Cambridge International A Level Biology Revision Guide

Cambridge International A Level Biology
446
Much of the Galapagos Islands, which belong to
Ecuador, is a national park. Since its establishment
over 50 years ago, the park authorities have done much
active conservation. They have restricted access to the
uninhabited islands and limited access to other areas
which are sensitive to human interference. A marine
reserve of 133 000 km 2 has been set up to protect the
environment from the destructive activities of fishing.
The reserve is cared for by local people as well as by
conservation organisations. Alien animal species, such
as rats and goats, are being removed and invasive plants,
such as elephant grass, dug up and destroyed. There are
captive breeding and reintroduction programmes, notably
for giant tortoises, coordinated by the Charles Darwin
Research Station.
There are restrictions on human activities in
national parks. Tourism brings in money to pay for the
maintenance of the parks, and also helps to inform people
about how conservation takes place. This raises awareness
of important issues and can elicit support from the public.
This works best if local people are involved in some way,
so they feel that the park is ‘theirs’ and can obtain benefits
from it. This may involve allowing them to use some areas
of the park for herding their animals or growing crops,
employing them as wardens or rangers, or using some of
the money raised from tourism to improve local health or
education facilities.
Marine parks, like that in the Galapagos Islands, have
been set up in many places to conserve fragile ecosystems
and areas at risk of overfishing, dredging and pollution.
The marine reserve off the coast of Little Cayman in the
Caribbean is a ‘no-take’ reserve that protects one of the
last spawning grounds of an endangered fish, the Nassau
grouper, Epinephelus striatus. The establishment of marine
parks and reserves around the coast of New Zealand has
increased biodiversity and also led to an increase in
fish catches.
Some conservation areas are designated by international
bodies. Wetland habitats, such as estuaries, salt marshes,
blanket bogs, ponds and mangrove forests, are ecosystems
with high biodiversity. Ramsar sites are wetlands considered
to be important for the conservation of wildlife. They are
designated under an international treaty signed at Ramsar
in Iran in 1971. Under the terms of the convention, a
designated site must be ‘used wisely’. This gives protection
against such threats as building development and extraction
of minerals. The ecologically important Okavango Delta in
Botswana is a Ramsar site.
The standard of management of parks and reserves
varies throughout the world. Some countries have the
resources and the national will to provide excellent
protection and careful management. Others do not.
Even though species and habitats are protected, the
threats remain so great that some species have to be
removed from their natural environment and placed
somewhere safer. The mountain forests of Panama
in Central America were the habitat of the golden
frog, Atelopus zeteki. It faced threats from habitat
loss, over-collection for the pet trade and the disease
chytridiomycosis, which has caused the collapse of many
amphibian populations across the world. In 2005, the
Houston Zoo in Texas established a conservation centre
in Panama so that the golden frog could be protected.
The Society Islands of French Polynesia in the Pacific,
including Tahiti and Moorea, have a rich biodiversity
including many endemic species. Studies of the different
species of the land snail genus Partula revealed how much
diversity can evolve on islands. However, by the end of
the 20th century, the number of species of Partula on the
Society Islands had fallen from 61 to 5. Individuals of the
remaining species were transferred to zoos around the
world for their protection and conservation.
QUESTION
18.15 Explain the importance of management of national
parks and other, similar protected areas.
Zoos
Zoos have a variety of functions in addition to providing
enjoyment and interest for visitors who can see and study
animals that they would not otherwise be able to see.
Zoos provide protection for endangered and
vulnerable species, and have had success with captive
breeding programmes, often with the long-term aim of
reintroducing the animals to their natural habitat. For
example, The Durrell Wildlife Conservation Trust at the
Jersey Zoo has been involved with the captive breeding of
various species of tamarins from Brazil (Figure 18.30).
A problem with breeding animals from small
populations is inbreeding. The cheetah, Acinonyx jubatus,
is a species classified by the IUCN as vulnerable
(page 417). Genetic diversity among cheetahs is very low
because they nearly became extinct 10 000 years ago and
only a few survived. Maintaining the genetic diversity is
an aim in the conservation of many species, including the
cheetah. In the wild, female cheetahs tend to mate with
many different males, which helps to increase genetic
diversity in the population.