Transcript Chapter 12: Marine life and the marine environment

CHAPTER
12 Marine
Life and the
Marine
Environment
Fig. 12.5
Overview
More than 250,000 identified marine species
 Most live in sunlit surface seawater
 Species success depends on ability to
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 Find food
 Avoid predation
 Reproduce
 Cope with physical barriers to movement
Classification of living organisms
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Three domains of Life
 Archaea
 Prokaryotic, includes
“extremophile”
bacteria
 Bacteria
 Prokaryotic, includes
what used to be in
Kingdom Monera
 Eukarya
 Eukaryotic cells
 Includes Protists,
Fungi, Plants, and
Animals
Archaea
Bacteria - Prokaryotic cells
 Cell wall differs from those bacteria
in Domain Bacteria
 Includes extremophile bacteria
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○ Acidophiles
○ Halophiles
○ Thermophiles
○ Etc.
○ These bacteria are found to
chemosynthesize in hydrothermal vents
Bacteria
Bacteria – prokaryotic cells
 Cell wall made of peptidoglycan
 Includes Staphylococcus, Bacillus,
Vibrio, Pseudomonas, etc.
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○ Only a very small % of bacteria are
pathogenic
○ Bacteria are very important in things like
nitrogen cycle, decomposition, food making,
etc.
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Cyanobacteria are photosynthetic
bacteria
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Archaea and Bacteria
○ Most numerous organisms on Earth
- Think about how much bacteria lives just on you
- Viruses are thought to out number bacteria but
if you are just talking about “live” organisms
then bacteria are the most numerous
○ Simplest of organisms
- But, can live in every thinkable habitat, even
those once thought to be unsuitable to life
Eukarya - Protists
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Algae
○ Photosynthetic
○ Can be unicellular, colonial, or multicellular
- Multicellular - “seaweed” – kelp, sargassum, sea
lettuce
- Unicellular – phytoplankton, produce majority of
oxygen in atmosphere, can cause red tides
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Protozoans
○ Heterotrophic
○ Unicellular
○ Amoeba, paramecium
Eukarya - Fungi
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Heterotrophic
○ Secrete enzymes and absorb nutrition
○ Since they are heterotrophic, they are more
closely related to animals than to plants
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Multicellular (mold) or unicellular (yeast)
Eukarya - Plants
Autotrophic, multicellular
 Many plant species cannot tolerate saltwater
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○ Very few species grow in/near ocean
 Sea grasses
 Mangroves
 Dune plants
Eukarya - Animals
Heterotrophic, multicellular, have
motility at some point in life cycle
 Wide variety
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○ From simplest of animals (sponges) to most
complex (mammals)
Viruses
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Acellular entities
○ Are they “alive”???
○ Do not have the machinery for life
processes, have to take over host cell
○ The ultimate “parasites”
Taxonomic classification
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Systemized classification of organisms
Kingdom
Phylum
Class
Order
Family
Genus
Species
 Fundamental unit
 Population of genetically similar, interbreeding
individuals
Classification by habitat and
mobility
Plankton (floaters)
 Nekton (swimmers)
 Benthos (bottom dwellers)
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http://i.ehow.com/images/GlobalPhoto/Articles/2110315/icephytoplankton-main_Full.jpg
Plankton
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Most biomass on Earth consists of plankton
Phytoplankton
 Microscopic algae, Autotrophic
Zooplankton
 Heterotrophic
 Protozoans, tiny animals, larvae of larger
animals
Bacterioplankton
Virioplankton
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Viruses that infect bacteria and eukaryotic cells
Plankton
o
Holoplankton
o
o
o
Meroplankton
o
o
o
o
Part of lives as plankton
Juvenile or larval stages in the plankton
Examples are lobsters, some fish species, etc.
Macroplankton
o
o
Entire lives as plankton
Example is algae, protozoans, small microscopic
animals
Large floaters such as jellyfish or Sargassum
Picoplankton
o
Very small floaters such as bacterioplankton
Nekton
Independent
swimmers
 Most adult fish
and squid
 Marine reptiles
 Marine mammals
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Fig. 12.3
Benthos
Epifauna live on surface
of sea floor
 Infauna live buried in
sediments
 Nektobenthos swim or
crawl through water
above seafloor
 Most abundant in
shallower water
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Hydrothermal vent
biocommunities
Abundant and large
deep-ocean benthos
 Discovered in 1977
 Associated with hot
vents
 Bacteria-like
archaeon produce
food using heat and
chemicals
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○ “chemosynthesis
instead of
photosynthesis”
http://bioinfo.bact.wisc.edu/themicrobialworld/Hydrothermal_vent.jpg
Number of marine species
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More land species than marine species
 Ocean relatively uniform conditions
 Therefore, less adaptation required, less speciation
 Don’t get this fact confused with # of individual organisms
 There are fewer different species in the ocean but greater #
 Majority of life on Earth lives in the ocean!!
