Chapter 13 - Life in the Ocean

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Chapter 13 - Life in the Ocean
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characteristics of life

• require energy
• can capture, store, and transmit
• ultimately from sun, earth heat or chemical
  reactions
• highly ordered
• reproduce
• change through time
• adapt to environment

3
capture and flow of energy

• cell
• energy capture
• from sunlight
• from food

4
capture and flow of energy

• trophic relationships
• autotrophs
• primary producers
• convert energy to food
• heterotrophs
• consumers decomposers
• consume food produced by others

5
capture and flow of energy

• depicting trophic relationships
• trophic levels
• food chain - simple
• food web - complex
• trophic pyramid

6
physical (abiotic) factors

• transparency
• dissolved nutrients
• temperature
• exothermic/poiklilothermic/cold-blooded
• endothermic/homeothermic/warm-blooded
• salinity
• extremes - 6 to 30 ppt

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physical (abiotic) factors

• dissolved gases
• cold water holds more
• oxygen
• not easily dissolved
• avg - 6 ml/l
• plants use at night
• large blooms can result in low oxygen levels esp.
  in closed basins

• CO2
• easily dissolved
• avg - 50 ml/l
• 60x that of the atmo.
• deep water has the most
• consumers
• downwelling cold water
• dissolving organisms

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physical (abiotic) factors

• pH
• avg seawater is about 8
• below CCD
• about 7.6
• lowered by CO2

• hydrostatic pressure
• animals equalize inside and outside pressure
• effects of high pressure
• gasses more soluble
• enzymes dont work
• metabolic rates higher

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physical (abiotic) factors

• factor interplay
• factors are interlinked
• also influenced by life

10
biotic factors

• diffusion
• tendancy of a concentration of a substance to
  even out
• from high concentration to low concentration
• faster in warm water
• across membranes

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biotic factors

• osmosis
• diffusion of water through a semi-permeable
  membrane
• diffusion from high concentration of water to low
  concentration of water

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biotic factors - osmosis

• isotonic
• concentration inside concentration outside
• Some animals in ocean
• hypotonic
• concentration of salts inside gt concentration of
  salts outside
• concentration of water inside lt concentration of
  water outside
• marine animal in fresh water
• animal gains water

• hypertonic
• concentration of salts inside lt concentration of
  salts outside
• concentration of water inside gt concentration of
  water outside
• animal in Great Salt Lake
• freshwater and some marine animal in ocean
• animal loses water

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biotic factors - osmosis

• examples and exceptions
• animal with salt concentration less than seawater
  drinks seawater
• cells lose water to even concentration in the
  blood
• animal dehydrates
• fish (?evolved in fresh water?)
• internal salinity 1/3 that of the ocean
• lose water through gills
• solution drink seawater and excrete salts
• seabirds - excrete salt through glands in skull
• salmon - large kidneys remove excess water during
  freshwater phase of life, able to recover salts
  from food and urine

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biotic factors

• active transport
• movement of dissolved substances from low
  concentration to high concentration
• requires energy

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biotic factors

• surface-to-volume ratio
• smaller cells are more efficient at transport and
  diffusion
• spherical cell
• surface area increases with the square of its
  diameter
• volume increases with the cube of its diameter
• cells divide to maintain proper ratio

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biotic factors

• gravity and bouyancy
• density differences
• water 1 g/cm3
• seawater 1.025 g/cm3
• marine fish 1.07 g/cm3

• adaptations
• gas bladders
• strong muscles
• less dense solutions in body ie.NH3Cl
• food stored in waxes and oils

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biotic factors

• viscosity and movement
• reduce drag to swim
• increase drag to stop sinking
• large surface area to volume ratio
• ornamentation
• warm water less viscous than cold
• water movement
• use of currents to move

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classification of environment

• light
• photic
• aphotic

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classification of environment

• location
• pelagic - open water
• neritic - shallow
• oceanic - deep water
• epipelagic
• mesopelagic
• bathypelagic
• abyssopelagic

• benthic
• supralittoral - above the tidal range
• littoral
• sublittoral
• inner - near shore
• outer - to the edge of the shelf
• bathyal
• abyssal
• Hadal

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Marine Communities

• organization
• organism
• population
• community
• ecosystem
• ecosphere

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Marine Communities

• organisms place
• habitat - organisms physical location within a
  community
• niche - organisms place (duties) within a habitat

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Marine Communities

• physical and biological factors
• examples
• temp, pressure, salinity
• crowding, predation, grazing, parasitism, shading
  from light, waste substances, competition for
  resources (food, oxygen, nutrients)
• limiting factors
• limits chances for success
• different for different animals
• steno- tolerant of a narrow range
• eury- tolerant of a wide range

