Transcript (habitats/ecology/zones), lecture 2

Marine Habitats
• What is a marine habitat?
• Where do we find (different) marine
habitats?
• Water quality parameters that effect life?
• Who lives there (marine organisms and
their necessary adaptations)?
• Marine Ecology (intro.)
Ocean Habitats
•There are two major marine provinces:
–the benthic (bottom)
–the pelagic (water column)
• The pelagic environment is
• The benthic
divided broadly into the:
environment is divided
– neritic zone
by depth into the:
– intertidal (littoral) zone
– subtidal (sublittoral)
zone
– Epi, Meso, Bathyal &
Abyssal zone(s)
– (other) hadal zone
– oceanic zone
• More specifically into the:
–
–
–
–
–
Epipelagic zone
Mesopelagic zone
Bathypelagic zone
Abyssalpelagic zone
hadalpelagic zone
Figure 10.12
Marine zones
• PELAGIC ZONES: “water column”
(1) Oceanic – beyond shelf break
(2) Neritic – area that lies over shelf
Then this is divided vertically by depth:
(1) Epipelagic: shallowest (w/ lots of light)
(2) Mesopelagic: below (minimal light, no primary
production, “twilight zone”)
(3) Bathypelagic, Abyssopelagic, Hadopelagic: at bottom
(no light, “deep sea environment”)
ORGANISMS THAT LIVE IN PELAGIC ZONE ARE IN
WATER COLUMN ONLY = PLANKTON and NEKTON
Each zone is different
•
•
•
•
Light
Temperature
Salinity
Other: Turbidity/Water Clarity/Sedimentation,
Dissolved Gases (such as Carbon Dioxide), pH
(ocean acidification), Pressure etc.
These are considered “Water Quality” parameters (as
they effect the quality of the seawater that serves
as “home” for so many marine organisms)
What does this mean to MARINE LIFE?
• Light effects WHERE plants and animals
can live.
• Temperature effects WHERE plants and
animals can live.
• Salinity effects WHERE plants and animals
can live.
• …WATER QUALITY PARAMETERS
determine the “health” of the environment
marine organisms live in.
• Light Differences
• The ocean can also be divided into zones
based upon depth of light penetration.
– The photic zone is the depth where light is
sufficient for photosynthesis.
– The dysphotic zone is where illumination is too
weak for photosynthesis.
– The aphotic zone receives no light from the
surface because it is all absorbed by the water
above.
• In the dysphotic zone, seasonal effects are minimal –
conditions tend to be uniform most of the year.
• The aphotic zone is permanently dark and cold.
– It contains many unique midwater fishes.
Fnft: Midwater Fishes
Fig. 12-16, p. 285
Fnft: A spatial classification of marine organisms
Figure 3.11
Figure 3.11
• Light penetration is different, based on:
– Levels of photosynthesis/primary production.
– Water quality/sedimentation/turbidity
– Location: proximity to shoreline.
• In turbid coastal
waters light rarely
penetrates deeper
than 20m.
– The water appears
yellow to green
because particles
reflect these
wavelengths.
Fnft: Yangtze River
Light Penetration
• Dictates how a species can grow
• Picture 1 is “shallow” subtidal coral –
notice “raised” edges
• Picture 2, much deeper down, shows a coral
that is FLATTENED (like a solar panel!) to
“catch” as much light as possible in deeper
waters
• This is SPECIES ADAPTATION!
Figure 10.1a
Figure 10.1b
• Temperature Differences
(these are certainly associated with light)
Properties of Seawater
Light and Temperature in the
Sea
• The range of biologically
important temperatures at the
Earth’s surface.
Water temperatures
(surface) worldwide
Properties of Seawater
Light and Temperature in the Sea
•
Fnft: Earth's sea surface temperatures obtained from two weeks of satellite infrared
observations July 1984. Temperatures are color coded, with red being warmest and decreasing
through oranges, yellows, greens, blues, and black.
Image courtesy MODIS Ocean Group, NASA GSFC, and the University of Miami
• Temperature can control
aspects of an organism’s
life:
– distribution
– degree of activity
– Reproduction
Barnacles
…Combined…
• Light
• Temperature
• = Global Climate Change
Properties of
Seawater
Light and
Temperature in the
Sea:
Our Planetary
Greenhouse
•
Pattern of atmospheric CO2 increase
over five decades. The slight annual variations are due to
seasonal CO2 uptake and release by land plants.
Reproduced from Robert A. Rohde.
• Other water quality parameters
(these are certainly associated with light and
temperature)
-- Salinity
-- Dissolved Gases (pH/ocean acidification,
carbon dioxide etc.)
+ Summary of all together included
Properties of Seawater
• Ocean Salinity
Geographic variations of surface ocean salinities, expressed in parts per thousand (‰).