 Diversity in the ocean is high, also – think about different types of fish
(seahorses to sharks, for example)
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Marine species overwhelmingly benthic rather than
pelagic
○ Most of these will be in shallow coastal benthic areas
Adaptations of marine organisms
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Physical support
 Buoyancy
 How to resist sinking
 Different support
structures in cold (fewer)
rather than warm (more
appendages) seawater
 Smaller size
Ciliate
Chaining tunicate
http://www.solaster-mb.org/mb/images
http://science.discovery.com/convergence/scienceofdeep/photos/gallery
Adaptations to marine life
Appendages to increase
surface area
 Oil in micro-organisms to
increase buoyancy
○ Over-time, if these
organisms die and sink
to bottom
○ Can become offshore
oil deposits
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Fish egg with oil droplet
Fig. 12.9
http://www.rpgroup.caltech.edu/~natsirt/aph162/webpages/dylanandco/lab1/image
Adaptations to marine life
Streamlining important for
larger organisms
 Less resistance to fluid flow
 Flattened body
 Tapering back end –
fusiform
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http://www.wissenschaft-online.de/sixcms/media.php/591
Adaptations to marine life
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Narrow range temperature in oceans
Smaller variations (daily, seasonally, annually)
 Remember it takes longer to change water temp than air
temp
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Deep ocean nearly isothermal
Fig. 12.11
Adaptations to marine life
 Cold-
versus warm-water species
 Smaller in cooler seawater
 More appendages in warmer seawater
 Tropical organisms grow faster, live
shorter, reproduce more often
 More species in warmer seawater
 More biomass in cooler seawater
(upwelling)
Adaptations to marine life
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Stenothermal
 Organisms withstand small variation in
temperature
 Typically live in open ocean
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Eurythermal
 Organisms withstand large variation in
temperature
 Typically live in coastal waters
Adaptations to marine life
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Stenohaline
 Organisms withstand only small variation in
salinity
 Typically live in open ocean
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Euryhaline
 Organisms withstand large variation in salinity
 Typically live in coastal waters, e.g., estuaries
Adaptations to marine life
Extracting minerals
from seawater
 High concentration
to low concentration
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 Diffusion
 Cell membrane
permeable to
nutrients, for
example
 Waste passes from
cell to ocean
Fig. 12.12
Adaptations to marine life
Osmotic pressure
 Less concentrated
to more
concentrated
solutions
 Isotonic
 Hypertonic
 Hypotonic
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Fig. 12.13
Adaptations to marine life
Dissolved gases
 Animals extract dissolved oxygen (O2) from
seawater through gills
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Fig. 12.15
Adaptations to marine life
Water’s transparency
 Many marine organisms see well
 Some marine organisms are nearly
transparent to avoid predation
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Adaptations to marine life
Camouflage through color patterns
 Countershading
 Disruptive coloring
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http://www.youtube.com/watch?v=PmDTtkZl
MwM
http://theplasticocean.blogspot.com/2012_07_01_archive.html
Adaptations to marine life
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Water pressure
 Increases about 1 atmosphere (1 kg/cm2) with
every 10 m (33 ft) deeper
 Many marine organisms do not have inner air
pockets
 Collapsible rib cage (e.g., sperm whale)
Main divisions of the marine
environment
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Pelagic (open sea)
 Neritic (< 200 m) and oceanic
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Benthic (sea floor)
 Subneritic and suboceanic
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Another classification scheme:
 Euphotic
 Disphotic
 Aphotic
Pelagic environments
Epipelagic
 Mesopelagic
 Bathypelagic
 Abyssopelagic
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Fig. 12.19
Daily Movement of the Deep
Scattering Layer
Benthic environments
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Supralittoral
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Transition from land to seafloor
Subneritic (under neritic)
 Littoral
(intertidal zone)
 Sublittoral
(shallow tidal
zone to 200m)
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Suboceanic
 Bathyal
(200-4,000m)
 Abyssal
(4000-6000m)
 Hadal
(below 6000m)
Fig. 12.19
Misconceptions
Ocean Literacy Principles
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3.e - The ocean dominates the Earth’s carbon cycle. Half the primary productivity on Earth
takes place in the sunlit layers of the ocean and the ocean absorbs roughly half of all
carbon dioxide added to the atmosphere.
5.a - Ocean life ranges in size from the smallest virus to the largest animal that has lived
on Earth, the blue whale.
5.b - Most life in the ocean exists as microbes. Microbes are the most important primary
producers in the ocean. Not only are they the most abundant life form in the ocean, they
have extremely fast growth rates and life cycles.
5.e - The ocean is three-dimensional, offering vast living space and diverse habitats from
the surface through the water column to the seafloor. Most of the living space on Earth is
in the ocean.
5.f - Ocean habitats are defined by environmental factors. Due to interactions of abiotic
factors such as salinity, temperature, oxygen, pH, light, nutrients, pressure, substrate and
circulation, ocean life is not evenly distributed temporally or spatially, i.e., it is “patchy”.
Some regions of the ocean support more diverse and abundant life than anywhere on
Earth, while much of the ocean is considered a desert.
5.g - There are deep ocean ecosystems that are independent of energy from sunlight and
photosynthetic organisms. Hydrothermal vents, submarine hot springs, methane cold
seeps, and whale falls rely only on chemical energy and chemosynthetic organisms to
support life.
Sunshine State Standards
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SC.6.L.14.3 - Recognize and explore how cells of all organisms undergo similar
processes to maintain homeostasis, including extracting energy from food, getting
rid of waste, and reproducing.
SC.7.L.17.3 - Describe and investigate various limiting factors in the local
ecosystem and their impact on native populations, including food, shelter, water,
space, disease, parasitism, predation, and nesting sites.
SC.912.L.15.5 - Explain the reasons for changes in how organisms are classified.
SC.912.L.15.6 - Discuss distinguishing characteristics of the domains and
kingdoms of living organisms.
SC.912.L.17.2 - Explain the general distribution of life in aquatic systems as a
function of chemistry, geography, light, depth, salinity, and temperature.
SC.912.L.17.7 - Characterize the biotic and abiotic components that define
freshwater systems, marine systems and terrestrial systems.