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Marine Communities competition

• within a species
• between species
• overlapping niches
• results
• survival and reproduction of the most successful
• less successful moves or dies off
• growth rate and carrying capacity

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distribution of organisms

• population density
• species diversity
• distribution patterns
• random
• rare
• same conditions must exist throughout the
  community
• clustered
• most common
• individuals of a spies cluster near optimal
  conditions
• uniform - vary rare
• motile vs sessile

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species interaction

• trophic
• symbiotic
• often species specific
• types
• mutualism
• commensalism - symbiont benefits, host is not
  harmed
• parasitism - host is harmed
• dependencies
• one species depends on another (for food) but
  they do not live in extended contact

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change in marine communities

• usually slow
• marine conditions rarely change rapidly
• some rapid processes - volcanoes, earthquakes,
  landslides
• climax community
• stable
• long established
• reestablished through succession
• may be slightly different

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evolution

• development of complex life forms
• through mutation and selection
• natural selection - survival of the
• fittest (for a niche)
• luckiest
• combination
• species
• reproductively isolated group of living organisms
• speciation extinction
• divergent convergent evolution
• phyletic gradualism punctuated equilibrium

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Organic evolution observations

• sedimentary rocks
• deposited in layers
• oldest layers are on the bottom
• layers may be correlated with other sedimentary
  layers
• fossil record
• oldest rocks have only simple fossils
• younger rocks have more organisms similar to
  those living today (at levels from species to
  kingdom)
• fossils record includes appearances and
  extinctions of many species

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Organic evolution observations

• geographic distribution of organisms
• many organisms are similar but unique
• they are confined to specific areas (islands,
  continents, water bodies)
• includes modern and fossil organisms
• distribution has changed through time

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Organic evolution observations

• anatomy
• cell structure is similar in all living organisms
• embryology - embryos of mammals, birds, and
  reptiles are very similar
• homologus organs - similar organs, different
  functions
• vestigal organs - no purpose in one, purpose in
  another

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Organic evolution observations

• genetics
• structure of DNA and RNA is the same in all
  living organisms
• similarity in genetic code varies between
  organisms (some organisms are more similar than
  others)

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Organic evolution conclusions

• the characteristics of populations of living
  organisms have changed through time
• life has become more complex
• life has become more diverse
• this is excepted as a factual observation
• all life is related

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Natural selection observations

• populations of organisms display a variety of
  characteristics
• characteristics may be useful, not useful, or
  detrimental
• the variety is reflected in an organisms genes
• mutations
• produced by random alteration of genes and passed
  to offspring during reproduction
• provides variety

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Natural selection observations

• artificial selection
• domesticated plants and animals can be bred to
  favor certain characteristics
• populations of wild and domestic plants and
  animals develop characteristics that favor their
  survival

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Natural selection observations

• the natural environment
• organisms with favorable characteristics for
  their niche are more likely to thrive and
  reproduce
• organisms with unfavorable characteristics are
  less likely to thrive and reproduce
• a new niche or stress on an existing niche will
  enhance selection

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Natural selection conclusion

• the natural environment provides conditions that
  result in evolution through the process of
  natural selection

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Evolutionary trends

• speciation extinction
• divergent convergent evolution
• phyletic gradualism punctuated equilibrium

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Natural selection speciation

• a population has a gene pool
• members of the population interbreed
• the population may become isolated from others of
  a species
• development of niches resource partitioning
• migration
• development of physical barriers
• populations may be selected
• by stress
• by opportunity
• isolation may result in genetic divergence

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Natural selection extinction

• stress on limiting factors reduce or destroy a
  population
• evolution into subsequent species
  (pseudo-extinction)

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Phylogeny

• relationships between organisms can be determined
  using
• genetics
• anatomy physiology
• Fossils

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Evolutionary trends

• speciation extinction
• divergent convergent evolution
• phyletic gradualism punctuated equilibrium

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primary productivity

• photo- and chemo-synthesis

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primary productivity

• measurement
• grams of carbon bound (appx 10 of producers
  mass)
• per square meter of ocean surface
• per year
• sampling
• measure oxygen produced in a suspended set of
  bottles
• follow carbon through the process (in the lab)

• breakdown
• phytoplankton - 90-98
• seaweeds - 2-10
• chemosynthesis - 1
• production
• avg - 75 to 150 g(C)/m2/yr

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primary productivity - limiting factors

• water - plenty
• CO2 - plenty
• nutrients
• non-conservative - change with bio activity
• nitrates, phosphates, silicates
• lost to organisms then to the depths
• replaced by runoff, upwelling, atmosphere

