not a yellow but just as much fun

[Freespool]

Jim,
Very interesting take on keeping the big vs. the small. Definitely makes me rethink my usual train of thought that the big breeders are the ones to leave alone. What's the deal with mercury levels in the big ones though? Those big threshers have been around a long time eating and bioaccumulating. I think I'd rather feed the neighbor's wife and kids with a smaller one, at least from a health perspective.

I think the more important idea is to try and only keep males, that is if you want to harvest threshers. They are VERY easy to identify with those huge claspers no matter what their size. Game managers have been managing deer and other large game for a long time by only allowing the harvest of males, and it seems to work well for the population. Maybe the same should happen with some species of sharks?

[Fiskadoro]

Originally Posted by Freespool

JWhat's the deal with mercury levels in the big ones though? Those big threshers have been around a long time eating and bioaccumulating...... I think the more important idea is to try and only keep males, that is if you want to harvest threshers.

Those are both good points.

You know it's kind of weird for me as it's such an old issue for me. I just posted kind of the same thing I've been saying for over a decade.

Honestly I've not been keeping up or looking for new information when it comes to T's and Mercury. The last thing I read on mercury was a few years ago and it said that adult T sharks were not as bad as tuna or swordfish when it comes to bio-magnification, but that's now old information.

As to the male shark idea: Yes you are absolutely right if if you want to harvest sharks, it's preferable that you only take males. I should of said something about that in my post. Females carry the young one male can mate with many females.


You might find this interesting but I feel the same way about lobsters. Same idea one male can mate with many females. I occasionaly keep smaller females when hooping is very slow but if possible I release all my females and never keep big females over three pounds. The larger the tail the more eggs they can protect and carry. On the other and I have no problem killing big males as larger males are canibilistic and eat their own young.

Jim

[THE DARKHORSE]

I just want all my favorite irons back!

[shortstack]

Originally Posted by THE DARKHORSE

I just want all my favorite irons back!

LOL!!!!!!!!

[Freespool]

Originally Posted by Jim Day

You might find this interesting but I feel the same way about lobsters. Same idea one male can mate with many females. I occasionaly keep smaller females when hooping is very slow but if possible I release all my females and never keep big females over three pounds. The larger the tail the more eggs they can protect and carry. On the other and I have no problem killing big males as larger males are canibilistic and eat their own young.

Jim

Makes perfect sense to me and I would advocate that as a management technique. That's what they do with Dungeness crab up north. It's illegal to take any females. Every year, they estimate that they have been harvesting ~90% of all the males in the population every year for a LONG time and the Dungeness fishery remains the most sustainable commercial fishery in Nor Cal.

One other point that supports keeping the big sharks. PIER has done recent research on catch-and-release mortality of threshers and they've found that when the fight time exceeds 2 hours, the survival goes WAY down. Those long tail-hook fights are the worst on them obviously. I would venture to guess that fights over 2 hours are mostly on big sharks, at least I would hope so.