One or many? Exploring the population groups of the largest animal on Earth

New research shows that Antarctic blue whales are likely a single population, rather than several isolated populations — information that will help conservationists as the whales, the world’s largest animal, try to recover from historic lows due to 20th century whaling.

Study Details Toxic Elements Found in Stranded Whales, Dolphins Over 15 Years

Researchers evaluated the prevalence, concentration and tissue distribution of essential and non-essential trace elements, including heavy metal toxicants in tissue (blubber, kidney, liver, skeletal muscle, skin) and fecal samples. Findings reveal how toxicant levels relate to their sex, breed, age and other demographic factors.

Killer whales’ diet more important than location for pollutant exposure, study says

Killer whales are some of the oceans’ top predators, but even they can be exposed to environmental pollution. In the largest study to date on North Atlantic killer whales, researchers in ACS’ Environmental Science & Technology report the levels of pollutants in 162 individuals’ blubber.

Northern and southern resident orcas hunt differently, which may help explain the decline of southern orcas

In the Pacific Northwest and British Columbia, southern resident orcas have experienced no net population growth since the 1970s. But northern resident orcas, with a similar diet and territory, have grown steadily. A new study may help explain why: The two populations differ in how they hunt for salmon, their primary and preferred food source.

Fossil CSI: Analysis of giant extinct marine reptile graveyard suggests mysterious site was ancient birthing grounds

Marine giants make migrations across the ocean to give birth where predators are scarce, congregating annually along the same stretches of coastline. A study suggests that 200 million years before whales evolved, school bus-sized marine reptiles called ichthyosaurs may have made similar migrations.

Study Finds High Levels of Toxic Pollutants in Stranded Dolphins and Whales

Researchers examined toxins in tissue concentrations and pathology data from 83 stranded dolphins and whales from 2012 to 2018. They looked at 11 different animal species to test for 17 different substances. The study is the first to report on concentrations in blubber tissues of stranded cetaceans of atrazine, DEP, NPE and triclosan. It also is the first to report concentrations of toxicants in a white-beaked dolphin and in Gervais’ beaked whales.