mackeral catch and release

i only noticed now that this topic hasn't been mentioned on the site. but it's quite topical at the moment, and i just thought i would bring it up here in case people weren't aware(i only heard recently myself).
but, supposedly, once mackeral have been caught, and handled by humans, there is a gradual, and irreversible breakdown in the fishes skin due to the oils, and heat from a humans skin. you're recommneded to crush the barbs, and simply shake the fish back into the water.........
this is a slightly contentious topic, as there seems to be a slight lack of scientific prove, and contradictary evidence. i'm not trying to start any arguements, this post is simply to highlight a subject few people seem to be aware of.

Patrick

I recently wrote to one of the UK's top fishery scientists at CEFAS about this:-

Hi Mike,

I wonder if you can answer this, or pass it onto someone who can?

Frequently the question of returning mackerel alive appears on the various angling internet forums.

There is a belief by many that once a mackerel has been touched by an anglers hands, even though the fish may swim away energetically, it is doomed.

Something to do with the heat/oil of the anglers hands (where it has been touched can often be seen as a handmark on the fish's skin).

Even though only microscopically damaged, the mackerel's skin continues to break down with death inevitable within 30 hours.

Shaking the fish off the hook or handling with wetted neoprene gloves is said to prevent the problem.

The problem is that when the mackerel shoals are on the beach, anglers will soon catch their self-imposed limit, but can't seem to stop fishing, often changing from feathers to a light spinning outfit and returning every fish they catch.

(If the above is correct, then they are better advised to cease fishing for mackerel and trying for the bass beyond/underneath the shoals perhaps, with less guarantee of catching).

Although this information is widely quoted, I can't find any authoritive reference to such information, although I vaguely mention talking to someone from CEFAS at the Recreational Angling Conference in Cardiff some years back, who confirmed that was the case.

It would be useful to quote an authoritive source to refer people (one way or the other) to when the subject comes up in the future.


Tight Lines - Leon Roskilly
Sea Anglers' Conservation Network (SACN)

SACN Latest: http://www.anglers-net.co.uk/sacn/latest

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Leon,

You are quite correct, and you've come to the right people!

In the late 1970s we carried out several experiments to try to find out why dead mackerel were being found in vast numbers in the SW, co-incident with the purse seine and trawl winter fishery.

The short answer is that the fish died due to skin damage interfering with their ability to maintain osmotic balance, and the skin damage was due to abrasion between crowded fish in the nets.

We found that mackerel caught on barbless hooks and never handled, just dropped into keep tanks or nets, survived quite well if allowed to swim freely, but holding a mackerel caused enough damage to eventually kill it, sometimes two days later.

I have a number of publications showing the results of all this work, and I can send you the most relevant if you send me your home address.

These are:

Lockwood, S. J., Pawson, M.G. and Mumford, B.C., 1977. "Effects of holding mackerel at different densities in nets of various sizes." M.A.F.F., Fish. Res. Tech. rep. No. 33, 10 pp


Pawson, M. G. and Lockwood, S. J., 1980. "Mortality of mackerel following physical stress, and its probable cause." I.C.E.S. rapp. proc. verb., 177: 439-443.


Holeton, G. F., M.G. Pawson & Shelton, G., 1982. "Gill ventilation, gas exchange and survival in the Atlantic mackerel (Scomber scombrus L.)." Can. J. Zool, 60: 1141-1147.


Lockwood, S. J., M. G. Pawson and D. Eaton., 1983. "The effects of crowding on mackerel (Scomber scombrus L) - physical condition and mortality". Fisheries Research, 2: 129-147.


So, when anglers have caught enough mackerel for a fry or for bait, they should stop fishing for them unless they are using barbless hooks and can return the fish to the water without touching them.


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Tight Lines - leon

Thats very interesting. I simply stop fishing mackerel once I have enough for bait for the session, usually four or five does. Quite often this only takes three or four casts but after that I simply put the mackerel gear away. Don't see the point in handling and stressing fish only to fire them back.

