Shane Gross / Blue whale (Balaenoptera musculus) swimming, Indian Ocean, off Sri Lanka. March.

Shane Gross / Galapagos sea lion (Zalophus wollebaeki) hunting shoal of Black striped salemas (Xenocys jessiae), Rabida Island, Galapagos, Ecuador. December.

Shane Gross / Green sea turtle (Chelonia mydas) near the surface in shallow water, Eleuthera, Bahamas.

Shane Gross / A Great hammerhead shark (Sphyrna mokarran) swimming towards the camera, Bimini, Bahamas.

Shane Gross / A Bottlenose dolphin (Tursiops truncatus), heavily scarred, possibly from shark attacks, on sand bank off Eleuthera, Bahamas.

Shane Gross / Great hammerhead shark (Sphyrna mokarran) swimming over sandy seabed, Bimini, Bahamas.

Shane Gross / Caribbean reef squid (Sepioteuthis sepioidea) portrait reflecting off the surface of the ocean at night, Eleuthera, Bahamas.

Shane Gross / Caribbean reef squid (Sepioteuthis sepioidea) portrait at night, Eleuthera, Bahamas.

Shane Gross / A Giant clam (Tridacna gigas) surrounded by Lettuce coral (Turbinaria reniformis), Kosrae, Micronesia.

Shane Gross / Common octopus (Octopus vulgaris) on a coral reef, The Bahamas. August.

Shane Gross / Common octopus (Octopus vulgaris) on a coral reef in The Bahamas. August.

Shane Gross / Common octopus (Octopus vulgaris) hunting on a reef off Eleuthera Island, Bahamas.

Shane Gross / Green sea turtle (Chelonia mydas) swimming over sand ripples, Eleuthera, Bahamas.

Claudio Contreras / Black grouper (Mycteroperca bonaci), and Caribbean Reef Shark (Carcharhinus perezi), Jardines de la Reina / Gardens of the Queen National Park, Caribbean Sea, Ciego de Avila, Cuba.

Claudio Contreras / Schoolmaster snapper (Lutjanus apodus) and Bluestriped grunt (Haemulon sciurus) seeking protection in Elkhorn Coral (Acropora palmata), Jardines de la Reina / Gardens of the Queen National Park, Carib...

Claudio Contreras / Flamingo Tongue (Cyphoma gibbosum), on featherstar, Cienaga de Zapata National Park, Matanzas Province, Cuba.

Claudio Contreras / Giant barrel sponge (Xestospongia muta) and diver, Guanahacabibes Peninsula National Park, Pinar del Rio Province, western Cuba.

Claudio Contreras / Spinyhead Blenny (Acanthemblemaria spinosa), Cienaga de Zapata National Park, Matanzas Province, Cuba.

Claudio Contreras / Black grouper (Mycteroperca bonaci), and Caribbean Reef Shark (Carcharhinus perezi), Jardines de la Reina / Gardens of the Queen National Park, Caribbean Sea, Ciego de Avila, Cuba.

Shane Gross / Panamic Cushion Sea Star (Pentaceraster cumingi) and a school of Yellow-tailed Grunt (Anisotremus interruptus), Galapagos Island, Ecuador. December.

Claudio Contreras / Red encrusting sponge (Monanchora barbadensis), Cienaga de Zapata National Park, Matanzas Province, Cuba.

Claudio Contreras / Painted tunicate (Clavelina picta), Cienaga de Zapata National Park, Matanzas Province, Cuba.

Claudio Contreras / Orange sieve encrusting sponge (Diplastrella sp.) and Red encrusting sponge (Monanchora barbadensis), Cienaga de Zapata National Park, Matanzas Province, Cuba.

Claudio Contreras / Red Mangrove (Rhizophora mangle) forest, Cienaga de Zapata National Park, Matanzas Province, Cuba.

Shane Gross / Unicorn leatherjacket filefish (Aluterus monoceros) at night, The Bahamas. February.

