● Aquatic Life Zones
● Types of organisms in an aquatic ecosystem
are mainly determined by salinity(amount of salt):
Saltwater/ Marine life zones
● Freshwater life zones
●
Limiting Factors
● All zones that we discuss have limiting factors.
● So what is a limiting factor?
● Limiting factor: a resource or environmental
condition that limits the growth, abundance, or
distribution of an organism or a population of
organisms in an ecosystem.
● Limiting factors that affect aquatic
organisms:
1. Temperature
2. Availability of light for photosynthesis
●
Confined to Euphotic (photic) zone
3. Dissolved oxygen content
●
Decreases with depth
4. Availability of nutrients (CO2, NO3-, PO43-)
●
CO2 increases with depth
5. Turbidity: degree of cloudiness in water
● Inhibits photosynthesis
Why are our oceans important?
● List at least 3 reasons our oceans are important.
● http://www.ted.com/talks/sylvia_earle_s_ted_prize_w
ish_to_protect_our_oceans
● What We Get From
The Ocean:
● Climate control
● Nutrient cycling
● Habitats
● Food
● Oil
● Etc.
Marine Zones
Note Break!!
● Looking at the words phytoplankton and
zooplanktion, what is the difference between the
two organisms?
● Remember what you know about the prefix zoo and
the definition of phyto is something pertaining to or
derived from plants.
● Types of Aquatic Organisms:
● Plankton: free floating organisms;
3 types:
● Phytoplankton
= Primary producers
● Ex: Diatoms, cyanobacteria
●
●
Zooplankton
= Primary and secondary consumers
● Single-celled to large invertebrates
like jellyfish
●
●
Ultraplankton
●
Tiny photosynthetic bacteria
Plankton!!!
Beautiful plankton
● http://www.planktonchronicles.org/en/episode/plankt
on
● Types of Aquatic Organisms
cont.:
● Nekton
●
Strong swimmers: fish, turtles,
whales
●
https://www.youtube.com/watch?v=B6M_XgiONoo&index=4&list=PL8B8EDD0D0
2DA14B7
● Benthos
Bottom dwellers: oysters, sea
stars, clams, lobsters, crabs,
worms
● Decomposers: mostly bacteria
●
Major Life Zones
3 Major Zones
● Horizontal Zones (Extending from land out to sea)
● EX: Intertidal zone
Limiting Factors in the
Horizontal Zone
● Temperature
● Salinity
● Nutrient availability
3 Major zones
● Vertical life zones
Limiting Factors of Vertical
Zones
● Temperature
● Nutrient availability
● Available sunlight
● DO
● As you move down through the zones all of these
factors decrease.
● Colder, darker, less dissolved oxygen, etc.
3 Major Zones
● Benthic Zones: Everything on the bottom. Includes
all zones.
Limiting Factors in the Benthic
Zone
● Organisms that are benthic must adapt to the limiting
factors listed in the zone where they live.
● For example, a barnacle in a tidal pool will have
different limiting factors than organisms on a deep
sea vent.
●Major Marine Ecosystems
1. Coastal Ecosystems
● From shore to edge of continental
shelf
● Warm, nutrient rich, shallow
● High in nutrients because of
increased photosynthesis
● Contains 90% of all marine species &
most fisheries
●Coastal Ecosystems: ecological
and economic services
● Maintain water quality by filtering:
● Toxic pollutants
● Excess plant nutrients
● Sediments
● Provide food, timber, fuelwood,
habitats
● Reduce storm damage and erosion
● Types of Coastal Ecosystems
Estuaries: where rivers meet the sea
A.
