Marine protected areas—or, to be more precise, those marine
protected areas which either completely prohibit or severely restrict fishing
activities—have been in the news since the late 1990s.
Back then, a number of marine conservation organizations,
encouraged by the big foundations that provide much of their funding, were promoting
the alleged benefits of shutting down fishing in a significant part of the
coastal ocean. Here in the continental United
States, the effort didn’t get very far, with the two most-debated closures taking
place in a
remote area of the Florida Keys and off the coast of
California.
After five years or a little more, the debate fell into a
sort of stalemate. Advocates of marine
protected areas achieved a few wins, and managed to stymie the recreational
fishing community’s efforts to pass “freedom to fish” laws at either the state or
federal level. At the same time, representatives
of the recreational sector managed to get freedom to fish language inserted
into the 2006 reauthorization of the Magnuson-Stevens Fishery Conservation and
Management Act, which states that
“with respect to any closure of an area under this Act which
prohibits all fishing, [the fishery management plan must] ensure that such
closure is based upon the best scientific information available; includes
criteria to assess the conservation benefit of the closed area; establishes a
review of the closed area’s performance that is consistent with the purposes of
the closed area; and is based upon an assessment of the benefits and impacts of
the closure, including its size, in relation to other management measures
(either alone or in combination with such measures), including the benefits and
impacts of limiting access to users of the area, overall fishing activity,
fishery science, and marine conservation.
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That language set a fairly heavy burden on marine protected
area proponents. It prevented them from implementing closures based on mere hope that such closures would
benefit fish populations; instead, they needed to demonstrate that imposing a
closure to protect fish populations was an approach based on the best available
science, that there was a link between the closure and a particular management
purpose, that criteria for evaluating the closure’s effectiveness in achieving
that purpose were put in place, and that a closure, rather than other
management measures, represented the best approach to managing the resources in
question.
Not surprisingly, few if any fully closed areas were adopted
in fishery management plans. Instead, the
regional fishery management councils tended to protect limited areas, often
because of their importance as spawning areas for certain species, and
prohibited fishing for such species, while fishing for other species not particularly
benefitted by a closure could continue.
However, Magnuson-Stevens' new language restricting the use
of closed areas only applied to management actions taken pursuant to such
statute; it didn’t restrict the creation of no-fishing zones, including very
large ones, pursuant to other laws.
However, efforts to put areas of the ocean off-limits to
fishermen slowed down after that, at least until a
few years ago, when the so-called “30x30” movement—promoted by organizations who
are seeking to place 30% of the Earth’s lands and waters in some sort of
protected states by the year 2030—began to pick up steam. Proponents of big no-fishing zones again
became active, calling for “fully protected” or “highly protected” areas of
ocean to be set aside.
“While it is unlikely that MPAs can significantly increase yield
in well-managed fisheries, it is widely agreed that strategically designed MPAs
can increase yield in overfished fisheries…Therefore, in regions where
fisheries management is lacking, highly protected MPAs may significantly
improve both fisheries catch and conservation if designed well.”
While we might disagree with some of the decisions made by
regional fishery management councils, it’s hard to imagine anyone—particularly a
commercial or recreational fishermen—describe the federal waters of the
United States as a region “where fisheries management is lacking.” Thus, the argument for implementing highly
restrictive marine protected areas in U.S. waters seems fairly weak.
Yet, increasing yield from existing fisheries isn’t the
only imaginable goal of marine resource managers. There are a host of marine species, ranging
from blue whales to petrels and other pelagic birds, which resource managers
are attempting to protect. It has been
argued that such species might benefit if regulators closed off part of the
continental shelf or the adjacent open ocean from most human activities,
including fishing.
Now, a recently-released paper suggests that the sort of
small marine protected areas most often imposed on coastal fishermen do little
or no good for large marine animals, and that even larger MPAs fail to provide
much protection over the course of many animals’ travels.
“Marine protected areas (MPAs), particularly large MPAs, are
increasing in numbers and size around the globe in part to facilitate the
conservation of marine megafauna under the assumption that large-scale MPAs
better align with vagile life histories; however, this alignment is not well
established.”
In conducting their study, the researchers tracked 36
species of sharks, whales, seals, turtles, and birds, (I was disappointed to
find that their definition of “megafauna” did not include teleost fish such as
bluefin tuna, blue marlin, or swordfish, all of which grow as large or larger
than the blue and mako sharks that were included in the data set) noting the
size of their range as well as the core areas within such range. Such ranges were then compared to the size
and coverage of marine protected areas, to provide some idea of how such MPAs might
benefit each species.
