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Following a similar line of reasoning as that expressed by Trevor with
regard to "spawning at least once," I would question the need to
avoid fishing during the breeding season. Unless fishing broadly disrupts
spawning by individuals other than those that are caught, spawning should be
adequate if the spawning biomass that gets to spawn is adequate.
These myths lead to regulations that create waste of harvesting resources
that are increasingly hard to justify. For example, rules that require the
discarding of egg-bearing lobsters have no biological justification other
than to reduce the fishing mortality rate, which could be accomplished with
direct controls on total harvest. Almost every female lobster that is
landed is bearing eggs internally, which is legal. Total egg production
would not be adversely affected if lobsters with external eggs were landed
and there were a cap on harvest that caused females without external eggs to
be left in the water to bear their eggs and reproduce.
This absurdity is exacerbated by the prohibition on taking "V-notch"
lobsters, which are females that have been marked with a notch in their tail
flipper to protect them from harvest. This "torture and release" program is
another example of a popular regulation that is wasteful of total resource
use.
With an 86% discard rate in the Rhode Island lobster trap fishery in 2006,
we need to think about the waste of fuel, bait, labor, etc associated with
the use of regulations that allow fishermen to catch too many animals, but
require them to throw most of those animals back. Better to simply keep
what is caught and stop fishing when the allowable take has been landed,
taking into account the size distribution of the population and the catch
for purposes of yield per recruit, fecundity, and the need to maintain an
adequate biomass to get long-lived species through a period of low
reproductive success.
Dick Allen
www.LobsterConservation.com
-----Original Message-----
From: Scientific forum on fish and fisheries
[mailto:[log in to unmask]] On Behalf Of Pranaya Parida
Sent: Wednesday, April 23, 2008 12:02 AM
To: [log in to unmask]
Subject: Re: Fishing Throws Targeted Species Off Balance
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Dear friends,
It's a good discussion whether the younger ones to be spared or the older
ones to be spared during fishing.
But the ethics/principle is neither there should be any recruitment over
fishing nor the growth over fishing.
To control the growth over fishing: we have to spare the younger ones
To control the recruitment over fishing: we have to spare the older ones
Another principle/ethics in fisheries management is " we should give a
chance to individuals to breed at least once in their life time."
For the stock assessment for fisheries management the calculation of the
Length at maturity (Lm50), generally helps the fisheries scientist to decide
the minimum size of the species to be caught.
No fish less than Lm50 should be caught for the fisheries management
purpose.
Again we should not catch the broods or there should not be any fishing
during the breeding seasons so that there should proper recruitment in the
ecosystem.
Thanking you for these discussions.
Kindly provide your valuable suggestion on my comments.
With best wishes,
--
*Dr. Pranaya Kumar Parida
Fisheries Specialist
AFPRO
Bhubaneswar
Orissa, INDIA
+91-9437471364*
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