Map showing ocean gyres where garbage accumulates
The ocean has become a repository of most of the waste humans generate. Every year, a large amount of plastic debris that enters the oceans releases persistent bio-accumulating and toxic compounds into the sea. Most of the plastic in our oceans is buoyant and lightweight so they get transported by ocean currents and gather in convergence zones in the sea. These zones have been called ocean landfills, garbage patches and even plastic soup by the media and environmental activists. Though this accumulation of plastic is visible and an indicator of the larger issue of marine litter, a majority of the plastic polluting the sea are small fragments that are not visible and hence not detected by satellite imagery for monitoring and studying.
It is almost impossible to quantify the exact amount of plastic debris that enters the oceans but land based sources of these inputs include poorly managed landfills, riverine transport, untreated sewage and storm water discharges, wind-blown debris, industrial and manufacturing facilities with inadequate controls, recreational use of coastal areas and tourist activities. In general, more litter is found near areas of thick human populations and consist mainly of consumer plastic items like bottles, shopping bags and personal hygiene products. Offshore sources of plastic pollution include fishing and recreation vessels, cruise liners, merchant shipping, oil and gas platforms and aquaculture facilities.
Studies have shown that plastic production had a steady growth rate since the 1950s till 2008 where the economic downturn saw a drop in 25% of production.
Natural resources account for a fifth of the wealth of developing nations. It is only recent times that we have realised that indicators of development like GDP do not account for the depletion of natural resources; in fact they tend to promote it because GDP treats both the production of goods and services and the value of asset liquidation as part of the product of a nation.
Artificial reefs are human-made underwater structures that allow and harbour marine life in featureless ocean beds. Some artificial reefs can improve hydrodynamics that promote surfing and sometimes contain sea erosion. They also ease the pressure on existing reef systems that have been over-fished or over-visited, and provide new habitat for marine life. They are usually constructed with secure, durable and environment friendly material and can form naturally in wrecks of sunken ships and submerged parts of oil platforms.
Artificial reefs for fish aggregation go way back in history. During the 17th century reefs of building rubble and rocks were used in Japan to grow kelp, while the earliest recorded construction of artificial reef in the US is from 1830s when logs from huts were used off the coast of South Carolina to improve fishing.
For November, we have a feature on coastal biodiversity; a quick and impressionistic study on the fisheries sector of North Malabar, adapted for TRINet blog, and the full study as a download.
We have three videos: A trip down the bizarre, dark alleys of seamounts and ridges under the ocean; one about tagging tuna in the deep sea, and Homeopathy explained by James Randi.
We also have a video, a photo essay and an article on the just concluded Census of Marine Life.
In the news, we have extreme action from green campaigns; the Nagoya Convention on Biodiversity, Jairam Ramesh on the environment - development debate and his interview on Time magazine; about pollution in our coastal cities; poaching fish in Kutch; sand mining in Mumbai, the POSCO clearance mockery and much more.
Marine algae at Kovalam
India is among the 17 mega diverse countries of the world – countries that harbour the majority of the earth’s species and hence considered very biodiverse. With a coastline of 8000 km and an Exclusive Economic Zone of about 2 million sq km, India shelters a wide range of coastal ecosystems – mangroves, estuaries, lagoons, backwaters, salt marshes, rocky coasts, sandy stretches and coral reefs. A large network comprising of 14 major, 44 medium and numerous minor rivers and their tributaries can be found generously spread across the subcontinent except for the western arid regions of the Rajasthan Desert.