fishing size limits

[agentaqua]

Want Sustainable Fishing? Keep Only Small Fish, And Let The Big Ones Go
</u>
ScienceDaily (Dec. 1, 2008) — Scientists at the University of Toronto analysed Canadian fisheries data to determine the effect of the "keep the large ones" policy that is typical of fisheries. What they found is that the effect of this policy is an unsustainable fishery.

In fact, the opposite policy (keep the small young ones and throw back the large old ones) would result in a more sustainable fishery. In short -- a big fish in the water is worth two in the net.

Put simply, a fish population will produce more young -- and therefore sustain more fishing -- if it is made up of big, old fish.

The team of scientists, led by Paul Venturelli, a graduate student in the Department of Ecology and Evolutionary Biology, used a simple population model, as well as evaluating data from 25 marine fish species. They also tailored their methods to allow for other possible causes for the results, such as the effect of climate.

Finding ways to replenish fishery stocks and improve management provides both ecological and financial benefits.

The research is published in the Proceedings of the Royal Society B.
Adapted from materials provided by University of Toronto.
Email or share this story:
Need to cite this story in your essay, paper, or report? Use one of the following formats:
APA

MLA
University of Toronto (2008, December 1). Want Sustainable Fishing? Keep Only Small Fish, And Let The Big Ones Go. ScienceDaily. Retrieved December 12, 2008, from http://www.sciencedaily.com­ /releases/2008/11/081130210013.htm
enlarge

Large mouth bass in a lake. A fish population will produce more young -- and therefore sustain more fishing -- if it is made up of big, old fish. (Credit: iStockphoto/Judy Ledbetter)

 

[Barbender]

I could not agree with a post more than this one. I have been saying this for awhile now. Taking the genetically superior fish out of the mix can only have negative long term repercusions.

 

[Last Chance]

Didn't California have a rule on salmon at one point that the first two you catch you keep regardless of size? I thought I read that somewhere.

Last Chance Fishing Adventures

www.lastchancefishingadventures.com
www.swiftsurebank.com

 

[Cuba Libre]

quote:Taking the genetically superior fish out of the mix can only have negative long term repercusions.

On what grounds do you think a "big" fish is necessarily genetically superior? Me thinks you need to take a genetics course ot two!! [B)]




20ft Alumaweld Intruder

 

[Cuba Libre]

quote:Taking the genetically superior fish out of the mix can only have negative long term repercusions.

On what grounds do you think a "big" fish is necessarily genetically superior? Me thinks you need to take a genetics course or two!! [B)]




20ft Alumaweld Intruder

 

[Five-oh]

Hope you don't mind if I field this one....

A big fish is better fit to compete for food, territory, spawning grounds and mates.A bigger fish carries more eggs. It's offspring inherit the size trait and are better able to compete for those resources as well. Big fish carry more energy reserves to survive during times of food shortages. Predators target the small, the weak, the injured. No predator tarkets the biggest, strongest, healthiest member of a school/herd.

Being a big fish increases the odds of being harvested by man (as we are greedy and naturally desire to keep the biggest fish). In time we will select for genetically small fish, as no big fish survive to spawn and pass on those genes.I'd agree that this is a negative long term consequence.


What else would make a small fish genetically superior asides from the fact that no-one will want to bonk them?

 

[agentaqua]

Good post, Five-oh.

In addition to all the obvious reasons (e.g. # of eggs produced is in proportion to size; size is related to age, etc.) - older (more experienced) "mothers" are better at releasing larvae at the right time for the plankton ploom, and also contribute better vitogellin reserves to their eggs. See: http://plankt.oxfordjournals.org/cgi/content/abstract/25/3/291

That's 1 hypothesis about the lack of rapid recruitment in the "rebuilding" of the Newfoundland cod fishery - the young cod are too inexperienced to have good reproductive success.

Fish also do learn from each other, and it's thought younger fish may try to emulate older fish - so that good mothers are also a good role model as to when/where to release eggs.

This last point was often ignored or even ridiculed by a few older fisheries managers, but seems to be gaining greater acceptance now.

So, what do we commonly do in marine fisheries management in Canada?

Have a lower size limit, only - i.e. allow only larger fish to be caught and kept.

