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
The Ocean and Earth All life on Earth depends on the ocean Microscopic plants in the ocean called phytoplankton create more than half of the planet’s oxygen The ocean helps regulate the weather water and nutrients Earth’s organisms need to survive The ocean also keeps Earth at a moderate temperature that allows life to exist 8 regions without oxygen Others can see in places with almost no light Some creatures can withstand thousands of pounds of water pushing down on them Each species has evolved to survive in its unique environment and each one plays an important role in the ecosystem Learning and Protecting Some human actions such as deep sea oil drilling and polluting are hurting the ocean The ocean is largely unexplored So scientists are unsure of how much damage humans have caused Many people are working to protect the sea But this can be difficult because most of the ocean is not owned by any one country
STRAIGHT TO THE SOURCE In 2000 a panel of ocean experts prepared a report for the US president on the importance of ocean exploration We cannot protect what we do not know and thus without ocean exploration we are ignorant of what needs to be conserved in a realm that covers most of the surface of the Earth The ocean provides a bounty of renewable resources but without knowledge of what’s out there how abundant it is and how quickly it is replenished we cannot plan for its environmentally sustainable use Every day governments make decisions on how to best regulate the use of the oceans yet they lack the basic knowledge to make informed choices Source President’s Panel for Oceanic Exploration Discovering Earth’s Final Frontier A U S Strategy for Ocean Exploration Washington DC US Department of Commerce 2000 PDF file What’s the Big Idea Take a close look at the excerpt What are the ocean experts trying to tell the president What arguments do they use to make their point How do you think their focus would change if they were presenting a report to another group of scientists 9
