Seven Ways to Save the Seas

A special report in the May 2011 edition of Popular Science reviewed seven ways of saving our oceans from the current path of rapid degeneration.

Reducing Fertilizer Used in Farming

There are many types of ocean pollution but the most devastating pollutants are the nitrogen and phosphorus found in our fertilizer and sewage. When it washes downstream, coastal waters become choked with heavily fertilized algae, which then dies and decomposes, consuming the oxygen in the water and asphyxiating animal life. This process, called eutrophication, has created at least 405 “dead zones” worldwide.

We have tangible evidence that eutrophication is reversible. The “no-till” farming method achieves equal yields using just half the energy. This method leaves the stubble and root structure of last year’s crops in place, new seeds are planted using modern seed drills, and fertalizer is deposited beneath the surface using fertilizer injectors. This method reduces phosphorus runoff by about 40 percent, atmospheric nitrogen release by about half, and overall erosion by up to 98 percent.

Pricing Carbon

Since the beginning of the industrial era, oceans have absorbed more than a quarter of the CO2 that humans have released into the atmosphere and when CO2 mixes with seawater it becomes carbonic acid. In the past two centuries our oceans have become 30 percent more acidic. In the Pacific Northwest acidic oceans have prevented oysters from spawning. For this and other reasons we must reduce CO2 production. This starts with eliminating oil subsidies but we will also need a way of making carbon production more expensive. One suggestion involves a carbon tax. A tax of just $12.50 per ton of CO2 by 30 percent kieeping some 214 million tons of pollution out of the oceans.

Curb Species Invasions

Slimy invertebrates called tunicates are just one of the 4,000 known invasive aquatic species worldwide. The best way to reduce invasive species is to prevent them from arriving in the first place. Efforts are underway to impose new ballast water regulations in the US. Meanwhile, dozens of companies are developing techniques for meeting those standards, including computerized filtration and ultraviolet irradiation. For established invaders, the best hope is to control their numbers, one creative solution invovles eating them. In 2009 the National Oceanic and Atmospheric Administration launched a program to stimulate an appetite among fishermen, chefs and diners for lionfish.

Fix the Water Cycle

Atmospheric warming is causing saltier oceans. However, cooler less salty water exists deeper in the oceans. One technique, known as Ocean Thermal Energy Conversion, or OTEC, might help. In the 1970s, engineers began using platform-based rigs to bring cold, deep water to the warm surface; the idea was that the temperature difference would drive a heat engine, generating energy. Used on a large scale, OTEC could have the healthy side effect of lower the surrounding surface temperatures. In the saltiest areas, pulling water from the deep might help create life-rich oases rich in nutrients that stimulate the growth of chlorophyll and phytoplankton.

Rescue Coral Reefs

In the past 20 years, nearly a third of the world’s coral has been destroyed. Around 90 percent of the reefs off the coasts of Sri Lanka, Tanzania, Kenya, the Maldives and the Seychelles are at risk. The primary cause of the die-off is coral bleaching. As temperatures rise, marine bacteria flourish and attack the algae that live symbiotically within every individual coral polyp. Eugene Rosenberg, a microbiologist at Tel Aviv University, has proposed that the presence of a different form of bacteria could protect coral reefs. Introducing these bacteria in what is known as “phage therapy” could reintroduce life into bleached coral reefs.

Fishing Smarter

Last year, fish consumption reached a global annual average of 37.5 pounds per person. Meanwhile, cod and bluefin-tuna populations have collapsed, and animals ranging from whales to turtles have been added to the Endangered Species Act. Fishermen also kill a lot of marine wildlife unintentionally in what is called “bycatch”. A United Nations report estimates bycatch at 7.5 million tons a year, or 5 percent of the total commercial-fishing haul. Because most available data is self-reported, the U.N.’s numbers “woefully underestimate” the problem. Better fishing methods could radically reduce bycatch.

Invest in Research

The oceans are huge, therefore investments to understand the oceans must be equal to the task. A total of 71 percent of the planet or 139 million square miles are covered by oceans. Oceanographers are building undersea sensor arrays in the Pacific Northwest to monitor temperature and acidity. However, much more needs to be done to properly understand the ocean and develop strategies to help manage them. NASA’s budget in 900 times greater than that of the Ocean and Atmospheric Administration. Clearly our oceans require greater more research funding.