Transcript Marine Ecolgy

Marine Ecology
Importance of the
Ocean Environment
Area
 Saltwater
covers about 71% of
the earth’s surface
Life:
There are 250,000 known species of
marine plants and animals, many
are food for other organisms, like
us.
Temperature
Solar heat is distributed by ocean currents &
as ocean water evaporates.
 The oceans are major players in the earth’s
climate & are a gigantic reservoir for carbon
dioxide; therefore they help regulate the
temp. of the troposphere.

Zones of the Marine
Environment
Two major zones that break
up into smaller zones –
coastal and the open sea
Intertidal or Beach
Zone
Broken up into five areas
Lower Shoreface
 The
deepest part of the beach;
farther into the water, before
the breaker bar that forms
waves
Upper Shoreface
 Shallow
zone where the waves
begin to form
Forebeach
 Contains
the swash zone –
place where the waves crash.
Backbeach
 Only
under water during high tide
Fore-Island Dunes
 Sand
dunes; doesn't flood often,
except during hurricanes, etc.
Constantly changing due to the wind
Estuary
Where fresh water and salt
water meet
An estuary is a coastal body of water, partly
surrounded by land, with access to the open ocean and
a large supply of fresh water from a river
Characteristics
Salinity
 Salinity
fluctuates with tidal cycles,
the time of year, & precipitation.
The organisms that live here must
be able to tolerate these conditions
Fertility of Estuaries
 Estuaries
are the most fertile
ecosystems in the world
 Greater productivity than either the
adjacent ocean or the fresh water
upriver
Reasons for High Fertility
Nutrients are transported from the land into
rivers that flow into the estuary
 Tidal action circulates nutrients and helps
remove wastes
 A high level of light due to shallow water
 Many plants provide an extensive
photosynthetic carpet

Difficulties

Sandy beach – Life must deal with a shifting
environment that threatens to engulf them & no
protection against wave action. Most animals
bury into the sand. They move with the tides,
so they’re always underwater & don’t dry out.
Difficulties (Continued)

Rocky shore – high wave action at high tide;
drying out & temperature changes during low.
Animals have a way of sealing in moisture like
a shell & find a way to cling to the rocks so they
don’t get washed away with waves.
Pelagic
 The
The Open Ocean
open ocean environment;
divided into neritic (open ocean
from the shoreline to a depth of
200m) and oceanic provinces
(depths > 200m).
Euphotic Zone
 Lots
of light.
From 0 - 200
meters.
Photosynthesis
takes place
here.
Bathyal Zone
 The
dimly lit
part of ocean.
From 200 1500 meters.
Benthic Characteristics (ocean floor)
The ocean floor consists of sediments
(mostly sand and mud)
 Many marine animals, like worms and
clams, burrow
 Bacteria are common & can go down 500
meters below ocean floor. The Benthic
environment extends from the shore to
the deep.

Sea Grass Beds
 Flowering
plants that have adapted to
complete submersion in salty water.
Location of sea grass
 Found
in shallow water to depths
of 10 meters where they can
photosynthesize. Sea grasses are
found in quiet, temperate, tropical,
and subtropical waters; not in polar
waters.
Examples
Eel, turtle, and manatee grass.
Ecological Importance
 Reduce
surface erosion, provide
food, & provide habitats for many
marine organisms.
 Animals that eat sea grass are
manatees, green turtles, parrotfish,
sturgeon fish, and sea urchins.
Abyssal Zone
 Completely
dark.
Extends to a depth
of 4000 to 6000
meters (2.5 to 3.7
miles). Water here
is very cold & has
little dissolved
oxygen.
Kelp

The largest of the brown algae, many reach
lengths of 60 meters (200 feet). Common in
cooler water & are found along rocky coasts.
Provide habitat for many animals like
tubeworms, sponges, clams, fish, & mammals.
Some animals eat the kelp.
Coral Reefs
Characteristics
 Built
from layers of calcium carbonate,
coral reefs are found in warm, shallow sea
water. The living portions must grow in
shallow waters where light hits. They are
the most diverse of all marine ecosystems.
Examples
Many coral reefs are made of red coralline
algae that photosynthesize.
 Others have zooxanthellae (symbiotic algae)
that live and photosynthesize in their tissues.
 Not all corals have zooxanthellae, but only
those with it build reefs.
 Coral animals also capture food at night with
stinging tentacles that paralyze zooplankton
and small animals that drift nearby.

Coral Reef Waters
 The
waters where coral reefs are
found are often poor in nutrients.
Yet, other factors are favorable
such as temperature, sunlight year
round, and zooxanthellae.
Growth
 Coral
reefs grow slowly; as one
dies, another organism grows
on it.
Types of Coral Reefs
Fringing Reef
 The
most common type of coral
reef. It is directly attached to
the shore of a volcanic island or
continent.
Fringing Reef Bora Bora NASA JPL Satellite: Space Shuttle Sensor: SIR-C/X-SAR
Atoll
A
circular reef that surrounds a
central lagoon of quiet water.
 An atoll forms on top of the cone of
a submerged volcanic island.
 More than 300 atolls are found in the
Pacific and Indian Oceans.
View of Midway Atoll from Space Shuttle
Atolls in The Maldives Landsat 7
Barrier Reef
A
lagoon of open water separates
the land from the barrier reef.
 The largest barrier reef is the Great
Barrier Reef off the coast of
Australia.
 The second largest is off the coast
of Belize.
Ecological Importance
of Coral Reefs
Provides a Habitat
 Provides
a habitat for a wide
variety of marine organisms.
Coastline Protection
 Protects
erosion.
coasts from shoreline
Benefits for Humans
 Provides
humans with seafood,
pharmaceuticals, and
recreational/tourism dollars
Coral Reef Risks
 Of
the 109 countries with large reefs,
90 are damaging them, and 27% of
the coral reefs are at high risk,
especially off the coast of
Southeastern Asia.
 In the western Atlantic, 30-50% of
all coral species are either rare or
endangered.
Coral Reef Risks Con’t
Silt washing from downstream has
smothered the reefs
 High salinity from fresh water diversion,
over-fishing, boat groundings, fishing
with dynamite or cyanide, hurricane
damage, disease, coral bleaching, land
reclamation, tourism, and the mining of
coral for building materials.

This bottle still shows a slightly burned
fuse from its use to blow up the coral.
©1997-2001 Jeffrey N. Jeffords
Protection of
 300
coral reefs in 65 countries are
protected as reserves or parks, and
another 600 have been
recommended for protection.
 The good news is coral reefs can
often recover from damage.