Many freshwater fisheries in Canada have a size retention "window" where really smaller, younger fish are allowed to get established, and older, successful spawners are allowed to spawn.

Yet, we do the opposite.

Anyone want to bite on this one?

 

[fish_in_fish_on]

I agree that big fish should be released for reproduction purposes, in the case of pacific salmon bigger females obviously carry more eggs but when they get one shot at spawning with dwindling stocks bigger older fish provide important genetic diversity.

It would be nice to see a slot size for retainable fish however this poses two problems. honesty and enforcement. i do not think there are enough honest people out there who would release a 35 or 40lb chinook let alone something bigger. and there is not enough enforcement out there in general to stop dishonest fisherman.

 

[Five-oh]

Managing a slot size would be difficult. There are alot of dishonest fisherman, but anyone who fishes barbed hooks for example, tend to hide their gear, because they know it's wrong.

Peer pressure can be an effective enforcment tool for ensuring the release of large fish. Its difficult to land a 40 pound spring without drawing any attention to yourself. And if I witness someone take an illegal fish, I'll say something to em and report em. You can be sure that the rest of their day on the water (should they decide to stay) will be an unpleasant experience.

If someone takes an illegal oversize fish...what joy does it become if they can't take a picture of it, can't show it to friends/other fisherman, can't clean it at the fish table or take it to the smoker...have to hide it and deny its existence.

To some extent I believe its the responsibilty of the sports fishing community to police itself, not through vigilanty justice, but through peer pressure and education.

 

[alumaman]

They have a slot limit for lake trout for selected or "trophy" lakes in the yukon, any lake trout between 26-39 inches goes back in the water, you can keep one over 39" and two or three under 26". these rules have been in place for a number of years and the fish quantities seem to be coming back. one large lake they pretty well shut down to any fishing for a couple of years. what they are finding now is the fish are becoming smaller because the genetics of the larger trout aren't there due to retention of fish over the slot limit.

 

[wolf]

Well when they first did the old one over 77 cm and one under there were a lot of fish killed on purpose and by accident as alot of people have no clue as to handle a larger fish,they bring it in the boat and take the hooks out as it slams its head on the deck then take a pic then throw it back in the water a fish say over 25 lbs if it isnt cradled and handled with proper gloves etc will most likly die a fish that size if not supported right will damage itself.
And I know from personal experience when they had that most retarded rule someone who got a fish just over 77 cm and bonked it and then an hour later they get a real good one (35lbs) well I you know what happens over goes the smaller fish in the bottom of the ocean.

It is really easy to do you go out catch 2 fish no matter what size then your done you cant fish anymore for years off of sooke we had to go through 15 wild coho to get the 2 hatchery you were looking for a complete waste of the coho stocks dont know why they didnt do get your 2 coho and then your off the water. it just makes me mad
As for the size for smaller fish now all you need to do is look at our herring fishery the stocks are way down and should be halted no feed = smaller fish


Wolf

Blue Wolf Charters
www.bluewolfcharters.com

 

[scott craven]

I couldn't agree more Wolf, let the guy catch his 2 fish and it's over. No more worrying about mortality rate of badly hooked fish.
This is not rocket science, if we can see it so clearly why can't
D.F.O. ???

 

[chris73]

r.s. craven, you know why DFO can't see it? Because the rule-makers are non-fishermen sitting in Ottawa and have not the slightest clue how salmon fishing looks like in reality nor do they even have the slightest inclination to learn it. Looks good on paper - good enough to pass...That's unfortunately how it works. Maybe if guys with connections into higher political ranks (like sushihunter, serengeti etc.) could personally teach some of those folks, maybe then at least some appreciation of our west coast practical problems will find an ear...

 

[Barbender]

Thanks Five O. Did not think that one would need explaining but I guess it did. Wolf you bring up other good points regarding handling of fish and what people do wrong. I have seen some real ugly things over the years. One time in Renfrew a guy came to the dock with his buddy with 4 nice springs. The problem was the fish had been sitting in the sun on his deck all day while he tagged out. You could see the skin all dried up and wrinkly. What a waste. People need to educate themselves on how to handle fish and how to release them.