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Fishing reefs up north we get a wide variety of small "bycatch" species, as well as undersized "targets" like coral trout and red emperor. Many are "blown", and few can "self-vent" (red emperor are notable for this ability). Much research has been done, with venting trials and cameras in cages, but not a huge amount of campaigning for public awareness exists in Qld at least.

The NT Fisheries has posted a video showing hollow-gutted, feeble, golden snapper (in a cage) on the seabed after venting at the surface using a hollow needle. Their policy discourages catch and release of golden snapper and black jewfish for this reason, and they have no size limit on these fish...just a bag limit. In contrast, WA has legal minimum lengths and fishing stores there stock release weights for undersized dhufish and snapper. It is interesting to note that NSW research found that some small snapper recovered even when the swim-bladder was vented by poking a hole in the inverted stomach poking out the mouth.

I had been using a venting needle made from a large gauge hypodermic needle, but it is a b...... to use properly, and the fish will be negatively buoyant when they reach the seabed.

The Qld Fisheries advice is to poke the needle through the side of the fish up front, but it often blocks with skin or tissue. It is also easy to bend a needle on a big, leathery cod. The divers in the Coral Reef Aquarium Fishery carefully use a hypodermic needle behind the vent of the fish, with the fish in a bin of water (to squeeze the air out). You can see bubbles when you do this. They do fish as small as damsels (less than 10cm). 

Some of the "flower pots" we catch are in the bommie cod family that can live for 45 years, or in the attractive wrasse family, so it is necessary to handle them well. When they "blow", with stomach poking out the mouth, they go stiff with tonic immobility and cannot swim. So spearing them back in does not work in deeper water. The worse the barotrauma the worse the "blow". 

I have had recent success with DIY release weights. Basically an inverted, weighted hook of bent stainless TIG welding rod with a loop bent in the gape. You poke the longer, blunt end of the hook through the gill opening and out the mouth of the fish, then shoot it back down on a handline or clipped onto the swivel on your rig.

The fish either recovers at depth and dashes off the hook, or you can just tug it back out. This way the fish gets back down into reef shelter fast and has its original  buoyancy intact.

The only downside I have had is the fish sliding off before I get it in the water, so a longer hook worked better. That might be an issue with fish that keep thrashing when "blown". You'd probably need a besser block to get a groper back down!

I reckon release of snapper affected by barotrauma will become an issue in deeper SA reefs, now they are off-limits for 3 years, so weights such as these could be worth carrying in deeper areas where "ruggers" are prevalent. Perhaps some sort of clip could be designed too??

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Edited by Plectropomus
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One reason some fish don’t appear to bloat is because their swim bladders rupture in the way up. 
 

From the reading Ive done - while release weights are the best of a bad lot - the internal injuries and mortalities that come from fishing in depths over 10 m - mean it’s not an option for catch and release. 
 

 More of a “get your bag and get out”situation

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12 hours ago, yellow door 1 said:

One reason some fish don’t appear to bloat is because their swim bladders rupture in the way up. 
 

From the reading Ive done - while release weights are the best of a bad lot - the internal injuries and mortalities that come from fishing in depths over 10 m - mean it’s not an option for catch and release. 
 

 More of a “get your bag and get out”situation

Trouble is the undersized bycatch. I use 10/0 circle hooks to try and avoid small fish, but I still catch undersized coral trout and non-target "flowerpots". I'm out there for a feed in deeper water, not catch and release sportfishing...but still have to catch and release. It will be the same with SA folk having to release all snapper. Red emperor have massive head and rib skeletal framework, and their swimbladder bursts out just behind the vent where the skin is thin. You can see this in clear water as a cloud of bubbles accompanies the fish on the way up. Same with "slatey bream". The worst affected are the "nannies" (small-mouth and large-mouth, aka crimson and saddletail snapper). Large-mouth nannygai from 50m plus are so "blown" their eyes are bulging out on stalks, their scales are lifting, and they look like they have a football in their mouth. Hard to see them surviving any sort of treatment in that depth. Luckily the undersized fish (<400mm) live inshore in shallower water

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10 hours ago, David_C said:

These are the ones that I sell. The trick is to use the heaviest weight possible - my heaviest is 1.45 kilos.

A lot of states are getting into these - I'm in the process of sending 250 of them to DPI NSW :)

I find it easier to have two people to release the fish but still not perfect

Release Weights.jpg

Good on you!!! From the point on these I assume you are puncturing the lower jaw to get them in? I tried longer, blunt, hook section to avoid this by slipping it under the gill cover and out the mouth....but (as you say) solo operation means they sometimes slip off before you can get them back in the water. It just needs care and attention.

