Wednesday August 31, 2022
AccessWire —
As parts of the Atlantic Ocean warm at unprecedented rates, researchers are looking to past warming trends to help understand how previous changes in climate have influenced marine life. A new study looks at the fossil record of one of Earth’s longest-lived species to provide new insights into historic changes in climate, and the impacts that it caused.
Published in the journal Holocene and funded by the Science Center for Marine Fisheries (SCEMFIS), the study looks at the fossil record of ocean quahogs to chart historical changes in ocean temperatures over the Holocene period, which covers the last 10,000 years of Earth’s history. Because there are no direct measurements of ocean temperatures for much of this period, indirect measures, like fossil records, can help reconstruct some of that history.
Ocean quahogs in particular are useful for this type of reconstruction. They can only live in colder waters, below 16 degrees Celsius. Since much of the Northwest Atlantic is warmer than that, their habitat is currently limited to grounds that are part of the Mid-Atlantic Cold Pool, a recurring area of cold bottom water in an area of the Atlantic known as the Mid-Atlantic Bight.
Because ocean quahogs prefer the waters of the Cold Pool to the surrounding waters, the change in ocean quahog habitats over time can also serve as a proxy for changes in the Cold Pool, and regional water temperatures, over the same period. Dating ocean quahog shells thus gives a history of climate change in the region.