AP Review
Chapters 7, 8, & 13
By: Adrienne Damicis
Chapter 7: Aquatic Biodiversity
This chapter addresses the following questions:
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What are the basic types of aquatic life zones, and
what factors influence the kinds of life they contain?
What are the major types of saltwater life zones, and
how do human activities affect them?
What are the major types of freshwater life zones,
and how do human activities affect them?
How can we help sustain aquatic life zones?
Case Study: Why should we care
about coral reefs?
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formed by massive colonies of tiny animals
called polyps
they build reefs by secreting a protective
crust of limestone around their bodies which
remains after the polyps die
there is a mutually beneficial relationship
between the polyps and tiny algae called
zooxanthellae
Case Study (Cont.)
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Coral bleaching occurs when a coral
becomes stressed and expels most of its
algae, leaving behind a white skeleton of
calcium carbonate.
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Causes include increased water temperature and
runoff of silt that covers the coral and prevents
photosynthesis.
More than 1/4 of the world's coral reefs have been
lost to coastal development, pollution, overfishing,
warmer ocean temperatures, and other stresses.
Case Study (Cont.)
Ecological and economic services:
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removal of carbon dioxide from the atmosphere
natural barriers that protect the coastline from
erosion by waves and storms
support at least 1/4 of marine species
support fishing and tourism industries worth billions
of dollars each year
Aquatic Life Zones
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Saltwater or marine (estuaries, coastlines,
coral reefs, coastal marshes, mangrove
swamps and oceans)
Freshwater
Organisms in Aquatic Life Zones
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Plankton
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Phytoplankton- plant plankton that are producers
Zooplankton- animal plankton that are primary or
secondary consumers
Ultraplankton- photosynthetic bacteria no more than
2 micrometers wide.
Organisms in Aquatic Life Zones
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Nekton- strongly swimming consumers (fish,
turtles, whales, etc.)
Benthos- dwells on the bottom (barnacles,
oysters, crabs, worms, etc.)
Decomposers- break down the organic
compounds and the dead bodies and wastes
of aquatic organisms into simple nutrient
compounds for use by producers (mostly
bacteria)
Benefits of a Marine Ecosystem
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Ecological: climate moderation, CO2
absorption, nutrient cycling, waste treatment
and dilution, habitats and nursery areas for
marine and terrestrial species.
Economic: food, pharmaceuticals, harbors
and transportation routes, recreation,
employment, minerals, offshore oil and
natural gas, building materials.
Estuaries and Coastal Wetlands
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Estuary- partially enclosed area of coastal
water where seawater mixes with freshwater
and nutrients from rivers, streams, and
runoff from land.
Coastal Wetlands- land covered with water
all or part of the year (river mouths, inlets,
bays, sounds, mangrove forest swamps, and
salt marshes.
Ocean Shores
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Intertidal zone- area of shoreline between
low and high tide
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Rocky shores- creates pools
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difficult to live in b/c of changing conditions
many organisms survive by digging into the sand,
hold on to something, or hide in protective shells
contains a great variety of species with different
niches
Barrier beaches- sandy shores
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home to many shorebirds
organisms survive by staying hidden from view,
burrowing, digging, and tunneling in the sand.
Barrier Islands
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Low, narrow, sandy islands that form
offshore from a coastline.
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Help protect the mainland, estuaries, and coastal
wetlands from approaching storm waves
Heavily targeted for real estate development
Dangerous place to live b/c the beaches are
constantly shifting and eroding and floods are
common.
Biological Zones in the Open Sea
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Euphotic Zone- lighted upper zone where
phytoplankton carry out photosynthesis
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nutrient levels are low (except around upwellings)
and DO levels are high.
Large predatory fish populate this zone (tuna,
swordfish, etc.)
Bathyal Zone- dimly lit middle zone, doesn't
contain phytoplankton.
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Zooplankton and smaller fish populate this zone
Biological Zones in the Open Sea
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Abyssal Zone- lowest zone, dark, and cold.
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Little DO
Enough nutrients on the ocean floor to support 98%
of the species living in the ocean.
Most organisms of the deep waters get their
food from detritus drifting down.
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Deposit Feeders- take mud into their guts and
extract nutrients from it.
Filter Feeders- pass water through or over their
bodies and extract nutrients from it.
Open Sea
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Average primary productivity and NPP per
unit area are low in the open sea except at
an occasional equatorial upwelling.
Largest contributor to the earth's overall NPP
Freshwater Life Zones
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Lentic bodies- standing bodies of freshwater
(lakes, ponds, inland wetlands, etc.)
Lotic systems- flowing systems such as
streams and rivers.
