span sixty years, will have travelled considerably further than the distance to the moon and back. The plight of the albatrosses has recently emerged as a conservation cause célèbre, and I have been pleased to help BirdLife International and others to make the case for a change of fishing methods, but despite some efforts to protect these incredible birds, long-line fishing boats continue to take a terrible toll. It is a situation, though, that as in so many other cases is complicated by the ability of countries to cooperate internationally, and is not helped by the fact that the USA has still not signed the International Agreement on the Protection of Albatrosses and Petrels. And alongside the decline of the albatrosses has come the near destruction of the populations of the large fish most prized in international markets. There is an awful congruity in the fact that the Chilean Sea Bass that these boats catch also live for sixty years and, like the albatrosses, they do not begin to breed until they are between 10 and 20 years old. If they are caught before that time the chances of any future stock are gone for good.
A long-lived Patagonia Toothfish is gaffed aboard a long-line fishing boat.
While the fish have become scarcer, the rewards to be gained from catching them have only increased. Controls are in place to help avoid the complete collapse of the populations of the most valuable species, but illegal fishing has become a major problem. Even with the best will, policing the vast expanse of ocean that is plundered by illegal fishing presents a massive challenge.
Given the low numbers to which many albatross species have already sunk (and some hang on as just a handful of remaining birds), it is obvious where these trends will take the world’s most charismatic and endangered sea birds. This situation is made worse still for some species because not only are they attracted to baited hooks, but they also go for pieces of discarded plastic. The adult birds pluck plastic items from the sea, mistaking our consumer detritus for food, and then they feed it to their young – which often kills them. Recently I was told of the vast rafts of plastic that now float in the Pacific Ocean some 500 miles off the coast of California. This appalling phenomenon of today’s world has doubled in size over the past decade and it now occupies an area of 540,000 square miles of the Pacific – nearly six times the size of the United Kingdom. This ‘plastic vortex’, as it has become known, comprises up to 100 million tonnes of man-made waste – plastic packages, bottles, cans, tyres and broken-down chemical sludge. This monstrous plastic island is situated in a relatively stationary region of the ocean because it is bounded by a system of rotating oceanic currents called the North Pacific Gyre. Its proportions are truly eye-watering and it puts the plight of these amazing sea birds, as well as all kinds of marine life including turtles, into its proper perspective, not least because hardly anybody seems to know about the problem so nothing is done about it. Call me a ‘busybody’ but I am determined to do all I can to make sure this is not the case for much longer…
On land there are just as many problems. Perhaps surprisingly, one of the main reasons for the extinction of many creatures over the past few centuries has been the sometimes subtle impacts caused by introduced species. Rats, for example, have found their way to remote oceanic islands courtesy of explorers’ ships. When aggressive generalists like these turn up in ecosystems where the native animals have evolved in isolation and do not have the defences to deal with alien invaders, mayhem can result. Indeed, most of the recorded extinctions that have occurred since 1600 have been due to the effects of introduced exotic species. The dodo, the very emblem of extinction, appears to have succumbed more to the pigs and monkeys released by sailors than it did to excessive hunting.
The native Red Squirrel has disappeared from most of its former range in Britain.
In the UK we welcome North American visitors with open arms – except perhaps for one: the grey squirrel. This charming-looking creature has a dark side. It has devastated our native population of red squirrels, hastened the disappearance of our native dormouse, and in some places has caused decline in songbird populations. It also causes untold damage to young hardwood trees such as oak, beech and ash. These little creatures are frustrating so many worthy efforts to re-establish native hardwood plantations, and they provide one more example of how our interference with natural systems can cause chaos.
I don’t suppose we will be able to do much about the grey squirrels, save controlling them locally when their numbers grow, but my heart sinks every time I hear of the latest big idea to introduce yet another new species of animal or insect from elsewhere in the world in order to deal with a problem caused by a previously imported species. And I am completely exasperated when such schemes from time to time are given the blessing of wildlife groups. Clearly even some of those who work closely with Nature, and who struggle so hard to protect her, sometimes think with the same mechanistic ideas that created the very problems they are trying to solve.
There is some good news, however. The Red Squirrel Survival Trust is for example, working hard to maintain and expand the populations of this wonderful creature. I have been pleased to help them with their effort to save these utterly charming creatures from what looks like imminent oblivion in these islands.
Elimination
While it is sometimes hard to comprehend the scale of the impact we have had on the Earth, the picture pieced together by the meticulous work of thousands of scientists tells an increasingly worrying story. Many in conservation circles believe that a sixth great extinction event is under way – a situation that might soon lead to a tsunami of species loss. This is not least because the rate at which species are being lost is now estimated to be between 100 and 1,000 times the natural background rate at which species disappear. Different kinds of animals and plants have always disappeared, but at the current high rates some projections suggest that by the end of this century we could lose up to 50 per cent of the total number of species that now inhabit the Earth.
Of course, during the long period that life has existed in abundance on Earth there have been times of rapid change. Indeed, etched into the fossil record are five periods when a large-scale loss of animal and plant species occurred – the last was when the dinosaurs disappeared, about 65 million years ago, marking a sharp boundary in the geological record between one epoch and another. Many believe the world recently entered a new one. And this one marks the fact that for the first time in the history of the Earth a single species has become the most dominant ecological agent – it is we humans, and that is why the period is called the Anthropocene. We are now the main reason for the rapid erosion of natural diversity, and whether we like it or not, this great living powerhouse is what sustains our well-being. We deplete and degrade it at our peril. In the pages that follow I will set out some of the reasons why this is the case, but for now it is enough to say that one reason why we are losing natural diversity so quickly is the rapid increase in our numbers.
Amphibian species are being lost at a terrifying rate. Fortunately the strawberry poison-dart frog remains common throughout its Central American range.
In 1900 the world population was about 1.6 billion. By the time I was born in 1948 it stood at 2.6 billion people. By the end of the twentieth century it had reached over six billion – marking a near fourfold increase in 100 years. In 2010 it will have exceeded 6.8 billion and is expected to continue climbing inexorably to about nine billion by 2050. While our numbers rise, and as we become richer and thus demand and expect more, the ability of our planet to meet our needs has significantly decreased. We are using up its natural capital and resources as if they were inexhaustible and without long-term value.
So far, as this has happened, food supply has managed to expand to keep up with demand. In part this has been achieved
