'We are disrespecting Ja's natural heritage'

By Dr. Peter Vogel, Contributor

The destruction of tropical forests is the major cause of environmental degradation. - Contributed

Today we begin a special five-part series focusing on the environment.

WORLD ENVIRONMENT Day is commemorated each year on June 5. It is one of the principal events through which the United Nations stimulates worldwide awareness, political attention and action for the environment. The theme of this year's observance of World Environment Day is "Connect with the World Wide Web of Life".

According to the United Nations Secretary General, it is a choice "that reflects the need for each and every one of us to recognise our role in preserving our fragile planet and the ecosystems, resources and natural processes that bind us all together. More than ever, life on earth requires of us a sense of universal responsibility - nation to nation, person to person, human to all other forms of life".

Two cities have been selected as the main venue for the international celebrations, Torino in Italy, and Cuba's capital Havana. Thus, Environment Day will draw particular attention to the Caribbean region, and the environmental issues facing our island nations.

BirdLife Jamaica thanks The Gleaner Company for inviting a series of articles highlighting environmental issues in Jamaica. The articles are focusing on the island's biodiversity, that is the variety of plants and animals as well as the biological communities and ecosystems that form our natural heritage.

Jamaica was once completely under water. When it eventually emerged many million years ago, animals and plants dispersing across the water slowly inhabited it: flying, floating and rafting. Oceanic islands like Jamaica have therefore relatively few species compared to the nearest continent.

In addition, the species composition is "unbalanced": certain groups of animals and plants are well represented while others are totally absent. The unbalanced species composition has resulted in unique ecological communities. For example, in Jamaica, the largest land herbivores are a lizard (Jamaican Iguana - which grows to a meter and a half in length), and a rodent (Jamaican Hutia or "Coney"), and the largest land predator is a snake (Jamaican Boa).

Endemic

Since dispersal across the sea happens rarely, a species colonising the island will be separated from the parent population and often evolve into a new species that then occurs nowhere else. Such exclusively Jamaican species are referred to as "endemic" to the island. Many of the successful colonisers have further "radiated" within Jamaica. This means that the ancestral species gave rise to two and more species after reaching the island, thus further increasing the number of endemics. For example, Jamaica's 17 species of native whistling frogs have evolved on the island from a single ancestor that journeyed across the sea.

Because of the large number of unique species on each island, the Caribbean has been ranked among the three hottest hotspots of biodiversity on a global scale. Jamaica, as one of the four largest islands in the archipelago, nurtures a major part of this richness in unique organisms. Plants and animals on islands are more vulnerable to extinction than those on the continent, mainly because of their very limited geographical range. They are therefore suffering first and most from human interference. Of the 113 birds known to have gone extinct over the last 400 years, 92 lived on islands. During the same period, the West Indian lost 19 out of 28 (68%) non-flying mammal species.

Alarming trends

Jamaica has contributed to these alarming trends. The island has most likely lost no less than five endemic vertebrate species over the last 120 years: two reptiles, two birds and a mammal. Many more species of plants and invertebrate animals are suspected to have gone extinct. However, our knowledge of the environment is so minimal that we cannot draw any firm conclusions as to how much we have lost.

Considered endangered

A large number of species must be considered endangered; they are likely to go extinct unless their habitat is properly conserved and/or species-specific conservation measures implemented. At highest risk are the endemic species. According to leading botanists, a staggering one third of Jamaica's over 800 endemic species of flowering plants is under threat. Similarly, many of Jamaica's endemic animals are unable to tolerate habitat disturbance and are highly dependent on the last remaining natural forests.

The major threats to Jamaica's biodiversity are habitat degradation and conversion; exotic (i.e. introduced) species; and collecting and hunting of specimens. In addition, pollution of land, air, rivers and sea has severe impacts.

Jamaica was once largely covered with forests. However, at the beginning of the present century, primary forests had only remained in areas least suitable for agriculture and human settlement: at high altitudes, on steep and rocky slopes, and in rugged limestone areas without surface water. Throughout the present century forest cover further declined dramatically. Accor-ding to figures from the Department of Forestry, well-stocked forests (with a minimum of 20% tree cover) have decreased over 95% during the last 75 years.

Estimates of annual deforestation rates have been highly controversial, though most studies indicate a rate of about three per cent during the last two decades. Today, probably about one quarter of the island has retained some form of forest cover though most is badly degraded and secondary. Well-preserved natural forest occupies considerably less than 10 per cent of Jamaica's surface; the most important areas are the Cockpit Country, the Blue Mountains, the John Crow Mountains, the Hellshire Hills and Portland Ridge.

Habitat conversion

Wetlands and freshwater ecosystems continue to suffer from habitat conversion, degradation and pollution. Issues of particular concern include the destruction of mangrove woodlands for development projects and charcoal burning, pollution of the Black River Morass by agricultural waste products, and ganja production in herbaceous swamps. Jamaica's coral reefs have collapsed because of a combination of natural and human induced stresses, including hurricanes, a die-off of an algae-grazing sea urchin, over-fishing and pollution. The waters in Kingston harbour and in proximity of other large settlements are chronically polluted by household and industrial sewage.

All of Jamaica's major ecosystems suffer from the intrusion of exotic species, i.e. animals and plants brought in by man either intentionally or accidentally. Exotic predators, including mongooses, dogs, cats and rats endanger rare animals such as the Jamaican Iguana and other vertebrate species. Introduced invasive plants, including Wynne Grass, Wild Ginger and Bracken overgrow natural and human induced forest clearings, and thus prevent natural forest regeneration. The exotic tree, Pittosporum undulatum, is spreading mainly along trails and clearings ever deeper into the forest of the Blue Mountains, out-competing the natural forest trees. Water Hyacinths overgrow the lower parts of many rivers, and Bottlebrush is threatening herbaceous swamps. Introduced from SE Asia, the Green Mussel is now established in the Kingston Harbour and may crowd out native species.

A perennial problem in Jamaica since many years, over-fishing has led to greatly reduced harvests particularly of the higher-valued snappers, groupers and jacks. Poorly controlled harvesting of conch is depleting the stock rapidly. Yam stick harvesting, charcoal production, orchid collection and the extraction of various other forest products appear largely unsustainable. Illegal hunting imperils the Jamaican-endemic Ring-tailed Pigeon and the Caribbean-endemic West Indian Whistling Duck.

Overall, we are greatly disrespecting Jamaica's natural heritage and threaten to impoverish it beyond future recovery. Jamaica is a blessed land, and not all is lost. The good news is that we still have substantial areas of good forest, wetlands, beaches and marine environments left. Also, many of the degraded areas can be rehabilitated with proper care. At the same time, large areas of little ecological value exist that can be used for much needed development including agriculture, housing, manufacturing, tourism and other ventures.

Many recent initiatives point in the right direction: the ratification of major international environmental treaties; the declaration of new protected areas; recent and ongoing planning ventures emphasising the sustainable use of natural resources; and the growing concern for environmental issues at all levels of the society. Jamaica still has the option to preserve her natural heritage in harmony with the development of her people ­ indeed; neither of the two is possible without the other.

Dr. Peter Vogel is Head of BirdLife Jamaica's Research and Wildlife Management Committee, and Lecturer at the Department of Life Sciences, UWI.

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