Last week’s environmental blog on the five threats to biodiversity may have been somewhat of a downer to your day. I apologise, although the facts needed to be voiced loud and clear. Without awareness of what humans are and have been doing to our planet since the explosion of our population, we can only hope to continue the destruction. Thankfully, although we have been doing a very good job so far of harming every ecosystem that we can lay our hands on, that is not the end of the story. Thankfully, some very clever people are figuring out ways to solve some of the problems we have faced, piece by piece.
So what are we doing about Climate Change?
The coral reefs in the shallows of the oceans and seas are the canary in the coal mine for global warming. Corals are a collection of species sustaining some of our most diverse and valuable ecosystems on earth. Around 4000 fish species, 800 hard coral species, and hundreds of others are dependent upon this highly sensitive ecosystem for survival. Unfortunately, they are declining at a faster rate than any other habitat thanks to global warming. Corals are bleaching with temperature increases, resulting in their death and an inability to sustain the fish, crustaceans, and other organisms that have lived amongst corals for thousands of years. Perhaps then, corals are a good place to start, to explain how we are going to keep this canary singing over the next century and for many years after that.
So it may seem controversial to say that we are producing GM corals to help the reefs survive global warming, but this does not mean a load of mad scientists are creating strange corals in a lab to unknowingly release into the wild. GM, or genetically modified, in this instance means selectively bred. Corals are being taken from the wild and grown at higher temperatures to identify differential survival amongst corals in a species. The corals that survive and reproduce better will have a greater resistance to temperature increases expected with global warming. Higher resistance corals can then be intensively reproduced to be put back into the wild.
Whether it makes you more comfortable with the idea of GM or not, scientists are basically speeding up evolution by increasing the selective pressure for corals to cope with higher temperatures. Regardless of how ethical some people may think this idea is, it could be one of the most viable ways of saving our coral reefs.
So what are we doing about habitat loss and deforestation?
There is no denying that humans have destroyed a vast expanse of habitat to make way for houses, roads, offices, and for the general industrialisation in place of a the diverse communities who existed before. Although many species have unfortunately fallen to extinction, conservationists and ecologists are working hard to understand how habitat loss and deforestation may effect different species. Through careful research to understand the effects of fragmenting habitats in a landscape, we are better able to direct efficient conservation, to protect the species that are most vulnerable to habitat loss.
A large amount of work to mitigate the effects of deforestation and habitat loss on species is to look at how the fragmentation of habitats effect different species. A growing amount of research has demonstrated that some species like living near the edges of habitats, where fragmentation may not affect them so badly as habitat edges actually become more abundant. On the other hand, some species require a large amount of habitat isolated from other areas. In the latter case, these species will suffer the most following habitat loss and deforestation.
A fantastic example of how this science has been used to help prevent species extinction was during the conservation of the Barbastelle bats in the UK. Barbastelle bats had declined drastically towards the end of the last century, as they relied on the wooded areas for foraging that were being cut down in the 1900’s. Scientists realised that if these wooded areas were connected by hedgerows, the bats would still be able to move along shrub-like structures across a landscape to find food. Planting more hedgerows meant bats didn’t have to travel so far to find an evening meal, and in the space of 10 years an area only supporting 29 breeding females swelled to 65 breeding females in 2008. With carefully planned conservation efforts, many species can be saved from extinction even in the plight of habitat loss.
So what are we doing about invasive species?
Invasive species threaten global biodiversity, through outcompeting, predating upon, and parasitizing naïve native species who are not adapted to fight against these alien introduced organisms. With often unpredictable, and sometimes disastrous consequences, conservationists and scientists have had to scheme cunning methods for the eradication of, or adaptation to invasive species settlement.
After finding a new invasive species, humans are faced with a number of options. We can either deal with the consequences of an invasive species settling in the new habitat, which is cheap, easy but far from ideal and in many cases prone to the risk of disastrous interactions with native species. The invasive can be excluded from the habitat, which is a continual effort, long-term, and very expensive. Alternatively we can control the species in that area, which is again a continual, long term and expensive effort.
It is worth bearing in mind that eradicating and controlling a species is very difficult, as once a population has shrunk to a certain size, it faces less competition. Without continuous effort will grow back to the size it was before often with such ferocious speed that efforts would be almost completely wasted.
