5 CHAPTER ONE LIFE IN THE OCEAN The sea is warm and still A golden-brown carpet of seaweed called sargassum stretches along the surface The bed of seaweed is part of the Sargasso Sea in the North Atlantic Ocean It is the best hiding spot for animals living in the open ocean A young loggerhead turtle rests inside the sargassum It eats smaller creatures such as shrimp fish crabs and snails that hide among the weeds Sargassum floats near the surface in large island-like pieces
A Long Journey Some ocean species remain in the same habitat their entire lives Others travel thousands of miles each year This is called transoceanic migration The main reasons for migration are to find food and to reproduce Many baby sea turtles emerge from nests on the Gulf Coast in Florida each year They swim to the powerful Gulf Stream This current takes them to the Sargasso Sea Here they live out their young lives hidden amongst the seaweed When they reach adulthood some of the females travel back to the same beach where they hatched to lay their own eggs 6 These creatures in turn eat smaller organisms most often the microscopic phytoplankton Phytoplankton make food from sunlight with the help of nutrients from the bodies and feces of larger organisms High above the surface of the sea a predatory bird soars A shark circles 300 feet 91 m below the surface These animals are a threat to the loggerhead They often eat turtles But the loggerhead is safe in the open ocean Ocean Diversity The Sargasso Sea is one ocean habitat But there are many others The ocean covers nearly 75
Coral reefs cover less than one percent of the seafloor But they support approximately 25 percent of ocean creatures percent of Earth It is very diverse It stretches from the icy polar regions to the sun-warmed equator It creeps along coastlines in what are called intertidal zones It supports coral reefs often called rain forests of the sea because of their diversity The open ocean called the pelagic zone is home to many species And in the deep sea unique organisms live and breathe Most of the ocean is unexplored But we know it is home to millions of strange and wonderful species Some ocean organisms have adapted to survive in 7