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Post by fish on Jul 7, 2023 22:20:19 GMT 12
This makes me angry. I've found the MPI press release. It has been copied verbatim by Stuffed, accept for this one line: "Divers found small 20 centimetre to 30 centimetre patches of the seaweed in the North Channel, north-west of Kawau. Finding exotic Caulerpa in another area of Tāmaki is disappointing but not unexpected given the nature of the seaweed.Now, what is the first thing you think of with North Channel? Strong tidal flows (as well as dropping he holding tank for me, due to said strong tidal flow, and looking for fish signs and work-ups, but I digress). The very next line in the press release is this one: "Caulerpa can easily be spread to new locations as it’s commonly caught up as tiny pieces of seaweed on vessel anchors and fishing gear.Now, no-one anchors in North Channel, cause it is rocky as fuck, deep and with strong tidal flows. Its the kind of country even the fisho's don't anchor in, they either drift fish or use Minn Kota's with spot lock to stay over sign. If the caulerpa had been found in Bon Accord, then yes, it's due to anchoring. I thought it odd the Stuffed story had zero detail on the actual location. Looks like some creative editing to push the narrative against those evil boaties. www.mpi.govt.nz/news/media-releases/plan-for-immediate-actions-after-pest-seaweed-found-around-kawau-island-auckland/
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Post by fish on Jul 7, 2023 22:25:59 GMT 12
Additionally, this photo is in the stuffed story with the caption " The seaweed is fast-growing and is known to smother shellfish beds and reduce diversity of fauna in the sea." The first thing any half-pie descent spear-fisher will spot in this pic is the 10 goat fish. Good eating they are. Also ground grazers, eating snails, worms and shit off the sandy areas. So, erm, if it reduces biodiversity, why does your photo have lots of fish and mint visibility? There appears to be a discrepancy in what they are saying and the reality.
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Post by sabre on Jul 8, 2023 7:19:51 GMT 12
And this from the Stuff article...
"Walsh told sailors to check their gear, especially anchors and chains, and people found any seaweed on their equipment, they should chuck it straight back in the waters it came from."
Why use the term "sailors" rather than boaties???
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Post by Cantab on Jul 8, 2023 8:05:13 GMT 12
That's nothing, in the documentation on regional pathways consultation we were referred to "exacerbators", no boaties ,yacties or launch owners to be found. Thought it was a bit judgmental and told them so.
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Post by DuckMaster on Jul 10, 2023 21:36:00 GMT 12
And this from the Stuff article... "Walsh told sailors to check their gear, especially anchors and chains, and people found any seaweed on their equipment, they should chuck it straight back in the waters it came from." Why use the term "sailors" rather than boaties??? Areas in the Med where this shit spread the fish are gone. You can see in that photo it's pretty sandy and open still. When all that sand is covered there won't be a fish to be seen... The locals at Blind Bay are allowed to fish again from the shore but no one has caught a thing since the fishing ban was lifted.
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Post by fish on Jul 10, 2023 21:39:15 GMT 12
And this from the Stuff article... "Walsh told sailors to check their gear, especially anchors and chains, and people found any seaweed on their equipment, they should chuck it straight back in the waters it came from." Why use the term "sailors" rather than boaties??? Areas in the Med where this shit spread the fish are gone. You can see in that photo it's pretty sandy and open still. When all that sand is covered there won't be a fish to be seen... The locals at Blind Bay are allowed to fish again from the shore but no one has caught a thing since the fishing ban was lifted. How do you know the locals haven't caught anything at Blind Bay?
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Post by harrytom on Jul 10, 2023 23:15:25 GMT 12
So they have tried tons of salt and covered with hessium type material,worked but costly,now using chlorine tablets,fish and chlorine do not mix,why not suction dredge? Be cost effective and dump ashore. Rather than put it back,treat it like Didimo and bring ashore?
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Post by sabre on Jul 11, 2023 6:55:46 GMT 12
And this from the Stuff article... "Walsh told sailors to check their gear, especially anchors and chains, and people found any seaweed on their equipment, they should chuck it straight back in the waters it came from." Why use the term "sailors" rather than boaties??? Areas in the Med where this shit spread the fish are gone. You can see in that photo it's pretty sandy and open still. When all that sand is covered there won't be a fish to be seen... The locals at Blind Bay are allowed to fish again from the shore but no one has caught a thing since the fishing ban was lifted. Not sure why you have quoted me as my post has nothing to do with yours? However it does appear that you are spreading misinformation once again as you so often do.
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Post by Cantab on Jul 11, 2023 6:57:40 GMT 12
There was a suction dredge attempt somewhere, its in the info links I think.
