One problem is that fisheries often target what scientists call BOFFFFs: big, old, fat, fecund, female fish. Their large bodies are prized by fishers, but BOFFFFs are a vital source of new baby fish. Take these away and the size spectrum quickly veers out of kilter. One way to manage this is to encourage the fishing industry to target medium-size fish, allowing mature ones to replenish depleted populations.
The phenomenon of a patch of abnormally warm water off the west coast of North America gained notoriety in 2014, when the first such “Blob” was spotted and given that name, after the horror movie creature that devoured everything in its path. That first Blob lasted years, from 2013 to 2016. It has been blamed for slicing some forage fish populations in half; starving seabirds; triggering a collapse in cod; shifting tuna as far north as Alaska; pushing whales into the path of crab fishing lines and ships; and allowing exotics, including glowing tropical sea pickles, to arrive in northern waters.
“…many sedentary marine species — including snails, worms, and mussels — are actually being transported in the wrong direction”.
“We know marine heatwaves are on the rise globally, but policymakers, fisheries experts, aquaculture industries and ecologists need to know how this will play out at regional levels, especially in terms of where they will occur and how much hotter they will be,” said lead author from the ARC Center of Excellence for Climate Extremes Dr. Hakase Hayashida.
Balmy temperatures can lead to conditions perfect for the spread of infectious diseases, Sanderson said. When sea ice melts too early in the season, seal pups must enter the water before they are ready to be weaned, leaving them weaker and more vulnerable to disease. Vanishing sea ice also means that seals and sea lions in cold regions will have less space to emerge from the water to rest, breed, or escape predators, forcing them to crowd more tightly together.
Parts of the Atlantic, Pacific and Indian Oceans all hit the record books for warmth last month, according to the U.S. National Centers for Environmental Information. The high temperatures could offer clues on the ferocity of the Atlantic hurricane season, the eruption of wildfires from the Amazon region to Australia, and whether the record heat and severe thunderstorms raking the southern U.S. will continue.
“With the ocean warming, we saw a shift in the ecosystem and in the feeding behavior of humpback whales that led to a greater overlap between whales and crab fishing gear,” said Jarrod Santora, a researcher in applied mathematics at UCSC’s Baskin School of Engineering and first author of the study, published January 27 in Nature Communications.
The current expanse of warm water stretches from Alaska to Southern California to Hawaii. It appears similar to conditions five years ago when the original “blob” was first taking shape, federal scientists said, although so far, the warmer-than-normal waters extend down only about 150 feet below the surface, rather than 600 feet five years ago.
…marine animals like fish, crabs and lobster are already more likely to be living near the threshold of life-threatening temperatures, and because in the ocean, there are fewer places to hide from extreme heat, said Malin Pinsky, lead author of a new study published Wednesday in the journal Nature.
“These results are stunning, in part because the impacts of climate change on ocean life were virtually ignored just a decade ago,” said Pinsky, an ocean researcher at Rutgers University. The study took a close look at cold-blooded marine species whose body temperatures are dependent on their surroundings.