Over the last days, four whales washed up dead on the San Francisco Bay in the US and two along the coastlines of Bangladesh - and evidence links anthropogenic activities to some of the deaths.
In the San Francisco Bay Area incident, the four gray whales were found dead in the span of nine days, with one possibly killed by a ship collision. Halfway across the world, two more whales were found in Bangladesh in only two days. One was found in Himchhari Beach - outside the port and tourism city of Cox's Bazar - on Saturday (April 10). It followed a fellow Bryde's whale found 1.25 miles (2 kilometers) away on Friday.
Gray Whales Along San Francisco Bay
While one of the four San Francisco gray whales has been identified to be killed by a ship collision, experts are still determining the death of the other three. According to Dr. Pádraig Duignan, Director of Pathology at the Marine Mammal Center, the event is "alarming" because it considers the challenges that gray whales currently experience.
The first of this string of gray whale deaths began on March 31 with a 41-foot (12.5 meters) adult female on Crissy Field, followed by another adult female on Moss Beach (April 3), then the one on Berkely Marina (April 7), and the last one the following day (April 8) in Muir Beach, Marin County.
The most recent casualty was subjected to a necropsy - its corpse was studied - with researchers finding bruises and hemorrhage to the muscle around its jaw and neck vertebrae. These findings strongly suggest death due to blunt force trauma, such as one sustained from a ship collision. Furthermore, experts who examined the Muir Beach whale found that the body was generally in good condition based on its blubber and internal fat.
Gray whales migrate 10,000 miles to mate and give birth along Baja California in Mexico during wintertime. Then, they return northward along the California Bay area in the spring and the summer to feed on smaller fishes - sardines, anchovies, krill - before going further north to cool down in the Arctic waters.
Bryde's Whales in Bangladesh
Jahirul Islam, executive director of the Marine Life Alliance, declares that the second whale to be at least 50 feet (16 meters) long, 10 feet (3 meters) wide, and weighs three to four tons.
Additionally, they believe that the whales could either be killed by one of the ships moving through the Bay of Bengal that faces Cox's Bazar; or that they could have died from eating plastics that litter the surrounding waters. The second whale was also found to have a similar injury mark on its back, which supports the theory that it was killed by a high-speed ship collision.
A representative for the Bangladesh environment and forestry department said that researchers have already collected samples from the whales for additional post mortem examinations.
Bryde's Whale is a term that generally covers three different species, with the complexity muddled by lack of definitive information about the details. The most common of these whales, Balaenoptera brydei, is a larger species found worldwide in warm and tropical waters. A smaller species, the Sittang or Eden's whale (B. edeni), is believed to be endemic to the waters of the Indo-Pacific ocean, which includes the Bay of Bengal.
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