Fish are being recruited to help forecast hurricanes thanks to a remarkable piece of serendipity. Tarpon, blue marlin and tiger sharks are all fish that enjoy swimming in seas of 26C – and by sheer chance this is the minimum sea temperature also needed to fuel hurricanes.
The deeper the warm waters go below the sea surface, the more intense the hurricanes can grow – when Hurricane Katrina passed over waters that were 26C some 100ft below the surface, the storm rapidly grew from a Category 1 to Category 5 hurricane before devastating the Louisiana coastline.
Because sport fishing for tarpon, blue marlon and tiger sharks is big business in Florida, marine biologists have been following the movements of the fish by tagging them with satellite tracking devices with temperature, depth, salinity and GPS sensors.
These showed that the fish closely followed the seasonal progression of the 26C seas during their migrations through the Gulf of Mexico, Caribbean and Atlantic.
But computer weather models have trouble picking out the boundaries of these 26C waters, so when meteorologists learned about the fish tracking study they jumped at the chance to use the satellite survey.
The only alternative way of measuring the temperature of the sea depths is to use underwater robots, but these are expensive and have problems coping with the strong currents in the Gulf of Mexico.
However, the fish are much faster and the satellite tags are relatively cheap. Although on the downside, fish can get caught.