Properties of
Seawater
Dissolved Gases
and Acid-Base
Buffering
•
The pH scale, showing the
concentration of H+ ions at each
pH value. Note that the
concentration scale is exponential.
The CO2 System
Gases in Seawater
Pressure
• Water is heavier than air
• Pressure changes ( a lot!) w/ increased
water depth
• 1 atm. of pressure = sea level (on land) but
in ocean each 10 m of depth (33’) you add
another atm. of pressure
Figure 3.13
Combined…
• These give us a “3 layered” (stratified)
ocean (based on depth) and specific areas
for our unique marine habitats to exist.
• Coral Reefs don’t grow in the Arctic (why?)
and Mangrove Forests aren’t found in the
Arctic (why?)
• Everything has a “place!”
Fig. 3.22
Figure 3.17
Ocean Conveyor “Belt”
What grows where?
Temperate vs. Tropical vs. Arctic Marine Habitats; examples
include: Coral Reefs, Kelp Forests, Polar Seas, SAV Beds,
Estuaries, Mangrove Forests etc.
Image courtesy MODIS Ocean Group, NASA GSFC, and the University of Miami
• Who lives in these zones?
The Domains of
Life
The Domains of Life
Marine organisms can also be classified by
lifestyle
• Plankton float in the water
and have no ability to
propel themselves against a
current.
– They can be divided into:
• phytoplankton (plants)
• zooplankton (animals)
• Nekton are active
swimmers and include:
–
–
–
–
fish,
Reptiles
mammals
birds
Plankton - Larvae
Plankton
(sorted by
Size)
Figure 15.02
• Nekton have the ability to swim against currents.
– They can actively search for a hospitable environment.
– Many fish school, which is another form of patchiness.
School of Fish
Figure 10.11
Major pelagic sediments
in the ocean are red clay
and biogenic oozes.
Foraminifera
Diatoms
“Marine Snow”
Plankton vs. nekton AND
• Benthic vs. Pelagic
• Benthic organisms
live:
– on the bottom
(epifauna)
– within the bottom
sediments (infauna)
• Some organisms cross
from one lifestyle to
another during their
life, for example being
planktonic early in life
and benthic later.
Flounder, a bottom fish
A Benthic Community
• The water column is shallow in the sublittoral zone.
• Bottom energy is a function of:
– wave energy
– tidal current
• Bottom energy at the sea bed diminishes as distance from
shore increases.
Benthic zone properties/sedimentation
• The sea floor can be divided into high energy
environments and low energy environments.
• Bottom energy affects organisms by:
–moving sediment around
–creating an unstable substrate
–controlling sediment size
Figure 13-5a
Shelf Sedimentation
• Physical factors regulate the number, type and distribution of
benthic organisms.
– The two major benthic communities based upon substrate
are:
• Soft-bottom communities are typified by unconsolidated sand and
mud substrates. Sandy areas harbor filter feeders whereas deposit
feeders dwell in muddy regions (e.g. estuaries/beaches).
• Hard-bottom communities are typified by rock and gravel
substrates. Seaweeds occur here and the animals tend to be filter
feeders, grazers, and predators (e.g. Coral Reefs and Kelp Forests).
©Ablestock.com
If you’re not benthic you’re…
• PELAGIC!
• A “Pelagic community” is a community of
organisms that live suspended in the water
column…they either float (plankton) or
swim (nekton).
• This is different than those that live on
shore, on the bottom (etc.)
Pelagic
Communitiy
Plankton
And
nekton
Bony fish
(pelagic species
examples
Marine
Mammals
that live in
the pelagic
zone
(Baleen)
Marine
Mammals
that live in
the pelagic
zone
(Toothed)
Other examples…
• PELAGIC vs. BENTHIC ORGANISMS in
some of the habitats we’ll study this
semester
• Top predators in the open
ocean are:
–
–
–
–
–
–
–
Mackerel
Squid
Jellyfish
Tuna
Porpoise
Shark
Humans
Tuna
Jellyfish
Shark
Squid
Pelagic
Pelagic:
Dinoflagellate
(A unicellular
planktonic algae)
And who
eats it…a
Whale
Shark
(pelagic)
Pelagic
pelagic
pelagic
Pelagic: Hawksbill Turtle
pelagic
• …benthic
Kelp (an algae)
Giant Kelp Community
Sea Urchins in a Kelp Forest Understory
Hermit
Crab
Benthic (cone snail
eats Goby)
Benthic: barnacle
and Littorina (snail)
Blue Ringed Octopus on coral
• “Combo” examples and those that fly…
BOTH! (but benthic right now)
pelagic
Pelagic (w/ benthic
attached!)
Puffin
Important seabirds
include:
Little Blue Penguin
Albatross
• Many birds, such as
wading shore birds, have
bill shapes that have
evolved due to their
foraging style (in the
BENTHIC habitat).