Claudio Contreras / Bicolor damselfish (Stegastes partitus), Guanahacabibes Peninsula National Park, Pinar del Rio Province, western Cuba.

Claudio Contreras / American crocodile (Crocodylus acutus), Jardines de la Reina / Gardens of the Queen National Park, Caribbean Sea, Ciego de Avila, Cuba.

Claudio Contreras / Golden coral shrimp (Stenopus scutellatus), Cienaga de Zapata National Park, Matanzas Province, Cuba.

Claudio Contreras / Foureye butterflyfish (Chaetodon capistratus) couple feeding on coral, Guanahacabibes Peninsula National Park, Pinar del Rio Province, western Cuba.

Claudio Contreras / Pederson cleaner shrimp (Periclimenes pedersoni), Cienaga de Zapata National Park, Matanzas Province, Cuba.

Claudio Contreras / Gray snapper (Lutjanus griseus) shoal swimming over Turtle grass (Thalassia testudinum), Jardines de la Reina / Gardens of the Queen National Park, Caribbean Sea, Ciego de Avila, Cuba.

Shane Gross / Tarpon (Megalops atlanticus) portrait, Eleuthera, Bahamas. December.

Claudio Contreras / Silky Shark (Carcharhinus falciformis) with hook, Jardines de la Reina / Gardens of the Queen National Park, Caribbean Sea, Ciego de Avila, Cuba.

Claudio Contreras / Caribbean Reef Shark (Carcharhinus perezi) group of three, Jardines de la Reina / Gardens of the Queen National Park, Caribbean Sea, Ciego de Avila, Cuba.

Dimitris Poursanidis / Neptune seagrass meadow (Posidonia oceanica) in the coastal zone of the Samaria National Park, Chania, Crete

Dimitris Poursanidis / Close up of the understory of a seagrass meadow, Agia Pelagia, Heraklion, Crete, Greece

Dimitris Poursanidis / Neptune seagrass (Posidonia oceanica) fruits washed ashore after a storm. Gouves, Heraklion, Crete, Greece

Dimitris Poursanidis / Noble pen shell (Pinna nobilis) is the largest bivalve in the Mediterranean. It is mostly found in seagrass meadows (Posidonia oceanica). National Marine Park of Alonissos Northern Sporades, Greece

Dimitris Poursanidis / Black-tailed wrasse (Symphodus melanocercus) sheltering within Neptune seagrass (Posidonia oceanica). Agia Pelagia, Heraklion, Crete, Greece

Dimitris Poursanidis / Meadow of Neptune seagrass (Posidonia oceanica), Chersonissos, Heraklion, Crete, Greece

Dimitris Poursanidis / Abandonded fishing gear in seagrass meadow, with red sea squirt (Halocynthia papillosa), Samaria National Park, Chania, Crete, Greece

Dimitris Poursanidis / A school of Siganids (Siganus rivulatus) fish swimming over meadow of little Neptune seagrass (Cymodocea nodosa). Agia Pelagia, Heraklion, Crete, Greece.

Dimitris Poursanidis / Neptune seagrass (Posidonia oceanica) meadow, Samaria National Park, Chania, Crete, Greece

Dimitris Poursanidis / A school of striped red mullet or surmullet (Mullus surmuletus) swim over seagrass meadow, Agia Pelagia, Heraklion, Crete, Greece

Dimitris Poursanidis / Abandonded fishing gear in seagrass meadow (Posidonia oceanica), Agia Pelagia, Heraklion, Crete, Greece

Shane Gross / Galapagos penguin (Spheniscus mendiculus) hunting off Bartolome Islet, Santiago Island, Galapagos, Ecuador. December.

Shane Gross / Galapagos sea lion (Zalophus wollebaeki) hunting shoal of Black striped salemas (Xenocys jessiae), Rabida Island, Galapagos, Ecuador. December.

Shane Gross / Galapagos sea lion (Zalophus wollebaeki) hunting shoal of Black striped salemas (Xenocys jessiae), Rabida Island, Galapagos, Ecuador. December.