A heat wave forming off the west coast in the Pacific Ocean resembles a 2014-15 phenomenon that led to major disruptions to marine life along the western seaboard, federal scientists said Thursday.

The National Oceanic and Atmospheric Administration (NOAA) wrote in a blog post that a growing belt of warm water that stretches from Alaska to California “ranks as the second largest marine heatwave in terms of area in the northern Pacific Ocean in the last 40 years, after ‘the Blob,’ ” referring to the 2014-15 heat wave.

{mosads}“It’s on a trajectory to be as strong as the prior event,” said scientist Andrew Leising of NOAA Fisheries’ Southwest Fisheries Science Center in La Jolla, Calif.

“Already, on its own, it is one of the most significant events that we’ve seen,”Leising added.

The 2014-15 event had major effects on marine life on the West Coast, including “multiple” fishery disasters and a massive coastal algal bloom that ended crabbing and clamming efforts along the coast for months, according to the NOAA. Salmon numbers also declined during that time. Whales including humpbacks were forced closer to shore, resulting in entanglements with fishing lines, while thousands of sea lions were reportedly stranded on shore.

“Given the magnitude of what we saw last time, we want to know if this evolves on a similar path,” said Chris Harvey, a scientist at NOAA’s Northwest research facility.

Scientists are hopeful, however, that the heat wave could dissipate if a ridge of high pressure that allowed upper layers of the ocean to warm ends in the next few months.

“It looks bad, but it could also go away pretty quickly if the unusually persistent weather patterns that caused it change,” said Nate Mantua, a scientist at NOAA’s Southwest facility.

At issue as to how long the heat wave will last is how deep the heat wave extends into the ocean. For now, scientists say just the top levels of the ocean have been affected by the warming.

“There are definitely concerning implications for the ecosystem,” said meteorologist Nick Bond of the Joint Institute for the study of the Atmosphere and Ocean in Seattle, who is also credited with dubbing the 2014-15 event “the Blob.” “It’s all a matter of how long it lasts and how deep it goes.”