Overview
- An analysis in Science Advances reconstructing 2001–2023 conditions reports a global chlorophyll‑a decline of about 0.00035 mg/m³ per year across oceans between roughly 45°N and 45°S.
- Coastal waters show a steeper decrease of about 0.00073 mg/m³ per year, and high‑chlorophyll events fell by roughly 1.8% over the study period.
- The team merged satellite ocean‑color records with in‑situ measurements using artificial intelligence to produce daily, high‑resolution estimates that address persistent observation gaps.
- Trends vary by region, with increases in algal blooms near the Canary Islands, northern Brazil and northeastern Australia largely linked to human‑driven nutrient inputs such as runoff after deforestation and fires.
- The findings align with separate research indicating that Prochlorococcus may decline by about half in tropical oceans by 2100 as temperatures exceed optimal growth thresholds.