Diamondback terrapin crossing a busy road enroute to a nesting site.
During the late 1800s' into
the late '20s of the previous century, diamondback terrapin (Malaclemys
terrapin) populations were greatly depleted in the wild due to harvesting
for the gourmet food market. Fortunately, several states acted in
a timely fashion to protect them from complete annihilation, and diamondback
numbers soon recovered in the wild. Their recovery was so dramatic
and successful, that the states lifted their protective status and
commercial trade in diamondbacks was once again allowed. Fortunately,
terrapin meat was no longer in demand and diamondbacks were allowed to
thrive in their natural habitats until recently. Now, diamondback
populations are no longer threatened by just commercial harvesting but
are faced with having to contend with urban progress as well as the effects
of commercial crabbing. Habitat destruction, road kills, mass drowning
in crab traps, and pollution are now threatening the status of diamondback
populations throughout their range. A number of states have the species
listed as either protected or of special concern. Among them is Florida
(home to 4 different diamondback subspecies), which has again adopted protective
measures to shut down commercial exploitation of terrapins.
Habitat Destruction and Road kills
Terrapins are found exclusively in brackish water habitats with the exception of the egg laying season, when gravid females venture out of the water and marshes to lay their eggs on dry land. Unfortunately, many nest sites have been destroyed by coastal development in the recent years. It is common knowledge that coastal property is prime real estate, and the continued encroachment of human development into diamondback habitat is not only depleting their habitat, but causing other lethal problems as well. Female terrapins that are no longer able to find nesting sites on developed barrier beach islands are forced to seek out alternative sites to lay their eggs. In the process, many gravid diamondback females are lost to traffic mortality annually, resulting in not only the deaths of the nesting females, but also the loss of viable diamondback eggs. A species cannot continue to survive without adequately replenishing its population.
Conservation efforts have been
underway in the state of New Jersey since 1991, headed by Roger Conant
Wood. The Terrapin
Project rescues injured terrapins and collects the eggs from
the bodies of recently killed terrapins. The potentially viable eggs
are incubated and the hatchlings over wintered before being released into
the wild. Sadly, road kill fatalities of adult females still remain
considerably higher than their rate of replacement, even with the feverish
efforts of Dr. Wood and others.
Another factor that is having devastating effect on diamondback populations is the drowning of terrapins in commercial and recreational crab traps. Conservative numbers suggest that tens of thousands of diamondbacks drown in these traps annually. Terrapins breath oxygen from the air, unlike the blue crabs that the majority of these traps were designed to catch. While road kills have been instrumental in reducing the number of females within a certain population, crab traps have the same effect on juveniles and males of the species. Female terrapins are twice the size of males and thus have a tendency not to be able to fit into the traps. The problem of terrapins drowning in crab traps is of such severity that entire populations could be wiped out by early next century unless effective measures are taken to avoid this end.
Currently, there seem to be two solutions to this issue: a modified trap design or an excluder device known as the Bycatch Reduction Apparatus (BRA). The modified crab traps are 6 feet tall compared to the traditional 2 feet tall traps. While traditional traps are fully submerged in the water, modified traps allow for two feet of the trap to extend out of the water, thus allowing caught terrapins access to air.
The BRA device prohibits the
entry of most terrapins while allowing the entry of the targeted crabs.
While both types of modified traps are costlier than traditional traps,
research has proven in both cases that the modified traps have actually
increased the number of crabs caught compared to that of traditional traps.
Terrapin enthusiasts should be encouraged to know that there is already
legislation in the works to make these modified traps mandatory in certain
While commercial harvesting
is done at a considerably smaller level than earlier this century, it too
is having a negative effect on wild terrapin populations. Although
its effects are not as serious as those caused by the other factors mentioned
earlier, coupled with these other factors, commercial harvesting can no
longer be categorized as "sustainable use." Most collecting is now
done for both the food industry and the pet trade. Once again, it
is the adult females that are most valued to the food trade and this raises
severe concerns as to whether the species can adequately replenish itself
with continued indiscriminate harvesting. The Diamondback
Terrapins eGroup was created by Vickie Hays in September of 2000 to
facilitate the exchange of knowledge between terrapin breeders as well
as provide a forum for those needing advice on the captive husbandry of
the species. It is our sincere hope that group and individual efforts
in breeding this beautiful yet delicate species will someday meet the market
demand for terrapins, whether as food or pets, and that commercial harvesting
from the wild can be eradicated altogether. Indeed, as stewards
of the earth's flora and fauna, our goal should be the preservation of
all species; especially the ones that have captured our hearts and dazzled
us with their incredible beauty, variation and tameness like the Diamondback
Terrapin. Let's keep the grin on the terrapin...