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Post by harrytom on Sept 6, 2023 12:42:13 GMT 12
Follow on from NIWA barotrauma video,still work in progress Many thanks for your query about the snapper release mortality experiments conducted in April and October/November 2022. The work has been completed, and was presented to a Fisheries New Zealand Science Working Group in June, where it was accepted, but unfortunately the final report is not yet available for release. However, I am happy to provide you with a summary of the findings below. Hope this is helpful. Experiments were conducted in April and October/November 2022. In April control fish were caught from a commercial longline set in shallow (6-12m) water depth (specifically chartered for the study). Treatment fish were caught by recreational fishers, marked (fin clip) to identify hook site (lip, foul, gut) and put in holding nets, a different net used depending on the day and depth of capture (<15m, 15-25m, 26-40m). The holding nets were monitored regularly during the experiment to check for mortalities. The same process was repeated in October/November, but as no control fish died in April, no control was used to allow for more treatment fish. A total of 960 treatment fish were included in the experiment. The data were used to examine the probability of a released fish dying, and the survival time (how quickly they die). For the probability of dying, there was no detectable effect of season (April v October/November) or fish size, but hook site and capture depth were important. The probability of death was lowest for lip-hooked fish in shallow water. This probability increased when fish were foul-hooked. For gut-hooked fish, the probability of death was higher than that for lip-hooked or foul-hooked fish. This was most pronounced in 5 –35 m depth. However, by 40 m depth the probability of death in foul-hooked fish was very similar to that of gut-hooked fish. Predicted probability of death in treatment snapper associated with the capture depth (m) for various lip-, foul- and gut-hooked fish. Error bands indicate the 95% confidence intervals. Survival time was also affected by hook site and capture depth, but the analysis did not suggest the experiment missed mortality by not monitoring long enough. 81% of mortalities took place within the first three hours after capture and 95% of the mortality took place within the first 24 hours. All fish were observed for at least 3 days, and some for six days. This study has provided some very useful information on the probability of released snapper surviving, depending on hook site and capture depth. Our next step is to survey recreational fishing activity to understand the number of fish being released, and the nature of their capture. Cheers Ian Dr Ian Tuck Principal Science Advisor, Aquatic Environment Fisheries Science and Information | Fisheries New Zealand – Tini a Tangaroa Ministry for Primary Industries | MPI Centre, 17 Maurice Wilson Avenue, Mangere 2022 PO Box 53030 | Auckland | New Zealand Tel: +64 9 909 8624 | Mobile: +64 (0)21 0227 0176 | Web: www.mpi.govt.nz |
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Post by harrytom on Sept 7, 2023 16:23:33 GMT 12
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Post by fish on Sept 7, 2023 22:41:45 GMT 12
The total number of fish in the ocean can be defined by simple arithmetic, with the following formula:
[original stock] + [new stock] - [mortality] = [remaining stock]
Any plan that does not reduce [mortality] will fail. The same formula applies both inside and outside reserves. Unless you actually reduce total [mortality], fish stocks will not recover.
The easiest way to reduce [mortality] is by simply reducing the number of fish we catch. We can also reduce mortality by ceasing destructive and wasteful fishing methods.
Recruitment of new stock is multiplicative, based on the [remaining stock]. The bigger the stock, the higher the numbers of new stock.
[new stock] = [remaining stock] x [reproduction rate]
If we reduce [mortality], we increase [remaining stock], causing the WHOLE fishery to recover. Furthermore, as the fishery recovers and [remaining stock] increases, we also get more [new stock] each year.
If we allowed the fishery to recover, we could start to increase catch limits again. In time, these catch limits could even be sustainably greater than our existing catch limits. To do this, we must simply kill less fish for a while. This was clearly demonstrated in the West coast snapper fishery.
New reserves are not the answer, because they do not reduce the number of fish killed. Reserves simply shift the fishing pressure, further increasing fishing pressure on remaining areas.
Virtually no one has ever said, "I'm not going fishing today" because of a reserve. People simply go and fish somewhere else and take the same number of fish.
The proposed reserves take away our freedom to fish as we explore our beautiful coastline. Reserves take away our best spots (e.g Mokohinau Islands.) Reserves take away many of the most sheltered spots (e.g. South of Kawau and the Northern side of Little Barrier sheltered from the prevailing wind). Reserves take away our ability to simply throw a line out in the place we have anchored for the night. Reserves further concentrate fishing effort in smaller areas, making it easier for 'the taxman' to steal our catch. Landing whole kingfish at heavily fished spots will become even more difficult. For some people, reserves will take away the ability to fish from their own land. For others, reserves will destroy their businesses (e.g. The Aldermans)
All the while, the proposed reserves will not increase the number of fish in the ocean.
