Tony Wu / Indo-Pacific sailfish (Istiophorus platypterus) in feeding frenzy, with the remains of a previously large school of sardines (Sardina sp) in background. Isla Mujeres, Cancun, Mexico.

Claudio Contreras / Aerial view of Contoy island from the north, Contoy Island National Park, Mesoamerican Reef System, near Cancun, Caribbean Sea, Mexico, January

Claudio Contreras / Social feather duster worm (Bispira brunnea) Cancun national Park, Caribbean Sea, Mexico, July

Doug Perrine / Barjacks (Caranx ruber), Yellowtail snapper (Ocyurus chrysurus), and Sergeant major damselfish (Abudefduf saxatilis) swimming around wreck of bow gun on C-58 shipwreck off Puerto Morelos, near Cancun,...

Alex Mustard / Whale shark (Rhincodon typus) silhouette of shark feeding on floating fish eggs (not visible) just below the surface in calm weather, with snorkeller taking photos nearby, Isla Mujeres, Quintana Roo,...

Alex Mustard / Whale shark (Rhincodon typus) silhouette, feeding on floating fish eggs (not visible) just below the surface in calm weather. Note the bow wave ahead of the shark. Isla Mujeres, Quintana Roo, Yucatan...

Claudio Contreras / French Angelfish (Pomacanthus paru) with a Smallmouth Grunt (Haemulon chrysargyreum) and Blade Fire Coral (Millepora complanata). Cancun National Park, Caribbean Sea, Mexico.

Claudio Contreras / Smooth Trunkfish (Lactophrys triqueter). Cancun National Park, Caribbean Sea, Mexico.

Claudio Contreras / Porkfish (Anisotremus virginicus) school. Cancun National Park, Caribbean Sea, Mexico.

Claudio Contreras / Green Seaturtle (Chelonia mydas) in profile above sandy shallow sea bed. Endangered, Cancun National Park, Caribbean Sea, Mexico.

Claudio Contreras / Queen Angelfish (Holacanthus ciliaris) among other coral fish. Cancun National Park, Caribbean Sea, Mexico.

Claudio Contreras / Saucereye porgy (Calamus calamus). Cancun National Park, Caribbean Sea, Mexico.