Great to see these being made. I have not seen any in North Queensland tackle stores. 

Is SA having any media campaign to help anglers release snapper with barotrauma? It would be good to see your product (and its use) highlighted with a video clip on social media. There is lots of negativity on the facebook sites, so your release weights would be a nice bit of positive news for a change.

Some folk up here just toss the blown fish back in to float. 

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Here’s something I posted a while back when the subject came up

 

Release weights and weighted drop nets give them a chance but alot of studies have some pretty unacceptable outcomes. Like 9 out of ten snapper released back to depth with these methods dying. And that still the best way to do it


(the snapper in the study below were caught between 8 and 70m)

".......all fish exhibited various clinical signs of barotrauma, including a prolapsed cloaca (60% of fish); gastric herniation (46%); ruptured swim bladder (73%); organ displacement (48%); and kidney (3%), liver (73%) and coloemic-cavity haemorrhaging (33%);with the frequency of nearly all positively associated with capture depth"

 
  •  
 
  • I just watched the video and even though the guy is recommending them - he still states that snapper released with those weights, only have a 10% chance of survivingwhich is still alot better than other methods like venting.

    • So while release weights are the best option - you are still killing 90% of the fish you releasI’m
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9 hours ago, Plectropomus said:

Good on you!!! From the point on these I assume you are puncturing the lower jaw to get them in? I tried longer, blunt, hook section to avoid this by slipping it under the gill cover and out the mouth....but (as you say) solo operation means they sometimes slip off before you can get them back in the water. It just needs care and attention.

Great to see these being made. I have not seen any in North Queensland tackle stores. 

Is SA having any media campaign to help anglers release snapper with barotrauma? It would be good to see your product (and its use) highlighted with a video clip on social media. There is lots of negativity on the facebook sites, so your release weights would be a nice bit of positive news for a change.

Some folk up here just toss the blown fish back in to float. 

The closest place to you that stocks me is at noosa. I don't advertise to businesses anymore - it's now all word of mouth and keeps expanding!

PIRSA were very strong about venting being an issue and asked me to make these for the SA Market. Mine are based on an existing design but with a thinner wire gauge.

With snapper, we put it into the corner of the top jaw - this is the safest place to put it without potentially puncturing the swim bladder - if expanded. PIRSA were going to do a campaign but then the snapper ban came in, so it never got done. So Dan from The Fishing Guru organised a very informative video on the matter :)

Heaps of people make their own and eventually, they are likely to be required on all boats, given the amount of snapper around (based on feedback from fishoes, not PIRSA). I sell all of mine for $10 - regardless of size - as it's all about encouraging people to use them. There are a lot of other species that suffer from barotrauma that they would work on as well.

David

 

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23 hours ago, David_C said:

The closest place to you that stocks me is at noosa. I don't advertise to businesses anymore - it's now all word of mouth and keeps expanding!

PIRSA were very strong about venting being an issue and asked me to make these for the SA Market. Mine are based on an existing design but with a thinner wire gauge.

With snapper, we put it into the corner of the top jaw - this is the safest place to put it without potentially puncturing the swim bladder - if expanded. PIRSA were going to do a campaign but then the snapper ban came in, so it never got done. So Dan from The Fishing Guru organised a very informative video on the matter :)

Heaps of people make their own and eventually, they are likely to be required on all boats, given the amount of snapper around (based on feedback from fishoes, not PIRSA). I sell all of mine for $10 - regardless of size - as it's all about encouraging people to use them. There are a lot of other species that suffer from barotrauma that they would work on as well.

David

 

Could I get hold of that video from Fishing Guru somehow? is it on YouTube?

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On 26/10/2020 at 4:36 PM, yellow door 1 said:

Here’s something I posted a while back when the subject came up

 

Release weights and weighted drop nets give them a chance but alot of studies have some pretty unacceptable outcomes. Like 9 out of ten snapper released back to depth with these methods dying. And that still the best way to do it


(the snapper in the study below were caught between 8 and 70m)

".......all fish exhibited various clinical signs of barotrauma, including a prolapsed cloaca (60% of fish); gastric herniation (46%); ruptured swim bladder (73%); organ displacement (48%); and kidney (3%), liver (73%) and coloemic-cavity haemorrhaging (33%);with the frequency of nearly all positively associated with capture depth"

 
  •  
  •  
 
  • I just watched the video and even though the guy is recommending them - he still states that snapper released with those weights, only have a 10% chance of survivingwhich is still alot better than other methods like venting.

