An ecosystem threat?
Although the charismatic nature of dolphins is enough to inspire some people to action, scientists’ chief concern arises from the dolphin’s pecking order in the ocean. As apex predators they may be amplifying negative effects lower in the food chain; if tiny prey organisms are getting sickened and fish eat them, and the dolphins consume the fish, the bioaccumulation of toxins might be serious. Dolphins are “sentinels of ocean health” Barco says.
The very fabric of dolphin’s lives may set the stage for the die-off to worsen. Dolphins are highly social creatures; they even breathe together. As a group, dolphins may come to the surface, issue a forceful exhalation through their blowholes and then all inhale, sharing aerosolized particles expelled from adjacent dolphins. Sex, nursing and playing also lead to direct contact. Moreover, small groups are continually striking off on their own, forming new groups, and latching onto other groups, thereby repeatedly introducing diseases into new communities. Without additional information about the underlying causes of the dolphin die-offs, some researchers worry the body count may only rise.