The Ocean Water and Its Creatures Objective 5.0: Describe the layers of the oceanic hydrosphere, including the pelagic zone, benthic zone, and intertidal zone.
Marine Ecosystems: are ecosystems based upon salty water • A. Cover ¾ of Earth’s surface & contain 97% of Earth’s water supply • B. Three groups of marine life, that range from the largest animals, live in the ocean & along with billions of microscopic creatures. 1. Plankton 2. Nekton 3. Benthos H.O.T.S.: Where do you think most marine animals would be located—where is the water warm and filled with light? Where would you want to live if you lived in the ocean—where the water is cold, dark, & filled with pressure OR where the pressure is less, and the water is warm & sunny?
Marine life • 1. Plankton: are organisms that float at or near the ocean’s surface; there are 2 groups of these; comes from the Greek word planktos, meaning “wandering” • Phytoplankton (plankton): microscopic photosynthetic organisms that float at or near the surface of the water; they use the sun’s energy to make food just like plants do • Zooplankton: small, often microscopic, organisms that eat phytoplankton
Plankton Zooplankton Phytoplankton
Marine life continued • 2. Nekton: the free-swimming organisms such as dolphins, sharks, fish FYI: Blue whale is the largest; 20 people could stand on its tongue & people could crawl through their arteries H.O.T.S. : How big do you think a blue whale’s heart is? 3. Benthos: organisms that live on or in the ocean floor. a. They live in mud, sand, & rock. b. Examples: crabs, sea stars (starfish), worms, coral, sponges, seaweed, & clams.
Nekton Whale shark
C. Wide range of habitats in the ocean 1. dark, cold, high-pressure • 2. great depths to warm sandy beaches • 3. icy polar waters to rocky coastlines • 4. oceans and seas occur all over Earth & contain many ecosystems
D. Abiotic factors that shape marine ecosystems: • 1. temperature • 2. amount of sunlight • 3. distance from land • 4. depth of water (distance below the surface of the water) • 5. sunny water: water absorbs light & can go down 200 m; this is where you find phytoplankton; they produce up to 95% of all oxygen available in Earth’s atmosphere • H.O.T.S.: If all marine life were to die, how would you be affected? How would others be affected?
E. The Benthic Environment: • 1. The ocean is divided into zones based upon depth & where different types of • benthos live. • 2. The zones are grouped into one major marine environment—the benthic • environment.
The Zones of the Benthic Environment • 1. Intertidal zone: area where ocean meets land a. it is located b/w the low-tide & high-tide limits, so it is above water part of the day (when tide is out & often battered by waves during this time) b. mud flats, rocky shores, & sandy beaches are found here c. animals & plants in the mud flats: periwinkle snails, herons, & sea grasses d. animals of the rocky shores: sea stars, sea anemones e. animals of the sandy beaches: clams, crabs, conchs, snails f. animals here either hold on with strong root-like systems or have shells to protect them from the waves
Intertidal Zone: http://www.mbayaq.org/lc/activities/lyrics_rocksong.asp?bhcp=1
2. Sublittoral zone • a. begins where the intertidal zone ends, at the low-tide limit, & extends to the edge of the continental shelf • b. temperature, water pressure, & sunlight remain constant here so animals here do not have to deal with the changes that the intertidal zone does • c. extends 200m below sea level, below the surface • d. most plants & animals such coral stay in the upper 100 m where sunlight reaches the ocean floor
Sublittoral zone: coral reefs • 1. coral reefs: • a. found in sunny, tropical areas • b. live in close relationship w/single-celled algae • c. forms from skeletons of corals over thousands of years • d. home to many species • e. dying due to global warming • f. slow growth rate (about the width of a dime in height/yr) • g. the tropical rain forests of the ocean because of their diversity
3. Bathyl zone • a. extends from the edge of the continental shelf to the abyssal plain • b. depth: 200 m to 4,000 m below sea level • c. no sunlight here so no plants • d. animals here: sponges, sea stars, octopi, brachiopods, echinoids
4. Abyssal zone:from the Greek word meaning "no bottom", and refers to the ancient belief that the open ocean was bottomless • a. on the abyssal plain at a maximum depth of 6,000 m • b. no plants & few animals here: crabs, sponges, tube worms, & sea cucumbers 1. tube worms live around thermal vents, hot-water cracks in the ocean floor that release heat & chemicals from inside the Earth 2. the water coming from these vents can be above 80°C 3. worms that live here are dubbed chemosynthetic because they use the chemicals coming from the vents for their food source • c. little is known about the abyssal zone because it is so deep & dark
Abyssal Zone Organisms Upper left: Christmas tree worms; To left: Sea cucumbers; Above top: anglerfish; Above: tubeworms from hydrothermal vents;
5. Hadal zone • a. The deepest benthic zone b. made of the floor of ocean trenches & any organisms there • c. less known about it than abyssal zone • d. organisms there: sponge, worms, clam
Hadal Zone Organisms Deep water squid, deep sea medusa, sea spider, sea pig, and sea basket. http://oceanlink.island.net/oinfo/deepsea/abysso.html
G. The Pelagic Environment • 1. it is the entire volume of water in the ocean & the marine organisms that live • above the ocean floor • 2. 2 major zones in the pelagic zone • a. Neritic zone • b. Oceanic zone
3. Neritic Zone: the water that covers the continental shelf • a. less than 200 m deep & much sunlight here • b. warm, clear, sunny, & shallow zone contains the largest amt of marine life • c. animals & plants here: seaweed, plankton, sea turtles, coral reefs, sponges, fish, dolphins • 1. brown seaweed is used for making Japanese soup, kombu 2. red seaweed used for sushi 3. some seaweeds are also used for adding taste & texture to ice cream
Seaweed Kombu, red seaweed, and seaweed used in ice cream & toothpaste
4. Oceanic Zone: the water that covers the entire sea floor except the continental shelf • a. deeper parts have cold water & great water pressure • b. organisms are more spread out & many eat dead things that fall • c. many unusual animals found here have adapted to pressure & darkness, & include giant squids, whales, fish that glow, anglerfish
Oceanic Zone small squid in the genus Abraliopsis Chaenophryne longiceps ctenophore Bathyctena hydromedusa Aequorea victoria