Articles tagged with Marine Mammals
Research on British Risso's dolphins reveals they form a single genetic entity, separate from those in the Azores and Mediterranean. The study suggests these dolphins have been isolated for some time, but further research is needed to determine their boundaries.
Researchers documented a previously undescribed orca behavior in the Gulf of California, where orcas hold and then ram sunfish to cause tissue fragmentation. The observed behavior may be a form of parental investment or simply entertainment, with potential benefits for the calf's nutrition.
The study found that dolphins visit two coastal communities along the Sea of Japan, with detection rates occurring once every ten days. The researchers recorded unique whistle characteristics in each bay, suggesting differences in sound environments or animal behavior.
Researchers analyzed 44 years of killer whale data in Washington state, finding a decline in the presence of endangered fish-eating killer whales. In contrast, populations of Bigg's killer whales, which prey on seals and other whales, are becoming more abundant.
Researchers found that Bigg's killer whales are increasingly present in Puget Sound, while southern resident killer whales are spending less time in inland waters. The data suggests that social cues may play a role in the changing distribution of southern residents.
Transient killer whales, humpback whales, and grey whales are spotted in the Salish Sea due to seasonal feeding and conservation efforts. Researchers attribute this increase to improved fisheries management, reduced whaling, and increased seal populations, allowing whales to thrive in their ancestral habitats.
Researchers at Kyoto University used visual survey data to predict the most suitable habitats for humpback whales around Chichijima Island. The analysis revealed shallow water depths with gentle slopes as critical areas, supporting conservation efforts in the Ogasawara waters.
The University of New Hampshire will lead a national effort to grow and strengthen America's seafood supply through aquaculture research, with a focus on sustainability and environmental friendliness. The $13.5 million initiative aims to expand domestic seafood production and improve food security.
A study published in Animal Behaviour found that bottlenose dolphins in Sarasota Bay associate more with others using human-centric foraging tactics. Human activities like foraging and red tide events influence dolphin social structure. The research suggests changes in social networks can have lasting consequences.
A case study of captive belugas reveals evidence of mirror self-recognition, suggesting this behavior may be innate in the species. The findings support the idea that some cetaceans possess cognitive abilities similar to those of humans and other animals.
An observational study published in Frontiers in Marine Science revealed that Guadalupe fur seals are experiencing significant hair loss due to an alopecia syndrome. The study highlights the need for urgent action to address early mortality and human impact on these vulnerable marine mammals
Researchers observed a whale skeleton over 15 years and found that it supported a sulphophilic community on the seafloor. This community persisted for more than 20 years, demonstrating the long-term importance of whalefalls in deep-sea ecosystems.
Researchers analyzed hormones stored in Rice's whale baleen to understand its life story. The study found evidence of stress and reproductive patterns, shedding light on the species' critically endangered status.
Researchers at the University of Washington decoded over 1,700 beluga whale calls in Cook Inlet, revealing insights into their social behavior, communication patterns, and vulnerability to human noise. The study suggests that shipping noise may be disrupting critical calf-mother communication, threatening the population's recovery.
Researchers analyzed centuries-old Swedish newspapers to reconstruct past porpoise distribution patterns in the Baltic Sea. The study found that harbour porpoises once occupied a wider area than they do today, with a loss of about one third of their historic range. Historical records provide valuable insights for conservation efforts.
In a study, pilot whales were found to make their calls louder in noisy waters to be heard. The whales' loudest calls are used for finding their pod after deep dives, but these are also the most difficult to hear over background noise from ships.
A new acoustic device, PAL Wideband pinger, has been found to reduce harbour porpoise bycatch in the Black Sea by approximately 74%. The device's wider frequency band (10-150 kHz) is believed to contribute to its effectiveness. Effective strategies to reduce bycatch are urgently needed for the critically endangered species.
The interim update to the State of the World's Migratory Species report warns that 49% of migratory species populations are declining, with 24% facing extinction, due to habitat loss and overexploitation. The report highlights the need for coordinated international action to address these threats and protect migratory species.
Research finds that humpback whales face a higher risk of getting entangled in fishing equipment during years with lower availability of cool-water habitat. The Habitat Compression Index can predict ocean conditions up to a year in advance, suggesting its potential as an early warning system for fishery management decisions.
A solitary bottlenose dolphin in the Venetian Lagoon is monitored by researchers who assess its remarkable adaptation to urban surroundings. The team highlights the need for human behavior management to ensure the dolphin's welfare, rather than focusing on wildlife protection measures.
