This Week in Whales: Dolphin Carnage in Peruvian Shark Fishery; Female Killer Whales Get Menopause; Shipping Noise Threatens Whales in British Columbia...
This week in whales (or close to it):
- There are two layers of wrong with this story. First, an undercover journalist has released footage he shot on a Peruvian shark fishing boat showing fishers harpooning, slaughtering, and butchering dolphins to use as shark bait. Scientists and conservationists have been claiming that this practice kills thousands of dolphins every year, while fishers and government officials have denied it’s taking place. Well, now that there’s documentary evidence, let’s see how they dance away from their denials. The report notes that while it is illegal in Peru to kill dolphins in this way, the practice is an “open secret.” With an estimated 500 vessels engaged in shark fishing, as many as 10,000 dolphins may be killed each year. The second layer of wrong with this story is that the fishers are fishing sharks, many species of which are endangered. If you’re a shark eater, I don’t recommend buying shark sourced from Peru. This article provides graphic details of the practice and the dolphin’s death, including gruesome images—consider yourself warned.
- An extremely rare Stejneger’s beaked whale, notable for its saber-like teeth, recently washed up in Venice Beach, California. Scientists hope a necropsy will shed some light on the animal’s death and unusual stranding location—the species is typically found in the Bering Sea and off the coast of Japan, nowhere near Southern California. Coinciding with two cryptic oarfish washing up in Southern California—the species is generally found hundreds if not thousands of feet below the surface (not on our beaches)—many are asking, “What’s going on?”
- Around this time last year, Hawaii’s coastal false killer whales were added to the endangered species list in response to a petition from the Natural Resources Defense Council. One of the bases for listing the species was the harm to the population from interacting with fisheries. With just 150 to 200 of this population left, they can hardly survive being caught and killed in fishing gear. Nonetheless, researchers recently found five fish hooks in the stomach of a false killer whale that was found dead on a remote beach in Hawaii. While the fish hooks didn’t kill the animal, they underscore the need for protective measures, like requiring fishers to use circle hooks to reduce accidental hookings. While the National Marine Fisheries Service recently enacted a rule requiring longline fishers to use circle hooks, it should look at whether other Hawaii fisheries should adopt similar rules. Such bycatch is a serious threat to marine mammals worldwide—stay tuned for more on this subject.
- Killer whales are one of only three species whose female members undergo menopause, joining humans and pilot whales. Female killer whales lose the ability to reproduce in their 30s and 40s, but can live to be up to 90 years old. Scientists believe the evolutionary justification for the menopause lies in killer whales’ unusual social structure, wherein both male and female offspring live with their mothers for the duration of the mother’s life. Playing a leading role in the family, these mothers and grandmothers potentially share expertise on foraging and other life matters. This “advice” is no joke as the mortality of adult males increases 14-fold the year after their mother dies. Now you can insert your own joke about mama’s boys.
- An international study concludes that increased tanker traffic near British Columbia is putting marine mammals at risk. We already know that shipping noise contributes to the general din in the ocean that is increasingly inhibiting the ability of many whales to communicate, forage, navigate and find mates. This 3-year long study shows that the median noise levels from shipping is reducing the “communication spaces” for fin, humpback, and killer whales and under “noisy conditions” the communication spaces of fin, humpback, and killer whales is reduced by 30, 94, and 97 per cent, respectively. Thus, for example, under the noisiest conditions killer whale communications would fail 97 out of 100 times across a distance of up to eight kilometers. It’s going to be harder and harder for grandma killer whale to pass on her knowledge (see bullet point above) if shipping noise isn’t reduced (there are ways to reduce shipping noise, as the end of this article notes). If steps aren’t taken, it’s only going to get worse as Canada’s plans for LNG and pipeline projects in British Columbia will increase tanker traffic.
- Increased ship traffic also leads to an increase risk of collision with marine mammals. The White House is reviewing a rule that would permanently restrict ships in designated areas along the Eastern Seaboard from traveling over 10 knots to prevent collisions with endangered North Atlantic right whales.
- Francisco Mayoral, noted defender of gray whales and ally in the fight to preserve Laguna San Ignacio from a commercial salt factory, has passed away at the age of 72. Laguna San Ignacio, on the west coast of the Baja California Peninsula in Mexico is a World Heritage Site, a biosphere reserve, a whale sanctuary, a migratory bird sanctuary, and the last place on Earth where gray whales can breed and calve undisturbed by human intrusion, and the movement to save it is one of the largest environmental campaigns in history. We'd like to thank Francisco Mayoral for his vision and dedication to whales.
Meanwhile, this week in Wales....
While not exactly news, this nifty guide to 36 hours in Cardiff, Wales, makes us want to grab our passports and head to cooler climes. We're glad Wales is getting some recognition over on our side of the pond.
Photo credit: NOAA