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primary productivity - limiting factors

• light
• quantity - can have too much or too little
• quality - color
• red and violet are best absorbed by green
• quantity and quality vary with
• depth
• red is absorbed near the surface
• concentration of organisms
• concentration of sediment
• adaptations accessory pigments - absorb light
  for chlorophyll

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Plankton

• floaters and weak swimmers
• producers and consumers
• collection and study
• plankton nets
• microscopic

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phytoplankton

• autotrophs
• depth of greatest productivity
• 20 m at noon
• 5-10 m daily
• compensation depth
• energy consumed energy produced
• go below - die

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global distribution of productivity

• polar
• low sun angle
• dark winter, long days in summer
• upwelling
• seasonal blooms
• temperate and subpolar
• good mix of light and nutrients
• seasonal

• near cont. shelves
• upwelling runoff
• 1 g(C)/m2/day
• tropics
• much sunlight CO2
• low nutrients
• 30 g(C)/m2/yr
• reefs - tightly cycle nutrient through the reef -
  more productive

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phytoplankton - dinoflagellates

• swim with whirling flagella
• reproduce through fission
• nutrients can causes blooms
• red tides
• some are bioluminescent

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phytoplankton - diatoms

• SiO2 shell (frustule)
• two perforated valves
• highly energy efficient
• store energy as oils - for floating
• some are benthic
• reproduction
• fission - generate new shell inside the parent
• smaller with each generation
• size gets too small
• sexually reproduce new offspring with no shell

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phytoplankton - nanoplankton

• very small
• coccolithopores - carbonate shells made of plates
  - chalk
• silicoflagellates

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Plants

• vascular
• sap
• transport substances through vessels
• non-vascular
• algae
• seaweed

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Plant structure

• problems
• shock
• abrasion
• water drag
• covered with a mucus-like substance
• lubricates
• retards drying
• deters grazers

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Plant structure

• fluids
• algae - isotonic
• angiosperms - hypotonic
• thermal stress - heat
• speeds metabolic rate
• may not have enough oxygen available at night
• damages pigments

• anchorage/substrate
• algae - solid base
• rooted plants - unconsolidated base
• depth
• less than 2 of ocean floor is shallow enough

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Plants - seaweeds

• thallus (plant)
• blade
• stipe
• gas bladder
• holdfast
• reproduction
• alternate sexual and asexual
• zonation due to depth other factors

• classification
• chlorophytes - green
• phaeophytes
• tan or brown
• kelp
• some are free-foating
• rhodophytes
• red
• most of worlds seaweeds

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Plants - angiosperms

• flowering plants
• moved from land to water
• live at the surface
• structure
• leaves
• stem
• roots extract nutrients from the substrate
• types
• sea grasses
• mangroves

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animals - classification

• artificial systems
• exterior similarities
• functions, colors, etc.
• natural systems
• originally based on structural and biochemical
  similarities
• now based on DNA
• Linnaeus
• K, P, sub-P, C, O, F, G, S
• scientific name
• genus-species
• permanent
• unchanging words - usually Latin
• internationally monitored

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animals - key events

• oxygen in the ocean and atmosphere
• 2 BYA - 1 oxygen
• 400 MYA - 20 oxygen
• thanks to photsynthetic oxygen
• metazoans - multi-cellular
• soft-bodies - first appx. 600 MYA
• Ediacara Hills, Aust.
• bizzare
• segmented worms
• shelled animals - first appx. 550 MYA
• arthropods - trilobites

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zooplankton

• consumers
• most animal groups represented
• create oxygen minimum zone just below the
  well-lighted surface zone
• size
• most less than 1 cm
• some gt 1 cm - macroplankton
• life cycle
• holoplankton - spend entire lives as plankton
• meroplankton - spend part of life as plankton

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Protista

• (zooplankton)
• foraminifera
• amoeba-like
• carbonate shells
• radiolarians
• amoeba-like
• spike-like pseudopods
• amoebas

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P. Porifera

• sponges
• suspension feeders
• structure
• collar cells - capture and digest
• amoeboid cells - transport food
• surface cells - protect
• spicules and spongin - support

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P. Cnidaria

• jellyfish, anemones, corals
• radial symmetry
• structure
• stinging cells - capture food, repel predators
• some nerve cells
• mouth/anus
• digestive cavity
• form - polyp or medusa

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P. Platyhelminthes

• flat worms - tape worms
• parasitic free-living
• bilateral symmetry
• structure
• mouth/anus
• nervous system, brian, eyespots
• no resp or excret systems

