We are beginning to appreciate that everything in nature is connected and interdependent. We are able to understand some of the mechanics of nature and can now see, for the first time in human history, the unintended consequences of our actions. Human activity has caused catastrophic disruption to the balance that existed in nature between wild land & marine habitats and animals, between insects and plants, between rivers and land, between the atmospheric air and the oceans and forests. It is all falling apart. The 2018 WWF Living Planet Report on the State of the Earth spells this out. We shall look at what is happening to pollinators and soil as well as the state of the oceans and fresh water habitats.
It has been estimated that 78% of wild plants in temperate climates and up to 94% in tropical forests are pollinated by animals. The animal pollinators include insects like bees, flies, butterflies, beetles, moths and wasps as well as birds and bats. Our food production substantially depends on these pollinators with 75% of leading global crops benefitting from pollination. These crops include fruits and vegetables that are a key source of nutrition for humans.
Pollinator populations are in decline mainly due to natural land being taken over for agricultural intensification or urban development. Natural land provides a nesting and foraging habitat for pollinators. Studies conducted in recent years have shown that insect populations in European nature reserves have dropped by 76% to 80% in the last 35 years. A study published in the journal of the US National Academy of Sciences last October has discovered that insect and bugs population in a sample of rainforests has fallen by 75% to 98% in the past 50 years. This has also caused a sharp decline in populations of insectivores (animals that feed on insects and bugs). The abundance, diversity and health of pollinators are also threatened by global warming, invasive species and pathogens.
A quarter of all life on Earth is found under our feet in the ground and soil. This includes microorganisms, microscopic fungi and bacteria; microfauna like hookworms and water dwelling tardigrades less than 0.1mm in size; mesofauna, such as mites; and megafauna that include soil living mammals such as moles.
These organisms influence the physical structure and chemical composition of soil. They are an integral part of enabling and regulating critical ecosystem processes such as carbon sequestration (absorption), greenhouse gas emissions and uptake of nutrients by plants. They are a priceless bank of potential medical applications as well as new biological controls of pests and bacteria, viruses or other organisms that can cause illness.
We are rapidly losing some of the oceans’ species-rich habitats such as coral reefs, mangroves and seagrasses. Coral reefs, for example, support more than a quarter of marine life. The Earth has already lost half the coral reefs in shallow water as a result of human activity and if we recklessly continue as we are today, 90% of all coral reefs will be gone by 2050. The implications of this for the planet and humanity are enormous.
This also threatens the livelihood and wellbeing of hundreds of millions of people – the world’s poorest. The UN Food & Agriculture Organisation estimates that fisheries and aquaculture alone account for the livelihood of 11-12% of the world’s population. Three to four billion people rely on fish for a substantial part of their protein intake. Around 200 million people depend on coral reefs to protect them from storm surges and waves.
Plastic pollution in the oceans and seas has also reached epidemic proportions. Plastic debris has been detected in all major marine environments from shorelines and surface waters to the North and South poles, as well as in the deepest parts of the ocean, at the bottom of the 11km deep Mariana Trench.
Almost 6 billion tonnes of fish, crustaceans and molluscs have been taken out of the ocean since 1950 as a result of indiscriminate over-fishing. At present there are 2.8 million motorised fishing vessels worldwide – frightening. It is estimated that by 2050, in our lifetime, not only would there be more plastic than fish in the world’s oceans and seas, but there will also not be any viable populations of any fish species left. Global sea catch peaked at 130 million tonnes in 1996 – we are still taking out 110 million tonnes of fish annually. As we have depleted the oceans of 90% of the big fish we are now catching them younger and smaller. Cod in the North Sea could live up to 25 years – only 10% of the cod population left is now over 13 years.
A 10 year study on loggerhead turtles showed that 35% of turtles analysed had ingested debris that was almost all plastic. Another study in the Mediterranean established that 18% of all tuna and swordfish examined had plastic in their stomachs as did 17% of Blackmouth Catsharks in the Balearic Islands most of which was cellophane and PET. Another study that looked into the risk of plastic ingestion by 186 seabird species globally found that 90% of the world’s seabirds have plastic fragments in their stomachs compared to 5% in 1960. The scientists that have undertaken this study predict that unless we take immediate action to stop the flow of plastic into the rivers, seas and oceans 99% of all seabirds worldwide will have plastic in their digestive system by 2050.
Freshwater ecosystems, such as rivers, lakes and wetlands, cover no more than 1% of the Earth’s surface and yet they are home to 100,000 different species of birds, fish, mammals, molluscs, reptiles, insects and plants. The Global Surface Water Explorer project shows that 2.4 million square km of the world’s rivers and lakes have remained unchanged over the last three decades. This may change. Freshwater is immensely valuable to all humans and yet these areas are the most threatened by fragmentation and destruction, overfishing, invasive species, pollution, habitat modification, forestry practices, disease and global warming. Just in case you have not yet caught on, this is all caused by humans. In many cases all or some of these factors have combined to cause catastrophic biodiversity losses.
The health of a fresh water ecosystem is defined by the quality and quantity of its water and its connectivity to other parts of the landscape and by the condition of its habitat and the diversity of animal and plant species that live there. Not surprisingly freshwater ecosystems are under unprecedented pressure and have suffered huge losses because of their proximity to human activity.
Wetland globally have declined by 50% since the 1900. We treat rivers like they were our home plumbing system. We block them up with dams and divert them causing mayhem and death to all water based life that depends on their flow for survival. We drown other habitats and land based life with the creation of artificial lakes. Dams block more than 25% of the sediment that would otherwise reach the oceans and seas that would feed into the estuary ecosystem. 70% of water removed from freshwater ecosystems is used for agriculture. The water quality in these systems is also being negatively affected by pollution and the nutrient rich run-off from disturbed surrounding land. Last but not least we then have global warming that is exacerbating the problems by changing the timing, availability and temperature of the waters. Like ourselves, plants and animals are also only able to survive within a temperature range.
Environmentalists, researchers and scientists today understand enough to know that maintaining the flow regime of a river is critical to support the key river functions and the ecosystems it traverses. We are also beginning to understand the complex interactions that land environments have with fresh water. The report encourages governments to legislate for the protection of freshwater and its flows. We can make positive change if we choose to. More than 1500 dams have been removed across Europe and the United States, thereby restoring the related ecosystems functions.
Scientific knowledge is unlocking the secrets of nature and unfolding before our eyes is a vision of such beauty and intelligence that we should be humbled by it. The balance in nature is exquisite and its power awesome. A healthy natural environment and the equitable distribution of wellbeing amongst human communities, go hand in hand. You cannot have one without the other.