At the dawn of the 21st Century, anglers and
fishery managers were fighting over striped bass.
More particularly, they were fighting over how the fish
should be managed—for maximum yield, which suggested some level of growth
overfishing and a spawning stock that lacked most of the older, larger and most
fecund females, or for a larger, stable, sustainable population that included a wide
range of ages and sizes, but yielded a somewhat smaller annual harvest.
A large number of anglers, many of whom had fished for
striped bass before and during the stock collapse of the late 1970s and early
1980s, argued that the latter approach would, in the end, be best for both fish
and fishermen.
“The job’s not done until we bring back the big bass,”
they pointed to research such as that referenced
in a joint National Marine Fisheries Service/United States Fish and Wildlife
Service report, which noted, in part, that
“The distribution of age classes in a population has
important implications for stock productivity and stability. Studies on striped bass have shown that
larger fish produce larger eggs and larvae, and larger individuals of these
life stages have a greater chance of survival.”
At the time that debate was going on, fishery managers were
generally focused on obtaining maximum sustainable yield from fish populations. Managing for MSY generally results in a
population that, while able to maintain itself under normal circumstances, is fairly
small and made up primarily of smaller individuals; the relatively high annual
harvest rate assures that most fish will be removed from the population well before
they attain a large size or older age.
Although the smaller individuals each contribute relatively little to
the spawning stock, they make up for low individual fecundity with high levels
of abundance, and collectively produce enough spawn to produce average
recruitment over the long term.
However, a spawning stock that is comprised of just a few
age classes, and is subject to relatively high levels of fishing mortality, is
vulnerable to recruitment failure.
Should it experience consecutive years of below-average spawning
success, while mature adults are steadily removed from the population, the size
of the spawning stock can quickly decline.
With few larger, older fish in the population to provide a reserve of
fecund females, the spawning potential of the stock will plummet and the stock
can easily collapse.
That is essentially what happened to striped bass during the
late 1970s and 1980s, when recruitment
in the critically important Maryland spawning areas tanked for 14 years,
beginning in 1975. Such poor
recruitment, coupled with excessive harvest, caused the stock to collapse, and
required heroic measures on the part of fishery managers to nurse it back to
health.
Not wanting to see history repeat itself, the anglers argued
for lower harvest levels that would lead to a more resilient stock in which the
older age classes were well-represented.
In more recent years, the
need for such a well-stratified stock—one which includes substantial numbers of
what biologists now sometimes refer to as “big, old, fat, fertile female fish”—has
become well-accepted among mainstream fisheries scientists. But fifteen or twenty years ago, the anglers
who sought to elevate the long-term health of the striped bass stock above the
opportunity for a large near-term harvest were staking out a seemingly radical
and certainly controversial position.
The depth of the controversy was illustrated by the
differing opinions held by various members of the Atlantic States Marine
Fisheries Commission’s Striped Bass Management Board; the split didn’t merely
divide different state delegations, but separated representatives sent to ASMFC
from a single state.
For example, at
the Management Board’s December 2002 meeting, Pat Augustine, the Governor’s
Appointee from New York, put forward a motion that would maintain the target
fishing mortality rate at 0.30, a level
that would allow about 26% of the adult population to be harvested each year.
In response, Gordon Colvin, who represented the New York
Department of Environmental Conservation’s Marine Bureau, argued for a more
conservative harvest level, saying
“as stated by some of the advisors, there is a clear
indication in this amendment of an objective that would accelerate, to the
extent that it’s reasonable to do so, the aging of the population, and it will
accelerate faster at a lower mortality rate.
“Our own analysis show that consistent with the stated
objective of the plan…”
The end result was Amendment 6 to the
Interstate Fishery Management Plan for Atlantic Striped Bass, a
management document that managed to satisfy neither side. While the new Amendment, adopted in 2003,
acknowledged that
“1)
There is growing concern that the management program contained in
Amendment 5 may not be appropriate to prevent the exploitation target in
Amendment 5 from being exceeded.
[and]
2)
Over the past few years many members of the fishing community have
raised the concern that the availability or abundance of large striped bass in
the coastal migratory population has decreased,”
a goal
“To perpetuate, through cooperative interstate fishery management,
migratory stocks of striped bass; to allow commercial and recreational fishing consistent
with the long-term maintenance of a broad age structure, a
self-sustaining spawning stock; and also to provide for the restoration and
management of their essential habitat, [emphasis added]”
and clear
objectives to
“Manage striped bass fisheries under a control rule designed
to maintain stock size at or above the target female spawning stock biomass
level and a level of fishing mortality at or below the target exploitation rate”
and
“Manage fishing mortality to maintain an age structure that
provides adequate spawning potential to sustain long-term abundance of striped
bass populations,”
it also failed to reduce the target mortality rate, which
made the Amendment’s acknowledgements, goal and objectives ring somewhat
hollow.