Pete

You wouldn't believe the amount of 'Huhs' and 'whats' I get from People now when I go.... 'Noooooooooo don't touch that mackeralllllll'.... :shock: :lol:

Apparently the Marine Institute have been carrying out tagging experiments for a few years - catching macks on rod and line (tough job huh!) and tagging them then seeing where they turn up in commercial catches. Irish-tagged mackerel have turned up in catches from Spain to Norway. Would guess they used barbless hooks and wore neoprene/latex gloves to minimise handling and stress. From talking to one of the guys, I don't think its the heat that causes damage but the abrasion caused by friction between hands and fish rubbing off the protective mucus on the fish's skin. Wetting your hands before handling a fish is always a good idea as it helps to reduce this friction. Have caught and released plenty of trout and salmon and always handle with wet hands, if I need to handle them at all. Much better to go barbless and shake the fish off the hook without any handling at all....

seems strange,im a coarse angler and we catch fish time after time with no problems.Ive even caught pike twice in the same day.

i dont know about all this friction with the fishs skin and hands(well i do :? )
buttt.........how many of you notice the amount of scales that come off the mackeral!! that must leave a big weak spot for desiese :shock: :shock: .

you can see the patches instantly on the fish once you handle it!

no matter what fish it is i always try and use a wet cloth, that is if i handle it at all.

Mackere skin is very special, extremely thin.

Even microscopic damage will start a slow breakdown of the skin that allows denser saltwater to be drawn into the flesh, causing death within about thirty hours.

what happens if another mackrel hits off another one will that makeral aslo die

was talknig to a guy who works in the local aqarium and he says that its simply that makrell are a very fragile fish when they try to stock thaem buy catching them across the road placinging them emediatlyin a bucket of water and then running acrooss the road with them without evan toching them 90 95% die in the first 30hrs

so my advice would b if you dont want to keap them then dont fish for them

I always throw the little ones back and after reading this realise i have been wasting my time.

Does anybody know if any other fish are affected in the same way?

Obviously some tagged fish are recaught but is it only Mackeral that die when in contact with our hot hands.?

By the way this is a great site very informative :) :)

If uve caught mackeral before u'll notice in the sun light there skin is like a rainbow so theres something going on there thats why i kicked up about scratching why down size your tackle to get smaller fish there skin is bound to be more delicate dont get me wrong here id plan 2-3 trips when the mackerals in to get bait to carry me through the rest of the year for pike and the odd sea expedition. This might sound silly but when was the last time u saw sombody throw a mackeral back in id rather put it on the barbi straight out the water with a bit of salt n pepper ud be surprised how good it tastes

If uve caught mackeral before u'll notice in the sun light there skin is like a rainbow so theres something going on there thats why i kicked up about scratching why down size your tackle to get smaller fish there skin is bound to be more delicate dont get me wrong here id plan 2-3 trips when the mackerals in to get bait to carry me through the rest of the year for pike and the odd sea expedition. This might sound silly but when was the last time u saw sombody throw a mackeral back in id rather put it on the barbi straight out the water with a bit of salt n pepper ud be surprised how good it tastes

Ahhhh that's quite simple.............The little ones i feel guilty for taking cause they didnt have a chance to grow bigger being so young and i cant really get my head round catching a prime food source ( Mackeral ) to use as bait to catch something you cant or have no intention of eating, seems a even bigger waste and doesnt make sense to me.

I know i need a shrink but it's just the way i think---sorry.

i'll probably get in trouble for mentioning this, but the scientists estimate that the commercial fleet can safely land 55,000 tonnes of mackerel in 2007. ( there's a bit of a reduction due to around 40,000 tonnes landed illegally). The rounding error these boys use is 1,000 tonnes.

also, according to a recent financial times article almost 90 per cent of some catches (smaller or younger fish of little commercial value) is dumped in some waters around Scotland and Ireland.

so this is much more significant than anything the angler might or might not do

Ahhhh that's quite simple.............The little ones i feel guilty for taking cause they didnt have a chance to grow bigger being so young and i cant really get my head round catching a prime food source ( Mackeral ) to use as bait to catch something you cant or have no intention of eating, seems a even bigger waste and doesnt make sense to me.

I know i need a shrink but it's just the way i think---sorry.

i understand the way catching a mack to catch something youve no intention of eating seems like a waste - but the way i justify it is - that is a demand that wont be placed on commercial fishing and therefore promoting it - ie you wont be going to the supermarket to buy it

your own caught will be far superior bait anyway