Data on unhatched embryos from an experiment on CO2 sensitivity of Northern sand lance (Ammodytes dubius) embryos conducted in 2018

Source data of two years of experimentation on Northern sand lance (Ammodytes dubius) embryos at different temperature and pCO2 conditions. Founder adults were sampled at Stellwagen Bank National Marine Sanctuary (SBNMS) (42° 9' 58.26\" N, 70° 18' 44.1\" W). Two complementary experiments were conducted in late 2018 (E1) and 2020 (E2), each rearing newly fertilized sand lance embryos to hatch over the course of 32-65 days. This dataset includes information on unhatched embryos from the first experiment.