Some species’ ranges were deemed to be “vast,” including
that of the blue shark (home range 4,388,000 square kilometers, core range
2,338,647 km2), the mako (species not specified, but presumably the
shortfin, given the number of samples, with a home range of 4,405,000 km2
and a core range of 2,053,393 km2), and the blue whale (home range 1,913,000
km2, core range 564,335 km2). Others, such as the humpback whale, merely
had a “large” range (home, 685,000 km2; core, 288,547 km2).
Either way, such animals wander around a lot of ocean.
Thus, marine protected areas can only provide very limited
protection. The paper completely
discounts the value of MPAs of less than 100 km2 when it comes to marine
megafauna, although such areas can create benefits for less widely traveled
species, which includes many fish (but not, I might add—although the paper didn’t—highly
migratory fish species which share a propensity for wide-ranging travel with
the blue and mako sharks).
While a large enough MPA might, in theory, protect a species
with a “vast” home range, creating such huge closures isn’t practical for, as
the study notes,
“MPA size quickly hits a ceiling of what is practical and
affordable to implement. For example,
in the Papahanaumokuakea Marine National Monument, (PMNM), one of the largest
MPAs worldwide, the home ranges of three intermediate-ranged breeding seabird
species were nearly fully enclosed in protected waters.
“Nevertheless, this expansive MPA with a footprint greater
than 1.5 million km2, remained too small to provide much at sea protection
for two vast-ranging albatross species that breed there, despite protection of
critical seabird habitat being cited as part of the designation of this MPA.”
The impact of MPAs, particularly smaller MPAs, on highly
migratory marine animals becomes particularly relevant when smaller protected
areas are proposed, and purported benefits to whales, turtles, seabirds and
similar species are used to justify closing such areas to fishing. While the paper makes it clear that the siting
and networking of multiple small MPAs can add up to significant protections for
the animals studied, it emphasizes
“the importance of identifying critical habitats throughout
annual cycles and understanding migratory connectivity of populations for effective
area-based conservation for marine megafauna…many, if not most large- and
vast-ranged species aggregate seasonally and by life stage, sex, or season, and
these aggregations that occur at smaller spatial scales have greater potential
to benefit from MPAs.”
The logical extension of that situation is that instead of
creating no-take MPAs that are in place throughout the year, it makes more
sense to impose time and area closures that protect animals when they are likely
to be concentrated in a particular place, but allow extensive access when the
protected animals are engaged in a different phase of their annual migration.
That’s a particularly important thing to remember when
creating new managed areas. For example,
the National Oceanic and Atmospheric
Administration is currently taking comments on whether Hudson Canyon, located
off New York and New Jersey, should be designated as a National Marine
Sanctuary. So far, only a handful of comments
have been received. However, it is likely
that most of the large marine conservation groups will be taking positions,
which will probably be submitted at the last minute to limit public response to
such positions.
While nothing is certain, it would be far from surprising if
a large proportion, perhaps most, of those organizations will not only be
supporting the sanctuary designation, but also requesting that the sanctuary become
a highly or fully protected area. Yet
while, as NOAA notes, Hudson Canyon is
“an ecological hotspot for a vast array of marine wildlife,”
most such wildlife is transient; the fish, marine mammals,
and birds that often abound there follow the movements of baitfish, and the
baitfish follow the flows of warm and cold water that are constantly moving
across the continental shelf. As far as
anyone knows, Hudson Canyon is not a pupping or nursery area for any species of
shark, nor is it a seasonal feeding ground for marine mammals. Instead, it is just an oftentimes rich bit of
water that can, when conditions are right, hold an impressive variety of life.
That means that it probably makes real sense to protect Hudson
Canyon from any sort of mineral exploration and extraction that might degrade
sensitive bottom habitat; it does not mean that it, or similar pieces of richly
populated water up and down the coast, should be subject to particularly
onerous fishing regulations that are different from those imposed elsewhere.
Currently, NOAA has no plans to impose fishing regulations
in Hudson Canyon that differ from the regulations imposed by the National Marine
Fisheries Service elsewhere on the coast.
But public comment could conceivably change that position although, at
this point, that’s probably not likely.
Still, given the limited benefits that MPAs provide to
wide-ranging marine species, we shouldn’t even have to worry about someone trying to close down more water to fishing access, whether that water is in Hudson Canyon, or
anywhere else on the U.S. coast.
The upside to any such action just isn't there.
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