Basically to many small bits end up back in ocean, pretty sure they ended up with worse coverage in a couple of years than what they started with.
The advice is pretty clear, there is no technical way to do it, its not a matter of money.
Maybe you could dam off the coast of nz and treat the lot? Cost a lot and really fuck the environment but stranger things have been done before. Cost most of Nz income for the next 300 years but that never stopped them before.
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Post by fish on Jul 11, 2023 10:34:30 GMT 12
So they have tried tons of salt and covered with hessium type material,worked but costly,now using chlorine tablets,fish and chlorine do not mix,why not suction dredge? Be cost effective and dump ashore. Rather than put it back,treat it like Didimo and bring ashore? There are a load of issues with suction dredgers. The weed grows tendrils / runners under the sand, like kaikuya. So you have to suck up half the seabed. With this you will suck up everything you are trying to save, worms, snails, shrimps, crabs etc. But the main problems come with what to do with the suctioned water. You need to suck up a substantial volume of water to entrain the sand and the weed you are after. It is not possible to store this onboard any dredge, so you need to be able to seperate the good from the bad and return it at the same time you are sucking. Sand, snails and crabs are kind of easy to seperate, you just build a big clarifying tank. The irony is that you want to return this stuff straight back to the marine environment. Then you need to separate the weed. This is harder cause it floats, so clarifiers wont work. You basically need filters. The problem with filters are 1) they are expensive, 2) they block fast, especially if you have sand and what-not going into them and 3) it is hard to get any great volume of water through them. It would be easier if you sucked everything up then used some sort of liquid biocide on them, like a massive chlorine contact tank on he dredge. This would work, but it would kill everything else you are trying to save. It would literally be a scorched earth approached. And all this relies on your diver guy at the dredge end managing to capture all the weed and not have any little bits float away while it is being disturbed. There are two key elements I think are very interesting. Firstly, no-one anywhere in the world has managed to erradicate caulerpa. Secondly, how much of a problem is it? All the photos and video of it in NZ show good well balanced ecosystems. Ducky claims all the fish are gone in the med, but the med is a different species that was bread to be toxic to fish. I would very much like to see a proper benthic survey of Blind Bay. I would expect there is far more sea life down there than Ducky says, AND if it not good, then it would be no worse than the kina barrens we have everywhere and no-one gives a shit about. Imagine if they shut down the fishing industry, Fizz boat industry and banned all boating and water activities across the Hauraki Gulf because of a few kina barrens?
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Post by em on Jul 11, 2023 12:07:36 GMT 12
Mentioning the Med you have jogged My memory . We spent 3 weeks in Antibes in sth France just before Covid lockdowns . Did a bit of boating and a heap of swimming the absence of sea life was very noticeable as was the clarity of the water . Antibes is similar to whangaparoa , bit of a peninsula but far more heavily populated and has a city just along the coast (nice) similar distance to Auckland from whanga . The water was crystal clear , even in the marina which is almost twice the size of westhaven . Anyway the memory that’s come back is a trip we took in the boat up the coast to a bay called villefranche . The vis there was excellent, from the boat you could see 10-15m to the bottom and at the time I thought I was looking at healthy sea grass meadows covering the bay . Up to that point we hadn’t seen any seaweed , underwater or floating so the masses of greenery were pleasing to the eyes . A quick google just now shows it was Caulerpa Taxifola and Racemosa . This is only the first page of what seems like an interesting abstract , cant see the rest without a subscription . FYI villefranche is close to Monaco and right next door to Nice . Anchors probably are the most likely vector for spread there because the currents and tide are minimal . Attachments:
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Post by harrytom on Jul 11, 2023 17:20:40 GMT 12
So they have tried tons of salt and covered with hessium type material,worked but costly,now using chlorine tablets,fish and chlorine do not mix,why not suction dredge? Be cost effective and dump ashore. Rather than put it back,treat it like Didimo and bring ashore? There are a load of issues with suction dredgers. The weed grows tendrils / runners under the sand, like kaikuya. So you have to suck up half the seabed. With this you will suck up everything you are trying to save, worms, snails, shrimps, crabs etc. But the main problems come with what to do with the suctioned water. You need to suck up a substantial volume of water to entrain the sand and the weed you are after. It is not possible to store this onboard any dredge, so you need to be able to seperate the good from the bad and return it at the same time you are sucking. Sand, snails and crabs are kind of easy to seperate, you just build a big clarifying tank. The irony is that you want to return this stuff straight back to the marine environment. Then you need to separate the weed. This is harder cause it floats, so clarifiers wont work. You basically need filters. The problem with