Barium : calcium and molybdenum : calcium ratios were investigated in shells of the tropical scallop Comptopallium radula . Three juvenile specimens were harvested alive in the southwest lagoon of New Caledonia after a 1‐yr hydrological survey. Calcite samples representing a few hours of biomineralization were laser‐ablated along the maximal growth axis and analyzed for Ba and Mo content with an inductively coupled plasma mass...

Ecological shifts from diatoms to other phytoplankton species have been related to decreasing Si : N and Si : P nutrient ratios. The Bay of Brest is such a perturbated ecosystem where Si has become limiting but where diatoms continue to dominate the phytoplankton throughout the productive period. Several hypothesis have been invoked to account for this dilemma. The most recent combines suspension feeder activity and Si recycli...