Scientists turned into a surprising conclusion when a 43-foot gray whale was spotted off the Israeli town of Herzliya previous year. The conclusion: It should have wandered across the usually icebound route beyond Canada, where warm weather had temporarily opened a clear channel three years before.

Scientists have as well discovered planktons in the North Atlantic where it had not existed for at least 800,000 years.

The whale’s odyssey, whose species lives in the Pacific, and the amazing look of the plankton points out a migration of species through the Northwest Passage, a perturbing indication of how global warming is affecting animals and plants in the oceans and on land.

Philip C. Reid of the Alister Hardy Foundation for Ocean Science in Plymouth, England said, “The implications are enormous. It’s a threshold that has been crossed.’’

He said in a telephone interview, “It’s an indication of the speed of change that is taking place in our world in the present day because of climate change.’’

The last time the world observed such a major raid from the Pacific was 2 million years ago, which had “a huge impact on the North Atlantic,” driving several species to extermination as the novices controlled the fight for food, Reid said.

Katja Philippart of the Royal Netherlands Institute of Sea Research, who is organizing the project funded by the European Union, said changes in the chemistry of the ocean and temperature can have implications for fisheries as species migrate northward to cooler waters.