We must stand up and oppose these new reserves that take away our freedom to fish. Instead of reserves, we need to demand reduction of quotas (recreational limits have already been reduced many times with no change to quotas). We must also demand the elimination of damaging and wasteful practices. If we do this, the WHOLE fishery would recover and we could increase catch limits again. With a larger breeding stock, we could all enjoy more productive fishing, wherever we wanted, and even sustainably take more fish than we do now.
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Post by harrytom on Sept 8, 2023 3:35:39 GMT 12
Here's an article from 1927,almost 100yrs no change and still have the ability to catch good numbers, interesting that trawling was banned back in 1927 on the manukau and the manukau doesnt hold great numbers today.So is trawling not that bad? paperspast.natlib.govt.nz/newspapers/NZTR19270728.2.18 |
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Post by harrytom on Sept 12, 2023 9:14:08 GMT 12
Is it just the gulf or the whole northland coast that is stuffed?? Left AK thursday arvo,out between little Barrier and around the mokes,out side gt barrier to almost cuvier then up past the poor nknights to cape karekare in the north before entering the bay of islands,left sunday 6.00pm up to cape karekare,outside the knights/mokes/barrier down to cuvier back up to barrier then to ak. Spent a lot time on deck with binocs searching the sea for life,birds/dolphins etc,no obvious schooling dolphin/kahawai and can count the amount of birds on one hand,not looking good. Admittidly was on a ship but still.Should of seen some life.
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Post by em on Sept 12, 2023 9:53:15 GMT 12
The white bait workups were in full swing off the coat up here until 2 weeks ago . Gannets are now in Whangārei Harbour after piper so kingis will be getting into too .
Usually quiet on the work up front here until late spring when stuff starts hatching and the buffet kicks off .
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Post by fish on Sept 12, 2023 10:23:07 GMT 12
Is it just the gulf or the whole northland coast that is stuffed?? Left AK thursday arvo,out between little Barrier and around the mokes,out side gt barrier to almost cuvier then up past the poor nknights to cape karekare in the north before entering the bay of islands,left sunday 6.00pm up to cape karekare,outside the knights/mokes/barrier down to cuvier back up to barrier then to ak. Spent a lot time on deck with binocs searching the sea for life,birds/dolphins etc,no obvious schooling dolphin/kahawai and can count the amount of birds on one hand,not looking good. Admittidly was on a ship but still.Should of seen some life. Was it blowey easterlies the whole time? Hard to spot things when the water is churned up. PS, harrytom, you didn't go on a CRUISE ship did you? how embarrassing. |
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Post by harrytom on Sept 12, 2023 11:59:37 GMT 12
Is it just the gulf or the whole northland coast that is stuffed?? Left AK thursday arvo,out between little Barrier and around the mokes,out side gt barrier to almost cuvier then up past the poor nknights to cape karekare in the north before entering the bay of islands,left sunday 6.00pm up to cape karekare,outside the knights/mokes/barrier down to cuvier back up to barrier then to ak. Spent a lot time on deck with binocs searching the sea for life,birds/dolphins etc,no obvious schooling dolphin/kahawai and can count the amount of birds on one hand,not looking good. Admittidly was on a ship but still.Should of seen some life. Was it blowey easterlies the whole time? Hard to spot things when the water is churned up. PS, harrytom, you didn't go on a CRUISE ship did you? how embarrassing. Yes I did,2 metre swell from the north avg windspeed 13 knts only birds were some black mutton bird style that worked in the wake where lights were shining,but got talking to a officer and he said they see very few schools of fish/dolphin/whales until 1 day north of nz,he said been coming here 5/6 yrs and noticed the decline,they have to drop speed to 10 knts while in nz waters. Hes never seen a fishing vessel working the coast. |
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Post by harrytom on Oct 21, 2023 13:09:33 GMT 12
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Post by fish on Oct 23, 2023 18:11:40 GMT 12
