Artificial light from major coastal cities can disrupt the nighttime biology of sharks, according to new research that provides the first-ever measurements of melatonin—a hormone tied to biological rhythms—in wild sharks.

Florida’s Indian River Lagoon (IRL) is increasingly stressed by nutrient pollution, harmful algal blooms, and rising atmospheric CO₂, which acidifies lagoon waters and reduces aragonite—the calcium carbonate shell-building organisms need. By mapping aragonite saturation across the IRL, researchers found nutrient-rich areas have lower aragonite levels, putting shellfish and other marine life at risk. This study provides the first comprehensive lagoon-wide assessment of aragonite saturation, filling a key knowledge gap on coastal acidification in shallow estuaries.

In 2025, BioMARatona saw more than 3,000 citizen science observations of marine life along Portugal’s coast. 

To the point:

Cellular energy threats: Presence of mercury was linked to inefficient fuel use during energy production in wild birds’ cells, while certain per- and polyfluoroalkyl substances (PFAS) may prevent protective responses to cell stress

Foraging shapes exposure: Older birds and males carried more mercury through diet, food choice and lifetime accumulation in a key component of the birds’ blood, however PFAS levels showed no such links, suggesting different contamination routes

Early marine algae adapted their light-harvesting systems for weak blue-green light, suggesting how photosynthesis evolved.

Iron-rich sediments transported by icebergs from West Antarctica failed to support algae growth in the Southern Ocean, because the iron was highly “weathered” and not readily bioavailable to algae—thus reducing the ocean’s carbon dioxide uptake.

Detecting weak and low-frequency underwater sounds remains a major challenge for ocean monitoring, navigation, and marine exploration.