© Marlene A. Condon
There is so much talk these days about sustainability that you are probably tired of hearing that word. However, a recently published book—The New Ecology: Rethinking A Science for The Anthropocene (Princeton University Press, 2017)—provides extremely valuable insight to what sustainability is truly all about and why it matters so much to each and every one of us.
Yale University professor and author Oswald J. Schmitz furnishes us with numerous in-depth examples of how human behavior can alter ecosystems (the communities of living things interacting with their non-living environments) so much that they can no longer support us. He does a superb job of making clear why humans must learn to take into account the natural world when deciding how to live their lives.
For example, codfish off the coast of northern New England and Canada were once so plentiful that they sometimes stopped the progress of ships! When discovered by European explorer John Cabot in 1497, no one could have imagined that the commercial cod fishery that would develop from these stocks would end 500 years later in a devastating collapse that would not be possible to resuscitate.
The story of this fishery provides a historically detailed case study that illustrates how human exploitation of a resource species can lead ultimately to an alteration in the proper functioning of the ecosystem and thus to disastrous consequences for humans. The inability of cod to recover by the end of the twentieth century resulted in serious economic and social consequences for the coastal communities of New England and Eastern Canada, as well as Europe.
Portuguese, French, Spanish, and English fishermen started harvesting cod off Newfoundland in the 1500s, when they mostly caught inshore fish by trawling baited long-lines or by casting small nets from rowing or sailing dories. The cod was salted and dried throughout the summer, and the fishermen would return with the preserved fish to Europe in the fall.
With the building of permanent settlements along the seacoast from Newfoundland to New England, however, fishing became a major enterprise. Larger ships, known as schooners, carried dories to harvest cod in offshore waters as well as inshore. Size-selective fishing began, with the largest fish (90-100-pound range) being valued more highly than middle- (60-90-pound range) or small-sized (less than 60 pounds) fish.
Increasing societal demand meant major American cities as well as European and Caribbean markets received fish, increasing the need to catch ever more cod, preferably the largest ones. With the development of the factory ship that could catch and hold larger quantities of fish, the small-scale 450-year-old inshore fishery was doomed to extinction as cod fishing became an industrialized activity.
Gigantic vessels employed emerging sonar technology (a product of World War II inventiveness) to electronically pinpoint the locations of codfish. The ships trawled huge nets behind them that could capture large amounts of fish in a single sweep. Factory fishing led to a rapid increase in harvests, which dramatically crashed in the mid-1990s, halting the entire northern cod fishery, probably forever.
The takeaway from this situation is that humans cannot just increase or decrease their “withdrawals” from the environment based solely upon changes in human demands or prices without any regard whatsoever to their effect upon the harvested population. When harvest levels fell, fishermen should have backed off to allow the cod to reproduce and rebuild their numbers. Instead, the fishing effort increased, and people added insult to injury by taking the largest fish.
By taking the largest individuals, people reduced the productivity of the cod because larger fish reproduce better than smaller ones. But it was not just the cod’s inability to reproduce their numbers as quickly as they might have that drove this fishery to extinction. No, it is more complicated than that, which is why understanding the life histories of our fellow creatures is so vital to our ability to sustain their existence as well as our own.
The larger codfish were top predators in their ecosystem. They fed upon mid-sized predators, such as squid, crab, and mackerel that feed upon small-bodied larval and juvenile cod (as well as other kinds of tiny animals).
Larger-sized adult cod are better able than smaller cod to assist their offspring to reach adulthood by limiting these mid-sized predators. In other words, it is now much more difficult for young cod to reach adulthood, which limits the numbers of adults to reproduce, which limits the numbers of young cod, and so on ad infinitum.
Because humans did not recognize cod as part of a system of interdependent species, they created a series of cascading effects that keeps the cod from recovering to harvestable levels, despite the now-decades-long moratorium on fishing. Accepting the reality that species are part of complex food webs that humans need to respect and work within is what sustainability is all about.
Professor Schmitz includes many other such narratives in his book, including a fascinating one explaining the importance of termites to such large animals as zebras, buffaloes, impalas, and wildebeests. (Who knew?) These accounts should probably be required reading for students and adults alike as they make the concept and importance of sustainability easy to grasp and to truly appreciate.
However, I feel the thesis of this book is seriously flawed. Professor Schmitz seems to believe that environmental problems wrought by people can be solved simply by teaching folks about the relationship of organisms with each other and their environment, which will, he hopes, lead to people choosing to live in a more thoughtful (i.e., sustainable) manner.
But even if people got the message and reacted accordingly, a burgeoning human population makes sustainability impossible. All organisms, including humans, must be limited in number because that is the only way in which the environment can function properly. Organisms need space, food, and shelter to live among us, but it is exceedingly difficult to get people to provide habitat for wildlife. Government does not help, what with regulations and tax laws that discourage appropriate landscaping.
Humans have significantly altered the world we live in, which some folks may believe is a good thing. But the diminishing capacities of the Earth’s ecosystems to sustain their proper functioning is cause for concern that must be addressed if we expect human life to persist on Earth.