About Don Walsh

Dr. Walsh, a marine consultant, is a retired naval officer and oceanographer. During his naval career he served at sea in submarines and ashore in ocean-related research-and-development assignments.

Recent Posts By the Author


Oceans: Putting up the 'Keep Out' Signs

Oceans: Putting up the ‘Keep Out’ Signs

By:

Proceedings, January 2013
Marine Protected Areas (MPAs) are designated sites found throughout the World Ocean that are set aside for special protection and management. They conserve and protect sensitive ecosystems as well as cultural history. Governments ranging from the national to the local levels have established MPAs in almost every coastal nation in the world.

At 132,000 square miles, Hawaii's Papahanaumokuakea Marine National Monument is one of the world's largest protected oceanic spaces. But the total global area of such preserves is still just a drop in the bucket. NOAA Photo

At 132,000 square miles, Hawaii’s Papahanaumokuakea Marine National Monument is one of the world’s largest protected oceanic spaces. But the total global area of such preserves is still just a drop in the bucket. NOAA Photo

The United Nations Law of the Sea Treaty (UNCLOS) gives signatory coastal states a 200-mile wide Exclusive Economic Zone (EEZ). This includes a 12-mile-wide territorial sea where those countries have full sovereign rights. Beyond that point, states have quasi-sovereign rights to regulate almost all activities out to their 200-mile boundary. Thus coastal states have clear authority to establish MPAs within their EEZs. However, at present most are located within territorial waters. Read More

 

Oceans: Alvin and Trieste

Oceans: Alvin and Trieste

By:

Proceedings, November 2012
Both are Navy-owned deep submersibles. One was retired in 1963, while the other is still active. But their histories are related.

The bathyscaph Trieste joined the U.S. Navy in 1958. Based at the Naval Electronics Laboratory (NEL) in San Diego, she was deployed to Guam for a series of deep dives in 1959–60 that included one to the deepest place in the ocean.

Trieste. US Navy photo

Trieste. US Navy photo

Read More →

Seasick: Our Acidic Oceans

Seasick: Our Acidic Oceans

By:

Proceedings, Sept. 2012
Carbon dioxide . . . it’s what makes our soft drinks zesty and champagne . . . well, champagne. It is also a major greenhouse gas. Absorbed into the sea it is an essential component for growth of plankton, the first stage of marine life. By contrast, excessive amounts can make some organisms sick and possibly extinct.

The beneficial role of CO2 is in the photosynthetic process that feeds phytoplankton, the microscopic plants of the sea. Carbon dioxide, solar energy and the chlorophyll pigment combine to make food for these organisms that are the first level of life in the sea. A critical byproduct of this chemistry is the respiration of oxygen by these tiny plants. The vast surface area of the World Ocean supplies 50–80 percent of Earth’s oxygen. Indeed, it is the lungs of our planet.

The sea has an enormous capacity to absorb CO2. Since the Industrial Revolution began about 1750, man’s activities have loaded the atmosphere with great quantities of it. However the oceans have been able to absorb about 50 percent of this anthropogenic CO2. Remarkably, this percentage has remained fairly constant over the past 250 years even as increasing amounts are injected into the Earth’s atmosphere. But this “carbon sequestration” comes at a price. When atmospheric CO2 dissolves in seawater there is a chemical reaction that forms carbonic acid, a very weak acid.

Scientists use the pH numerical scale to define the relative acidity or alkalinity of a solution using a range of 0–14. Distilled water is neutral at a value of 7.0. Numbers lower than this are acidic and those above are alkaline. At present the average pH for the oceans is 8.1, so it is slightly alkaline—but this number is decreasing steadily. To be clear, it is unlikely that the oceans’ pH will ever drop below 7.0, so the term “acidification” refers to relative acidity as seawater becomes less alkaline. The accompanying graph shows the relationship between dissolved CO2 and increasing acidity in the sea from the years 1850–2100 (estimated).

Read More →

The Farming of the Sea

The Farming of the Sea

By:

Fishing is one of mankind’s oldest organized activities. From the time our earliest ancestors first sorted through tidal pools to the present day, we have been fishermen, and fishermen are essentially hunters. Today, that hunting has become increasingly difficult. High-tech, super-efficient methods have led to drastic overfishing of the most valuable stocks. In addition, loss of fish habitat, pollution, and acidification of the oceans have combined to naturally reduce those fisheries that are still viable. It is known what measures should be taken to develop global sustainable fisheries, but few governments have the discipline to enforce the necessary restrictions.

The World Ocean covers 71 percent of our planet’s surface and has a volume of 350,000,000 cubic miles. But the idea that it contains a vast store of harvestable protein for humankind is fiction. The fact is, fish in the oceans can never be a primary source of animal protein for a growing world population now at 7 billion people. The present world fish catch is about 85 million tons a year. It has remained at that level for nearly two decades. Furthermore, 80 percent of the fish stocks now taken for human consumption are at or have exceeded their exploitable limits. The hunter roaming the oceans is rapidly losing his prey.

Read More →