Us fishermen the best to protect our fishing waters.

[aurebu]

I'm not quite sure how things work in the UK, but by experience in Norway, and Sweden I've notised that the ground owners are the worst possible keepers of the lakes and rivers. Usually there is set an expensive fishing license to be able to fish in a lake, or river, and then they don't do much to take care of the fishing recourse. well, they might set a bag limit, or not let you take fish under a certain size. After years of studying trout, and char I've found this to be the worst way possible to take care of your lake or river. Instead of a minimum size, and a bag limit, why not try a maximum size, and no bag limit. Trout and Char can have a life span of 6 to 40 years, depending on food supply, and water quality.

 

In a test pond we set a maximum weight just above the averagage size of the fish in the pond. After six years the over populated pond which initially had an average size of trout of 50g and agerage age of max 6 years, now had an average size of fish of 400g, and max age of 7-8 years. There also started to show up fish that where 2-3 kg. The density of fish in the pond did not change. No new fish where added, ond no net fishing was allowed. What also happened was the sediments started to change in the pond. Larger fish rummaging for food stirred up the bottom causing more nurishment to spread in the water, water creatures such as daphnia grew in numbers, the meat color of the fish went from white to red, and all insects grew in size and number. But also the number of hatchlings grew. The first years, the number of spawning fish went down, but then grew in numbers, more eggs where laid. Since there where more larger fish in the pond that had become predators, the number of hatchlings growing to mature size went down. This is an ongoing project that started in 2000. The past two years the average size of fish has gone down a little. this is natural since a gap in the population has occured. This is the fish between 200g, and 500g that there aren't that many of any more. This summer ther was a large amount of fish form newly hatched to about 200g, then a gap up to the size of 500g. and then a lot of fish from 500g and up. this is because we have set a maximum weight of fish to be 500g. However the 200g fish are all 3 year olds that haven't spawned yet, and wont spawn for the first time until they are four or five.

 

I other words, the whole pond is more healthy than before, the fish are eating a bigger variety of prey, growing faster, and bigger, and there are more predators, and more hatchlings. now there are more people fishing in the pond because they now catch bigger fish, and can catch fish that are 2-3 kg though these are released again.

 

What stands to se in the future is how big the population of large fish will get. How the life span of the fish in the pond will grow. when the average side of fish passes 1 kilo the max weight that people can take with them will be set to one kilo My guess is that the average size of fish in the pond will eventually settle at somewhere between 1 and 3 kg.

[Newt]

Interesting test results aurebu - and welcome to AnglersNet.