Background Articles

Under extreme heat stress, corals expel their symbiotic algae and colour (that is, ‘bleaching’), which often leads to widespread mortality. Predicting the large-scale environmental conditions that reinforce or mitigate coral bleaching remains unresolved and limits strategic conservation actions1,2. Here we assessed coral bleaching at 226 sites and 26 environmental variables that represent different mechanisms of stress responses from East Africa to Fiji through a coordinated effort to evaluate the coral response to the 2014–2016 El Niño/Southern Oscillation thermal anomaly. We applied common time-series methods to study the temporal patterning of acute thermal stress and evaluated the effectiveness of conventional and new sea surface temperature metrics and mechanisms in predicting bleaching severity. The best models indicated the importance of peak hot temperatures, the duration of cool temperatures and temperature bimodality, which explained ~50% of the variance, compared to the common degree-heating week temperature index that explained only 9%. Our findings suggest that the threshold concept as a mechanism to explain bleaching alone was not as powerful as the multidimensional interactions of stresses, which include the duration and temporal patterning of hot and cold temperature extremes relative to average local conditions.

It already has caused coral bleaching in Hawaii and may be tied to strandings of marine mammals along the California coast.

Biologists say early retreating sea ice is potentially causing vegetation productivity changes on the tundra across Alaska and the Arctic. Uma Bot, a climate variability expert with the University of Alaska–Fairbanks, says the land warms up more quickly when sea ice recedes earlier than usual. “‘Cause the tundra is temperature limited and if it has more …

The aquaculture industry has failed to bring epidemic of sea lice under control in B.C.’s Clayoquot Sound.

South winds and warm water are hitting sea ice on Arctic waters with a double whammy.

The top of the world saw record-beating average temperatures flashing through all three summer months.

The monthly temperature for the entire country was 1.7 degrees above normal.

“Whenever a seismic boat goes past and we drop our gear, the fish aren’t there. Any fisherman, or fisherman worth their salt, will tell you there’s an impact. They’ve seen it first-hand.”

Halifax-based scuba diver Lloyd Bond says in the last three years he's seen increasing numbers of butterfly fish, seahorses, cornet fish, trigger fish, puffer fish, and many other species not native to Canadian waters.

What caused roughly 60,000 dead murres to wash ashore in Alaska? The answer to this could be very important to the murre (or turr) populations in the Atlantic.

For example, when looking at water in some areas around St. Lawrence Island, from 2010 to 2017, the bottom temperature went up by eight degrees Celsius (about 14° Fahrenheit).

Stop land damage and change food production to halt climate crisis, United Nations scientists warn in second IPCC report

Average temperature for month amid Arctic heatwave was 58.1F (14.5C), nearly 1F above previous high set in July 2004

These changes seem to be heralding population spikes and downturns for a number of species like walleye pollock and Pacific cod, and even more pronounced in small, fatty forage species.

On July 16, Alaska Ocean Observing System, UAF Fairbanks and Alaska Sea Grant sponsored a community workshop on Harmful Algal Blooms—certain poisons coming from certain blooms of algae produced by

Earth’s natural cycles can’t account for the recent warming seen over the past 100 years, new research suggests.

From California to Alaska, animals born during the infamous Blob are coming of age.

During a workshop in Nome this week, scientists and residents discussed algal toxins’ role in the changing Bering Sea ecosystem.

A researcher says her team couldn't believe the distance travelled.

Mexico has spent US$17 million to remove over a half-million tons of sargassum seaweed from its Caribbean beaches, and the problem doesn't seem likely to end any time soon.