Keeping Them Wet
"In past editions of the Tagging News we have frequently published tips on how to handle fish correctly to ensure their maximum chance of survival. We also continually stress these points in our tagging manual and tagging DVD that are issued to our new members. However, there is an ever increasing amount of research being done on the subject of fish survival after catch and release and it is critically important that we incorporate what the science is telling us into practice."
Keeping them wet!
In past editions of the Tagging News we have frequently published tips on how to handle fish correctly to ensure their maximum chance of survival. We also continually stress these points in our tagging manual and tagging DvD that are issued to our new members. However, there is an ever increasing amount of research being done on the subject of fish survival after catch and release and it is critically important that we incorporate what the science is telling us into practise.
Of all the impacts that a fish endures when it is caught on a line, the most important factor which affects its likelihood of survival is the amount of time it spends out of the water. Research has shown in a range of different species that anything over 30 seconds out of water will result in serious damage to the fish which will greatly reduce its chances of survival. I tell my fellow anglers on fishing trips that it is like you running a 400m sprint and then having someone push your head underwater so that you cannot breathe! When a fish is caught on a line it is fighting for its life. Its heart rate and respiration rate are greatly increased, as too are the levels of stress hormones such as cortisol, which stimulates the release of glucose. The exertion uses up the oxygen in the blood and fish, like humans, switch to anaerobic respiration, and produce lactate. All runners will know, a build-up of lactate often results in cramps and reduces mobility. With all of these negative effects already taking place, removing a fish from the water and subjecting it to an extended period of hypoxia (oxygen deprivation) is paramount to a death sentence. Even if the fish seems to swim off strongly, the combination of exhaustion and physiological stress renders them highly susceptible to predators. When one also considers that fish tend to excrete more urea and ammonia after a catch and release event and that these substances are important prey detection cues for sharks, it really highlights how much care we have to take when practicing catch and release.
Pioneering work done by Warren and Amber Potts and their team of students from Rhodes University working with members of the Rock and Surf Super Pro League (RASSPL) has shown that one of the best ways to overcome the problem of rapid hypoxia and increased stress is to have a bucket filled with fresh seawater close at hand. When a fish is caught in the surf that is going to be released, the first thing to do once it is landed is to place it head first into the bucket so that it can keep breathing. The fish is unhooked in the bucket and then once you have your camera and necessary equipment ready, the fish can be removed from the bucket, placed on a wet stretcher or landing mat with a wet cloth over its eyes to calm it down and it can then be measured and tagged. Once this is done the fish is immediately placed head first back into the bucket and the relevant information can then be recorded. The fish can then be carried in the bucket back to the sea for release.
Obviously if you don’t have a suitable bucket with you and you are fishing off the rocks, a rock pool filled with fresh seawater (not one with warm, stagnant water or a large octopus) will do just as well. Similarly, if you are fishing off a boat and you don’t have a bucket, the live bait well may suffice. Clearly with very big fish the bucket idea won’t work so well but it is incumbent on the angler if he/she wishes to tag and release the fish to make sure that the fish stays in the water as much as possible.
As a reminder, other general tips on handling fish correctly include:
1. Be organised and have your equipment ready before you start fishing (i.e. bucket filled, tag inserted into applicator, tag card and pencil close at hand, measuring stretcher or tape ready with wet cloth, camera close by, etc.).
2. Use good strong tackle and well serviced reels to ensure fight time is minimised.
3. Crimp the barbs on your hook/s and preferably use single hooks rather than trebles and circle hooks rather than J-hooks.
4. Land your fish carefully and avoid gaffing. Preferably use a custom made stretcher or a soft knotless landing net to land your fish. If these are not available, keep your hands wet and use a soft, wet cloth to hold the fish.
5. Don’t drag your fish over the beach or rocks and support it carefully with one hand under the head and one under the abdomen in a horizontal position if you pick it up.
6. Once you have landed a fish, keep it wet and follow the protocol discussed above to ensure that the fish is breathing in water as much of the time as possible.
7. Remove the hook from the fish’s mouth, if the hook is swallowed don’t try to remove it but rather simply cut it off close to the eye of the hook.
8. Work quickly and efficiently, measure your fish accurately and tag it correctly. Don’t stand and lift your fish to take a photo, rather kneel down and pose with it in the water or on the stretcher.
9. Carry your fish back to the sea in the bucket (or in the stretcher if it is too big). Release your fish in water deep enough so that it is not stranded after the next wave. If the fish is weak, take time to hold the fish upright gently in the water with its head facing into the current and allow it to recover.
10. Obviously when dealing with potentially dangerous fish such as sharks and stingrays, great care must be taken by the angler to avoid injury.
By following the 10 points mentioned above you can ensure that the fish you have tagged and released has a much better chance of survival and that it can continue to grow and breed and perhaps give someone else the pleasure of being caught again in the future!