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P. Nematoda

• roundworms
• structure
• flow-through digestive system
• important sediment-feeders

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P. Annelida

• segmented worms
• structure
• head
• flow-through digest
• segment with circ, excret, nerv, musc, repro
  systems

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P. Mollusca

• characteristics
• soft body
• most have a shell
• bilateral symmetry
• flow-through digest
• circ, excret, nerv, musc, repro systems
• classes
• polyplacophora
• gastropoda
• bivalvia
• cephalopoda

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P. Arthropoda

• characteristics
• exoskeleton
• must molt to grow
• striated muscle
• articulated
• classes
• insecta - poorly represented at sea
• Crustacea
• crabs, krill, lobsters, barnacles
• copepods
• zooplankton
• crustaceans
• 70 of animals

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P. Echinodermata

• five-way symmetry
• start as bilaterally symmetrical
• classes
• asteroidea - sea stars
• tube feet
• water vascular system - locomotion feeding
• ophiuroidea - brittle stars
• widely distributed
• echinoidea - sea urchins and sand dollars
• holothuriodea - sea cucumbers

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other Phyla

• Bryozoa - important ancient reef builders
• Brachiopoda - very important bivalved shell
  animals in the Paleozoic
• Hemichordata - important transitional phyla

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P. Chordata

• invert
• tunicates - suspension feeders
• lancelets
• example amphioxis
• transitional species

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Fish (vertebrates)

• agantha
• jawless fishes
• lampreys, hagfish
• condrichthyes
• cartiliginous fishes
• sharks, skates, rays, chimera

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Fish (vertebrates)

• osteichthyes - bony fishes
• shape - antidrag
• movement - eel-like or hinged-tail
• maintenance of level - swimming or gas bladder
• gas exchange - gill membranes
• osmotic problems (advanced fish) - hypotonic
  (lose water) - drink water excrete salt -
  conservative kidneys
• feeding defense - sight, hearing (inc. lateral
  line), coloration (cryptic coloring and
  top/bottom counter-shading), schooling

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amphibians

• none exclusively marine
• adapted to land and freshwater
• permeable skin

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reptiles

• characterisics
• lungs
• scales
• salt glands
• groups
• sea turtles
• 8 species
• all endangered
• streamlined shells, flippered feet
• marine crocodiles - one species, in tropical W
  Pacific
• marine lizards - only Galapagos marine iguana
• sea snakes
• 50 known species
• highly venomous

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birds

• sea birds - 270 species
• warm-blooded
• characteristics
• salt-excreting glands
• avoid land except for breeding
• obtain almost all food from the sea
• groups
• Tubenoses - albatrosses petrels
• pelicans et. al.
• gulls puffins
• penguins

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mammals

• characteristics of marine mammals
• streamlined
• warm-blooded
• resp. system modified to collect and retain large
  quantities of oxygen

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Mammal orders

• cetacea
• evolved from early ungulates (horses and sheep)
• horizontal tail flukes that move up and down
• toothed whales - orca, dolphins, porpoises - echo
  location
• baleen whales - filter-feeders
• carnivora
• pinnipedia - seals, sea lions, walruses
• fissipedia - sea otters, polar bears
• sirenia - mantees

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rocky intertidal

• problems
• wave shock
• wetting and drying
• land and water predators
• daily and annual sediment movement
• benefits
• lots of food
• stirred up food and gasses
• many niches
• very diverse
• zoned

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sand and cobble beaches

• problems
• as above
• loose bottom
• moving sand
• abrasive
• mixed with food
• much less habitable

80
salt marshes and estuaries

• salinity can vary greatly
• salty - brackish - fresh
• vertically and horizontally
• leads to complex zonation
• isolation at low tide
• raises salinity
• raises temp
• estuaries
• highly diverse and productive
• marine nurseries

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open ocean

• top 200 meters
• 83 of biomass
• almost all productivity
• deep scattering layer
• top of the dark zone
• move up to feed at night
• can see shadows of prey above
• may have light organs to mask own shadow
• bathypelagic
• little food available
• bizarre animals
• little known

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deep sea floor

• dark
• cold
• slightly hyper saline
• weak currents
• organisms
• blind
• many scavangers, some predators
• low metabolic rate
• may eat less than once per year
• may live to be 100
• large
• fragile

83
vent communities

• discovered in 1977
• chemosynthetic producers
• superhot water (350EC)
• some animals (tube worms, clams) house
  chemosynthetic bacteria for food

84
reefs

• materials are tightly cycled
• corals
• other animals
• types
• fringing
• barrier
• atolls