OIl and Whales dont mix

Whales stranded in a Madagascar lagoon. Photo: Tim Collins

As oil exploration intensifies in our waters, we need to understand the potential impacts of not only oil drilling, if indeed commercially-viable oil deposits are found, but also of oil exploration on marine biodiversity.

Way back in 1990, in a far- reaching paper written by myself and petroleum geologist Phil Plummer, the potential dangers of petroleum exploitation to the marine environment, which is not only beautiful and unique but very important to livelihoods and the present and future economy of Seychelles, were highlighted.


The scientific confirmation this month that the deaths of over 100 melon-headed whales, which stranded on the shores of a lagoon in northwest Madagascar in 2008, were most likely caused by sonar deployed by an ExxonMobil petroleum survey vessel is new proof that we need to put many safeguards in place. The independent scientific report was released on 25th September 2013.

Seismic survey vessels operating in the area were first considered to be the likely culprits in the Madagascar incident, not least because melon-headed whales are an open-ocean species that had never before been recorded in the island’s shallow tidal lagoons.

After the stranding, the International Whaling Commission commissioned an Independent Scientific Review Panel to examine that evidence. After meticulously examining the evidence including face to face interviews, the Panel found that a survey vessel using a high-power multi-beam echosounder system (MBES) was “moving in a directed manner down the shelf-break the day before the event, to an area approx. 65 km offshore from the first known stranding location”. This, the Panel believed frightened the whales, which use a form of sonar for navigation, and when they fled, they swam into the shallow muddy area where they stranded and eventually died.

The use of air guns to conduct seismic surveys for oil in the sea bed is also causing concerns. Since the intense sounds from these air guns can either cause physical damage to marine mammals or cause them to flee, the U.S. Marine Mammal Protection Act requires observers to examine the area for marine mammals for a period of at least 30 minutes. If a marine mammal appears within an exclusion zone of 500 meters from the center of the seismic operation, the operation must shut down, and visual examination must resume.

It is to be remembered that Seychelles created and led the movement ( The Indian Ocean Alliance) to ensure that the International Whaling Commission designated the Indian Ocean as a Whale Sanctuary in 1978, one of the most significant events ever in international conservation. In 1982, buoyed by the success of the Indian Ocean Sanctuary the country successfully championed the global moratorium in all commercial whaling. National legislation dating back to the 1980’s strictly protects all marine mammals s in Seychelles waters.