| Not
many people in Louisiana have seen a sawfish, but nearly
everyone knows about the wicked-looked serrated “saw”
that it carries on its snout. Nowadays, only an occasional
sawfish shows up along the coast here, but it wasn’t
always this way.
Some
old reports stated that these unusual fish were fairly common
here and apparently even spawned in Louisiana waters. At
least one report documented the presence of juvenile sawfish
in the lower Atchafalaya River. Sawfish are still pretty
common in parts of Florida, but even there, are not seen
nearly as often as in the past.
The
NOAA Fisheries Smalltooth Sawfish Recovery Team recently
released a plan to help recover the U.S. Distinct Population
Segment (DPS) of smalltooth sawfish (Pristis pectinata).
Some scientists believe this to be one of the most critically
endangered fish species in America; it has been designated
as endangered under the Endangered Species Act (ESA) since
April 1, 2003. The plan is intended to reduce the number
accidentally caught in commercial fishing nets and lines,
as well as protect coastal habitats. The recovery plan also
provides recommendations intended to guide federal fishery
managers as they set rules for the different fisheries in
the southeastern United States. To see the full plan visit
http://www.nmfs.noaa.gov/pr/.
The
plan calls for research on where sawfish are being accidentally
caught and on what types of gear. It calls for fishing boats
to carry modified gear that would minimize captures of sawfish
and to carry equipment to release any that are caught. It
also calls for better education of commercial and recreational
fishermen. To protect the habitat of juvenile sawfish, the
plan would require other agencies to consult with the National
Marine Fisheries Service before approving developments that
affect the most important mangrove and other heavily vegetated
coastal habitats.
Sawfish,
like sharks, skates and rays, belong to a class of fish
called elasmobranchs, whose skeletons are made of cartilage.
Sawfish are actually modified rays with a shark-like body,
and gill slits on their ventral side. Early sawfish developed
around 100 million years ago, but these first sawfish are
actually distant cousins to the modern day sawfish, which
first appeared around 56 million years ago. Sawfish get
their name from their "saws" — long, flat
snouts edged with pairs of teeth which are used to locate,
stun, and kill prey. Their diet includes mostly fish but
also some crustaceans. Smalltooth sawfish are the only domestic
marine fish, and the only elasmobranch, listed under the
ESA.
Sawfish
saws have great significance to many cultures around the
world, and practitioners of traditional Chinese medicine
make remedies from sawfish livers, eggs and gall bladders.
The fish use their saws as a weapon to kill and capture
prey, and also as a sensory organ in murky water or to detect
buried prey.
Smalltooth
sawfish is one of two species of sawfish found in U.S. waters.
Smalltooth sawfish commonly reach 18 ft (5.5 m) in length,
and may grow to 25 ft (7 m). Little is known about the life
history of these animals, but they may live up to 25-30
years, maturing after about 10 years. Like many elasmobranchs,
smalltooth sawfish are ovoviviparous, meaning the mother
holds the eggs inside of her until the young are ready to
be born, usually in litters of 15 to 20 pups.
Worldwide,
all seven species of sawfish are listed by the World Conservation
Union as critically endangered.
Sawfish
species inhabit shallow coastal waters of tropical seas
and estuaries throughout the world. They are usually found
in shallow waters very close to shore over muddy and sandy
bottoms. They are often found in sheltered bays, on shallow
banks and in estuaries or river mouths. Certain species
of sawfish are known to ascend inland in large river systems,
and they are among the few elasmobranchs that are known
from freshwater systems in many parts of the world.
Smalltooth
sawfish have been reported in the Pacific and Atlantic oceans
and Gulf of Mexico; however, the U.S. population is found
only in the Atlantic Ocean and Gulf. Historically, the U.S.
population was common throughout the Gulf of Mexico from
Texas to Florida, and along the east coast from Florida
to Cape Hatteras. The current range of this species has
contracted to peninsular Florida, and smalltooth sawfish
are relatively common only in the Everglades region at the
southern tip of the state. No accurate estimates of abundance
trends over time are available for this species. However,
available records, including museum records and observations
from fishermen, indicate that this species was once common
throughout its historic range; in places it was once so
abundant it was considered a nuisance. Populations of smalltooth
sawfish have unquestionably declined dramatically in U.S.
waters over the last century.
While
there are few reliable data available for this species,
and no robust estimates of historic or current population
size exist, available data indicate that the species' distribution
has been reduced by about 90 percent, and that the population
numbers have declined dramatically, perhaps by 95 percent
or more.
Sawfish
are extremely vulnerable to overexploitation because of
their propensity for entanglement in nets, their restricted
habitat and low rate of population growth. The decline in
smalltooth sawfish has been caused primarily by bycatch
in various fisheries, especially in gill nets. Because adults
can grow very large, and potentially damage fishing gear
or even pose a threat to fishermen, many incidentally captured
sawfish were killed before they were removed from fishing
gear, even if the fishermen had no interest in keeping them.
Juvenile
sawfish use shallow habitats with a lot of vegetation, such
as mangrove forests, as nursery areas. Many such habitats
have been modified or lost due to development of the waterfront
in Florida and other southeastern states. The loss of juvenile
habitat likely contributed to the decline of this species.
Under
the Endangered Species Act, it is illegal to catch or harm
an endangered sawfish. However, some fishermen catch sawfish
accidentally while fishing for other species. NMFS and the
Smalltooth Sawfish Recovery Team have developed guidelines
telling fishermen how to safely handle and release any sawfish
they catch. Some states have taken additional step to protect
this species; the states of Florida, Louisiana and Texas
have prohibited the "take" of sawfish. Florida's
existing ban on the use of gill nets in state waters is
advantageous for this plan, as are the management plans
for the three national wildlife refuges in Florida that
protect their habitat.
Comments
on the species’ recovery plan may be sent by fax,
e-mail or mail.
- E-mail:
send to smalltoothsawfish.recoveryplan@noaa.gov,
include in the subject line: Smalltooth Sawfish Recovery
Plan.
- Mail:
send to Smalltooth Sawfish Coordinator, NOAA Fisheries
Service, Southeast Regional Office, Protected Resources
Division, 263 13th Avenue South, St. Petersburg, Florida
33701
- Fax:
(727) 824-5309
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