Questions with video
https://www.youtube.com/watch?v=XLumSN4G5P4 (5 min)
B. Coastal
Wetlands: land covered with
water all or part of year:
●
Inlets, bays, sounds, mangrove forests,
salt marshes
1.
https://www.youtube.com/watch?v=jmebAjdMr
Ls (3 min)
● Coastal Ecosystems:
c. Coral Reefs
● Formation
●
●
Tiny animals (polyps) secret
calcium carbonate shells,
which become coral reefs
Polyps and zooxanthellae
algae have mutualistic
relationship:
●
●
Algae provide oxygen from
photosynthesis & chemical
energy
Coral polyps provide home
● https://www.youtube.com/wat
ch?v=nWyw5H88PBw (3 min)
● Coastal Zone: Coral Reefs
● Ecosystem Services:
●
●
●
Marine equivalent of
tropical rain forests
Provides habitat for onefourth of all marine species
Moderates climate b/c takes
up CO2
● Economic/ Social
Services:
●
●
●
Food
Potential medicine
Employment & Recreation
https://www.youtube.com/wa
tch?v=cbN161yBBGA (4
min)
● Coastal Zone: Coral Reefs
● Causes of Degradation:
● (Human-caused) Warmer ocean
temperatures leading to coral bleaching:
kills algae and thus the polyps
● https://www.youtube.com/watch?v=iW8nCAL
x5iA
How do we contribute to coral
bleaching?
● https://www.youtube.com/watch?v=aEdoizge
NJk
●Open Ocean: Three vertical zones:
1.Euphotic zone: lit upper zone
●
●
●
Phytoplankton perform photosynthesis
Nutrient levels low & d-Oxygen levels high
Have fast swimming, predatory fish
2.Bathyal zone
●
Dimly lit, few producers
● Have zooplankton and
smaller fishes
●Open Ocean: Three vertical zones:
1. Euphotic zone
2. Bathyal zone
3. Abyssal zone
●
●
●
●
●
Dark & cold
No photosynthesis, little d- oxygen
High nutrients
Have deposit & filter feeders (eat marine snow),
slow fish
https://www.youtube.com/watch?v=BXGF3XS-yAI
(2 min)
Deep Sea Adaptations
● https://www.youtube.com/watch?v=UXl8F-eIoiM
● Major threats to
marine systems:
● Coastal development
● Habitat destruction
● Overfishing
● Use of fishing trawlers
● Pollution
● Introduction of
invasive species
● Climate change
Ocean Acidification
● https://www.youtube.com/watch?feature=player_em
bedded&v=cAwZ7VCYn44
● https://www.youtube.com/watch?v=5cqCvcX7buo
(20 min)
Aquatic Life Zones
● Freshwater Zones: services:
● Climate moderation
● Nutrient cycling
● Flood control
● Habitat
● Food
● Recreation & employment
● Etc.
● Freshwater Life Zones: includes:
● Lentic (standing) bodies of freshwater:
Lakes
● Ponds
● Inland wetlands
●
● Lotic (flowing) systems of freshwater:
Streams
● Rivers
●
● Lakes: bodies of standing fresh water formed
when precipitation, runoff, or groundwater
seepage fill depressions in earth’s surface
Aquatic Life Zones
● 4 Lake Zones:
1.
Littoral zone
● Near shore with rooted plants
● High biodiversity: turtles, frogs, crayfish,
some fish
2.
Limnetic zone
● Open, sunlight area away from shore
● Main photosynthetic zone
● Some larger fish
●Lake Zones:
3. Profundal zone
●
●
Deep water too dark for photosynthesis
Some fish
4. Benthic zone
●
●
●
Decomposers & detritus feeders
Some fish
Nourished primarily by dead matter
Aquatic Life Zones
● Lake Types Based on Nutrient Levels:
● Oligotrophic lakes
Low nutrients and low NPP
● Very clear water
● Eutrophic lakes
● High nutrients and high NPP
● Murky water with high turbidity
● Cultural (artifical) eutrophication: input of
excess nutrients (fertilizers) causing excess algal
growth
●
● Oligotrophic lake
● Eutrophic lake
The Effect of Nutrient Enrichment on a Lake
Aquatic Life Zones
●Freshwater Degradation:
● Dams destroy habitat
● Flood control levees and dikes along
rivers alter flow & destroy habitat
● Pollutants from cities and farms on
streams, rivers, and lakes
● Draining wetlands for agriculture &
development