7. Why should we care?

Posted: 13 October 2000

Author: Sylvia Earle

Author Info: Dr Sylvia Earle is an oceanographer and founder of Deep Ocean Exploration Research (DOER) in 1992. She holds numerous awards and honors for her work in marine science and conservation, including the 1997 Bal de la Mer Foundation's Sea Keeper Award. Dr Earle has led more than 50 underwater expeditions and holds a depth record for solo diving (1,000 metres). She is also author of numerous publications concerning marine science, including Sea Change (published by Constable, London, 1995, £18.95)

How we look after the ocean will determine the future of life on earth - forever - says Sylvia Earle.

'Why should I care about the ocean? People don't drink salt water. I can't swim, I don't eat fish, don't like boats and - I get seasick. If the ocean dried up tomorrow, what difference would it make? Who needs the ocean?'

My first reaction to this challenge from a young reporter in Australia was indignation; then I glimpsed a suppressed smile and played along. "Okay," I said. "Get rid of the ocean and what would Earth be like? Probably a lot like Mars. Cold, barren, inhospitable."

Inspired, I went on, thinking of the many ways the ocean affects all of us, all of the time, no matter where on the planet we live.

Living soup

From afar, I mused, astronauts quickly grasp the truth: Earth is dominated by the sea. In short, the ocean is our life support system, the driving force behind climate and weather, the key to temperature regulation, the source of most of the oxygen in the atmosphere, the place where enormous quantities of carbon dioxide are absorbed. It is also home for most of life on Earth. Water is the single non-negotiable thing life requires, and this planet is blessed with lots of it, most of it - 97 per cent - ocean.

The ocean is our life support system© Still Picture/EIAEvery time I slip on a face mask and flippers and dive into the sea, it is like diving into the history of life. Even a bucketful of seawater may hold a living soup of young planktonic sponges, jellyfish, starfish, arrow worms, peanut worms, annelids, crabs, bryozoans, fish, and much more. Most of the 30 or so phyla and dozens of classes of life that have ever existed on Earth still prosper in the sea, and about half occur only there. Some, such as the groups that includes horseshoe crabs and the once numerous lamp shells are today represented by only a few species, but others, such as the annelids, are so species-rich that their numbers may rival insects. A few feet from any shore, it is possible to encounter more of the broad categories of plants and animals than can be found in the richest terrestrial forest, meadow or swamp.

In the past half century, new discoveries have been made that are bringing into focus the many ways this living ocean affects humankind. The recent El Niño phenomenon, a fluctuating current off the coast of Peru, has made people worldwide aware of the global connections among ocean currents, winds, rainfall, temperature, crops, flooding, drought, the stock market - and the economies of nations far removed from the western coast of South America.

The sea always has been valued as a liquid highway, dividing and uniting cultures worldwide, sometimes serving as an important arena for aggression or defence. It has also yielded a treasure trove of history, especially in recent years as new technology has made possible the recovery of long-lost artifacts from ship wrecks and has revealed ancient shorelines. New access to the deep sea has begun to provide insight into the nature of earthquakes and other grand earth processes that have direct impacts on the lives of people far inland. Oil and gas reserves under the ocean are being tapped and used worldwide, and alternate energy sources explored, ranging from power derived from waves and tides to the thermal differential between cold, deep water and warm surface temperature.

Distilled energy

The past 50 years have not only yielded new discoveries about the ways the ocean affects humankind. Increasingly, there is evidence of the many ways that we are affecting the ocean.

One way is through the large quantity of life we take from the sea. People don't consume many marine plants directly, but every time we make a meal of tuna, swordfish, mackerel, cod, haddock, halibut, shark, rockfish, flounder, orange roughy, lobster or dozens of other commonly served sea creatures, we consume the distillation of energy generated by millions of microscopic creatures. It takes thousands of pounds of minute planktonic plants working through complex food chains to produce a pound of most of the fish that people eat - top predators that are to the sea what lions, tigers, eagles and owls are to the land.

Extraction of hundreds of millions of tons of wildlife from the sea in the past few decades has begun to alter the nature of ancient ocean ecosystems. Once abundant species have collapsed and entire ecosystems, from coral reefs to kelp forests, are showing clear signs of stress.

If the ocean did not matter to the future of humankind, perhaps we could justify using the waters of the world as a convenient place to dump sewage and discard whatever we don't want nearby where we live. Perhaps we could extract wildlife without worrying about the sustainability of populations of fish, whales, shrimp, oysters, seaweed, crabs and clams - as well as the many other forms of life that comprise the living sea. Perhaps we could continue behaving much the same way that we do right now.

Dying Reefs

However, we have learned enough in the past half century about the importance of the ocean to human survival and wellbeing to understand that we must change our ways - if we are to have an enduring, prosperous future. Dying coral reefs, sharp declines of more than a hundred once-common species of fish, a growing anoxic "dead zone" in the Gulf of Mexico, a 50 per cent loss of shoreline mangrove forests, increasing abundance and extent of toxic algal blooms - are among recent signs that the ocean is in trouble. The ocean is our life support system. If it is in trouble, so are we.

This would be terrifying news but for one thing. During the same few decades when we have done the most harm, we have also learned more about the nature of the ocean and its importance to our survival and well-being, than during all preceding human history. With knowing comes caring, and with caring, there is hope that we will seize the opportunities now available to protect the natural wild ocean systems that provide the underpinnings of how the planet works.

We have the power to eliminate - or perpetuate. The choice is ours about whether there will or will not be great whales thriving in the waters of Antarctica at the turn of the next century; whether there will or will not be cod and bluefin tuna chasing capelin and herring in the North Atlantic; whether there will or will not be coral reefs along certain shores. What we do, or chose not to do, right now, will surely shape the nature of the ocean - and our own lives - in the near future.

More sobering - but also inspiring - is the certainty that what we do, or chose not to do, will shape the future for all who follow, forevermore.