Articles tagged with Marine Mammals
A new study has confirmed that killer whales take only one breath between dives, providing insights into their unique physiological habits. The researchers used drone footage and biological data from tags to gather information on the animals' habits, revealing that residents spend most of their time making shallow dives.
A study analyzing canned salmon from 1979 to 2021 found stable anisakid worm levels in coho and sockeye salmon, while pink and chum salmon showed a rise. This suggests that the marine food web has adapted to changing conditions, with rising parasite levels indicating potential ecosystem shifts.
Researchers at the University of British Columbia have discovered a new population of killer whales in the Northeastern Pacific, with distinct physical characteristics and a diet that includes marine mammals and sea turtles. The orcas were identified through shark-bitten scars and observations by fishermen and birding enthusiasts.
A new study reveals that marine heat waves disrupt the ocean food web in the northeast Pacific Ocean, shifting energy and impacting predators and prey. Gelatinous zooplankton thrive during heat waves, drawing energy out of the ecosystem and potentially affecting fish and marine mammals.
The Belt Sea population of harbour porpoises is declining at a rate of 2.7% annually due to by-catch, deoxygenation, pollution, and lack of fish. Limiting net usage or using acoustic alarms on nets could be an immediate solution to mitigate the issue.
A study found that the avian influenza virus H5N1 has adapted to spread between birds and marine mammals, with nearly identical genome sequences detected in four sea lions, one fur seal, and a tern. The virus's ability to infect birds remains unchanged, while its transmission among marine mammals is concerning.
A study found polycyclic aromatic hydrocarbons (PAHs) in Southern Resident killer whales and Bigg's killer whales off the coast of B.C., with contaminants from oil spills and wildfire smoke. The presence of PAHs suggests recent exposures to toxic chemicals, emphasizing the need for improved pollution management.
Researchers found that commercial ship noise completely masks Cook Inlet beluga whales' most commonly used calls, compromising their critical communication. The study documents the complex vocal repertoire of the population and provides a quantified measure of masking by ship noise on their communication.
The study found that England's only resident population of bottlenose dolphins has declined to just 48 individuals due to various human impacts. The researchers call for urgent measures to protect the population and its habitats.
A recent study by RMIT University and the Marine Mammal Foundation has revealed alarming concentrations of PFAS chemicals in Burrunan dolphins off the coast of Melbourne and Gippsland, south-east Australia. The findings are the highest reported globally, with one juvenile dolphin found to have a PFAS liver concentration of 19,500 nanog...
Jessica Kendall-Bar, a UCSC Ph.D. graduate, has won the Science & SciLifeLab Prize for Young Scientists for her groundbreaking research on elephant seal sleep habits while at sea. Her work revealed that these marine mammals sleep bilaterally during deep dives and have a flexible sleep duration range-wide 'sleepscape.'
Scientists have observed wolves directly hunting and consuming sea otters and harbor seals in Alaska's Katmai National Park. This new evidence challenges previous assumptions about wolf behavior and diet. The study highlights the unique role of wolves in nearshore ecosystems in Alaska.
New research reveals that endangered whales and dolphins inhabit the Hellenic Trench off Greece year-round, challenging seismic surveys and oil and gas exploration. The study confirms the presence of four species, including sperm whales, in both summer and winter, highlighting the need for conservation measures.
A new study examines the life expectancy and lifespan equality of four marine mammal species in zoos and aquariums compared to their wild counterparts. The study found that marine mammals live longer in captivity, with a three-fold increase in life expectancy and a decline in deaths in the first year of life.
Researchers from FAU Harbor Branch deployed an autonomous wave glider to survey marine managed areas off Puerto Rico, recording grouper mating calls and determining spatiotemporal distribution of the two species. The study highlights the importance of spatial and temporal expansion of existing regulations to protect threatened species.
Researchers at Florida Atlantic University uncover the finer-scale feeding patterns of the whitespotted eagle ray, revealing a significantly broader diet than previously described, with high proportions of cockles and wedge shells. The study's findings suggest that these rays can play a facilitative role in reducing predation threats f...
A 500-million-year-old tunicate fossil named Megasiphon thylakos has provided unprecedented insights into the early evolutionary history of this enigmatic group. The fossil's unique morphology and soft tissue preservation suggest that ancestral tunicates were stationary, filter-feeding adults with a non-moving lifestyle.
A team of researchers developed a new technique using drone photographs to estimate the age-structure of free-ranging dolphin groups, aiding in timely conservation efforts. By analyzing the distance between a dolphin's blowhole and dorsal fin, they can infer its total body length and age.
A new analysis reveals megalodon's ability to regulate its body temperature, with temperatures up to 13°F warmer than surrounding water. This suggests the shark was warm-blooded and had an evolutionary advantage that may have contributed to its extinction.
