Life in the Ocean

Three Groups of Marine Life Plankton – organisms that float near the ocean’s surface – mostly microscopic Phytoplankton: plantlike Zooplankton: animal-like

Three Groups of Marine Life Nekton – free swimming organisms of the oceans (mammals, whales, dolphins, sea lions, fish). Most abundant in surface water

Three Groups of Marine Life Benthos – organisms that live on the ocean floor in mud, sand & rock. crabs, sea stars, worms, coral, sponges, seaweed, clams

Benthic Environment The ecological zone of the ocean that includes the ocean floor and all the organisms that live on or in it Divided into different zones based on depth Intertidal Sublittoral Bathyal Abyssal Hadal

Intertidal Zone Located between the low- and high-tide limits Is covered with water twice a day as the tides change The organisms that live in this zone must be able to breathe underwater and on land Must be able to keep from being washed out with the tide. Clams, oysters, barnacles, crabs, starfish, sea anemones

Sublittoral Zone Begins at the low-tide limit and extends to the edge of the continental shelf Depths reach to 200 m Temperature, water pressure, sunlight are fairly constant Most animals stay in the upper 100 m to reach the sunlight

Bathyal Zone Extends from edge of continental shelf to abyssal plain 200 m – 4,000 m Lack of sunlight = few plants Animals include: sponges, brachiopods, sea stars, echinoids, octopuses

Abyssal Zone Scientist know very little about this zone Very deep and dark 4,000 and below – can reach 6,000 m Few animals/ no plants Some crabs, sponges, worms, sea cucumbers Live around hot-water vents & in extreme conditions

Hadal Zone The deepest benthic zone Consists of deepest ocean floor and trenches Less is known about this zone than the abyssal zone Few animals: a type of sponge, a few worms, a type of clam

The Pelagic Environment The environmental zone that includes the entire volume of water in the ocean and the marine organisms that live above the ocean floor Two major zones Neritic Zone Oceanic Zone

Neritic Zone Includes the volume of water that covers the continental shelf Warm, shallow zone Largest concentration of marine life Lots of sunlight Lots of benthos to serve as food Fish, plankton and marine mammals

Oceanic Zone Includes the volume of water that covers the entire sea floor except for the continental shelf In deeper parts, the temperature is colder and the pressure is greater Organisms spread out more Some animals include giant squid, whales

Resources http://www.beachwatchers.wsu.edu/ezidweb/animals/ http://go.hrw.com http://marinebio.org/species.asp?id=33 http://waynesword.palomar.edu/algae1.htm http://www.seasky.org/reeflife/sea2a.html http://paleo.cortland.edu/tutorial/Brachiopods/brachiopoda.htm http://www.bisdragons.com/students2001/oceans/abyssalplains/animals.html http://www.marksmarine.net/encylo/clown/clown_fish.htm http://www.whales.org.au/gallery/index.html