under the sea

The Earth's oceans are symbols of boundless living wealth. They have provided nourishment and avenues for exploration for millenia. Currently, three-quarters of all stocks of commercially usable sea fish and shellfish have been severely exploited, almost to the point of extinction. This has resulted from a combination of consumer demand, lack of initiatives of governments and fisheries to push through with countermeasures.

However, the time has come now to sit back and take stock, so to speak if we are to continue to eat from the seas. Fish and seafood are the most important sources of protein in the daily diet of almost half the earth's population. According to the FAO global fish consumption is set to grow atleast 2% per year. But this increase in consumption patterns cannot be supported for very long in the face of depleting fish stocks.

Migratory species and large predators are worst affected: tuna, swordfish, halibut and shark. 90% of these varieties have been wiped out in just five decades. This not only has catastrophic effects on world economy but also unpredictable effects on ocean ecosystems of the world. In addition to exceeding catch amounts, fishing methods like bottom trawlers devastate coral reefs and habitats for juvenile fish. Other trawlers comb the seas often using sophisticated technology to ensure catch. Due to their huge nets as big as 100meters, there is also a high amount of by-catch which is usually discarded. Overfishing combined with climate change is putting incredible pressure on our oceans but scientists claim there is still hope for recovery if measures are in place now.

The oceans belong to everyone and therefore to no one, so the is nobody to take responsibility for the problem of overfishing. Countries like the Netherlands have pledged to only supply 'eco-fish' supplied from sustainably managed farms from 2011 which is a commendable step. Australia and New Zealand have devised a sort of trading system between fishermen and introduced individual caps for them. Consumers can do their role by educating themselves on what species they can eat and what species to avoid. Additionally there are guides printed and the most popular one seems to be Seafood Watch published by the Monterey Bay Aquarium, California which gives information on recommendations for your plate.

Seafood provides many essential nutrients - especially omega 3, 6 fatty acids - needed for well being. However there are many other foods that provide the same benefits so cutting down on amount of seafood consumed is a good way to reduce demand. Many high profile restaurants have dropped endangered fish species off their menus so it is time that other consumers also demand fish sourced from sustainable fisheries or aquaculture farms that support eco-friendly practices.

In conclusion: fish for your consumer choice.

why carbon sinks?

Everybody is talking about reduction of green house gases and carbon-cuts. What a lot of people don't realise is that even if carbon amounts in the atmosphere are reduced today, the effects of current levels of carbon already present is going to be felt for atleast 100 years - this is how long it takes for carbon to dissipate. In other words: even if we reduce carbon emissions now, the carbon already present can contribute to global warming.

This realization is the reason why there is a current scramble for carbon sequestration technologies. The idea behind this is to capture carbon and then bury it under the earth, in the sea-bed or to come up with a method where the conversion of carbon is accelerated.

Currently forests have been acting as a great 'carbon sink' whereby carbon is naturally captured. However due to global warming there have been speculations that forests could release huge quantities of carbon and create a situation in which they do more to accelerate warming than to slow it down. While deforestation is responsible for about 20% of greenhouse gas emissions from human activities, forests currently absorb more carbon than they emit.

But the problem is that the balance could shift as the planet warms, the report concludes, and the sequestration service provided by the forest biomes could be lost entirely if the Earth heats up by 2.5C or more. Droughts, more pest invasions, and other environmental stresses would trigger considerable forest destruction and degradation. This could create a dangerous feedback loop, it adds, in which damage to forests from climate change would increase global carbon emissions that then exacerbate global warming.

The other biggest natural carbon sink are the oceans of the world which are already showing stress due to acidification because of excess carbon. Plankton in the ocean also act as a carbon sink and they will slowly die as the oceans become more acidic and warm up. The other big carbon sink is the permafrost which is said to contain large amounts of methane. Global warming will cause it to melt which will release all the methane which is more potent than CO2 as a GHG.

The need for reducing carbon emissions as well as to reduce the amount of carbon already in the atmosphere is pressing. So there is a twin objective to be met in order to combact enhanced global warming. Does this make it harder to reach our objectives? Perhaps. But it also impresses upon us the incredible delicacy of the Earth's natural regulating systems.

rainforests of the ocean

I had the opportunity to go to Lakshadweep which are a group of islands off the west coast of India in September 2008. The entire archipelago is built on dead coral beds giving the islands white sandy beaches and crystalline blue-green waters. It was visually stunning and definitely one of the most beautiful places I've been to.

