Four Russian and Chinese security ships were tracked by the Coast Guard in a sign of increased activity by key U.S. adversaries in the Arctic, the Alaska office of the Coast Guard said on Tuesday.

Growing up in Alaska, two brothers understood the grueling work, risks and rewards of fishing on the Bering Sea. Read Chapter 3 of No Return: The final voyage of the Destination.

After the Destination sinks, loved ones find themselves in anguished negotiations over how to split a $5 million liability-insurance policy. A brother finds it hard to let go of the crew and the vessel. Read Chapter 8 of No Return: The final voyage of the Destination.

With winter ice largely gone for two years, a food chain is at risk. What lies ahead for a body of water that produces some of the world’s biggest seafood harvests and helps sustain communities ranging from Alaska to Seattle, homeport for much of the Bering Sea fleet?

The animal die-offs offer the world a stark example of the perils of rising ocean temperatures, which already are upending parts of the Bering Sea ecosystem as climate change — driven by greenhouse-gas pollution — unfolds in Alaska at a breakneck pace.

Despite the importance of the Bering Sea for subarctic oceanography and climate, relatively little is known of the foraminifera from the extensive Aleutian Basin. We report the occurrence of modern deep-water agglutinated foraminifera collected at seven sites cored during Integrated Ocean Drilling Program (IODP) Expedition 323 in the Bering Sea. Assemblages collected from core-top samples contained 32 genera and 50 species and are described and illustrated here for the first time. Commonly occurring species include typical deep-water Rhizammina, Reophax, Rhabdammina, Recurvoides and Nodulina. Assemblages from the northern sites also consist of accessory Cyclammina, Eggerelloides and Glaphyrammina, whilst those of the Bowers Ridge sites consist of other tubular genera and Martinottiella. Of the studied stations with the lowest dissolved oxygen concentrations, the potentially Bering Sea endemic Eggerelloides sp. 1 inhabits the northern slope, which has the highest primary productivity, and the potentially endemic Martinottiella sp. 3 inhabits Bowers Ridge, which has the lowest oxygen concentrations but relatively low annual productivity. Martinottiella sp. 3, with open pores on its test surface, has previously been reported in Pliocene to Recent material from Bowers Ridge. Despite relatively small sample sizes, ecological constraints may imply that the Bering Sea experienced high productivity and reduced oxygen at times since at least the Pliocene. We note the partially endemic nature of the agglutinated foraminiferal assemblages, which may at least in part be due to basin restriction, the geologically long time period of reduced oxygen, and high organic carbon flux. Our results indicate the importance of gathering further surface sample data from the Aleutian Basin.