Orcas have long been considered a single global species, with different forms in different regions, known as “ecotypes.”
However, scientists have long recognised the differences between resident and transient orcas, known as Bigg's killer whales, in the North Pacific. Resident orcas maintain close-knit family pods and prey on salmon and other marine fish, while Bigg’s orcas roam in smaller groups and hunt other marine mammals such as seals and whales.
Scientists studying endangered southern resident orcas have noticed a steady increase of mysterious gray patches and gray targets (circular lesions which may appear on concentric rings – ed.) on the whales’ skin from 2004 to 2016.
To date, researchers managed to identify six distinct types of lesions, with the two most common types being gray patches or targets. Some resemble tattooed skin.
They do not know the cause of the lesions and are worried that they could be due to underlying health problems in the struggling population.
Sharks elicit strong emotions, be it the thrill of a planned encounter underwater or fear propelled by social media and lack of information. Of the more than 400 species of sharks, it is the small family of mackerel sharks that is most iconic. These sharks prompted me to share why one of them, the salmon shark, is an especially remarkable species.
Over ten years have past since my last dive in Hood Canal. I’m not sure why, probably because I’ve been so focused on exploring the pristine waters of British Columbia that the extra effort of driving so far south has always deterred me. But when Adventures Down Under, a dive shop in Bellingham, invited me to join their group for a Hood Canal dive charter, I was too curious to say anything but yes.
very now and then I get an assignment close to home, which means my dive buddy and I can usually load up the car with dive and photography gear, and maybe a kayak or two, and head out for a full weekend of adventurous exploring. If the location is exceptional, like an assignment to dive in Washington State’s San Juan Islands, we often allocate several days to experience all that’s available.
A dive trip to the U.S. State of Alaska is a true adventure, both above and below the surface. The rich green waters of the Pacific Northwest are full of life and photographic opportunities. The liveaboard dive boat, Nautilus Swell, is a great way to experience Southeast Alaska.
The chemicals cling to fat and can cause reproductive and immunological problems. While the researchers noted a slight decline in the level of PCBs over time, the chemical lingers on 30 years after it was banned,
Another recent publication predicted that problems from PCB contamination would plague the local orcas for at least 60 more years.
