Warming planet is hazard to fish through increased salinity and algal blooms

Prymnesium parvum has wreaked calamitous damage on angling spots in Norfolk, making it an economic and environmental threat

Many effects of global warming appear gradually but can cause sudden and devastating changes. A rise in sea levels is one; it makes estuaries and lagoons slightly more saline, which in the case of the Norfolk Broads, suddenly threatened a big attraction, angling.

This is because tiny "golden" algae called Prymnesium parvum, which thrive in slightly saline or mineral rich water, can turn toxic, suffocating the fish by destroying their gills.