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.

The number of moon jellyfish in Alaska waters has increased. Warm ocean temperatures and plentiful food in the form of zooplankton have contributed to the increased sightings

NOAA scientists and partners have released a Climate Vulnerability Assessment for groundfish, crabs, and salmon in the Eastern Bering Sea. They looked at the potential impacts of changing climate, ocean temperatures, and other environmental conditions on 36 groundfish, crab and salmon stocks. Of the

The quota for the Bering Sea and Aleutian Islands crab fisheries will be set by Alaska Department of Fish and Game in mid-October

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

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

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.

DFO documents reveal treatment failures and inability to protect migrating salmon.

Scientists have identified a spike in ‘vagrant’ species of fish including damselfish, wrasse and triggerfish

UChicago grad student analyzes ecosystem changes due to climate change on clams, snails, worms, crabs, urchins, starfish and more

Warming ocean waters are an invitation to all sorts of pathogens with the potential to remake ocean life.

March becomes the hundredth month in a row with temperatures above normal. "It is unique and shows how fast climate change is happening in the Arctic," says climate scientist Ketil Isaksen at the Meteorological Institute (MET).

Fish provide a vital source of protein for over half the world's population, with over 56 million people employed by or subsisting on fisheries. But climate change is beginning to disrupt the complex, interconnected systems that underpin this major source of food.

The survey started in 1971 as a review of commercially important fish like cod and halibut, but has grown into an annual scientific assessment of all sea life hauled up from the deep.

The winter commercial crabbing season in the Norton Sound will begin February 25 with a quota less than half of its 2018 figure and a third of the 2017 quota.

Greenhouse gas emissions provide extreme warming on Svalbard.