GeoLog

bivalve

Geosciences Column: Dating a bivalve

Just as the rings on a tree can be used to determine its age, the bands on a bivalve’s shell can tell us the how long it’s been around for. Warm, food-filled waters lead to greater growth in the summer and low plankton abundance (the principle food source for filter-feeding molluscs) leads to limited growth during the winter months – hence the banding. But pinning down the age of a bivalve m ...[Read More]

Geosciences Column: Larvae, Climate and Calcification

The absorption of atmospheric CO2 by the oceans results in a decline in ocean pH, hence ‘ocean acidification’, and reduces the availability of carbonate. This presents a problem to calcifying organisms (those that deposit calcium as either calcite or aragonite as hard parts) because they cannot produce their shells, valves (in the case of bivalves), or tests (in the case of diatoms) as readily. To ...[Read More]