AN unusually large mass of toxic algae is spreading in the waters off the west coast of the United States, threatening ocean animals and even humans, according to a report in Liberty Voice.
The lethal bloom of algae – now being referred to as ‘red tide’ – has caused deadly infections in dolphins and sea lions in the near-Pacific waters.
Although scientists claim the toxic algae does not pose a threat to humans when consuming commercially caught fish, the Washington Department of Fish and Wildlife has shut down all fishing for crabs.
Furthermore, environmental authorities in Oregon have closed the coastline to those who dig for clams and other sought after molluscs.
Local health officials warn that eating locally caught shellfish can be life threatening.
Algae blooms are fairly common in coastal waters, especially off the north-western coast of the US. But a new study conducted by scientists on bloom formations over the last decade shows that this may be the biggest bloom of toxic algae since the beginning of the century.
Scientists are worried about domoic acid, a chemical compound metabolised by a particular species of algae, Pseudo-nitzschia, that can cause very harmful symptoms to ocean animals.
Currently, commercially caught fish pose no health risk to humans, according to scientists. However, crabs and clams that are harvested from the coastline pose potentially serious health risks.
The toxic algae bloom is ‘geographically quite extensive’, said Vera Trainer, an oceanographer at National Oceanic and Atmospheric Administration (NOAA) Marine Biotoxins Programme.
She said that NOAA has measured high levels of domoic acid from Monterrey Bay, California, to Homer, Alaska.
According to a press release sent out by NOAA, the domoic acid level in Monterrey Bay was the highest ever recorded.
Officials from the NOAA announced that they will be sending a team of scientists to study the growing toxic algae bloom to determine its size and obtain samples for further research.
Initial theories from scientists claim that an unusually warm area of water in the Pacific may have caused the spike in the bloom, but further studies are needed to confirm.
The oceanic phenomenon is commonly known as red tide since the toxic algae gives off a rust-like colour.
However, Trainer explained that this is a misconception – the blooms are not always red, and they are not influenced by tides.
The toxic algae is responsible for the recent deaths of dolphins and sea lions off the coast of California that consumed contaminated fish.
What is now being called ‘sea lion sickness’ has drastically increased within the last decade. In nearly all cases, sea lions suffered from seizures before dying.
When fish and shellfish take in the toxins, they are not affected, but it begins to collect in their bodies. When humans consume contaminated seafood, the toxicity is often in a much greater magnitude. This can cause interference in nerve signal transmission in the brain.
Trainer says people should not stop buying commercially caught fish, considering they are closely monitored by local health officials.
Larger species of fish, such as salmon, do not feed on algae and are therefore not affected.
But the California Department of Public Health has issued a health advisory stating people are at risk if they consume locally harvested ‘clams, crabs, and even small fish such as anchovies and sardines’, reported Liberty Voice.