Fishing for Red Snapper in New Zealand
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| Kathryn Svendsen catches a Red Snapper in New Zealand |
We signed onto a fishing charter with a friend and two others to do some fishing, specifically for Red Snapper. We traveled out from port and dropped our lines in, and came up with a number of fish. I think I had the largest one, but my wife outdid me in sheer numbers. It took her a while, but once she got the hang of it she was a machine. She must have caught between eight to ten of them.
The process of fishing is fairly familiar to most people; use a fishing rod with hook, bait the hook, and send the thing to where the fish are. Catch, fillet, cook, eat. And, I have to say, the cooked fish was very nice. The boat's skipper did all the baiting and filleting, and we had the local fish and chip shop batter and cook up our fish. All very nice and a memorable morning to boot.
I did, however, notice one thing that really bothered me. Fish that were smaller than the legal limit, under 12 inches fork to nose length, were thrown back. You would think that it is a good thing, letting them get bigger for others to enjoy later, for them to breed and add to the population, and just because it is the right thing to do. However, there was a problem.
Sometimes you could hear it when the fish came out of the water; a hissing sound like air rushing out of a leaking tire. Other times you heard nothing but instead saw a bulbous white balloon poking out from the fish's mouth. Then there were the times that you saw or heard nothing at all, but in my mind I wondered. What had we just done?
The answer, for those who haven't already guessed, is that the fish's swim bladder had expanded, hugely in fact. You see, the swim bladder is in all bony fish and is used the same way a scuba diver uses a buoyancy compensater to maintain a desired depth. Add gas to the swim bladder to go up,
and remove it to go down. Fins help with the actual movement, but to stay at one place in the water column you have to be neutrally buoyant. This is where the swim bladder comes in. It is like a bag holding air, and it is located right beneath the kidneys.
So, here is the problem. We caught the fish at about 30 meters, or around 100 feet down. When they bit, we reeled in, quickly I might add, and brought the fish up to the surface. In doing so the pressure decreased, and the gas in the air bladder does what gas does when it comes from down deep to the surface. It expands. Not only in the swim bladder, but in the blood, which is why divers get the bends if they come up too quickly. So the fish have two problems. First of all their swim bladders get so large that they may rupture or even be pushed out through the mouth. This pressure and rupturing can impact the kidneys which are closely associated with the swim bladder. Then there is the problem of bubbles in the body, whether blood or joints or heart doesn't matter; anywhere is bad and possibly lethal.
When we caught a small one and released it, were we in fact doing a good thing, or just postponing the death of the fish by a few hours? I looked up some research on it and mortality rates increase the deeper the fish are caught. There is a moderate variation on numbers, but at 30 meters a large percentage of the fish thrown back will not recover. We think we are doing a good thing by tossing the small ones - but we actually do not know. I think we are sentencing many of them to their death and we feel good about the fact that they were released. Released to suffer and die is more like it.
I do not have an answer for the where and what, but do know that the few I tossed back may not be swimming around today because of the injury they received. I think operators need to be more aware and should be given a maximum depth to fish. Anything past 20 meters is likely to cause death in released fish. I don't know this for a fact, but it would be good to know what the line is.
I believe we can do a better job managing the fishery - knowledge imparts power.
So, here is the problem. We caught the fish at about 30 meters, or around 100 feet down. When they bit, we reeled in, quickly I might add, and brought the fish up to the surface. In doing so the pressure decreased, and the gas in the air bladder does what gas does when it comes from down deep to the surface. It expands. Not only in the swim bladder, but in the blood, which is why divers get the bends if they come up too quickly. So the fish have two problems. First of all their swim bladders get so large that they may rupture or even be pushed out through the mouth. This pressure and rupturing can impact the kidneys which are closely associated with the swim bladder. Then there is the problem of bubbles in the body, whether blood or joints or heart doesn't matter; anywhere is bad and possibly lethal.
When we caught a small one and released it, were we in fact doing a good thing, or just postponing the death of the fish by a few hours? I looked up some research on it and mortality rates increase the deeper the fish are caught. There is a moderate variation on numbers, but at 30 meters a large percentage of the fish thrown back will not recover. We think we are doing a good thing by tossing the small ones - but we actually do not know. I think we are sentencing many of them to their death and we feel good about the fact that they were released. Released to suffer and die is more like it.
I do not have an answer for the where and what, but do know that the few I tossed back may not be swimming around today because of the injury they received. I think operators need to be more aware and should be given a maximum depth to fish. Anything past 20 meters is likely to cause death in released fish. I don't know this for a fact, but it would be good to know what the line is.
I believe we can do a better job managing the fishery - knowledge imparts power.
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