Study links rapid growth of ocean macroalgae to global heating and nutrient pollution Study links rapid growth of ocean macroalgae to global heating and nutrient pollution Scientists have warned of a potential “regime shift” in the oceans, as the rapid growth of huge mats of seaweed appears to be driven by global heating and excessive enrichment of waters from farming runoff and other pollutants. Over the past two decades, seaweed blooms have expanded by a staggering 13.4% a year in the