2Factors that Affect Life in the Ocean Amount of sunlightTemperature of the waterWater pressureHow does depth affect each of these?Where would you expect to find the greatest abundance of organisms?
3Three Major Groups of Organisms Grouped according to their habits and where in the water they livePlankton - floatersNekton - swimmersBenthos – bottom dwellers
4Whale shark eating plankton Float at or near the surface (up to 200 m deep in open ocean)Plankton comes from the Greek word planktos that means driftingMany are microscopicFoundation of the ocean food webWhale shark eating plankton
5PlanktonPhytoplankton, primarily diatoms and dinoflagellates along with brown algae and cyanobacteria, use photosynthesis to make food.Source of food for zooplankton
6PlanktonZooplankton includes animal-like protists (radiolarians, forminiferans, ciliates and zooflagellates), jellyfish, siphonophores such as the Portuguese man-of-war, and copepods and krill (two types of crustaceans)KrillPhoto credit: Jamie Hall, NOAACopepodphoto by Uwe KilsModel of a radiolarian atthe Smithsonian MuseumPhoto by Hofikai
7NektonAll the organisms that swim freely in the ocean, independent of currentLive in shallow or deep waterThree main types:Cordates - bony fish, whales, sharks, turtles, snakes, eels, porpoises, dolphins and sealsMolluscan – octopus and squidArthropods - shrimpVideo of nekton in the depthsof the ocean:
8Nekton Great White Shark A young loggerhead sea turtle Photo by Irvin CalicutA Caridean Shrimp- moves primarily by swimmingCommon OctopusPhoto by Albert KokBottlenose Dolphin
9Benthos Organisms that live on the ocean floor Includes: Plants - seagrassProtists – brown, red, and green algae (seaweed)Many invertebrate animals – sea stars, sea anemones, sponges, sea urchins, oysters, clams, crabs, sponges, coral, etc.Sally Lightfoot CrabPhoto by Peter Wilton
10Major Life Zones Three major environments or life zones: Intertidal NeriticOpen-OceanPhotosynthetic ZoneBathyalAbyssalHadal
11Intertidal Zone The region between high tide and low tide Most changeable zoneVaries back and forth from dry to under water twice a dayOrganisms must also withstand the affects of waves breaking on the shore.Photo Credit: Eric Guinther
12Intertidal ZoneMany organisms attach themselves to rocks so as to avoid being washed out to sea.Others burrow into the wet sandStarfish, barnacles, anemones, seaweed, sea urchins, clams, mussels, hermit crabs, etc. live here.A beautiful array of starfish , sea urchins and mussel shells in the rocky intertidal zone of Kachemak Bay.
13Neritic ZoneFrom low-tide line to edge of continental shelf, down to about 200 metersAlso called coastal watersPlenty of sunlight for photosynthesisPlankton, nekton, and benthos all found hereRichest life zone in the oceanA close-up of a small mass of sargassum weed. The numerous small round spheres are floats filled with carbon dioxide. These provide buoyancy to the algae.
14Open-Ocean Zones Photosynthetic Zone – Extends from the ocean surface to approximately 200mSunlight penetrates the entire zonePlankton and nekton live in this zone
15Photo credit: Réunion Underwater Photography Open-Ocean ZonesBathyal Zone:Begins at continental slope and continues to depths of about 2,000 metersWater temperature about 4°CLittle if any light, so no photosynthesisMany forms of nekton live here including whales, squids, and octopusesBenthos organisms also live here, including sponges and sea starsGreat biodiversity in this zoneOctopuses and octopi are both correctSperm WhalesPhoto credit: Réunion Underwater Photography
16Open-Ocean Zones Abyssal Zone: 2,000-6,000 meters No sunlight Skeleton of a Glass SpongeAbyssal Zone:2,000-6,000 metersNo sunlightGreat pressureTemperature 2-4°CCreatures that live here may be blind or bioluminescentGiant SquidPhoto: NTNU Museum of Natural history and Archeaology
17Open-Ocean Zones Hadal Zone: Very deepest parts of the ocean, below the abyssal zoneTotally darkImmense pressureCreatures removed from this zone will die in the lower-pressure areas above. The most common creatures found here include jellyfish, viperfish, tube worms, sea cucumbers and deep sea angler fish.Video: