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| Be sure to study your lecture notes along with lecture quizzes 3 (Tropics), and 5 (Poles). Lecture quiz 4 was a 'pop' quiz without any content. This outline should help you organize your lecture notes but be sure to review all diagrams in your lecture notes. I. The Benthos A. General Considerations
2. The benthos is found intertidal, shelf, bathyal, abyssal, hadal 3. Almost all large plants are benthic (macro-algae) in the photic zone (epiflora) 4. Both epifaunal and infaunal benthos found (animals) 5. Major area of decomposition 6. Sediments (eroded crustal material) sink when currents no longer keep them in suspension
b. found over much of central north Pacific and polar regions
2. found in temperate waters less than about 4-5,000m deep (dissolve deeper) = South Pacific, North Atlantic and South Atlantic, Indian Ocean
2. found in high latitude sea floors (around Antarctica, North Pacific) and equatorial Pacific
b. example is manganese nodules (layers of metals: Fe, Mn, Ni, Cu, Co)
ii. do not get buried (theories about infaunal worms moving sediments may explain this)
2. oxygen added as water circulated through tubes in substrate (mostly tube worms) 3. cement sediments for tubes (especially worms) 4. compact fecal pellets (ghost shrimp/mud shrimp and sea cucumbers 5. bore into rock (clams)
2. carnivores - starfish 3. omnivores plus: 4. filter feeders - plankton eaters (phyto/zoo/or both) ... brittlestars, sand dollars 5. deposit feeders - injest sand/mud, digest organics, release cleaned sediments ... sea cucumbers 6. absorptive feeders - absorb organics from water ... sea urchins in polluted water (not reproductive) 7. scavengers - eat anything - plant, animal, alive, dead ... crabs, lobsters
b. hermaphroditic
b. Broadcast spawning
b. pelagic
ii. planktonic may be swimming or non swimming (75% benthic species) (MPL)
- different times (weeks or months usually) for each planktonic species to stay in the plankton before becoming benthic |
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II. The Tropics - shallow water benthic areas A. Basic tropical ecology: few environmental changes throughout the year (stable)
2. Although there is plenty of light, few plants grow because they are nutrient limited 3. Without a plant base, little else exists; a desert 4. Clear, blue water 5. Unique, very productive ecosystem = coral reef (but only 1% of tropical surface area)
2. Fringing reef along edge of island as planktonic coral larvae settle and grow 3. Barrier reef with a lagoon as island sinks and coral grows upward 4. Atoll as island sinks below sea level but coral continues to grow up forming a ring (usually the ring is broken) 5. If island sinks too fast and coral can not keep up, the whole thing sinks out of sight (seamounts, guyots)
2. May feed on small creatures using stinging cells on tentacles 3. Two types of coral
b. Hermatypic: reef builders; limited to the photic zone in the tropics; all have symbiotic zooxanthellae that they depend on for food=a mutualistic symbiosis
ii. clear water with little sediment (for light) iii. hard bottom for attachment of the coral animal iv. light for zooxanthellae in their tissues (restricted to photic zone)
- coral gives zooxanthellae CO2, fecal material for nutrients (N,P,K), and a place to live vi. reef builders are mainly colonial forms enlarging as coral heads with asexual reproduction year after year enlarging the coral heads
b. Fertilization is in the water c. Fertilized egg (zygote) develops into planula planktonic larvae d. Planula larvae sink and swim as part of the plankton (many eaten by filter feeders) e. Planula larvae eventually sink to the bottom, metamorphose into a polyp, and secrete a corallite to become the benthic coral animal f. grow as a solitary polyp -or- colonial polyps (=coral head)
b. Coral reefs also have a large amount of coralline algae and shells from snails and urchins adding to reef structure
b. living base as deep as 150m up to 50m: few species (light limited) (sponges) c. transition zone from 50m to 20m d. buttress zone from 20m to low tide: heavy surf, much oxygen, much light; hardy species live there, buttress and groove formations break up reef and may create tunnels from lagoon to reef wall (eroded by sediments from lagoon) (lots of coral) e. algal ridge on windward side (coraline algae): severe habitat - caps buttress zone near sea level, needs surf and high oxygen levels from crashing waves f. windward reef flat: lagoon area between algal ridge and island, calm; many species - patch reefs (micro-atolls) g. island h. leeward reef flat: calm, many species - patch reefs (micro-atolls) i. knoll (well below sea level) - on top of buttress zone on leeward side j. buttress zone on leeward side (also with possible buttress and groove formations) from knoll to 20m k. transition zone 20m to 50m l. living base from 50m to 150m (leeward) m. dead base below 150m
b. Biological = growth of coral and added CaCO3 (as volcanic islands sink, as sea level rises, as reef harmed by waves)
b. Biological = coral can't grow fast enough, animals eating reef (parrot fish, crown of thorns), bleaching (?may or may not create breakdown) * crown of thorns a major problem for coral reefs or a natural cycle?
ii. When population levels are normal there is a balance of nature iii. When populations of this starfish explode there are problems with the coral reefs and possibly with the islands that they protect iv. Throughout history there have been periodic population explosions (from sediment layers and ancient tales) v. This starfish hurts man (with spines) vi. 1960's population explosion may have been result of over collecting of predator snail, periodic historical reasons, man's addition of more runoff from land adding nutrients to water that favored larval starfish or other factors. Most areas of population explosion have settled down but is problematic on some reefs.
b. About 1,200 miles long c. Between 10 and 150 miles offshore d. Composed of many reefs (2,000 +)
b. Area of reef is not sinking (as in classic coral reefs on 'sinking' islands) c. History
b. As glaciers melted sea level rose, coming in over this flat plain, carrying coral larvae c. Many coral heads developed in this shallow area d. As this area deepened some of the coral heads grew upward and managed to keep up with rising sea level
b. Formed table reefs and ribbon reefs depending on the environment
2. Some animals destroy reefs (like crown of thorns and parrot fish) 3. Coral and other organisms build up reefs
2. Many unique things (clown fish and anemone host, sharks) 3. Some poisonous things can kill humans in this area
b. Sea Snakes c. Blue Ring Octopus (most poisonous octopus) d. Stonefish
b. Some areas for science c. Some areas for commercial fishing d. Some areas for oil drilling e. Some areas set aside for non entry f. Philosophy is to protect the reef so that it will be exactly the same in the years to come |
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III. Poles A. Six month daylight (2-3 month high productivity); six month dark
2. Antarctica: south, large continent, covered with ice; summer = December, January; (land surrounded by ocean)
b. ice rind (.5 cm and less) - traps salt c. pancake ice (1/2-1 meter pieces across, edges built up like lily pads) d. ice floe (solid)
2. hills and valleys of ice 3. thickness varies from summer to winter 4. submarines have gone under the ice
2. Ice may depress continent 3. 90% world's ice is in Antarctica 4. World's most violent weather in Antarctica
b. N. Atlantic Ice Patrol: protects boat traffic c. icebergs float east across N. Atlantic (N. Atlantic gyre) d. last approx. 2 years; move 5-15 miles/day, slow melting e. few icebergs in N. Pacific because of Bering Strait and Aleutian Islands
b. large icebergs - some as big as 100 miles across c. not much boat traffic, no patrol
2. Most research from Antarctic
b. Zonation in Antarctic
b. where bottom contacted: life dead (more than 2m along shoreline, down to about 15m)
2. mechanically grinding against bottom d. physical factors determine life forms
2. often rise and float to surface (ice less dense than water) and stick under sea ice 3. may carry organisms picked up from bottom (trap) 4. anemones are characteristic of this zone (they remain attached)
b. bottom changes from cobbly rocks (Zone II) to a sponge mat c. diverse community, stable, dominated by biological factors (predation) and not physical factors d. lots of creatures - sponges, starfish, worms, corals, etc.
2. Most extreme weather 3. Used to be farther north; moved south through tectonic movement 4. IGY (International Geophysical year) of 1950s put international attention on studying Earth. Antarctic was one focus - countries cooperated instead of conflicting for "science" 5. Antarctic Treaty: established after the IGY 1961, 30 year treaty (was up for review in 1991)
b. no land claims, international cooperation, no nuclear weapons c. concern with mining claims and pollution reviewed by all countries who are party to the Treaty - agreement to stop mining for time being because countries can't agree on terms for mining exploration or development d. major international problem if one country steps outside of the Treaty without unanimous agreement (like problems with ownership of deep sea floor) 7. Compromise agreement to extend treaty as is agreed upon in 1998 - add 50 year ban on mining (until 2048) 8. Exploration in polar areas is an extreme challenge
b. Exceptional explorers = Sir Ernest Shackleton, Scott/Amundsen race to the south pole, Peary/Cook and the north pole.
