In a signal of increasing concerns over Arctic shipping, U.S. and Canadian coast guard vessels have conducted their first joint Arctic offshore oil spill drill near the Bering Strait.

Two days of testing of vessels and equipment were scheduled at Port Clarence, a protected bay near the strait, although poor weather limited actual deployment of spill gear to one day, said Coast Guard spokesman Chief Petty Officer Kip Wadlow.

Port Clarence has been designated by the Coast Guard as a port of refuge for vessels in distress.

A Coast Guard skimming system was successfully deployed from a Canadian vessel participating in the drill, but bad weather also prevented deployment of a large ship emergency towing system provided by the state of Alaska, Wadlow said.

The exercise was held July 17 and 18.

The Bering Strait separates Alaska and Russia, and there is increasing concern among Coast Guard and Alaska officials about growing non-U.S. vessel traffic, including oil tankers and liquefied natural gas carriers, using Russia’s Arctic northern sea route from Europe to Asia. The route transits the Bering Strait, which can be constricted by ice and bad weather.

The loss of summer Arctic sea ice, which is at record lows this year, is making the Arctic sea routes more available for commercial shipping, including for vessels that are not strengthened for ice.

So far this year, Russian authorities have given permission to 204 vessels to use the northern sea route, up from 250 in 2012 and 130 in 2009, Alaska officials said. Some of those are fuel carriers.

Alaska Lt. Gov. Mead Treadwell he has been informed by the Coast Guard that at least two tankers carrying fuel from Norway to Asia are among vessels now en route to the Bering Strait.

Wadlow said this is the first joint U.S.-Canada spill drill held in Arctic waters, although joint exercises are regularly done at Dixon Entrance, along the U.S.-Canada border in southeast Alaska.

The exercise at Port Clarence involved the Coast Guard cutter SPAR, a 225-foot buoy tender, and the Canadian Coast Guard’s 272-foot icebreaker Sir Wilfrid Laurier, and involved the test deployment of oil skimming systems.

The SPAR is routinely on patrol in the Aleutians and Pribilof island regions with a primary mission of maintaining aids to navigation. The Sir Wilfrid Laurier, with a home port in Victoria, B.C., operates seasonally in Arctic waters.

“The exercise provided an opportunity for our crews to compare operating practices and learn from each other, and it supports the key tenets of the Coast Guard’s recently released Arctic Strategy, which are to improve awareness, modernize governance and broaden partnerships in the Arctic region,” said Cmdr. Matt Jones, chief of spill prevention for the Coast Guard’s 17th District, which covers Alaska, in a statement.

Industry-sponsored Arctic offshore spill exercises have been held in Arctic waters, such as drills conducted in the Beaufort Sea by Alaska Clean Seas, a spill co-operative, but the Bering Strait and western Alaska coastline are far from industry-operating areas and are vulnerable to a spill from a fuel carrier transiting the Chukchi Sea or the strait.

The bulk of the marine traffic is non-U.S. registered vessels and Alaska’s laws for spill contingency plans do not apply, Treadwell said. In contrast, U.S. vessels operating in Alaskan Arctic waters are required to have spill contingency plans on file with the state. In the plans, ship owners show they have spill responders under contract.

U.S. and Alaska officials are also working on a joint U.S.-Russia spill response capability for the Bering Strait region, but it has not yet been finalized, state officials have said.

State officials are concerned also whether the U.S. Coast Guard will be given adequate resources by Congress to deal with increased risks from vessel accidents as the Arctic waters open.

“They’re borrowing resources now from elsewhere in Alaska,” to step up a Coast Guard presence in the Alaskan Arctic, said Fran Ulmer, a former Alaska lieutenant governor who now chairs the U.S. Arctic Research Commission, an advisory body of citizens and scientists who give advice to federal agencies on Arctic research priorities.

The Coast Guard is operating flight service facilities on a seasonal basis this year in Kotzebue for search and rescue, but Ulmer is concerned that helicopters and flight crews are just being transferred from other Alaskan coastal regions where they are also needed. She is concerned that Congress may be unwilling to put any substantial funding behind new protections needed for the Arctic.