Transcript Aquatic Diversity

AQUATIC LIFE ZONES:
SALTWATER (MARINE) Ecosystems: Estuaries, coastlines,
coral reefs, coastal marshes, mangrove swamps, continental
shelf, & deep ocean
AQUATIC Ecosystems: Lakes and Ponds, Streams and
Rivers, and Inland wetlands
TYPES OF ORGANISMS:
Plankton – free floating (or weak swimmers)
(phytoplankton – primary producers & zooplankton – primary consumers)
Nekton – strong swimmers (fish, turtles, whales)
Benthos – bottom dwellers (oysters, barnacles, crustacean, worms)
Decomposers – mostly bacteria
SALINITY &
TEMPERATURE
DETERMINE THE
DISTRIBUTION OF
THE OCEANIC
REALMS
Physical & Chemical Characteristics
Water provides buoyancy = physical
support, reduces the need for large
supporting structures of trunks and
legs, helps aquatic organisms move
vertically
Water provides consistency = keeps
organism from drying out or
requiring water, constant
temperature range
Water provides readily dissolved
nutrients – b/c water is the universal
solvent the nutrients are ready for
uptake by primary producers
Adaptations for Floating
Water provides constant flux – like
wind terrestrially, water gives
constant circulation and disperses
organisms and their larvae & dilutes
toxins
Primary Productivity
No primary producers
– many organisms rise
to the euphotic zone at
night to feed
Abyssal
Very little nutrients
(marine snow) ~250, 000
named organisms
Coastal zone makes up only <10% of
the ocean and contains 90% of all
marine organisms
Diversity of organisms in each layer is
determined by: 1) temp 2) sunlight
3) dissolved oxygen 4) nutrients
(dissolved CO2 to from carbonate ions
for shells), nitrates, phosphates
ESTUARIES/Salt Marsh
Ecological and Economic Benefits
 Partially enclosed area of
coastal water where
freshwater & silt from rivers
meets the sea.
 High productive area
 Temperature & Salinity vary
daily rhythms of the tides,
seasonally with river input
fluctuations, and with
unpredictable storms
Chesapeake Bay
BAYS, SOUNDS, & INLETS
 Serves as a breeding ground
form any organisms
(waterfowl, marine organisms)
 Filtrates sediments, excess
nutrients and pollutants
 Acts as a buffer to inland
areas during storms
Lie along the coast line in
estuaries and intertidal
communities of the tropics
and subtropics.
Mangroves provide habitat form
many organisms & reduce long
term beach erosion
Act as a filtering system –
especially for heavy metals that
settle into the anoxic soil below
Adaptations to live in anoxic / nutrient
poor soil; marine water conditions; &
limited supply of freshwater
 Leaves secrete excess salts
 Pneumatophores –”roots” for
uptake of gases
Chesapeake Bay: – THE DEAD ZONE
The Chesapeake watershed
incorporates six states (DE, MD
NY, VA, PA, & W. VA)
Protect
Important waterfowl nesting site:
herring gulls, osprey, bald eagle
WHAT??
Oyster beds, Blue
Crab support large
economic industries
DEAD ZONE : Anoxic Conditions
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EUTROPHICATION:
increased nutrients =
increased algal mats =
increased bacteria growth =
decrease in available oxygen
Sewage
AGRICULTURE
Contaminants like sediment, phosphorus,
nitrogen, toxic metals, herbicides and
pesticides, organic material, oil, and
bacteria. Roadways release oil and grease,
tailpipe emissions. Lawns contribute
fertilizer and animal waste. Construction
sites release quantities of mud.
DUNE SYSTEMS
Vegetation is
crucial for the
success of the
dune system
Construction & Development
should ideally be behind the
secondary dune system
Economically dunes are
important in the reduction of
storm surge damage to coastal
development
Barrier Island Systems
Helps protect main land
development.
Also protects coastal dunes
& estuary systems.
CORAL REEF DYNAMICS
• Most biologically diverse
aquatic system (niche
availability)
• Three categories of organisms
1) sessile – attached organisms
2) borrowing organisms
3) fishes
• Live between 18°C to 30°C
(even one degree above that
can trigger bleaching)
Photomicrograph of algae
clusters in coral polyp
Coral Reefs exist in low nutrient
waters (oligotrophic) and therefore
rely on an endosymbiotic algae
(zooxanthellae) to provide
nutrients
Over harvesting certain organisms can
cause coral death – CROWN OF THORNS
CASE STUDY
Removal of
certain species,
especially the
Triton, allows
Crown of
Thorns starfish
population to
increase. COT’s
are natural
predators of
corals and can
deplete the reef
if populations
are too high.
LENTIC ZONES (standing bodies of water)
LAKES, PONDS, & INLAND WETLANDS
Littoral Zone
High biodiversity –
phytoplankton, plants
(duckweed) floating,
submergent, emergent,
insects, amphibians, fish
Limnetic Zone
Main photosynthetic zone
Profundal Zone
Little to no photosynthesis,
cooler water, lower
dissolved O2
Benthic Zone
Very little oxygen; no
photosynthesis; clams,
fish, insect larvae,
decomposers
NUTRIENT LEVEL IMPACTS OVER TIME
Thermoclinewater temp
changes rapidly
with depth
SEASONAL CHANGES OF TEMPERATE LAKES
In winter the cold
temps cause the
lake to separate
in to different
layers (density)
Wind blowing
cause vertical
currents bringing
up nutrients and
dissolved oxygen
Surface water cools/
Warming temps
sinks – thermocline
cause the
disappears-dissolved
thermocline to
oxygen & nutrients
return
rises
INLAND WETLANDS
Marshes
Swamps
BOGS
LOTIC ZONES (moving water) – rivers, streams, creeks
Surface water (precipitation) flows through the drainage
basin or watershed as runoff into streams & tributaries to
rivers and carries with it nutrients & dissolved oxygen.