b. often in large groups, eaten by fish, seals, birds, whales c. baleen whales of Antarctic feed only on krill d. whaling has decreased number of baleen whales and krill population has increased e. with more krill, penguin population increases (penguins eat krill) f. krill are second step in the polar food chain (like copepods here) f. Japanese and Soviets make krill butter and krill cheese (how much can be harvested?)
b. cannot fly: excellent swimmers, use wings as flippers c. colonies found mostly in Antarctic but as far north as Galapagos in areas with cold current d. have short dense under feathers and thick hard outer feathers to protect them from the cold e. have thick layer of fat f. huddle in groups, rock back on their feet to keep heat in g. fish and krill eaters h. reproduction on land in rookeries often with over a million birds
b. females come next, usually go to same nest (and same male) as last year c. mating d. two eggs laid e. parents take turns incubating eggs with warm brood patch on their chest f. parents rotate, going to sea to feed and bathe every few hours g. chicks hatch h. parents take turns feeding chicks till they are ready to leave i. everyone leaves
b. after laying egg, females leave to feed c. males incubate egg on top of their feet under a flap of fatty skin, for 2 months (they do not feed) d. when chicks hatch, females return to help care for them and males leave to feed e. in six months the young can care for themselves f. emperor penguins are the largest penguin (up to four feet tall and 100 pounds)
b. was not hunted by man because its fur usually damaged by its predator (the leopard seal) c. feeds on krill (fancy teeth that form a seive) 5. Walrus: Arctic only, North Pacific and North Atlantic
b. in summer rests on shore c. very large animals d. only seal with tusks: upper canine teeth can be 39 inches
2. uses tusks as hooks to climb on ice; chops hole in ice and hangs on ice to breathe
2. when clam siphon is seen they swish their heads in the bottom making a depression, then hydraulically jet water in and out of their mouth through their tongue to drill a hole down to clam 3. clam is sucked out of shell, leaving shell and hard outer covering of siphon intact 4. shell is dropped by hole (empty and with skin of siphon inside out)
2. babies cared for by parents for over two years
b. black skin under white fur holds heat, thick blubber insulates too c. nomads (loners) usually d. babies (often twins) born in winter ice den with mom e. babies stay with mom for two years while learning to feed on seals and other marine mammals f. carnivores on seals and other animals IV. Deep-Sea
2. cold and constant temperature (-2 to +5 degrees C) 3. great pressures 4. areas of abyssal plains, oceanic ridges and rises, trench systems 5. hard to study - high costs, hard to keep organisms alive from this area, observations are dangerous
2. Numerous species of infaunal worms remain because they never get a chance to compete due to their 'cropper' - sea cucumbers 3. Most species still rely on the surface waters for their food (regular trophic pyramid that is photosynthetic based) as a 'rain' of organic material drifting down:
b. marine snow (mucus and jelly houses covered with bacteria) c. fecal pellets d. large dead organisms (like 'whale falls')
2. migrates to surface at night (to feed) 3. migrates to depth in day (to hide) 4. composed of small fish and crustaceans
b. attract mate c. just to 'see' d. to frighten predators
b. sharp teeth c. distensible stomach d. luminescent lure e. black lined stomach (to keep bioluminescent prey from showing)
b. male parasitic on female
b. sharp teeth c. distensible stomach d. black lined stomach e. bioluminescent lure f. parasitic male
b. plate boundaries c. rift valleys of oceanic ridges and rises
- minerals precipitate out near ocean bottom and form 'chimneys' (up to 40 feet tall)
* chimneys choke off in time and water vents elsewhere
- chemosynthetic, capable of producing 'cell food' (for cellular respiration) from minerals in the water - live all over vent areas as mats and in the water
- mussels - with red bodies
- octopus
- grow in large concentrations - white flexible tubes and deep red body - no gut - rely on symbiotic bacteria for food (similar to relationship of reef-building corals with their zooxanthellae) - one of the fastest growing invertebrate animals (up to 3-4 feet per year) |
| © 2001 Genny Anderson (Revised 3 November 2008) |
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