A new study published in the Proceedings of the National Academy of Sciences confirms that the Megalodon shark was warm-blooded, with a body temperature estimated at around 27°C. This discovery provides empirical evidence for the extinct species' internal heat production, shedding light on its biology and ecological role.
A study by Florida Atlantic University's Harbor Branch Oceanographic Institute found domoic acid toxin in 87% of samples from the southern Indian River Lagoon, which can harm shellfish, finfish, birds, and humans. The toxin is more prevalent in cool temperatures and high salinity waters, suggesting it may be a resident population.
A longitudinal study using acoustic telemetry monitored rays in clam leases, finding that rays spent more time near sites than reported, but not necessarily preferring them. The study highlights the need to understand if clam leases are part of rays' natural foraging habitats and if they interact with the clams.
Hammerhead sharks maintain elevated body temperatures during deep dives by minimizing heat loss, likely through 'breathing' cold water by closing their mouths and gill slits. This thermoregulation strategy could be widespread among other deep-diving sharks and fishes.
A new study found that male California sea lions have grown bigger as their population increased over the past 50 years. The researchers analyzed skull and bone samples to find that males expanded their ecological niche, foraging on a more diversified group of prey. This expansion allowed them to grow larger despite increased competition.
Scientists recorded brain activity in wild elephant seals, revealing they take short naps during deep dives, averaging just 2 hours of sleep per day at sea. They switch between getting a lot of sleep on land and less when foraging at sea.
A new study reveals that northern and southern resident orcas differ in their hunting behaviors, with males catching more salmon per hour than females. Southern resident males outperform females by 152%, highlighting a distinct pattern of foraging that may contribute to the population decline.
A new study reveals a sharp threshold in the relationship between mass gain and pup production in female elephant seals, suggesting a physiological tipping point. The researchers found that dive depth was the strongest predictor of mass gain, with animals gaining more than 260 kilograms having almost guaranteed pup success.
Researchers found that current anti-predator gear can reduce clam mortality by four- to tenfold, with double-layered treatments showing the highest survival rates. However, rays were still capable of interacting with the gear for prolonged periods, potentially diverting them from other natural habitats.
A University of Houston engineer has made a groundbreaking discovery that could improve pharmaceuticals by controlling the growth of ammonium urate crystals. By manipulating tautomers, researchers found that a small fraction can control crystal growth, potentially preventing crystallization and related health issues.
A study by Oregon State University researchers found that synchronized fishing with dolphins in Brazil increases the number of fish caught and supports both species' survival. The cooperative relationship is specific to this population of dolphins and has been passed down through generations of fishermen.
A new subspecies of bottlenose dolphin, Tursiops truncatus nuuanu, has been identified in the eastern tropical Pacific Ocean. This subspecies is smaller than other common bottlenose dolphins and prefers deep offshore waters between southern Baja California and the Galapagos Islands.
A new study suggests that sensory deterrents can work in some circumstances and may be part of the solution to reduce bycatch. The authors found that LED lights were the only technology to date found successful in trials across all marine megafauna groups, but also led to increased bycatch in some species.
A distinct population of oceanic manta rays was identified off the coast of Ecuador, with an estimated total population of over 22,000 individuals, making it more than 10 times larger than any other known subpopulation. The population is large and potentially healthy due to favorable conditions in the region.
A study published by the University of Zurich has found that vocal communication in vertebrates has a common and ancient evolutionary origin, dating back to around 407 million years ago. The research used vocal recordings and contextual behavioral information from 53 species across four major clades of land vertebrates.
A team of researchers has observed orcas killing white sharks in South Africa using drone and helicopter footage. The study provides the first direct evidence of this behavior, showing that orcas are capable of pursuing, capturing, and incapacitating white sharks.
Researchers have identified a complex of proteins in a tiny marine invertebrate that share similarities with the human immune system, suggesting an earlier origin for the building blocks of our immune system. The study could ultimately guide the development of new immunotherapies and improve understanding of transplant rejection.
A 12,000-year analysis of El Niño's impact on animal communities reveals a tipping point where five or more major events per century lead to dramatic changes in eastern Pacific ecosystems. This finding suggests that strong El Niño events will play an increasingly important role in shaping future ecosystems.
Researchers deployed video cameras on Navy dolphins to study their hunting behaviors in San Diego Bay and the Pacific Ocean. The footage revealed the dolphins' prey preferences, hunting strategies, and even encounters with a sea snake.
A new study using elephant seal data has found that the North Pacific Blob's subsurface warming persisted for over two years, with temperatures extending 1,000 meters below the surface. The extensive subsurface warming raises questions about its mechanisms and potential connections to surface warming.
