Latest news with #Subarctic
Indianapolis Star
2 days ago
- Science
- Indianapolis Star
Scientists find blue whales suddenly going silent. Why they think it's happening.
Changing ocean conditions making whale prey scarce are causing the mammals to stop singing, a recent study has found. Researchers at the Monterey Bay Aquarium Research Institute, Cascadia Research Collective and other national institutions spent six years monitoring the acoustic sounds of blue, fin and humpback whales off the California coast from July 2015 to June 2021, according to a study published in February. Researchers set out to determine whether the frequency of whale songs changed seasonally and whether that frequency was indicative of changes within marine ecosystems. As a result, scientists found the levels of whale songs among different species correlated with their ability to locate and consume prey. Marine biologists began the research in 2015, when a marine heatwave dubbed "The Blob" caused a large percentage of krill — teeny, shrimp-like creatures — to disappear. Humpback, blue and fin whales largely depend on krill as a primary food source. The heatwave disrupted ocean circulation patterns, which impacted the number of cold, nutrient-rich waters that support the small crustaceans, according to the National Oceanic and Atmospheric Administration (NOAA). This led to a scarcity of food supplies for fish, seals, penguins and whales. Additionally, increasing temperatures contributed to the spreading of a toxic algae bloom between 2015 and 2016 in the northeastern Pacific, leading to the most widespread poisoning of marine mammals ever documented. In 2015, NOAA confirmed a then-record 53 instances involving whales getting caught in fishing gear. The following year, the agency found 55 instances in which whales became entangled. As humpback whales can switch between feeding on krill and fish, like sardines and anchovies, they experienced the most positive song detection trend throughout the six-year study. However, blue and fin whales, which are larger than humpback whales, did not exhibit the same positive trend. The two species are more specialized in foraging for krill. With the declining prey population, they were forced to spend more time hunting, leaving little time for singing, researchers found. There is concern for similar patterns to continue as ocean temperatures continue to increase over time. Marine heatwaves also occurred in 2018 and 2019 during the summer months, when whales fatten up on krill to prepare for the rest of the year, according to NOAA. In a report issued in June, the agency revealed a steep decline in Pacific gray whales. A new count suggests there are about 13,000 gray whales, the lowest number since the 1970s. In 2019, there were about 20,500 gray whales. From 2019 to 2023, the species suffered from an Unusual Mortality Event that scientists say stemmed from localized ecosystem changes in Subarctic and Arctic feeding grounds. Gray whales rely on prey in the area but changes in the ecosystem caused widespread malnutrition, reduced birth rates and increased mortality. In other parts of the United States, there are signs that similar issues might be occurring. Earlier this month, a boat in Barnegat Bay, New Jersey, struck a 26-foot-long minke whale that ventured into shallow waters. Preliminary necropsy findings indicated the mammal was thin with an empty gastro-instestinal tract and little digestive material present, the Marine Mammal Stranding Center, the organization that conducted the testing, found.
USA Today
2 days ago
- Science
- USA Today
Scientists find blue whales suddenly going silent. Why they think it's happening.
Changing ocean conditions making whale prey scarce are causing the mammals to stop singing, a recent study has found. Researchers at the Monterey Bay Aquarium Research Institute, Cascadia Research Collective and other national institutions spent six years monitoring the acoustic sounds of blue, fin and humpback whales off the California coast from July 2015 to June 2021, according to a study published in February. Researchers set out to determine whether the frequency of whale songs changed seasonally and whether that frequency was indicative of changes within marine ecosystems. As a result, scientists found the levels of whale songs among different species correlated with their ability to locate and consume prey. More time hunting, less time singing Marine biologists began the research in 2015, when a marine heatwave dubbed "The Blob" caused a large percentage of krill — teeny, shrimp-like creatures — to disappear. Humpback, blue and fin whales largely depend on krill as a primary food source. The heatwave disrupted ocean circulation patterns, which impacted the number of cold, nutrient-rich waters that support the small crustaceans, according to the National Oceanic and Atmospheric Administration (NOAA). This led to a scarcity of food supplies for fish, seals, penguins and whales. Additionally, increasing temperatures contributed to the spreading of a toxic algae bloom between 2015 and 2016 in the northeastern Pacific, leading to the most widespread poisoning of marine mammals ever documented. In 2015, NOAA confirmed a then-record 53 instances involving whales getting caught in fishing gear. The following year, the agency found 55 instances in which whales became entangled. As humpback whales can switch between feeding on krill and fish, like sardines and anchovies, they experienced the most positive song detection trend throughout the six-year study. However, blue and fin whales, which are larger than humpback whales, did not exhibit the same positive trend. The two species are more specialized in foraging for