Researchers have identified three previously unknown genotypes of Helicobacter bacteria in pygmy sperm whales stranded along the southeastern US coast. The discovery raises new questions about microbial pathogens on ocean health and their impact on vulnerable species.
A SFU study found that warmer temperatures in the Arctic can cause malnutrition in seals, intensifying risks to Inuit food security and northern ecosystems. The research analyzed samples from 38 Arctic ringed seals and found high levels of persistent contaminants such as PCBs and mercury.
Research shows Australian sea lion pups can learn foraging behaviour from their mothers, a discovery that could aid conservation efforts. The pups adapt to their mother's foraging style, changing their feeding patterns and habitats.
A recent study found that seals near glacier fronts have fuller stomachs, indicating intense feeding activity. This discovery has implications for Arctic marine ecosystems as glaciers retreat and habitats disappear.
Scientists captured rare view of beaked whales by listening to their natural sounds, revealing deep-diving behavior. The study provides the first detailed description of Gervais' beaked whale dives anywhere in the world.
Researchers use advanced technology to pinpoint locations of elusive beaked whales diving to the seafloor off the Louisiana coast. The study reveals new insights into their behavior and detection range, shedding light on these mysterious creatures.
Despite sea ice losses, Svalbard polar bears' body conditions have improved due to increased fat reserves and access to land-based prey. The study found that the number of ice-free days in the Barents Sea region increased, but the mean body condition index of adult polar bears rose following 2000.
A global study reveals signs of complete extinction in the Canary Islands, where a previously undetected mass mortality event was identified in mid-2022. The affected species is no longer capable of reproducing, potentially leading to local extinction with severe ecological consequences.
Researchers studied diet changes among three whale species, fin, humpback, and minke whales, over 28 years. The study found that whales are adapting their feeding habits in response to limited resource availability and increased competition.
New research reveals that Indigenous communities in southern Brazil hunted large whales 5,000 years ago, long before previously thought. The study provides strong evidence of active hunting and sheds light on the economies, technologies, and lifeways of postglacial societies along the Atlantic coast of South America.
A Harvard-designed bio-logger captures high-fidelity audio of sperm whale codas, which are later analyzed by machine learning models to uncover structured communication. Recent results show that sperm whales have their own alphabet and use vowels and diphthongs in their language.
Researchers found that killer whales and Pacific white-sided dolphins cooperate while hunting salmon in British Columbia waters. The orcas use dolphin echolocation to locate Chinook salmon, which the dolphins then scavenge for food scraps after the orcas eat their share.
A new species of ancient sea cow has been discovered in Qatar, revealing that sea cows have shaped the Arabian Gulf's seagrass ecosystems for over 20 million years. The fossil site, Al Maszhabiya, yielded more than 170 different locations containing sea cow fossils.
Researchers observed a female Antarctic leopard seal exhibiting postmortem attentive behavior, or PAB, where she cared for her deceased pup for over 20 days. This unique phenomenon is rare in marine mammals and sheds light on the complex behaviors of these apex predators.
A new study by UH Mānoa-Led research revealed 25 distinct underwater vocalizations in Hawaiian monk seals, including a previously undocumented foraging call and a novel 'combinational' communication strategy. The findings provide a baseline for understanding the acoustic world of this endangered species.
Research reveals West Coast transient killer whales are two distinct subpopulations, differing in diet, hunting grounds and social behavior. The inner coast transients are expert navigators of nearshore inlets, while the outer coast whales thrive in deep canyons and rugged underwater terrain.
Researchers at the University of British Columbia have identified eight per- and polyfluoroalkyl substances (PFAS) in B.C. sea otters, with concentrations three times higher on average in otters near major cities and shipping routes. This proximity effect highlights the need for government regulation to prevent PFAS spread.
A new study reveals that different prey within a single species can provide vastly different levels of nutrition for marine predators. This variation can lead to predators consuming more prey than necessary, highlighting the importance of understanding prey quality in maintaining ecosystem balance.
Researchers tested a popular evolutionary theory by comparing maternal length and fetal sex in over 100,000 whales. They found that the fetal sex ratio skews female for longer body size, suggesting that female calves benefit more from heritable fitness than males do. The findings contradict the Trivers-Willard hypothesis.
Scientists observed Hector's dolphins' subsurface behaviors, which may increase their risk of bycatch. The study sheds light on the conservation efforts for this critically endangered species.
