Arfivik

It is difficult to accurately estimate the age of wild animals, especially long-lived species such as killer or bowhead whales. Traditionally, scientists have used methods such as counting growth rings in teeth or ear plugs to estimate a whale’s age. However, the types of tissues can only be obtained by dead animals. By taking small tissue biopsies of whales’ skin, researchers can now determine their age more accurately and with less invasive methods. Therefore, they make use of the "epigenetic clock" by studying a specific modification of DNA called methylation. The idea is, that methylation patterns predictably change with age and by analysing these patterns, the individual’s age can be estimated. Parsons et al. (2023) estimated ages of southern resident killer whales and bowhead whales within 2–3 years of their known chronological age using skin samples of stranded and alive whales from the last 40 years. By accurately determining whale ages, scientists gain vital insights into their life history, population dynamics, and age-related diseases. This knowledge plays a crucial role in conservation efforts and understanding changes in their environment, prey availability, and overall well-being. The discovery of the Charlotte whale, as the Vermont’s fossil is known, helped to explain the geology and glacial history of North America. Thanks to this and other marine fossils and sediments found in the region, we now know that portions of Ontario and Quebec (Canada) and the US states of Vermont and New York were not so long ago covered by the Champlain Sea, an arm of the Atlantic Ocean that once extended from the Gulf of St. Lawrence to the Great Lakes. The Champlain Sea was short-lived and formed when the ice retreaded from this area 13,000 years ago, leaving a deep basin that was filled with water from the Atlantic Ocean and became populated by marine mammals such as belugas, fin whales, bowhead whales and walruses. Free from the pressure of tons of ice, the earth crust slowly rebounded until, 3000 years later, the land was again above the sea level, the connection with the Atlantic Ocean closed and the basin transformed into the freshwater river valley it is today.