HAPPYWHALE * STUDENTS HAPPENINGS : GLOBAL MARINE ESSAY

BY 2023 - the Northern shrimp population was estimated to have dropped to around 200 million.

Complicating matters is the fact that much of the research on marine heat waves comes from just a few countries, including Australia, the United States, China, Canada, Spain and Britain.

RISING ocean temperatures can set off a domino effect through the marine food web, starting at the bottom with plankton.

Since the end of most commercial whaling in the 1970s and '80s, humpback whales in the North Pacific had been recovering, reaching a peak population of 33,000 in 2012.

But then came the heat event known as '' the Blob '' that blanketed much of the region from 2014 to 2017. The heat wave diminished wind and waves, limiting the nutrients that typically get churned up to the sea surface.

Fewer nutrients meant fewer phytoplankton, fewer zooplankton, fewer fish and fewer of everything else that eats them.

After the Blob dissipated, researchers learned that the effects of a severe marine heat wave could endure long after the event itself has passed.

Ted Cheeseman, a Ph.D. candidate at Southern Cross University in Australia, had co-founded Happywhale., a database of tens of thousands of marine mammals built on photos submitted by researchers and whale watchers around the world.

Last year, Happywhale published a study that concluded the humpback whale population in the North Pacific has fallen by 30 percent from 2012 to 2021, attributing the decline to the loss of food like krill during and after the Blob.

With '' an estimate of 7,000 whales having disappeared and not showing up anywhere else, Mr. Cheeseman said, '' there's really no other explanation.''

Looking Ahead : Eventually parts of the ocean might enter a constant state of marine heat wave, at least by today's common definition.

Alistair Hobday, a biological oceanographer at Australia's Commonwealth Scientific and Industrial Research Organisation, has been conducting public briefings with marine heat wave forecasts months ahead of time.

People are tuning in - and responding.

This Master Marine Climate Essay continues. The World Students Society thanks Delger Erdenesanaa and Harry Stevens.