Polluted sea or coast?

IndiaBlooms reports:

The Indian Costal Guard [sic] is using dispersants to neutralize the oil spill from the carrier ship M.V Rak in its desperate attempt to reduce the impact.

According to the Ministry of Earth Science, only the left over untreated oil will reach the shore which takes about 48 hrs from the spill location to reach the shore.

The ministry also informed that the Regional Centre of National Institute of Oceanography, Mumbai is keeping a close eye on the situation by regularly collecting water samples to monitor the impact of the oil spill.

Why would the coast guard use dispersants? Because, as the Hindu reports, our eco-warriors concentrate only on what they can see:

But field ecologist Deepak Apte said that the oil spill had to be seen in perspective. “The impact of the oil spill is not measured based on just the volume. The timing is important too. The mangrove ecology is under continuous stress since last year’s oil spill after the collision of [msc] Chitra and [mv] Khalijia. This is the seeding season for mangroves. Even a thin film is enough to kill the seeds and can have a major impact on the mangrove ecology.”

What do we know about dispersants? A quick trawl through the world’s ocean of data landed this catch. The US National Academies Press writes:

One of the most difficult decisions that oil spill responders and natural resources managers face during a spill is evaluating the environmental trade-offs associated with dispersant use. The objective of dispersant use is to transfer oil from the water surface into the water column. When applied before spills reach the coastline, dispersants will potentially decrease exposure for surface dwelling organisms (e.g., seabirds) and intertidal species (e.g., mangroves, salt marshes), while increasing it for water-column (e.g., fish) and benthic species (e.g., corals, oysters).

To paraphrase: dispersants stop the oil from reaching the shore by sinking it into the sea. You save the shore and kill life inside the sea. Did the coast guard make an informed decision about which is economically worse: a polluted Juhu beach and Mumbai harbour, or a sea bereft of fish? It seems very unlikely that they did this. Much more likely is that they wanted to “save face” after their initial denials of the leak. If you sink the oil and it does not reach the land, then people forget about it. During the year when the unavailability of fish causes prices to skyrocket, you can always blame something else.

Mumbai’s seas: an ecology past repair

From HT:

Industrial effluents, oil drilling, climate change and environmental degradation along the coast have driven away seven fish and prawn species from the Arabian sea near Mumbai over the past five years, according to recent data released by the Central Institute of Fisheries Education in Versova (see box).

Besides this loss of diversity, the quantity of fish has also fallen. The average catch has fallen to almost one-eighth the level seen five years ago, according to experts. For instance, the silver pomfret catch has dropped to 2,000 tonnes from 15,000 tonnes in the period, according to the municipal corporation.

Interestingly, the online edition seems to have no “box”. The print version lists the vanished species as ghol (Protonibea diacanthus), koth (Otolithoides biauritus), dara (Polynemus indicus), wam (Congresox telebonoides), karkara (Pomodasys hasta) and the sand lobster (Thenus orientalis).