The fish at Darwin Island are so plentiful they can blot out the sun. Here a school of bigeyed jacks is surrounded by an even larger mass of creolefish.

The World Under Darwin: Stunning Images Portray the Rich Marine Life Beneath the Birthplace of Natural Selection

Galapagos Islands, Ecuador- Cold water, high currents and low visibility aren’t a combination of surroundings that travel magazines frequently boast about. In the Galapagos, however, the conditions translate into high productivity, big ocean critters and life found nowhere else in the world with the added bonus of existing in the shadow of Darwin’s greatest discovery. It is for these reasons that biologist, diver, and underwater photographer Jeff Milisen jumped at the opportunity to spend 10 days exploring this unique archipelago.

Giant oceanic manta rays come to the Galapagos in search of food and to get cleaned by the plentiful barberfish and angelfish.

The Birthplace of the Theory of Evolution

Nearly every basic biological principle is somehow rooted in the theory of natural selection. In 1835, Charles Darwin arrived at the isolated Galapagos Islands on his historic voyage aboard the HMS Beagle. The isolation experienced by the founding species to these volcanic islands expedited evolution to create a menagerie of new, endemic life forms. Darwin was so impressed by the diversity of terrestrial life contained therein, that he was inspired to write “On the Origin of Species” and introduced the world to the theory of evolution. One hundred and eighty years later, the Galapagos is a celebrated national park, marine reserve, UNESCO World Heritage site, and stands as a flagship for conservation success stories.

Thousands of years ago, cormorants flew to the Galapagos from the mainland of South America. The rich abundance of food and a complete lack of predators meant that flight was no longer a necessity, so the wings shriveled and the birds were grounded. This is now the only species of flightless cormorant in the world.

Species Found Nowhere Else

The unique wildlife continues well past the shorelines. The isolation has not only provided the right conditions for many of the fish and aquatic life to evolve in strange ways, many land animals have also adapted to a life back in the sea. Cormorants that once arrived in the skies have since lost the ability to fly. Marine iguanas scour the subtidal rocks for their favorite algae. The Galapagos even hosts its own species of penguin.

Due in part to their cold blood, reptiles have yet to conquer the ocean as thoroughly as they have conquered much of the earth’s land space. Marine iguanas are the world’s only marine lizard. They spend their early mornings basking on the black lava rocks at the shore, heating up for their next feat. Once properly incubated, the lizards take to the sea in search of their favorite food-algae.

Outside the masses of creole fish, swirling school of jack, entranced shivers of hammerheads and groups of Galapagos sharks, schools of tuna would patrol the nearshore waters looking for reef fish that lost their way.

Life Abounds

The Galapagos Islands straddle the equator, so while cold ocean currents fuel an explosion of life, the warm climate allows for a variety of biomes from coral reefs to temperate ecosystems and abundant pelagic life. As a diver drifts with the racing currents, they will encounter schools a thousand strong of a multitude of different fishes.

Looking for the Big Life

Lots of little fish attract lots of bigger fish. In fact, the Galapagos were recently recognized as having the highest concentration of sharks on earth. And while the surrounding seas are packed with silky, Galapagos, and endemic horned sharks, the big draw are the huge masses of scalloped hammerheads that swim by as if in a trance.

Perhaps the most iconic sharky residents of the Galapagos are the masses of hammerhead sharks that encircle Darwin and Wolf Islands. Female hammerheads form large schools in order to compete for breeding rights with the intermittent males. The larger females defend their optimal spot in the center of the school while younger, immature females are pushed to the edge.

Jeff Milisen, 34, is a Hawaii-based marine biologist and underwater photographer. His past projects have featured subjects ranging from deadly cone snails, innovative open ocean aquaculture, big sharks, and, most recently, plankton portraits. Over the past year, his images have placed in 4 international photography competitions including 8th place in Ocean Views, Gold in Our World Underwater and “Best of Show” in the coveted Ocean Art Competition. More of his art can be viewed here or just follow him on Instagram and Twitter (@JeffMilisen).

Hammerheads rule over the islands of Darwin and Wolf. The Galapagos Sanctuary was recently recognized as having the highest abundance of sharks in the world. In certain conditions, the flow of hammerhead sharks cruising through the view can be constant.