filters are 1) they are expensive, 2) they block fast, especially if you have sand and what-not going into them and 3) it is hard to get any great volume of water through them. It would be easier if you sucked everything up then used some sort of liquid biocide on them, like a massive chlorine contact tank on he dredge. This would work, but it would kill everything else you are trying to save. It would literally be a scorched earth approached. And all this relies on your diver guy at the dredge end managing to capture all the weed and not have any little bits float away while it is being disturbed. There are two key elements I think are very interesting. Firstly, no-one anywhere in the world has managed to erradicate caulerpa. Secondly, how much of a problem is it? All the photos and video of it in NZ show good well balanced ecosystems. Ducky claims all the fish are gone in the med, but the med is a different species that was bread to be toxic to fish. I would very much like to see a proper benthic survey of Blind Bay. I would expect there is far more sea life down there than Ducky says, AND if it not good, then it would be no worse than the kina barrens we have everywhere and no-one gives a shit about. Imagine if they shut down the fishing industry, Fizz boat industry and banned all boating and water activities across the Hauraki Gulf because of a few kina barrens? The most intense video I have seen,by niwa,bypass the log in, I imagine it would smoother crabs,snails etc,only fish to be seen are spotties? www.facebook.com/GreatBarrierLB/videos/niwa-footage-caulerpa-brachypus-in-blind-bay-aotea-2021/1455558218133461
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Post by fish on Jul 11, 2023 20:01:59 GMT 12
There are a load of issues with suction dredgers. The weed grows tendrils / runners under the sand, like kaikuya. So you have to suck up half the seabed. With this you will suck up everything you are trying to save, worms, snails, shrimps, crabs etc. But the main problems come with what to do with the suctioned water. You need to suck up a substantial volume of water to entrain the sand and the weed you are after. It is not possible to store this onboard any dredge, so you need to be able to seperate the good from the bad and return it at the same time you are sucking. Sand, snails and crabs are kind of easy to seperate, you just build a big clarifying tank. The irony is that you want to return this stuff straight back to the marine environment. Then you need to separate the weed. This is harder cause it floats, so clarifiers wont work. You basically need filters. The problem with filters are 1) they are expensive, 2) they block fast, especially if you have sand and what-not going into them and 3) it is hard to get any great volume of water through them. It would be easier if you sucked everything up then used some sort of liquid biocide on them, like a massive chlorine contact tank on he dredge. This would work, but it would kill everything else you are trying to save. It would literally be a scorched earth approached. And all this relies on your diver guy at the dredge end managing to capture all the weed and not have any little bits float away while it is being disturbed. There are two key elements I think are very interesting. Firstly, no-one anywhere in the world has managed to erradicate caulerpa. Secondly, how much of a problem is it? All the photos and video of it in NZ show good well balanced ecosystems. Ducky claims all the fish are gone in the med, but the med is a different species that was bread to be toxic to fish. I would very much like to see a proper benthic survey of Blind Bay. I would expect there is far more sea life down there than Ducky says, AND if it not good, then it would be no worse than the kina barrens we have everywhere and no-one gives a shit about. Imagine if they shut down the fishing industry, Fizz boat industry and banned all boating and water activities across the Hauraki Gulf because of a few kina barrens? The most intense video I have seen,by niwa,bypass the log in, I imagine it would smoother crabs,snails etc,only fish to be seen are spotties? www.facebook.com/GreatBarrierLB/videos/niwa-footage-caulerpa-brachypus-in-blind-bay-aotea-2021/1455558218133461That is the video I'm talking about. The guy filming will be on scuba, which is very noisy underwater. It will be scaring away any fish worth eating. But as a spear fisho, that footage looks brilliant. There are triplefins and spotties. If you are quiet and sneaky, you will soon come across something to shoot. But to answer your question, we really don't knw if this will smoother the snails, crabs and worms etc. If MPI know, they haven't told us. I would very much like to see a full benthic survey done of Blind Bay. Moreso, it would be key in informing MPI on how hard they need to go in managing this / banning boating. IF Blind Bay has reasonable life down there, then I don't think caulerpa is going to be a big issue. If it is as dead as a desert, then we have grounds for major concerns, and thus far more aggressive rules and controls.
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Post by harrytom on Aug 2, 2023 19:06:12 GMT 12
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Post by fish on Aug 2, 2023 19:44:52 GMT 12
It's everywhere bro. Love this comment though: Kaiwhakatere of Waiheke Marine Project, Miranda O’Connell, said the group conducted underwater drone surveys in January and March. After Caulerpa was found at Kawau in July the group realised it needed to do another survey, O’Connell said. ” We believe currents are one of the biggest vectors, along with boats and fishing gear.”
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