So the control or eradication of invasive species sounds like an ongoing and uphill struggle, which it is. Modern ecological theory has been used, however, to target control of invasive species, minimising effort whilst maximising the control and mitigation of invasive species spread.
I said earlier about small populations growing faster, and reproducing at a faster rate due to less competition with other individuals of the same species. If a population becomes even smaller, and individuals become more spread out, however, that population size becomes unsustainable. For instance, if a population was so thinly distributed throughout the countryside that individuals were very unlikely to find a mate, so unlikely that most would never find a buddy to start a family with, then that population would continue to decline to extinction. This principle is one of the best known ecological theories to describe population growth, and has been used very smartly in the control of invasive species.
In the US, the Gypsy moth is an invasive species responsible for the decimation of the timber industry in large areas of the countryside. It was understood that it would be almost impossible to completely eradicate the species stretching across many states in America, so instead they targeted the belt across the US where the moths were beginning to invade. Here, they kept the population so sparse that it was unsustainable. The moth population is currently controlled in these areas to the extent that a female and male moth are so unlikely to come into contact, that they are constantly driven to the brink of extinction in these areas, preventing spread across america. It is like a battlefield going across the US. The moths coming from one side, battled by ecologists wanting to protect the expanses of timber woodland on the other. Whilst the moths won their battle across a large stretch of the US, they aren’t having the rest of it without a fight!
So what are we doing about pollution?
All too frequently, horror stories are splurged across the news about pollution damaging our ecosystems, from the swallowing of plastic by marine animals, to the light pollution that confuses birds, reptiles and other species. Perhaps one of the most prolific forms of pollution in the ocean is the oil spillages by tankers that suffocate and poison birds, mammals and fish within any distance of the accident. With horrific consequences to oil spillages, better methods for the eradication of this pollution have been a big priority. Hopefully, with new methods for eradicating oil spillages, such accidents can have a lower impact on our ecosystems than has been reported in recent years.
Microbes are tiny organisms that we are unable to see with the naked eye, yet are some of the key drivers of nutrient cycling and energy production across the globe. Many species break up hydrocarbons for growth and survival, and this is one of the main components of crude oil. Because of this, scientists hope to manipulate microbes to clear up oil spillages. Such microbes already grow and thrive around oil refineries around the world, sometimes to the extent that they become a nuisance in the pipework of these oil companies. It only takes a small helping hand, then, for them to thrive equally as well in sites that are suffering from crude oil spillages that effect kilometres of ocean at a time. It is an exciting idea to think that we are using these forms of biological control to naturally clear up pollutants created by human’s mistakes. A point worth bearing in mind here, however, is how these microbes may not be native to the areas put to use. It sounds suspiciously like other stories of biological controls turning into uncontrollable invasive species… just food for thought.
So what are we doing about overexploitation?
Overexploitation comes in many forms from poaching on land, to the fishing of intentionally caught food and accidental bycatch to the point of extinction. In recent years, however, some intelligent ecological principles have again been applied to fishing, to protect populations whilst allowing fishermen to continue working and ultimately, stay in business.
Again, the key principle of population growth was applied here, but this time for a different goal than what was used to protect against invasive species. A lot of work was undertaken to see what the minimal viable population size of fished animals is in our oceans. This means, that we carefully looked at the characteristics of the species, such as how fast it grows to maturity, how many offspring it can produce, and how likely it is to die from factors other than fishing. All of these factors were used to calculate how much fishing pressure it would take to reduce a population below a threshold at which it is able to sustain itself.
These calculations sound very abstract, and almost impossible to get right, but where adhered to by policy and therefore fishermen in our seas, they have proven to sustain fisheries across the world keeping both fishermen and the fish in the sea happy.
As well as dictating the maximum amount of fish we can sustainably take from the ocean, nets have been modified, and regulated to reduce harmful and unnecessary bycatch from our oceans.
To do your bit, when buying fish at the supermarket you can look for a label to say it has been sustainably fished in this way. Then you can eat happy, knowing that you are funding governments and companies that are working to try and maintain the biodiversity on our planet.
So perhaps humans aren’t so bad after all?
Hopefully, after reading this blog you can rest a little happier this evening. Yes, humans have had and are still having a catastrophic effect on the biodiversity of planet earth. Thankfully though, there are an army of intelligent and hardworking people working to support a more sustainable generation and work towards a more sustainable and biodiverse future.