At a time when more flora and fauna are vulnerable to extinction, policymakers from around the world are already weighing in the pros and cons of biodiversity loss. Global figures indicate that around a quarter of the world’s animal and plant populations – which means around a million animals are either endangered or critically endangered. These events occur as a result of habitat destruction, fragmentation and other anthropogenic factors.

Alarming statistics

Shedding light on the importance of preserving habitats, Sampath Seneviratne, Professor in Zoology at the Department of Zoology and Environmental Sciences, University of Colombo said that figures for global estimates have been obtained from mammals, reptiles, birds, amphibians, fish and flowering plants.

“This is the known life on this planet. Then there are bacteria, fungi and lichens for example which we don’t have the exact number of species or at least a good estimate of the number of endangered species. But we know those figures in previously mentioned animals. When we put figures together, which means the total number of species endangered under IUCN criteria, a quarter of animals and plants are critically endangered. This means that without any substantial human intervention, within the foreseeable future, the critically endangered species could go into extinction and the endangered species will become critically endangered. This is one alarming aspect,” Prof. Seneviratne said.

Loss of livelihoods

Ecosystem services carried out by various flora and fauna are now being appreciated by environmentalists, researchers and even policymakers. But over the past decade or so, more anthropogenic activities have caused a shift in the balance of nature. “In May 2019 an intergovernmental panel on environmental protection, a powerful authoritative group issued a policy document. It says that a million species will go extinct in the foreseeable future from the face of the planet. People may not perceive it as a big deal. However, the second part of this document says that as a result of that extinction around 43% of the livelihoods of people would be affected either directly or indirectly. If one million species disappear they will disappear with a lot of interactions and would lead to an ecosystem collapse which would end up in drastic consequences. But this is the same thing that happened to our economy.  The ecology and economy have the same principles- there are thresholds and safeguards. When safeguards and thresholds are not in place, seemingly stable ecologies could collapse and so would economies. The same phenomena could be applied to ecology in certain models. When the ecology is affected the health and economy suffer,” Prof. Seneviratne added.

Causal factors  

Even though many blame climate change for the rapid decline in species populations, more obvious causes exist. Habitat destruction is considered one of the main causes of the disappearance of animals and plants on this planet. “Most countries have some sort of wildlife protection law, wildlife department, forest department, ministry and other governmental bodies. Therefore it is an integral element in any governance structure. The world is progressing in terms of education, technology etc., but why is the environment deteriorating? It’s certainly not climate change. What we know from science across the globe is that habitat destruction is the main cause of the disappearance of animals and plants. There are main habitats including ocean habitats and terrestrial habitats. People don’t understand issues in wetlands, grasslands, mountains, deserts and in the aquatic environment such as coral reefs, deep trenches, seagrass beds, algal forests and wetlands.

Wetlands belong to both sea and land. Each habitat carries a unique assortment of species which are intimately connected. If you remove that habitat from the system these species will go extinct. What kind of intimate relationships do they have? Some are born, live, breed and die in these habitats. So if you destroy a rainforest these species don’t have anywhere else to go. However, some species don’t have such strong connections with their habitats. They can adjust to a certain extent, like certain fish that live in coral reefs. Some species have a critical stage in their life in which they require a particular habitat. For example, if we take wetlands, nearly 90% of marine fish spend at least one stage of their life in a coastal wetland. When you remove coastal wetlands those populations suffer. Wetlands are highly sensitive to human disturbances.

Most animals that make the large environment home are intricately tied to that sensitive environment. In that light even more than rainforests, these wetlands are sensitive. If we take the grasslands there are relatively fewer species compared to wetlands and rainforests. But grasslands are vulnerable because we love grasslands as well. So we use grasslands and as a result, grasslands across the globe are more threatened than wetlands and rainforests. Humans are not a mountainous species but mountain habitats are affected by climate change and indirect effects. Since the human population is increasing at an alarming rate, all these habitat types are under pressure and that is the single biggest problem for life on this planet.”