It is home to some of the most stunning coral formations as well as sea-turtles, reef sharks, rays etc. Its delicate reef ecosystem is a reminder of how precious our natural biodiversity is. Almost all of the corals surrounding the islands were destroyed by the El Niño phenomenon but now show signs of recovery. To truly enjoy the splendor of the reefs snorkeling or scuba diving is a must. It immediately puts into perspective your smallness in the grand scheme of things. 2008 was the year of the coral reef - coral reefs all over the world are endangered as a result of human activity. Corals are very sensitive to temperature, salinity and acidity - all of which are being affected by global warming. Humans are effectively changing the balance of the last great frontier - the ocean systems.

Coral reefs support a plethora of species and are a hot-spot for biodiversity; much like the rainforests. They support 25% of all marine life and almost every marine creature spends part of its life cycle in coral reefs along with many species of fish which are of commercial importance. Apart from this, it buffers the shoreline from wave action. Places with healthy coral reefs and mangrove forests were found to be less damaged after the 2004 tsunami.

Threats to reefs apart from global warming include tourism, bottom trawling, blast mining of coral and pollution. Collapse of the reefs means decline of fish stocks, loss of biodiversity and subsequent loss of economy. 20% of the world's coral reefs have been effectively destroyed and show no immediate prospects of recovery. Scientists seem to be pessimistic about the future, with some reefs expected to vanish by 2020.

Coral reefs need to be protected to ensure future posterity. The way to do this is to reassess the way we live. Think about what you use as it eventually ends up in the ocean regardless of how near or far you are from the coast.

rebirth of the primordial soup?

One of the most devastating effects of global warming is how it affects the oceans and seas of the world. In order to understand how climate change affects the oceans, it is essential to know how oceans affect global weather.

Oceans dominate the movement of water, supplying most of the water vapour in the atmosphere by evaporation. Of this, 91% is returned to the oceans as precipitation, the remainder is transported and precipitated over landmasses. Runoff and groundwater from land flow back to the oceans.

The oceans and the atmosphere are tightly linked, and together form the most dynamic component of the earth’s climate system. Oceans store heat. When the earth’s surface cools or is heated up by the sun, the temperature change is greater and faster over land than over the oceans.

Winds and currents are constantly moving the ocean’s waters. The Gulf Stream Drift, for example, is powered by cold, dense, salt-laden water sinking off the north polar coastal regions and moving south in the depths, pushing the surface warm water from the tropical and subtropical Atlantic (including some from the Gulf of Mexico) up north to bathe the shores of Western Europe, producing a climate that is surprisingly mild for that latitude.

Global warming and melting of the polar ice-caps freshens the surface water, reducing its density and preventing it from sinking. As a result, the Gulf Stream slows down, or may even reverse, bringing severe winters to northern Europe while the rest of the earth heats up.

All over the world ocean waters are warming as a result of global warming putting stress on marine ecosystems and sea life, already under siege from pollution, overfishing and habitat destruction. Warmer oceans also mean that ice caps are going to be melting faster, the rising sea-level will put underlying coastal areas at risk of being submerged. Sea levels are predicted to rise 7 to 23 inches by the end of the century, plus 4 to 8 inches if recent melting in Greenland and Antarctica continues. Many scientists consider these conservative estimates.

Apart from this there is going to be a direct influence on global weather patterns with increase in hurricanes and typhoons. We have already seen evidence of this. Additionally, winters in northern Europe and Scandinavia have grown wetter, while those in southern Europe and the Middle East have become dryer. European farmers have encountered an earlier and longer growing season. The habitats and life cycles of many marine and terrestrial species have changed. There have been changes to the monsoon in India and the Pacific Southwest as well.

Food for thought: The planet's weather not only supports its varied species of life, it also supports global economy. The biggest economic sectors directly affected by climate change are agriculture and the fishing industry. The warming up of our oceans is a bigger threat to human survival than anything else we currently face. A continued increase in ocean temperatures will see the top predator species of the food chain extinct with oceans reverting back to the primordial soup stage of early creation.