Oceans And Seas

The oceans are emptying fast

The fast-vanishing fisheries in their common sea. You’d think there would have been a sense of the need for urgent action at the annual meeting of the cumbersomely named General Fisheries Commission for the Mediterranean. After all, scientists had warned that 22 of the sea’s 23 stocks of bottom-living fish – including hake, mullet and red shrimp – are over-exploited, and called for drastic catch reductions in fishing.

This was typical of the way governments have approached the ravaging of the seas, where we still catch what we can without, like farmers, taking care to maintaining and increasing the stock. And few measures have been more disastrous than the EU’s Common Fisheries Policy, whose meetings, former agriculture and fisheries minister William Waldegrave once told me, reminded him of “Buffalo Bill and Wyatt Earp arguing over who should shoot the last buffalo”.

If so, it’s about time. For while geologists and economists are still arguing about when “peak oil” will hit us, we have long left “peak fish” in our wake. After growing almost fivefold since 1950 – twice the rate of population growth – the wild harvest from the seas peaked at some 93 million tons in 1997, and has been declining since; the total catch has only continued to grow thanks to increasingly widespread fish-farming.

At least three quarters of the world’s fish stocks are being exploited at, or well beyond, the limit at which they can be sustained. And Europe’s waters are even more denuded, with 87 per cent of its stocks overfished.

Five years ago, leading fisheries scientists predicted that at the present rate, every commercial fishery in the world could be wiped out before 2050.

This is serious stuff, not least because a billion people around the world depend on fish as their primary source of protein. Yet governments continue to pour some $20 billion a year into subsidies to enable their fleets to deplete further the resources on which both the people and the fishermen depend. Guided by satellites and radar, huge ships – dragging nets up to 50 miles long, with openings that would swallow 16 jumbo jets – mop up the ever-scarcer shoals. And to cap it all, nearly a tenth of what is caught is thrown overboard again, dead or dying, as “discards”.

It’s all both barmy and, strangely, rational. For since no one owns the fish, few see much point in conserving them. It’s what arch-conservative environmentalist Prof Garrett Hardin dubbed “the tragedy of the commons”: each fisherman gains from overexploiting the resource, since the gains accrue exclusively to him while the loss is shared by everyone. The result is a rush to ruin.

NASA to Launch New Ocean-Watching Satellite in June | Blue Channel 24

NASA is preparing a sophisticated new observatory, designed to study the relationship between the saltiness of Earth’s oceans and the planet’s climate, for its launch into orbit next month.

The Earth-observing Aquarius/SAC-D mission will measure the salt levels, or salinity, of the ocean surface, and the subsequent interactions between ocean circulation, the water cycle and other drivers of the planet’s climate.

“It’s really going to be a great leap forward for the science of oceanography,” Eric Lindstrom, Aquarius program scientist at NASA Headquarters in Washington, D.C. said in a briefing Tuesday (May 17). “We have, in the Earth science division, 13 missions on orbit now. A key missing piece, in demand by the ocean science community, is salinity. This determines the density of surface water of the ocean, and density variations and wind drive ocean circulation. This is why we want to get this missing piece.”

Age of Aquarius

The $287 million Aquarius satellite is set to launch June 9 atop a Delta 2 rocket from Vandenberg Air Force Base on the central coast of California.

As the observatory orbits 408 miles (657 kilometers) above Earth, it will continuously take measurements on the concentration of dissolved salt at the ocean surface within a swath that is nearly 250 miles (400 km) wide per orbit.

Every seven days, Aquarius will obtain enough data to be compiled into a complete and global map of ocean salinity. These observations will help reveal how salinity changes over time and from one part of the ocean to another.

Other instruments onboard the satellite will simultaneously collect other data, such as measurements of ocean surface winds, over the entire surface of the Earth.

“Measuring surface winds are important measurements,” said Gary Lagerloef, Aquarius principal investigator at Earth & Space Research in Seattle Wash. “We use that data to correct for surface roughness on salinity measurements.”

Tracking sea salt from space

Aquarius will use a set of highly precise microwave radiometers to detect microwave emissions from the ocean surface. These emissions are modulated, or changed, based on the electrical conductivity of the water itself, which is influenced by the salinity. [The World's Biggest Oceans and Seas]

By tracking variations in ocean surface salinity, Aquarius will monitor changes in the water cycle caused by evaporation and precipitation over the ocean, river runoff, and the freezing and melting of sea ice.

Oceans and Seas

Oceans and Seas

Oceans and seas

Oceans and Seas

Oceans and Seas