Freshwater Lakes
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Littoral Zone- top layer; shallow sunlit water
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Limnetic Zone- open, sunlit water surface
layer away from the shore
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high biological diversity and adequate nutrients
main photosynthetic body of the lake, supplies most
of the food and oxygen for the lake's consumers
Profundal Zone- deep, open water where it's
too dark for photosynthesis
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Low DO
Benthic Zone- bottom of the lake
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mostly decomposers and detritus feeders
nourished by detritus that falls from zones above
Freshwater Lakes
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Oligotrophic- small supply of plant nutrients
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often deep, with steep banks
crystal clear water, small populations of
phytoplankton and fish, low NPP
Eutrophic- large or excessive supply of
nutrients
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typically shallow, murky water, high NPP
Mesotrophic- between the two extremes of
nutrient enrichment
Freshwater Streams and Rivers
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Source Zone- headwaters, or mountain
highland streams of cold, clear water, rush
over waterfalls and rapids
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dissolves large amounts of oxygen from the air
lack of nutrients, low productivity
Transition Zone- headwater streams merge
to form wider, deeper streams that flow
down gentler slopes
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warmer water, more producers
Freshwater Streams and Rivers
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Floodplain Zone- streams join into wider and
deeper rivers that meander across broad,
flat valleys
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higher temperatures, less DO, high concentrations
of silt
support fairly large populations of producers and
rooted aquatic plants along the shores
Often polluted from excessive inputs of nutrients and
other anthropogenic pollutants
Human Activities on Freshwater
Systems
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We have built dams, levees, and dikes that
reduce the flow of water and alter wildlife
habitats in rivers; established nearby cities
and farmlands that pollute streams and
rivers; and filled in inland wetlands to grow
food and build cities.
Chapter 13: Sustaining Aquatic
Biodiversity
This chapter addresses the following questions:
What is aquatic biodiversity, and what is its
economic and ecological importance?
o How are human activities affecting aquatic
biodiversity?
o How can we protect and sustain marine biodiversity?
o How can we manage and sustain the world's marine
fisheries?
o How can we protect, sustain, and restore wetlands?
o How can we protect, sustain, and restore lakes,
rivers, and freshwater fisheries?
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Aquatic Biodiversity
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oceans cover 71% of the planet's surface
63% of known fish species exist in marine
systems - 50% in coastal waters - 12% in the
deep sea - 1% in the open ocean - 37% live
in freshwater systems
Marine Biodiversity
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Greatest marine biodiversity occurs in coral
reefs, estuaries, and the deep-ocean floor
Biodiversity is higher near coasts than in the
open sea because of the great diversity of
producers, habitats, and nursery areas
Biodiversity is higher in the bottom region of
the ocean because of the greater variety of
habitats and food sources on the ocean
bottom
The lowest marine biodiversity probably is
found in the middle depths of the open
ocean
Maintaining Aquatic Sustainability
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Integrated Coastal Management- communitybased effort to develop and use coastal
resources more sustainably. The overall aim is
for groups competing for the use of coastal
resources to identify shared problems and
goals. Then they attempt to develop workable,
cost-effective, and adaptable solutions that
preserve biodiversity and environmental quality
while meeting economic and social needs.
Solutions to Protecting Wetlands
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legally protect existing wetlands
steer development away from existing
wetlands
use mitigation banking only as a last resort
require creation and evaluation of a new
wetland before destroying an existing
wetland
restore degraded wetlands
try to prevent and control invasions by
nonnative species
Chapter 8: Community Ecology
The chapter addresses the following questions:
What determines the number of species in a
community?
o What different roles do species play in a
community?
o How do species interact with one another in a
community?
o How do communities change as environmental
conditions change?
o Does high biodiversity increase the stability of a
community?
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Island Ecology
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Theory is island biogeography- a balance
between two factors determines the number
of different species found on an island: the
rate at which new species immigrate to the
island and the rate at which existing species
become extinct on the island.
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Features that affect these rates are the island's size
and its distance from the nearest mainland.
Types of Species
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Native species- normally live and thrive in a
particular community
Nonnative species- also called invasive or alien
species
Indicator Species- serve as early warnings of
damage or danger to a community
Keystone Species- have a much larger effect on
the types and abundances of many other
species in a community than their numbers
would suggest
Foundation Species- create and enhance
habitat that benefits other species
Species Interactions
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Interspecific competition- competition for
shared or scarce resources such as space
and food
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Resource partitioning- species competing for similar
scarce resources evolve more specialized traits that
allow them to use shared resources at different
times, in different ways, or in different places
Predation- members of one species feed
directly on all or part of a living organism of
another species.
Species Interactions
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Parasitism- one species feeds on part of
another organism (the host) usually by living
on or in the host
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Mutualism- two species interact in a way that
benefits both
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the parasite benefits and the host is harmed
pollination mutualism between plants and animals is
the most common form of mutualism
Commensalism- interaction that benefits one
species but has little, if any, effect on the
other species
Ecological Succession
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Ecological succession- the gradual change
in species composition of a given area
Primary succession- the gradual
establishment of biotic communities on
nearly lifeless ground
Secondary succession- biotic communities
are established in an area where some type
of biotic community is already present
Primary Succession Species
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Pioneer species- attach themselves to
inhospitable patches of bare rock
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vital to soil formation
Early successional plant species- grow close
to the ground, can establish large
populations quickly under harsh conditions,
and have short lives.
Midsuccessional plant species- herbs,
grasses, and low shrubs.
Late successional plant species- mostly
trees that can tolerate shade
Ecological Stability, Complexity,
and Sustainability
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Living systems maintain some degree of
stability or sustainability through constant
change in response to changing environmental
conditions
Inertia or Persistence- the ability of a living
system to resist being disturbed or altered
Constancy- the ability of a living system to keep
its numbers within the limits imposed by
available resources
Resilience- the ability of a living system to
repair damage after an external disturbance