Amphibian
Declines
Serious declines in amphibian populations have been documented
in many areas around the world in the last 20 years, including
North America, Central America, Europe, and Australia.The declines
are significant because they are occurring in some of the largest
parks and wilderness  areas and because the cause(s) of the declines
remain largely unknown. In North America, there have been significant
declines in the Sierra Nevada mountains involving at least six
native frog species. Many isolated frog populations in the desert
Southwest have disappeared. Throughout the Great Lakes area,
significant declines have occurred in addition to the appearance
of severe deformities (e.g. extra or missing legs, missing or
displaced eyes). In the southern US, many Coastal Plain species
are suspected to be in decline. It is unlikely that a single,
global factor is affecting amphibians. Among the most likely
causes are habitat destruction/alteration, pesticides/herbicides,
introduction of non-native species (especially fish), disease,
and an increase in ultraviolet radiation due to atmospheric
ozone depletion. Amphibian deformities have become a high-profile
topic and cause for concern, but in most areas, declines are
occurring in the absence of deformities.
 Conserving Freshwater Turtles
Many freshwater turtles face serious threats to their survival.
The large river-dwelling species, especially, have been heavily
impacted. Freshwater turtles are relished as food, and a huge
national and international commercial trade occurs in many parts
of the world, including North America. Many species are sold
for their organs and shell to be used in various cultural medicines,
tonics, and elixirs, especially in Asia. A number of countries
have lost a significant proportion of their freshwater turtle
fauna to supply the medicinal export trade to China and elsewhere.
A multi-million dollar pet trade drains wild populations of
freshwater turtles and terrestrial box turtles. Turtle ranchers
in the United States are one of the world's main suppliers,
replenishing their breeding stock from wild populations. Freshwater
turtles are threatened by habitat alteration, elimination, and
degradation, as well as through the unnatural overabundance
of efficient nest predators, such as raccoons. Research suggests
that the consequences of a reduction in population size are
extremely serious for turtles. Their life history characteristics
(e.g., long life, high adult survivorship, low recruitment)
make it very difficult for them to recover from chronic stress.
Sea
Turtle Conservation
All sea turtle species are threatened or endangered with extinction
and protected by the U.S. Endangered Species Act and a number
of important international conservation treaties. Sea turtle
populations have been reduced in size worldwide due to human
interference at nesting beaches and in marine habitats. Specific
threats to sea turtles include habitat alteration and destruction,
marine pollution (especially by plastic debris), incidental
capture by recreational and commercial fisheries, and direct
take of turtles and their eggs for commercial and local use.
Recovery efforts for sea turtle populations are focused primarily
on determining the locations of critical habitats and reducing
threats to adults and juveniles in these areas. Because sea
turtles are highly migratory and travel through the national
and international waters of many nations, conservation efforts
must include the development of multilateral agreements to manage
and protect them on a regional level.
 Species At Risk in Deserts
The conservation of desert herpetofauna is largely a matter
of adequately controlling the multiple and often overlapping
human activites that impact fragile desert habitats. These include
urbanization, agriculture, livestock ranching, off-road vehicles,
mining, oil and gas exploration, construction of solar and wind-driven
power plants, energy transmission corridors, military training
sites, and a complex array of highways. The net impact of these
activities is difficult to measure, but the resulting fragmentation,
degradation, and destruction of desert habitats decreases the
abundance and diversity of the herpetofauna through time. A
clear warning sign of our lack of stewardship is the current
listing of several key desert herps as threatened or endangered
(e.g., desert tortoise). Only through co-ordinated planning
by federal, state, and local governments, environmental organizations,
scientists, and a concerned public can we hope to succeed in
conserving the remarkably diverse herpetofauna of our North
American deserts.
Conservation
Priority: Protect the Habitat!
Ultimately, the key to protecting amphibians and reptiles is
to conserve natural habitat. Some small species might be able
to persist for decades on a few acres of disturbed woodland,
but larger species occupying the top levels of the food chain
require the protection of thousands of acres to maintain viable
populations. Habitat can be protected in many ways: a landowner's
personal stewardship of his or her property, government incentives
or regulation, or acquisition and dedication as conservation
lands. International organizations, government agencies, and
private organizations (e.g., The Nature Conservancy) have protected
millions of acres of habitat that sustain amphibians and reptiles.
