The effects of elevated carbon dioxide concentrations on the metamorphosis, size, and survival of larval hard clams (<i>Mercenaria mercenaria</i>), bay scallops (<i>Argopecten irradians</i>), and Eastern oysters (<i>Crassostrea virginica</i>)

Abstract

We present experiments that examined the metamorphosis, growth, and survivorship of larvae from three species of commercially and ecologically valuable shellfish ( Mercenaria mercenaria , Argopecten irradians , and Crassostrea virginica ) at the levels of CO 2 projected to occur during the 21st century and beyond. Under CO 2 concentrations estimated to occur later this century (~66 Pa, 650 ppm), M. mercenaria and A. irradians larvae exhibited dramatic declines (&gt;50%) in survivorship as well as significantly delayed metamorphosis and significantly smaller sizes. Although C. virginica larvae also experienced lowered growth and delayed metamorphosis at ~66 Pa CO 2 , their survival was only diminished at ~152 Pa CO 2 . The extreme sensitivity of larval stages of shellfish to enhanced levels of CO 2 indicates that current and future increases in pelagic CO 2 concentrations may deplete or alter the composition of shellfish populations in coastal ecosystems.