Earth and Planetary Sciences · Oceanography
Heat stress before spawning changed reproductive traits in the coral Acropora aspera, but the effects depended on temperature and exposure time. Longer heat exposure increased egg volume while sperm production showed a more variable response.
Adding calcium oxide to Los Angeles Harbor water lowered particulate organic carbon and dissolved oxygen when alkalinity rose by about 1,000 micromoles per kilogram. Smaller alkalinity increases, and other tested additions, produced no statistically significant changes in calcium carbonate precipitation or organic carbon partitioning over four days.
Blue mussels from an Irish hybrid zone responded to repeated heat stress with time-dependent changes in stress-related genes. One key heat-shock gene (hsp24) was strongly induced 24 hours after heat exposure, but expression dropped at later time points. The findings show that how mussels cope with warming may depend on when researchers measure their responses—an issue that matters for managing both wild populations and mussel farming.
A new paper reviews fossil evidence from past “hyperthermals” to understand how rapid warming has repeatedly driven extinctions in both marine and land ecosystems. It argues that modern biodiversity loss could become similarly long-lasting because today’s warming is faster and adds direct human pressures.
Marine protected areas rely on protecting “connectivity”—how marine life and impacts move across space. A new systematic review finds that research on these links has grown, but MPA assessment often still treats nature and people separately, with limited attention to how they affect each other.