    • So while release weights are the best option - you are still killing 90% of the fish you releasI’m

90% mortality sounds extreme. I am doing more digging, and found this article on Fishing World:

https://www.fishingworld.com.au/news/fish-facts-snapper-barotrauma1

 

Maybe that is one of David_C's release weights in the cover picture on the article :) :) 

One might imagine "Fishing World" is  pro-angling, but it is surprising different studies (even on the same species) give such different mortality rates. I have contacted Bill Sawynok (from InfoFish) to ask about the fate of tagged fish released after venting. InfoFish were heavily involved in the "Release of Line-caught fish" program funded by the Fisheries research and Development Corporation (FRDC). Their early studies are summarised  in newsletters at:

http://infofishaustralia.com.au/released-fish-survival-news/

and  final reports at:

http://infofishaustralia.com.au/released-fish-survival/

 

However, long-term survival is most important, and there have now been a decade or so of recaptures available from angler's tagging fish and recording depth/barotrauma/release method.

 

I will post these once Bill gets back to me with some summaries.

 

PS I really like that idea of a weighted drop net too!!

 

 

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Bill Sawynok from InfoFish sent me this extract from their 2018-19 Annual Report. He is going to analyse the snapper tagging data and send some plots too. Thorough gentleman!

 

West Australian Dhufish

For the last 10 years from 2009-2010 to 2018-19 there were 708 West Australian Dhufish tagged. Figure 54 shows the numbers tagged each year, average length and the size range of fish tagged over the past 10 years. The largest Dhufish tagged was a fish of 1,260mm in 2002/03.

Figure 54: West Australian Dhufish tagged, average length and size range (bars)

 

Depth of capture was recorded for 2,301 Dhufish and Figure 55 shows the recapture rate for fish tagged at different depths. The recapture rate for fish tagged in over 100m depth needs to be treated with caution due to the low number (14) of fish tagged. The highest recapture rate was for fish caught from 0-19m at 12.5% and from 20-49m at 12.0%. There appear to be little difference in the recapture rate for fish tagged in depths up to 50m.

 

Release method was recorded for 1,142 Dhufish and Figure 56 shows the recapture rate for fish released using different release methods. The highest recapture rate of 12.1% was for fish released using shotline (release weight used to return fish to the bottom) while venting has the lowest recapture rate of 7.4%.

 

 

 

Figure 55: West Australian Dhufish tagged at different depths and recapture rates

 

 

 

Figure 56: West Australian Dhufish tagged and recapture rate from different release methods

 

recaps frfom different depthss.png

recaps frfom different release mthods.png

relesse by size.png

Edited by Plectropomus
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2 hours ago, Plectropomus said:

Bill Sawynok from InfoFish sent me this extract from their 2018-19 Annual Report. He is going to analyse the snapper tagging data and send some plots too. Thorough gentleman!

 

West Australian Dhufish

For the last 10 years from 2009-2010 to 2018-19 there were 708 West Australian Dhufish tagged. Figure 54 shows the numbers tagged each year, average length and the size range of fish tagged over the past 10 years. The largest Dhufish tagged was a fish of 1,260mm in 2002/03.

Figure 54: West Australian Dhufish tagged, average length and size range (bars)

 

Depth of capture was recorded for 2,301 Dhufish and Figure 55 shows the recapture rate for fish tagged at different depths. The recapture rate for fish tagged in over 100m depth needs to be treated with caution due to the low number (14) of fish tagged. The highest recapture rate was for fish caught from 0-19m at 12.5% and from 20-49m at 12.0%. There appear to be little difference in the recapture rate for fish tagged in depths up to 50m.

 

Release method was recorded for 1,142 Dhufish and Figure 56 shows the recapture rate for fish released using different release methods. The highest recapture rate of 12.1% was for fish released using shotline (release weight used to return fish to the bottom) while venting has the lowest recapture rate of 7.4%.

 

 

 

Figure 55: West Australian Dhufish tagged at different depths and recapture rates

 

 

 

Figure 56: West Australian Dhufish tagged and recapture rate from different release methods

 

recaps frfom different depthss.png

recaps frfom different release mthods.png

relesse by size.png

It's definitely interesting but these are only based on recapture rates - so the survival rates may be higher. We just don't know.

For me, the way the fish is released makes all the difference. Unfortunately there are some fishoes who don't give a damn and sadly, many of these fish are unlikely to survive. How the fish is netted, how it is held, how long it's out of the water - makes a significant difference. I've seen some people gaff fish they are going to release - what the heck!

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