You know how we are constantly worrying about the latest invasive species, this story is interesting. It is about some 130yr ship wreck discovered in the Great Lakes. But two elements are fascinating. The ship was found by doco filmers studying and invasive mussle. But the sip is lying in 90m of water. Looking at the light and vis, I would have said 20 m. That is the whole point of the doco. This invasive mussle is cleaning up the Great Lakes and dramatically improving water quality. To the point you can see clearly a shipwreck at 90m (with an RUV). There is a comment that this is changing the ecology of the Great Lakes. We've all quiped about how fanworm has improved water quality in Marina's etc. It is likely we are going to carrying on getting loads of alien species showing up in NZ. I jus think this is an example that they wont all be bad, and some might actually be really good for our environment. www.stuff.co.nz/world/us-canada/300994574/ship-lost-in-storm-128-years-ago-found-in-nearperfect-condition |
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Post by harrytom on Oct 26, 2023 11:29:10 GMT 12
Seal deaths around NZ. Starvation maybe the cause? www.msn.com/en-nz/news/other/hundreds-of-seals-mysteriously-dying-across-new-zealand/ar-AA1iMML9Watched TV3 Ocean Bounty from Sunday night. It was based the RMS Niagara. found her by sonar but they could smell oil in the air and found a small slick. Dropped a camera down and on retrevil had black oil on part of the cord. Maybe not too far away from rupturing?? A salvage expert thinks you could use robotics to drill and put a tap on bunker tanks and suck it up to a barge,estimates 1000 ton maybe onboard. |
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Post by fish on Oct 29, 2023 19:26:41 GMT 12
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Post by harrytom on Oct 29, 2023 22:33:01 GMT 12
Tried Ruakura Kingfish at Harbourside restaurant and if you served me sea growen kf i couldnt tell the difference. Salmon now thats a different story wild not as pink and not so oily. Be interesting to see if the snapper farm pens go in at the firth. |
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Post by fish on Oct 30, 2023 9:01:08 GMT 12
Tried Ruakura Kingfish at Harbourside restaurant and if you served me sea growen kf i couldnt tell the difference. Salmon now thats a different story wild not as pink and not so oily. Be interesting to see if the snapper farm pens go in at the firth. Salmon is very easy to tell the difference. Even farmed salmon you can tell the difference between regions it is farmed. I once worked for the UK's biggest Salmon producer on contract down in Wiltshire. The boss was as Scottish as you could get. We would usually get Scottish farmed salmon ex Fraserbourgh. We had to do taste testing of all our products every afternoon. One day he has a bite of salmon and goes nuts, flies into a rage. The broker had sent us Norwegian Salmon, which was clearly inferior to the scottish stuff. That taste testing was tough. Twice a week I'd have to eat fresh Nova Scotia lobster. Prawns. Scollops. Smoked salmon gravilax. Terrible job. If I ever went out for a posh dinner I'd just have the chicken. Can't enjoy top shelf seafood at a restaurant when you have to eat it 5 days a week for work. |
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Post by harrytom on Oct 30, 2023 16:07:53 GMT 12
Tried Ruakura Kingfish at Harbourside restaurant and if you served me sea growen kf i couldnt tell the difference. Salmon now thats a different story wild not as pink and not so oily. Be interesting to see if the snapper farm pens go in at the firth. Salmon is very easy to tell the difference. Even farmed salmon you can tell the difference between regions it is farmed. I once worked for the UK's biggest Salmon producer on contract down in Wiltshire. The boss was as Scottish as you could get. We would usually get Scottish farmed salmon ex Fraserbourgh. We had to do taste testing of all our products every afternoon. One day he has a bite of salmon and goes nuts, flies into a rage. The broker had sent us Norwegian Salmon, which was clearly inferior to the scottish stuff. That taste testing was tough. Twice a week I'd have to eat fresh Nova Scotia lobster. Prawns. Scollops. Smoked salmon gravilax. Terrible job. If I ever went out for a posh dinner I'd just have the chicken. Can't enjoy top shelf seafood at a restaurant when you have to eat it 5 days a week for work. What a terrible job having to taste test seafood  Why when seafood ,even for that matter chicken/lamb etc,why do chefs have to ruin good food by sticking sauce on it and ruining the natural flavours? When I do go out I ask them to hold off of the sauce. Went to one place and had smoked moki,could of been any fish with the amount of crap they stuck on it. |
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Why when seafood ,even for that matter chicken/lamb etc,why do chefs have to ruin good food by sticking sauce on it and ruining the natural flavours? When I do go out I ask them to hold off of the sauce. Went to one place and had smoked moki,could of been any fish with the amount of crap they stuck on it.