It took millions of years of evolution for the world's oceans to develop the biodiversity that we take for granted. Fish, corals, sharks, turtles, and whales all depend upon a dynamic balance of salinity and waterborne micronutrients, as well as limited levels of pollutants. Now, in a matter of only decades, human activity has stopped and is now reversing that process. The human impact takes the form of agricultural runoff of pesticides, excessive carbon dioxide in the atmosphere, and sewage and other pollution pumped into the overwhelmed waters. As a result, in crisis spots all over the globe, advanced oceanic lifeforms are being devastated by the contamination, both directly and indirectly, because that same pollution greatly promotes the growth of more primitive lifeforms, such as algae, which compete with and push out the more advanced forms.
A Los Angeles Times article entitled "A Primeval Tide of Toxins", published on 30 July 2006, illustrates the terrible problem by highlighting some of the trouble spots around the world. For instance, Moreton Bay, Australia, once a thriving fishing area, has been devastated by an ancient fireweed that flourished 2.7 million years ago, and is an ancestor of modern-day algae. The weed, Lyngbya majuscula, is so prolific that it can cover an ocean floor the size of a football field in less than an hour. It is so venomous that merely touching it causes severely painful boils and welts, causing skin to peel and scar. Even contact with seawater in the bay can cause extremely painful inflammation of the skin. Australian authorities dismissed the people's complaints, until marine botanists at the University of Queensland placed samples of the weed in a drying oven, producing fumes that drove the building's occupants outside, coughing and choking.
The devastation of Moreton Bay's ocean life is just one of countless examples. Off the coast of Georgia, decades of intensive trawling have wiped out the shrimp. Consequently, commercial trawlers are now harvesting the cannonball jellyfish — slimy and reeking of ammonia — that have taken over the ecosystem. Jellyfish have done the same to the waters off the coast of Spain, forcing the use of nets to protect swimmers from getting stung. In the Adriatic Sea, a sticky mixture of algae and bacteria washes onto and fouls beaches, or congeals into floating human-sized blobs. On Florida's Gulf Coast, toxins from red algae have killed hundreds of sea mammals and caused serious respiratory problems for coastal residents. On Maui's southern coast, foul-smelling green-brown algae is ruining beaches and angering condominium owners. On Sweden's Baltic Sea coastline, blooms of cyanobacteria have turned the water into a noxious and fetid yellow-brown slush, upon which floats dead fish.
Even the equatorial paradises have not been immune to the environmental damage. In 1980, off Jamaica's northern coast, a hurricane destroyed a magnificent stand of staghorn corals which nurtured numerous species of fish. Research scientists expected the corals to recover quickly, as they always had in the past. But they did not, because of environmental stressors, including sewage, fertilizer runoff, and overfishing. Now, the once ecologically valuable reef lies dead, covered in bacteria and algae. Jeremy Jackson, a marine ecologist and paleontologist with the Scripps Institution of Oceanography, noted that "We're pushing the oceans back to the dawn of evolution, a half-billion years ago when the oceans were ruled by jellyfish and bacteria."
During the past couple of decades, most people took little heed or action as they learned that pollution and overfishing were destroying the vital ocean ecosystems. Now that the predictable consequences are affecting humans, perhaps we will finally admit that we can no longer use the world's oceans as one big septic tank. As a popular slogan from the 1960s states, "What goes around, comes around."