Beaked whales are recorded in the Foz do Amazonas Basin using passive acoustic monitoring, demonstrating their first documentation in Brazilian waters. The study contributes to understanding cetacean biodiversity and showcases the effectiveness of acoustic monitoring for categorizing elusive sea creatures.
A new study finds that sargassum seaweed can significantly slow down sea turtle hatchlings in Florida, increasing their risk of predation and heat exposure. Researchers found that even small amounts of sargassum can impede hatchlings' progress, with leatherbacks taking 54% longer to crawl through light sargassum.
A global review highlights the need for better tools to understand juvenile fish habitats, which are facing increased pressure from various factors. The study recommends incorporating metrics like growth, survival, and contribution rates to assess habitat quality.
Researchers found river otter scat containing parasites that infect prey, indicating otters may play a crucial role in shaping their ecosystems. The study also discovered diverse diets and invasive species among the otters' meals.
Researchers have identified a previously undocumented class of PFAS in the blubber of killer whales, accumulating in fat-rich blubber. This discovery challenges the long-held assumption that PFAS primarily bind to proteins and accumulate in liver or blood.
Scientists have discovered a new species of ancient whale, Janjucetus dullardi, from a 26-million-year-old fossil found in Victoria's Surf Coast. The discovery reveals a fast, sharp-toothed predator with a compact body and big eyes.
The study analyzed the northbound migration of northern fur seals, revealing that they concentrate foraging activity along continental shelf-breaks and near anticyclonic eddies. The findings provide new insights into the seals' response to oceanographic conditions and highlight the importance of long-term monitoring in understanding th...
Researchers from Florida Atlantic University's Harbor Branch Oceanographic Institute have developed a multi-sensor biologging tag on the whitespotted eagle ray, enabling long attachment times and detailed data collection. The study provides insights into the rays' behavior, habitat use, and social interactions.
A recent study found that the 2014-2016 Northeast Pacific marine heatwave caused unprecedented ecological disturbance, resulting in widespread kelp and seagrass declines and mass mortality events. The research highlights cascading impacts on species interactions, plankton communities, and offshore ocean productivity.
Killer whales have been observed detaching kelp stalks and using them to massage each other's backs, a behavior dubbed "allokelping". This social bonding behavior may promote skin health and strengthen relationships among the whales.
A team of whale experts discovered that southern resident killer whales regularly use lengths of bull kelp as tools to groom each other during social interactions. The whales fashion the tools by breaking off the ends of kelp stalks and then press them against a partner, rolling them between their bodies for long periods.
The Barents Sea system – gateway to the changing Arctic book documents six years of interdisciplinary research on the Barents Sea. Researchers used various platforms, including drones, satellites, and underwater robots, to collect data and make predictions about future changes.
Researchers have discovered that dolphin brains process echolocation as a form of tactile sensation, using neural pathways similar to those found in the cerebellum. This study provides insight into the unique auditory processing abilities of dolphins, which are distinct from other marine mammals.
A global research team tracked over 100 species of marine animals, revealing key migration patterns and hotspots critical for conservation. The study, MegaMove, uses satellite data to inform a new blueprint for ocean conservation, highlighting the need for targeted mitigation efforts.
Wild animals studying seals' extreme environments could provide answers to pressing problems in human reproductive health. Seals' unique physiology offers insights into managing gestational diabetes and improving IVF success rates.
An 11-year-old Asian small-clawed otter developed left-sided paralysis after a fall, but improved with treatment for a suspected fibrocartilaginous embolus. Follow-up MRI showed a diminished lesion one year later.
A study reveals widespread overlap between feeding grounds for seabirds, marine mammals, and regions with high wind potential. Researchers propose developing risk maps to predict conflicts and recommend expanding marine protected areas and strengthening spatial planning tools.
Researchers used a novel approach to estimate megalodon's body length and shape, finding it closer in shape to a lemon shark or large whale. The study suggests the prehistoric predator may have reached about 80 feet in length and weighed an estimated 94 tons.
Researchers propose that timing hypothesis explains the mystery of missing blue whale calves, where births occur in fall and winter, and calves are weaned before returning to feeding areas. This explanation offers alternative insight into high pregnancy rates vs. low sightings of mother-calf pairs.
Baleen whale species that flee from killer whales produce calls at deep frequencies undetectable to their predators, while others sing higher-frequency songs that are easily heard. This 'flight' vs 'fight' difference influences all aspects of baleen whale behavior, from migration patterns and communication to mating and feeding habits.