One of the world’s most destructive invasive species is gaining new ground — or water — in Canada and up to Alaska. Carcinus maenas, which translates to “raving mad crab,” outcompetes many local crab species in devouring clams, oysters, and mussels, and they sometimes even eat other crabs and juvenile fish. They destroy seagrass, an essential habitat for juvenile salmon, herring, rockfish, and many other marine animals.
Colombia has some of the strictest illegal fishing laws in the world, but people still need to stand up and enforce them. Erika Lopez has taken on the role of guardian of Malpelo, an island 314 miles (506 kilometers) west of Colombia.
Sometimes the tiniest critters can pack the greatest punch. Phytoplankton, which are unicellular microalgae, can cause mass mortalities of animals such as dolphins and manatees and be the source of serious human illness.
Maintaining a respectful distance from potentially harmful species underwater is a tenet of good recreational diving and a frequent topic of charter boat predive briefs. But those venomous fish you have learned to avoid might save your life someday.
