The unstoppable loss of biodiversity
Biodiversity is a measure of the range of variation occurring in the natural world. This includes variation within and between species, and their ecosystems. Changing a habitat will alter the diversity of the species contained within it. A change in the number of species will gradually affect the nature of the habitat. Biodiversity is important to man for agricultural and pharmaceutical reasons.
Conservation of biodiversity is divided into two groups: Ex situ: gene banks, tissue culture, captive breeding and in-vitro methods.
Ecosystems and the species within them are continually evolving to cope with ‘change’. Natural rates of change have been accelerated by man’s activities, such as those induced by changes in land use, pollution and over-population. Accelerated change causes species extinction and ecosystems are irreversibly disrupted and the gene pool can no longer cope with change.
Coral reefs are the most productive marine ecosystem. They are home to 35 000–60 000 species of plants and animals. 25% of the world’s marine life lives in reefs. They are comparable to rainforests in their biodiversity. Marine communities depend on reefs for social, economic and cultural life. And they protect many coastal communities from storm waves.
It is thought that there are cures for cancer and AIDS in the reefs.
Major threats to coral reefs include:
- fishing with explosives
- human runoff
- cyanide fishing
- collection and dredging
- water pollution
- careless recreation
- global warming
- storm damage.
In the last four decades, mankind has destroyed 14 million ha of coral reefs. Reefs of 93 countries have been damaged by human activity.
CASE STUDY - Jamaica’s coral reef ecosystems – Negril Marine Park - The Negril coral reef has between 3% and 15% live coral. Today the dominant species are the harmful microalgae, their growth supported by nutrient ‘floods’ of nitrate, phosphates and ammonia (found in soap, sewage and fertiliser) exacerbate the ‘local situation.’ Coral needs clean, clear nutrient-free water in which to thrive! The microalgae overgrow the corals and block out sunlight.
Given the situation locals, furthermore hotel owners and the Government, have become ‘Guardians of the Sea’. This group formed JCRAP (Jamaica Coral Reef Action Plan), the only known coral reef protection group in the world! Its solutions to the local problem include reassessing water quality, requiring permits to be issued for beach front building, relocating beach squatters (and their poor sanitary arrangements), providing adequate sewage disposal, planting buffer zones between land and sea to capture fertiliser runoff, watershed protection and retraction of tourism licences.
The diversity of life within ecosystems is an irreplaceable asset to humans, serving integral roles in both social and economic structures. Much of what they do is also tangible, soil generation and productivity, water cycling and cleansing, climate control and so on! The case study above has demonstrated just one ecosystem and what is being done, but all ecosystems are under threat from man’s unstoppable march forward. To enable informed decisions to be made in the future, there is a need for global co-operation in association with long-term investments to maintain monitoring of the world’s ecosystems.