Rising algal blooms threaten global ecosystems and marine life
Rising algal blooms threaten global ecosystems and marine life
Harmful algal blooms are increasing worldwide, with severe impacts on aquatic ecosystems and wildlife, according to a report published by The Guardian. The phenomenon, linked to pollution and global warming, has been identified as a possible cause behind the mysterious deaths of hundreds of elephants in Botswana in 2020. Scientists now suggest toxic cyanobacteria, triggered by sudden climate shifts, may have contaminated water sources, although definitive proof was delayed due to the pandemic.
Algal blooms, which thrive in warm, nutrient-rich waters, are exacerbated by agricultural runoff and rising global temperatures. While some algae support ecosystems, others release toxins or deplete oxygen levels, creating “dead zones” where most marine life cannot survive. These blooms are increasing in frequency and scale, with coastal areas seeing a significant rise between 2003 and 2020, and freshwater systems experiencing a 44% increase in the 2010s.
The consequences range from mass fish deaths to altered food chains. In northern regions, blooms have repeatedly wiped out farmed fish populations. Toxic outbreaks have also been linked to neurological effects in marine mammals and rising jellyfish numbers, which thrive in low-oxygen environments.
Scientists warn that continued warming will worsen these effects, reducing oxygen levels in water and limiting natural mixing between ocean layers. While some argue for drastic reductions in fertiliser use, others caution against compromising global food security. Experts stress the need for balanced approaches to protect ecosystems while addressing the root causes of algal bloom proliferation.