krill. With the declining prey population, they were forced to spend more time hunting, leaving little time for singing, researchers found. Pattern may continue as ocean temperatures rise There is concern for similar patterns to continue as ocean temperatures continue to increase over time. Marine heatwaves also occurred in 2018 and 2019 during the summer months, when whales fatten up on krill to prepare for the rest of the year, according to NOAA. In a report issued in June, the agency revealed a steep decline in Pacific gray whales. A new count suggests there are about 13,000 gray whales, the lowest number since the 1970s. In 2019, there were about 20,500 gray whales. From 2019 to 2023, the species suffered from an Unusual Mortality Event that scientists say stemmed from localized ecosystem changes in Subarctic and Arctic feeding grounds. Gray whales rely on prey in the area but changes in the ecosystem caused widespread malnutrition, reduced birth rates and increased mortality. In other parts of the United States, there are signs that similar issues might be occurring. Earlier this month, a boat in Barnegat Bay, New Jersey, struck a 26-foot-long minke whale that ventured into shallow waters. Preliminary necropsy findings indicated the mammal was thin with an empty gastro-instestinal tract and little digestive material present, the Marine Mammal Stranding Center, the organization that conducted the testing, found. Michelle Del Rey is a trending news reporter for USA TODAY. Reach her at mdelrey@
Yahoo
21-06-2025
- Science
- Yahoo
Gray whale numbers decline to lowest since early 1970s, according to new data
The number of Pacific gray whales decreased significantly during the most recent count to the lowest numbers since the 1970s, while the number of whale calves also hit its lowest numbers on record. Gray whales, known for their migrations along the Oregon Coast in winter and spring, dropped to an estimated 12,900 adults and 85 calves in the latest data taken by the National Oceanic and Atmospheric Administration. It was a sharp decline from a year ago, when the number of gray whales was estimated at 19,260 for 2023-2024, and calf numbers were estimated at 221 in 2024 and 412 in 2023. "Our main concern and question is why the population does not appear to be demonstrating the same resilience as it has in rebounding from previous downturns," Sarah Mesnick, ecologist and science liaison with NOAA, said. The new data reversed hope from scientists that gray whales were rebounding after they endured an 'unusual mortality event' from 2019 to 2023 and worried instead that whales may be struggling to keep up with a changing environment. "The environment may now be changing at a pace or in ways that is testing the time-honored ability of the population to rapidly rebound while it adjusts to a new ecological regime,' said David Weller, director of the marine mammal turtle division at the NOAA Science Center and an authority on gray whales. Researchers in Mexico reported numerous dead gray whales early in 2025 in and around coastal lagoons as well as few gray whale calves. This suggests that many female whales may not be finding enough food in the Arctic to reproduce. So far in 2025, 47 gray whales have stranded dead on the West Coast, up from 31 in 2024 and 44 in 2023, the last year of the UME. While some of the stranded whales appeared skinny or emaciated, others did not. 'The lead scientists point out that this new estimate stands out because it reflects an extended downward trend in a population that has demonstrated short-term resilience in the past,' Mesnick said. 'The populations have previously rebounded quickly from downturns, including earlier previous UMEs, and we are going to continue to monitor the population.' According to NOAA and under the Marine Mammal Protection Act, UME "involves a significant die-off of any marine mammal population; and demands immediate response." Causes of UME are attributed to infectious disease, biotoxins, ecological factors, human interactions and other undetermined factors. The gray whale population was large, at about 27,430 between 2015-2016. In the following years, a decline started from 2019-2023 to below 15,000 that was considered as unusual mortality event. It appeared that whales might by rebounding after 2023, but the latest numbers dispute that notion. Scientists attributed the die-off to localized ecosystem changes that affected the Subarctic and Arctic feeding grounds. The changes in these areas contributed to malnutrition, reduced birth rates and increased mortality. The migration routes, specifically the California Current ecosystem and the Arctic ecosystem, have experienced significant changes in recent decades as well, officials said. The current research shows a connection between gray whale numbers and changes in sea ice in the Arctic, where most gray whales feed during the summer, NOAA concluded. 'They're migrating from Mexican reproductive ground, or nursery grounds, to foraging grounds in the Arctic,' Mesnick said. 'It's one of the longest migrations on the planet.' Ecosystem changes in the Arctic feeding areas the whales depend on to put on weight and maintain fitness are likely the root cause, Weller said. Decline in calf numbers has been linked to sea ice cover in the Bering and Chukchi seas. In May 2024, a juvenile gray whale washed ashore on a beach in Bandon along the southern Oregon Coast. In 2023, four reported gray whales washed ashore Oregon beaches, one being a calf. Mariah Johnston is an outdoors journalism intern at the Statesman Journal. Reach her at mjohnston@ This article originally appeared on Salem Statesman Journal: Gray whales decline to lowest numbers since 1970s
