The oceans support beautiful and fascinating life forms that could not exist on land. Some are familiar, like the blue whale, a mammal, which is the largest animal ever seen on the planet. Weighing more than 20 elephants, a mature blue whale has a heart the size of a small car served by blood vessels so wide that a full-grown trout could swim through them. Much of the life found in the oceans is, however, fantastic and strange, from the large single-celled organisms, called xenophyophores, that can be measured in inches, to giant jelly fish with tentacles that trail over 100 feet. Within the past two decades, scientists discovered communities of animals living around geysers on the seafloor miles beneath the surface.
Healthy oceans exert multiple and profound influences over our lives.
Our reliance on the seas goes far beyond the 15 pounds of seafood each person in the United States eats, on average, every year. From the alginates in beer that help keep the foam from collapsing, and diatoms for filtering swimming pool water, to crab shells that are used to produce absorbable surgical sutures, the oceans provide many of our lives' necessities and luxuries. Wetlands cleanse water and provide nurseries for fish, and coastal vegetation and coral reefs buffer the margins of land from violent storms. Ocean waters are constantly moving and, as they collect and distribute heat from the sun, they influence climate in every corner of the planet. The health of different areas of the oceans can be described as threatened, critical, or terminal.