It takes a village

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It takes a village Marine Communities
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One characteristic of life is that it is
organized
Life has a hierarchical organization
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Some terminology..
A population is a group of the same species
A community is a group of populations sharing the
same space.
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Biodiversity range of species present
Which picture shows more biodiversity?
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When populations share space, there
is competition for resources
Food, light, space..
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Competition can occur between members
of the same species
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It is better to be able to adapt to a wide range
of environments than a narrow one
22-27 C max
1-40 C max, 12-30 C preferred
Which has a better chance of survival?
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Scarcity of resources, disease, competition limit
population growth when it reaches the
carrying capacity of the environment.
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gt50 of all known organisms live in a symbiotic
relationship (the lives of two or more organisms
are linked and they live together)
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Parasitism (one organism takes nutrients away
from host, hurting the host) is the common form
of symbiosis.
Lamprey on fish
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Lets take a trip through some of the marine
communities..
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Rocky Intertidal Communities
Intertidal means between high and low tide
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Rocky Intertidal Communities
What are the challenges to living here?
Need rugged protection or ability to go with flow
Waves!
Dry part of the time
Move!, closed shells, live in tidal pools
Solar heating
Get in shade or die.
Tolerate a wide range of salinities
Fresh water input
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Rocky Intertidal Communities
Benefits?
LOTS of food!
Nutrients from shore for plankton
Dissolved gases from wave action
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How many phyla do you see?
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Rocky Intertidal Communities
Rocky intertidal communities are
densely populated and rich in biodiversity!
Many habitats and ecological niches (the
relationship between the organism and its place
in the habitat)
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Beach Communities
Beaches are inhospitable to most organisms!
Sand is abrasive, especially to small ones
Rocks pound you.
Survival - be microscopic or burrow
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Salt Marshes/Estuaries
Muddy. Brackish water (salt fresh mix)
Benefits?
Challenges?
HIGH primary productivity (sea grasses,
mangroves)
Variable salinity
Ebb/flow of tides
Good nutrients
Good mixing
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Salt Marshes/Estuaries
Good places for burrowers, skitterers -- clams,
worms, crabs
Many species use them as juvenile nurseries -
mostly slow water
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Coral Reef Communities
Benefits?
Challenges?
High wave energy
Good home for other species - 25 of all fish
species found in reefs
Sensitive enviromental indicators
Warm,clear water Narrow range of pH and
salinity
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Coral Reef Communities
Tiny creatures deposit CaCO3 (calcium
carbonate) structures to protect others from
waves, predators.
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How many phyla do you see?
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More than 1 million species predicted for reef
systems!
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83 of oceans biomass in upper 200 m
What about the rest of the ocean?
Constraints
No light so no photosynthesis no primary
productivity except on bottom
Pressure!
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Now for the weird and bizarre!
Deep scattering layer clustering of fishes,
squid, others just below maximum depth of light
penetration
Life on fallout from layer above AND each other!
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Adjustments to habitat
Some organisms are bioluminescent (create light
via chemical reactions)
Need to find mates, attract food!
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Or eat something larger than yourself!
Gulper eel may eat only 1-2X per year!
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Deep Sea Floor Communities
Challenges?
Always cold (2-4C)
High pressure (400X at surface)
Adaptations?
VERY sensitive to movement of prey
water motions from meters away
chemical sensors from kilometers away
Slow movement, slow metabolism
Long lived
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Deep Sea Floor Communities
Delicate skeletons -- below calcium
carbonate compensate depth, so not much Ca.
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Insights to Early Life Communities
Deep rock communities and hydrothermal vent
communities are thought to be similar to
the communities of earliest life
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Deep Rock Communities
Single celled organisms (bacteria, archaea) found
up to 800 m below surface of ocean IN ROCK!
Chemosynthesis source of
primary productivity
Extremophiles capable of living in
hot and/or
saline environs
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Extremophiles may give us clues to life on
Mars and other planets.
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Extremophiles are being used for environmental
clean-up
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Hydrothermal Vent Communities
High temperatures (350C)
High levels of hydrogen sulfide H2S
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Water from circulation at ocean ridges
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Worms, clams live in symbiosis with
chemosynthetic bacteria IN organisms.