at filtering water, and hasn't gotten out of control. Caulerpa is good at absorbing nitrogen and phosphorus (so also improves water quality), and may well be a solution to kina barrens. Who knows?

I'd love to go out to Bland Bay or Whangaparapara for a spear fish and see for myself what is going on, but the CAN notices makes it a bit complicated. If only they would install mooring bouys for public use, and we could all move on.

 

PS, it is interesting that we have TWO new exotic species here. That says to me that if the vector was a one off thing like a boat anchor, getting two species was just plane bad luck. If it was an ecological vector, like the marine heatwaves, la nina and the East Auckland current, it would be more plausible to get two new species.

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32 minutes ago, K4309 said:

I'm actually quite interested in these native species of caulerpa, but haven't been able to find any information on them yet. Any google search for anything related gets buried in stories about the exotic species. To compare attributes to the exotic species, particularly range, habitat and growth rates.

These are the two native NZ species.

https://en.wikipedia.org/wiki/Caulerpa_articulata

https://en.wikipedia.org/wiki/Caulerpa_brownii

32 minutes ago, K4309 said:

I was under the impression that both exotic species were toxic, both from the expert at the boatshow and comments on here. So I was surprised to see that statement on the MPI site that they are not toxic, or at least they do not cause toxicity in edible fish. It is not actually clear from the statement, other they don't have the toxin the main aquarium species has.

It is toxic to NZ fish and therefore has no natural predators in NZ.  Assuming the NZ fish were able to adapt to it then they would likely store the toxin on their flesh potentially making the fish toxic.  MPI are saying this will not happen.  However as we know nature has a way of adapting.

Apparently it is not toxic to humans in small doses according to tests done on rats (can't find the reference now).  However every publication says "do not eat"....

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