Earthweek: a diary of the planet

For the week ending Friday, Nov. 19.

Hybrid salmon

Canadian officials say a new hybrid species of coho and Chinook salmon has been found between Vancouver Island and the British Columbia mainland, possibly the result of climate change. Andres Araujo at Fisheries and Oceans Canada says the hybrids look like a mix of the two species, and genetic markers confirm that they are indeed hybrids. He and colleagues point out that dry conditions in recent years have lowered the water level of the Cowichan River spawning area, which delayed the Chinook’s late-summer spawning. This probably brought those fish into contact with the coho and allowed them to interbreed later in autumn.

Rabbit ‘hotels’

Plummeting rabbit populations across the U.K. have prompted its National Heritage organization to ask landowners to create innovative rabbit “hotels” to help the bunnies survive. A new rabbit hemorrhagic viral disease has seen rabbit numbers decrease by 88% in the East Midlands and 83% in Scotland between 1996 and 2018. Across all of Britain, populations fell by 43% between 2008 and 2018. The project asks people to arrange piles of branches around rabbit warrens to provide safety from predators and to create new sites for females to give birth.

La Niña cooling

Unusually warm weather should prevail in much of the world in the coming months despite the La Niña ocean cooling in the Pacific, the U.N. weather agency says. “The cooling impact of the 2020/2021 La Niña, which is typically felt in the second half of the event, means that 2021 will be one of the 10 warmest years on record, rather than THE warmest year,” World Meteorological Organization chief Petteri Taalas said. He added this will be only a brief respite from the heating trend predicted in the years to come due to greenhouse gas emissions. The WMO predicts a 70% to 80% chance of La Niña through March.

Eruption surge

The 10th week of La Palma’s volcanic eruption saw hundreds of powerful seismic tremors lead to new lava vents opening up, releasing fresh streams of lava. One flow from the Cumbre Vieja volcano threatened a Canary Island neighborhood that had already been evacuated three times since the intense eruption began on Sept. 19. Volcanologists say the greatest volume of lava is now coming from a new, secondary cone. Satellite images reveal that nearly 2,750 buildings have so far been destroyed by the eruption.

Different meltdown

An underground ice wall that was created to contain contaminated groundwater seepage at Japan’s meltdown-plagued Fukushima Daiichi nuclear power plant has itself partially melted, according to operators. The Tokyo Electric Power Co. says it is launching “remedial work” to strengthen the wall of frozen ground. Large amounts of radioactive water have been stored at the facility since a 2011 earthquake and tsunami knocked out power to the plant’s cooling units, triggering reactor meltdowns. Nearby residents are concerned about plans to release stored water still contaminated with tritium more than a half-mile offshore in 2023.