A few "high profile" species such as marine turtles, tortoises,
large lizards, and even amphibians have provided the impetus
for important preservation efforts.
Conservation
efforts for species with complex life cycles must protect the
full range of habitats required by all life stages. For example,
many freshwater turtles need cover, basking sites, and feeding
and nesting areas; pond breeding amphibians require undisturbed
spawning sites, safe migratory routes, and upland habitats,
often at considerable distances from ponds, for feeding and
overwintering. Conservation efforts need to ensure that habitats
are connected to avoid the consequences of isolation and habitat
fragmentation and shredding.
Research
has shown that habitat protection must include the regional
landscape as well as the local population. Many species form
metapopulations whose function and continued existence are as
vital to a species's existence as are local populations. Habitats
need to be protected in a manner that recognizes the dynamic
nature of reptile and amphibian populations both in space and
time.
Conservation
Genetics
Genetic diversity is the ultimate foundation of biodiversity,
and genetic technology has many applications in the conservation
of amphibians and reptiles. Thanks to recent technical advances,
molecular genetic studies using mitochondrial DNA and microsatellite
(nuclear) DNA can be undertaken nondestructively using a single
drop of blood, a fragment of shed skin, a fecal sample, or even
a toe clip. Molecular genetic assays help identify populations,
the fundamental units of wildlife management. Phylogenetic studies
based on DNA sequences have proven valuable for uncovering cryptic
species which are not apparent through morphology alone. These
findings can be used to set conservation priorities on the basis
of evolutionary distinctiveness. Molecular genetic markers can
also be used to identify species found in commercial trade and,
in some cases, can even trace the location from which a specimen
or product originated.
Ecotourism
Ecotourism is tourism which is planned and carried out in a
manner which protects natural and human resources, promotes
conservation by producing economic benefits, protects habitat,
and generally provides a basis for the protection of biodiversity.
Ecotourism, particularly nature-based tourism, is one of the
fastest growing segments of tourism; visitors marvel at some
of the most sensitive and protected areas in the world. And
it can have both positive and negative impacts on remaining
natural areas. As part of this market, herpetological tourism
has grown more than 400% over the past 5 years alone. The SSAR
is concerned that ecotourism be planned and carried out in a
sustainable and responsible fashion. Herpetological tours, whether
for scientific research or simply photography and observation,
should follow sound conservation practices under the auspices
of the regulations of the host governments.
Education
and Conservation
All successful conservation programs include a strong educational
component. The focus of education may be directed at certain
groups (landowners, legislators, recreationists) but the most
significant are aimed at a broad segment of society. Nowhere
is this more true than in the conservation of amphibians and
reptiles, where generations of prejudice, unwarranted fears,
and confusing information all become major barriers that must
be overcome. Despite impediments, amphibian and reptile conservation
is proceeding well in some areas thanks, in part, to successful
education. For example, understanding the importance of American
alligators to their entire ecosystem has led to effective conservation
programs. Such recognition occurs only with a broad based and
accurate flow of information. Educational programs about herps
and the ecosystems they depend upon must continue if we are
to maintain the diversity of amphibians and reptiles throughout
the world.
Conservation
on the Internet
There are many World Wide Web sites for wildlife conservation.
Most major conservation organizations have their own web site
as do many conservation groups, national parks, zoos, and natural
history museums. We have provided links (below) to many organizations
involved in the conservation of amphibians and reptiles.
Where
Can I Find More Information?
For information on the Federal endangered and threatened
species program, contact the Division of Endangered Species,
U.S. Fish and Wildlife Service, 1849 C Street NW, Washington,
DC 20240.
For
information within your State, please visit our website
of state conservation links.
You can contact your natural resource or wildlife management
agency using addresses found in Levell (1997). Most agencies
now maintain Internet sites.
Levell,
J. 1997. A Field Guide to Reptiles and the Law. 2nd Ed., Serpent's
Tale Books, Lanesboro, MN.
|
