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

• The benthic environment is divided by depth into the: – intertidal (littoral) zone

– subtidal (sublittoral) zone

– Epi, Meso, Bathyal & Abyssal zone(s)

– (other) hadal zone

• The pelagic environment is divided broadly into the: – neritic zone

– oceanic zone

• More specifically into the:– Epipelagic zone

– Mesopelagic zone

– Bathypelagic zone

– Abyssalpelagic zone

– hadalpelagic zone

•There are two major marine provinces: –the benthic (bottom)

–the pelagic (water column)

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

• 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.

Properties of Seawater

Light and Temperature in the Sea

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 SeawaterLight and

Temperature in the Sea:

Our Planetary Greenhouse

• Pattern of atmospheric CO2 increase

over five decades. The slight annual variations are due to seasonal CO 2 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

Geographic variations of surface ocean salinities, expressed in parts per thousand (‰).

• Ocean Salinity

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?

Image courtesy MODIS Ocean Group, NASA GSFC, and the University of Miami

Temperate vs. Tropical vs. Arctic Marine Habitats; examples include: Coral Reefs, Kelp Forests, Polar Seas, SAV Beds,Estuaries, Mangrove Forests etc.

• 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

Figure 15.02

Plankton (sorted by

Size)

• 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.

“Marine Snow”

Foraminifera

Diatoms

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.

Figure 13-5a• Bottom energy affects organisms by:

–moving sediment around

–creating an unstable substrate

–controlling sediment size

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.)

PelagicCommunitiy,PlanktonAndnekton

Bony fish (pelagic species)examples

MarineMammalsthat live inthe pelagiczone(Baleen)

MarineMammalsthat live inthe pelagiczone(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

Squid

Tuna

Shark

Jellyfish

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!)

Important seabirds include:

Puffin

Albatross

Little Blue Penguin

• Many birds, such as wading shore birds, have bill shapes that have evolved due to their foraging style (in the BENTHIC habitat).