A wave of dead or dying gray whales washing off the coast of the American West Coast from the beginning of spring is a cause for concern to scientists, but the reason behind the worrying increase in the number of fatalities remains largely a mystery.
In the late 19th century, gray whales were hunted to the point of near extinction, and their existence looks uncertain again after 61 mammals were washed ashore only this year on American shores.
Worrying statistics are expected to be much worse as only about 10 percent of dead whale carcasses are likely to land.
As many as 610 may have died since the New Year, mark a significant dent in the already declining population of the grays of just 27,000.
According to scientists, most found dead grabs showed typical signs of malnutrition, with some starving. But it is the reason behind the apparent lack of food sources that continues to baffle experts.
The reason behind the disturbing rise in the number of fatalities among grays remains a mystery. Sixty-one of the large mammals were washed ashore this year on the shores of the American West Coast
According to scientists, most found dead grays showed typical signs of malnutrition, with some creatures even starving
Grays is currently in the middle of his annual migration season, seeing them travel from the coast of Mexico all the way to the shores of Alaska in search of new food areas.
To survive the debilitating 10,000 back and forth, the whales need to be coated in a thick layer of blubber to help them retain their energy and warmth as they go through changing water temperatures.
Disruptions in the food chain, however, prevent many beings from building up a substantial insulating layer, and as a result they die prematurely during the tiring journey.
& # 39; It is clear that there is something wrong with the feed because the gas reservoirs of these animals are empty or very low & # 39 ;, said Justin Viezbicke, California, coordinator for stranding marine mammals for the National Oceanic Atmospheric Administration (NOAA) to the press democrat.
A possible cause of the gray whale's misery is that they have achieved what is known as a & # 39; carrying capacity & # 39; – the maximum number that their habitat can keep
A total of 37 whales have been found dead in California this season. The average death toll for whales in the state during the entire migration period is usually between 20 and 25.
The combination of the body counts with those found in Oregon and Washington, 61 of the mammals found dead in total, set 2019 on track to match or exceed the last major death in 2000, where 86 were found dead.
& # 39; There are more dead whales than they should & # 39 ;, said UC Davis Research Associate Frances Gulland, a veterinarian and member of the US. Marine Mammal Commission. & # 39; It's sure enough to worry about what's going on in the food areas. & # 39;
A possible cause of the misery of the gray whale, scientists have theorized, is that they have achieved what is known as a & # 39; carrying capacity & # 39; – the maximum number of whales that can maintain their habitat.
They believe that perhaps there is simply not enough food to go around for each of the creatures, leaving the least persistent of the species.
But scientists also say they are investigating whether the recent warming trends in the Arctic and the melting ice caps could have influenced the whale's prey.
But scientists also say they are investigating whether the recent warming trends in the Arctic and the melting ice caps could have influenced whale prey
2019 is well on its way to match or exceed the last major death peak observed in 2000, with 86 deaths found.
& # 39; We really need to be aware: is there a relationship with climate change? And is this related to other factors that can also influence other species? & # 39; John Calambokidis of the Cascadia Research Collective told KTOO.
& # 39; Can gray whales be an early warning signal for other things to look out for? & # 39;
The Arctic is warming at twice the speed of the rest of the world – with temperatures in the Bering Sea as much as nine degrees warmer than last summer.
Calambokidis said that the apparent warming of the oceans and the withdrawal of ice shelves seem to drive gray whales north to hunt for food than ever before.
But the phenomenon & # 39; warm blob & # 39; – a broad, continuous band of hot water that flowed down from the west coast of Alaska in 2014 and 2015 – may have had a domino effect that is now only visible among the gray whales.
& # 39; There seems to be a lack of food, but it is not 100 percent clear what causes it & # 39; said Elliott Hazen, a research ecologist with NOAA & # 39; s Southwest Fisheries Science Center at the PD . & # 39; In short, is it a long-term change? Is it still a reflection of the hot water events we had in 2015? There is no clear smoke cannon. & # 39;
Johnson added that reports from Mexico this year suggested that 50 percent of the whales that arrived last year on the warm coasts of the country were already underweight.
Fewer calves were also born during their stay in the south than normal, officials say.
Ohnson added that reports from Mexico this year suggested that 50% of the whales that arrived on the warm coasts of the country last year were already underweight
In another display of unusual behavior, grays – known for swimming close to the shore – have begun to deviate from their traditional course to the north and walk to places such as the San Francisco Bay.
Typically, one or two gray whales would be observed passing under the Golden Gate Bridge at this time of the year, but this season's experts have seen that as many as five enter the bay simultaneously.
Among the dead, the majority of women found are female. Scientists say this makes sense because the mothers and their young are the last to start the migration and therefore have the least reserves.
Among the dead, the majority of women found are female. Scientists say this makes sense because the mothers and their young are the last to start the migration and therefore have the least reserves
But experts say they are afraid that so many adult grays have been found lifeless on the shoreline because they are usually good at buffering against really bad conditions. by reducing reproduction rates for a few years until food stocks improve.
& # 39; If you are starting to get adult mortalities, these large predators, it is a sign that they have been through some bad years, most likely & # 39 ;, said Hare. & # 39; For that reason, I see them as sentinels of ecosystem change. I really think they are telling us something. & # 39;
Every summer, NOAA examines the dietary patterns and patterns of the gray whale. Last year's results are now being intensively analyzed to see if they can explain the increase in deaths this spring.
NOAA says it is conducting a study this year to specifically determine whether there are more whales competing for limited resources, or for whatever reason, that food is less nutritious or does not give them so much energy to support them during migration .
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