Scientists review recent experiments and find noise regulations may need to be changed to protect marine mammals from pile driving noise. The current guidance is 7 years old and may not provide sufficient protection for species like harbor porpoises and seals.
The vaquita porpoise, the world's smallest marine mammal, has relatively healthy genetics and can potentially survive if illegal 'gillnet' fishing ceases promptly. Inbreeding poses a threat, but the species may rebound due to its naturally low genetic diversity.
A new genetic analysis suggests that vaquitas can recover if deaths from gillnets are halted, despite initial concerns about inbreeding depression. The species' natural resilience and genetic diversity provide a high probability of survival.
Paleontologists discovered sets of fossils representing three new ichthyosaurs, including the largest ichthyosaur tooth ever found. The discovery includes a 15-meter-long ichthyosaur and the largest trunk vertebra in Europe, rivaling the 21-meter long Shastasaurus sikkanniensis.
A recent study confirms that tuberculosis strains associated with marine mammals were also present in inland populations in pre-colonial South America. The researchers found three new ancient TB genomes from human remains in the highlands of Colombia, which resemble a TB variant found in seals and sea lions.
Researchers found that dynamic ocean management is more effective in reducing accidental catch than permanent marine protected areas. Dynamic closures track real-time data and close smaller areas as species hotspots shift, resulting in up to 57% reduction in bycatch.
Whale-watch vessels with louder petrol engines significantly disrupt short-finned pilot whale resting and nursing, according to a study. The researchers found that mothers who were approached by the vessel with the petrol engine spent on average 29% less time resting and 81% less time nursing their calves.
Researchers have discovered a new species of otter in Germany that dates back to 11.4 million years ago. The Vishnu otter genus was previously known only from Asia and Africa, but this finding suggests they also occurred in Europe.
A new study highlights the need to balance wildlife conservation with local community needs in Peru and Chile. Small-scale fisheries are struggling due to protected sea lion and seal populations, which compete for resources and damage fishing gear.
A new study finds that female walruses in the Chukchi Sea rely on biomarkers from algae growing within sea ice as a primary food source. The researchers tracked these markers using liver tissues from harvested animals, revealing a difference in foraging behavior between males and females.
Researchers discovered three phases of growth that explain how cetaceans shift their nasal passage from a parallel to an angled orientation. This finding provides insight into the developmental process and could inform our understanding of cetacean evolution.
Sea otters have a higher basal metabolic rate than predicted for their size, with skeletal muscle being the primary source of this hypermetabolism. This process, known as thermogenic mitochondrial leak, allows them to maintain a normal body temperature in cold water environments.
Fossilised footprints from 58 million-year-old rocks in Wyoming reveal that early mammals used marine habitats, pushing back an estimated 9.4 million years of previous assumptions. The prints showed diverse tracks, including those of semiaquatic mammals and artiodactyls.
Researchers have proven that a sexually transmitted herpesvirus causes cancer in California sea lions, with parallels to human cervical cancer. The study suggests pollutants and viruses play a role in cancer development, making sea lions a valuable model for human cancer research.
A recent study found that viral-caused cancer in California sea lions is significantly increased by exposure to toxins in the environment. The disease has claimed 18-23% of adult sea lion deaths, highlighting the need for improved efforts to prevent ecosystem contamination with pollutants.
A new study reveals that California's coastal gillnet fisheries took a greater toll on harbor porpoises than previously thought, with the population recovering dramatically since their ban. The Morro Bay stock has rebounded by seven-fold, from an estimated 570 animals in 1991 to approximately 4,200 porpoises today.
Scientists have identified a novel skin disease in dolphins caused by climate change, with patchy and raised lesions covering up to 70% of their bodies. The study provides the first-ever case definition for freshwater skin disease in bottlenose dolphins.
A new study reveals that dolphins adjust their heart rate to suit the length of their planned dive, conserving oxygen and avoiding decompression sickness. This conscious adjustment allows them to safely dive for long periods, providing insights into marine mammal physiology.
Mercury concentrations in ringed seals from the Canadian Arctic have remained stable since 1977, with limited declines detected. Climate parameters may be influencing mercury accumulation in seals, according to a 45-year study.
A new report by the Pacific Northwest National Laboratory suggests that marine renewable energy devices are unlikely to cause harm to marine animals or environments. The study found that small numbers of operational devices may not significantly affect marine ecosystems, but further research is needed to confirm this.
A global analysis of over 300 marine species spanning more than 100 years shows that mammals, plankton, fish, plants, and seabirds are changing in abundance as oceans warm. Some marine species are benefiting from climate change, while others are declining due to warming temperatures.