Human Induced Extinctions

dodo

This is the sixth in a series of seven posts regarding the threats I see facing humanity. This threat is human-induced extinctions. Scientists have determined that we live in a new geologic era, described as the Anthropocene, where human activity is the predominant factor in describing how the Earth is behaving. It is reflected in the erosion that comes from agricultural practices, creating new river deltas much faster than in previous times. It is reflected in the effect of industrial and civilian gas emissions, which affect the composition of the atmosphere. It is reflected in the crowding out of wildlife due to the incursion of human activities into locations where wildlife has existed for millions of years.

Perhaps there is no place where the effects of humanity has been so pronounced as in the ocean depths. There we have found the ultimate repository of the plastic we use so gratuitously, single use plastic that finds its way into the ocean waters. Stories abound about the wildlife found to be starving to death, because inert plastic has filled the stomach and gut of an animal. It literally feels full, since the stomach is full, but will not take in new nutrients since there is no urge to fill the stomach. That is one form of human incursion into the oceans. Another is the cruel and indiscriminate fishing practices that go on throughout the oceans. Huge dragnets haul all creatures up and then the catch is sorted once it reaches the surface and is dying. Much is either discarded or kept as junk fish, good only to be ground up as food for other fishes, or for pet food. Some is from species we identify with as being intelligent, like dolphins. I remember the TV show Flipper, which anthropomorphized a dolphin beyond recognition. But it is undoubtedly true that dolphins are intelligent, and capable of compassion, since the stories of dolphins assisting humans to survive are common.

The worst fishing practices are those that drag the bottom of the ocean. Those vessels disturb all of the creatures colonizing the ocean floor. Very few of these species are considered as human food, yet those that are (like flounder) are highly prized. The ocean floor will not recover for hundreds of years, yet the fleets of fishing ships keep trawling continually.

Oceans are one thing, but no human has their natural habitat under the sea. The problems of species extinction exist for each class of plant and animal. Though it is extremely difficult to quantify (how do you prove a negative?), the rate of species extinction is estimated at between 10 to 100 times greater than the rate of extinction normally present on Earth without an external cause. And anecdotal evidence is that insect populations are being affected extensively. Journals such as Science in 2017 published a story titled Where Have All The Insects Gone? The article noted that scholarly research on insect populations is scarce, but that in certain long-term studies of populations, the number of insects found in fields has been reduced by over 80%. The study referred to the “windshield effect,” noting that many people have seen fewer insect / windshield collisions over the years. The damage to bee populations has been severe, with the colony collapse disorder causing massive losses to bee populations. A cause for the reduction has not been definitively named, but the class of insecticides known as Neonicotinoids is, as the police would say, “a chemical of interest”. These chemicals were originally marketed as reducing the need to spray more toxic organophosphates and organochlorine insecticides. They often are used to coat the seeds, and when the plant sprouts, the insecticide is absorbed into the plant where it provides defense. But since it permeates the entire plant, it is expressed in the pollen as well. That is how it appears to affect pollinator populations. Since honeybees are used in commerce, the losses in honeybees was noted first. But concern exists for all other pollinator species.

Much has been written about the intrusion of humanity’s effects on tropical forests. Nowhere is that seen more clearly than when a road is cut through virgin forests. Once a road is available, it is soon followed by those who exploit the opening. Forestry now tackles the old-growth trees, reducing stable ecosystems into a maze of forest edges. Species that once had free range across a canopy now find themselves having to traverse new agricultural lands to get to the next patch of undisturbed forest. And when populations of people begin to live in these newly opened lands, a market in bush meat is created. The Amazon is ground zero to display the effects of roads and subsequent land disturbance. Take a quick trip on Google Earth to the Amazon, and note that wherever you see a road, you will also see the encroachment of cleared land and settlements.

We as humans do not always understand the impact of our actions. We do not know what will happen when insect A is eliminated from a portion of its normal range. What other species used insect A as a food source? What insects or plants did insect A help keep in control? Will we see a reduction in birds due to the lack of insect A? Humans, being emotional animals, are much more capable of generating sympathy for the large, photogenic animals that are endangered. But the smallest insect may have as much impact or more on the ecosystem as a large furry mammal.

We as a civilization do not yet seem concerned by the loss of species we are seeing. Even in countries where an effort has been made to reduce the loss of species, a change in the government can reverse decades of efforts almost overnight. In the US, there is no mistaking the intent of the Trump administration to roll back the provisions of the Endangered Species Act. There is a strong belief that laws and regulations limiting the ability of a property owner to develop property as they see fit, represent an unconstitutional taking of the owner’s property right. Since insects or birds or other animals cannot hire a lawyer to defend their right to life, it falls to environmental groups to challenge regulatory repeal. Still, the attitude of the administration towards science-based evidence remains clear. Science and scientists are viewed with disdain, and they are clearly leftist in their politics since they so often stand against the rights of those with property.

What can science do to deal with these problems? It would seem that an effort to develop new pesticides that do not have such systemic effects is required. These efforts are proceeding within the large agrichemical companies, but it takes years and sometimes decades before a novel chemical class is commercialized and finds its place in the marketplace. It appears that legislative action across the world may be needed to ban certain classes of chemicals shown to cause excessive harm. The role of scientists would seem to also include quantifying the loss of species, and doing research to show what happens when one thread of the web of life is pulled out.

Maybe the best use of scientists would be to increase their role in educating the public as to the risks we are running by conducting our current experiment of causing the extinction of so many species. In the Old Testament of the Christian Bible, humanity was given stewardship over the creatures of the Earth. If nothing else, we have been proven to be bad stewards.

 

 

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