The collapse of biodiversity?

This month saw a new report from The World Conservation Union (IUCN) which highlighted the tragic fact that species of whales, dolphins and porpoises, part of the Cetaceans family, have been put on the endangered species list and may disappear in the next 10 years. This unfortunately is just one of many such disturbing reports that are pointing to the collapse of biodiversity.

The publication called, Dolphins, Whales and Porpoises: 2002-2010 Conservation Action Plan for the World’s Cetaceans is the result of 15 years of study and is the third Action Plan to be recommended to help track levels of the endangered species as well as provide conservation guidelines. The report is not only for scientists but provides information for decision-makers.

The first plan was issued in 1988 and since this time there has been both success and failure in preventing the depletion of species of Cetaceans. A number of larger well-known whale species are now showing signs of recovery but it is the lesser species that are struggling to prevail in the world of commercial fishing and changing ecosystems. A freshwater dolphin known as the baiji is the most endangered species with estimates that there may now be as few as 20 - 25 dolphins remaining. The report hopes to turn things around for as many Cetacean species as possible.

However the Cetacean family are not the only ones at risk, there are vast numbers of creatures that are becoming threatened and the results are having an alarming affect on the Earth's biodiversity.

What is biodiversity?

Biodiversity is the term used to describe the variety of species found on our planet. The good news is that there still remains more animal and plant species today than there have ever been on the Earth. More and more species are being discovered and so far 1.5 million species have been categorized and identified. As more and more species are discovered in the rainforests, coral reefs and through deep sea dives, the eventual figure may become much higher.

To date only 5% of the ocean has been investigated yet this whole area equates to three-fifths of the Earth. Life is so diverse that new species of bacteria are being discovered 2 - 3 km below the surface of the Earth. It has even been speculated that the biomass at this level may be greater than the biomass at the surface of the Earth. There are no figures for the number of biological species that may exist on the Earth but estimates have put this figure between 5 million - 100 million. So with biodiversity remaining at an all time high, what are the concerns about?

Man. The impact of humans on the Earth is changing it on a global scale which has never been seen before and at a pace which has not been equalled in 3.5 billion years of life on Earth. Although life has an amazing ability to recover from localized disasters such as storms, fires, volcanoes and other natural disasters, it cannot rejuvenate effectively when wide-scale changes are happening on a global level and at such a ferocious rate. The result is a devastating loss of biodiversity.

The factors involved in the collapse of biodiversity.

The first major contributor is the rapid increase in population of the human species. There is an ever increasing need to feed an ever growing population which has led to environmental pressures and this in turn has either led to the extinction of many species or has resulted in many species being placed on the edge of extinction. The Earth has a limited amount of resources and can sustain only a finite number of biological organisms.

The second major contributor is man’s ability to dramatically change its environment on a scale not experienced since the cataclysmic events which led to the destruction of the dinosaurs. Not only has man changed the habitats of entire biospheres to a point where these biospheres collapse, but on a much larger scale through the burning of fossil fuels he has changed the climate of the Earth. Only now are the effects of these changes on plant and animals on a global scale, being realized.

The third major contributor is the introduction of foreign species, which have followed the spread of humans. These can be categorized as both domestic and non-domestic animals. They can have a detrimental effect either due to the fact that they have no natural predators and disproportionately affect the ecology of an area without effective population control, or the fact that they change their habitats in such away that they make the habitat unsuitable for the indigenous species.

The fourth contributor is the effect man has on complex ecosystems. In many ecosystems there are cornerstone animals and/or plants. By removing a single cornerstone species it is possible to rapidly destroy an entire ecosystem and the species within it. Some extinctions are so recent that there are films of the last remaining individuals of that species, one such species is the Australian Tasmanian tiger.

What is the rate of destruction of biodiversity?

Total destruction can be looked at as the extinction of a species. A good dramatic example would be the well documented Dodo, which lived on the Island of Mauritius and was hunted to the point of extinction by early Portuguese settlers.

There are however many local extinctions events where local habitats are destroyed, and although the local destruction of single habitat does not lead to the collapse of an entire species, if enough local extinctions take place the population of a species is reduced below a sustainable freehold, and the species will start to collapse and eventually become extinct.

A good example of a dramatic loss of biological diversity can be seen on the Island of Hawaii. Before the arrival of man there were a great number of animals and plant on this island. Man arrived on the island and brought with them a number of foreign species, which in turn wiped out local populations. Although to the causal holiday maker Hawaii is a lush tropical place, to the biologist it is becoming a barren wasteland.

Further to this, 50,000 years ago there were herds of large mammals such as the ones found in Africa on all the continents. 40,000 years ago, they were nearly all lost in Australia. 13,000 years ago they were destroyed in the Americas and 1000 years ago in New Zealand. The loss of herd animals in all of these continents coincided in the arrival of man. Humans hunted these species at rate which was higher than the rate in which these animals could reproduce and this led to the extinction of animals such as the North America bison , woolly mammoth, saber tooth tiger and giant sloth.

Today by using more and more of more efficient and innovative technologies, trees have are being felled at 10 times the rate at which they being replaced. Fish are being harvested at 70% of their total population.

Natural extinctions

Extinctions happen as a natural part of evolution. Without considering the events taking place today there have been 5 major extinction events on the Earth where there has at least a 50% loss of biodiversity.

The last took place 65 Million years ago with the extinction of the dinosaurs. This event occurred when a 10 mile wide meteor crashed into the Earth off the Gulf of Mexico. This last extinction took place over a period of tens and thousands of year. In the lead up to each one of these events there has been between 100 - 1,000 fold increases in the rate of extinction. Looking at the current rate of extinction biologists believe that we are entering a sixth extinction event.

The speed at which we are entering this extinction event indicates that there could be a 60 - 70% reduction in biodiversity not in the next 1,000 - 10,000 years as was the case with the dinosaurs, but in the next 100- 200 years! This is the true impact of mans existence in the relatively short time that we have occupied the Earth.

Without taking a radical approach to the population explosion of the human species and its constantly growing need for resources we may end up with an Earth populated with a very few domesticated species, and lose the splendor of species such as the African Elephant, the Asian Tigers, and the South American primates.

New discoveries

Each year we are discovering more and more incredible facts about different species of animals on the Earth. Recently we have discovered that there is a greater commonality between the human race and the chimpanzee to the extent where taxonomists are considering grouping the chimpanzee in the same branch as humans and the neanderthals. There have been reports by animal behavioral scientists that are showing that animals too having amazingly complex social structures. The answer to some of our growing medical needs such as the next generation of anti-microbial agents lies in species that may be destroyed before the discoveries have been made.

Ethically one could argue that we are transient on this planet and it is our duty to leave an Earth for generations to follow which is every bit as splendid as the one we have been privileged to occupy for the miniscule amount of time that each individual has been on this amazing planet. It would be unthinkable to live on this planet and only know the species that have existed here too through media archives. Sadly however if humanity does not set it priorities correctly and quickly this may be the only reference to the magnificence that is biodiversity.