Environment & Ecology Quiz: Marine Pollution, Oil Spills and Ocean Acidification

Carbon dioxide dissolves in seawater and reacts with water to form carbonic acid, which dissociates into bicarbonate and hydrogen ions; the extra hydrogen ions lower the pH, and they also combine with carbonate ions, leaving less carbonate for shells and coral skeletons.

Methylmercury discharged with factory effluent into Minamata Bay entered fish and shellfish, biomagnified up the food chain and poisoned the people who ate them, producing the nervous disorder named after the bay and recognised in 1956.

Microplastics are conventionally defined as plastic particles less than five millimetres across.

Eutrophication begins with nitrogen and phosphorus from fertiliser, detergent and sewage. The nutrients feed an algal bloom; the bloom is short-lived, and when it dies the bacteria that decompose the mass consume large amounts of dissolved oxygen.

The tanker Exxon Valdez struck a reef in Prince William Sound in 1989, releasing crude oil that coated a long stretch of a cold, sheltered coastline where oil breaks down slowly, and killing large numbers of seabirds, sea otters and salmon.

MARPOL is the International Convention for the Prevention of Pollution from Ships, adopted in 1973 and modified by the Protocol of 1978, and it is the main pollution instrument of the International Maritime Organization.

Oil spill response in Indian waters runs under the National Oil Spill Disaster Contingency Plan, and the Coast Guard is its central coordinating agency, working with major ports, state governments, oil companies and the Navy on reporting, containment with booms, recovery with skimmers, use of dispersants and shoreline clean-up.

The hydrogen ions released when carbonic acid dissociates combine with carbonate ions to form bicarbonate, so the pool of free carbonate shrinks.

Oilzapper is a consortium of oil-degrading bacteria developed by the institute and used as bioremediation: the bacteria break the hydrocarbons in crude oil and oily sludge into harmless products, which makes it a cheap, low-waste option for contaminated soil at refineries and spill sites.

Sustainable Development Goal 14, Life Below Water, commits countries to conserve and sustainably use the oceans, seas and marine resources, with targets on reducing marine pollution from land-based activities, protecting coastal ecosystems, addressing ocean acidification, ending overfishing and conserving coastal and marine areas.

A containment boom is a floating barrier with a skirt below the waterline and floats above it, towed or anchored around a slick to hold the oil in a smaller area so that it can be recovered and kept away from beaches, mangroves and water intakes.

The London Convention of 1972, formally the Convention on the Prevention of Marine Pollution by Dumping of Wastes and Other Matter, controls the deliberate disposal of waste at sea from ships, aircraft and platforms, prohibiting the most hazardous categories outright and allowing others only under permit; its later Protocol tightened…