Unfortunately, those who sought to reduce fishing mortality
ultimately found themselves justified, for the female spawning stock biomass
peaked in 2003, the same year that Amendment 6 was approved, and then began a
long slide from which it has not yet recovered.
A
new benchmark stock assessment, released in 2013, not only documented the
decline, but advised that the Amendment 6 reference points were, as some of us
had warned a decade before, far too high.
New, lower
fishing mortality reference points—a target of 0.18 and a threshold of 0.219—were
adopted in 2014. An
update to the stock assessment indicated that, at the end of the 2015 fishing
season, the female spawning stock biomass stood at 58,853 metric tons, well
below the 72,032 metric ton target and just slightly above the 57,626 metric
ton target that denotes an overfished stock.
Those are the sort of numbers that should make fishery
managers realize that that health of the striped bass stock is not as robust as
it should be, and cause them to act in a very conservative and precautionary
manner until spawning stock biomass shows a material increase.
Unfortunately, some managers want to act in a very different manner. At the
Striped Bass Management Board meeting held last October, representatives of the
Chesapeake Bay jurisdictions, led by the Maryland delegation, along with the
usually conservation-averse representatives from New Jersey and Delaware sought to increase striped bass mortality by convincing the rest of the
Management Board to consider reference points that take into account not only
the biological needs of the striped bass, but also various “socio-economic”
considerations.
“Current [fishing mortality] target and threshold are those
that will maintain the populations at [spawning stock biomass] target and
threshold.
“There is a trade-off between preserving [spawning stock
biomass] and allowing fishing.
“The Board has raised concerns that the current [biological
reference points] are too conservative for various biological, ecological, and
socio-economic reasons, and may be restricting fishing unnecessarily.”
The Management Board has appointed a working group to look
into the issue and make a recommendation, which the Management Board can either
adopt or reject.
In other words, here we go again. The same arguments that we faced when
Amendment 6 was being drafted are, like a B-movie monster, coming back to life
just when we thought they were finally dead.
Except this time we know that the striped bass stock slid
downhill when fished at higher levels, and that bass are far less abundant than
they were just ten years ago.
When it comes to fisheries issues, those who expect the
worst are seldom disappointed, so it’s probably time to get ready for another
fight. This one will likely be short and
sharp, and focused on ASMFC’s February meeting, when the reference point issue
will probably be decided.
If the decision favors socio-economic factors instead of
biology, that decision will almost certainly infect the next stock assessment, and damage the
striped bass management process—and the health and abundance of the striped
bass stock—for at least the next five years, if not beyond.
So have a nice holiday season, and be ready to speak up for
the striper when the New Year begins.
Because it might be a new year soon, but the same old fight is
still going on.
I used to be surprised when I would read an article that described fishery managers making the same mistakes over and over again. I have come to realize that most fishery managers today don't support stock conservation first, rather measures that will simply allow individuals to harvest more fish.
ReplyDeleteI am all for considering the "socio-economic" impacts when developing fishery management strategies, but lets be honest and remove the "socio" part. The loudest voices for those seeking increases in harvest rates are ALWAYS those with the most "skin" in the game. Its been my experience (also 50+ years) that when stocks are healthy fishing activity (trips) increase. Almost simple as that. While I'll be surprised, hopefully the mistakes of the past will influence future management direction.
You're 100% right--abundance drives effort. Nothing is better for business than having a lot of fish around, so that people can reliably catch a few when they go out.
DeleteAnd yes, it's generally about short-term economics, although one of the most conservation-hostile New Jersey reps honestly does push the "socio" aspect, always lamenting the loss of the good old days when people could fill pails with tiny fish, which he presumes were later eaten.
The argument that larger harvest quotas will be an economic boost is extremely short sighted. When the proposal to reduce the rec. daily bag from 2 to 1 bass some charter capts. resisted,they said it would hurt business. The next breath they were complaining that they couldn't catch the 2 fish limit. You can't fix stupid.Kill them all today , the hell with tomorrow.
ReplyDelete