ecology chapter 25: aquatic environment

• Classification physical features

• Water Salinity-major feature that influence

adaptation• 2 Categories

– Freshwater (Lotic ＆ Lentic)– Saltwater (Coastal ＆ Open-

water)

25.1 Lakes Have Many Origins• Lakes and Ponds

- inland depressions containing standing water

25.1 Lakes Have Many OriginsFormed by glacial erosion and

depositionFormed from deposited silt,

driftwood and other debris Formed from shifts of Earth's

crustFormed from nongeological

activities

25.2 Lakes Have Well-Defined Physical Characteristics

• Factors that influence the distribution and adaptation:

OxygenTemperature Light

25.2 Lakes Have Well-Defined Physical Characteristics

THE NATURE OF LIFE VARIES IN THE DIFFERENT ZONES

CONCEPT 25.3

Aquatic life richest at shallow waters

•Area dominated by emergent vegetation

Aquatic life richest at shallow waters

•Zone of floating plants

Bottom Ooze•Region of great biological activity•Anaerobic bacteria are dominant organisms

•Organic matter reaching bottom greater than amounts that can be utilized by bottom fauna form a muck

•Muck is rich in hydrogen sulfide and methane

Periphyton or Aufwuchs

•Organisms closely associated with the benthic community

•Periphyton- mostly algae and diatoms living on plants; fast growing and lightly attached

•Aufwuchs- form crust-like growth of cyanobacteria, diatoms, water moss, and sponges, on stones, wood, etc.

THE CHARACTER OF A LAKE REFLECTS ITS SURROUNDING

LANDSCAPECONCEPT 25.4

Eutrophication•The run off of rich nutrients from the land to the lake or other bodies of water

•Typical eutrophic lake: High surface-to-volume ratio

•Abundance of nutrients especially nitrogen, phosphorous, and organic matter

Oligotrophy•Condition of being poor in nutrients.•Low surface-to-volume ratio

Dystrophic•Receives large amounts of organic matter from surrounding land

•Usually highly acidic•Highly productive littoral zones

CHAPTER 25.5FLOWING-WATER HABITAT

AQUATIC ECOSYSTEMS

S T R E A M

R I V E R

• If gradient is less steep, velocity decreases and the stream begins to meander.

• River is forced to deposit its load of sediment in a fan-shaped area about its mouth to form a delta.

FAST MOUNTAIN STREAM SLOW MOUNTAIN STREAM

• Riffles are the sites of primary production in the stream.

• Pools are the sites of decomposition

CHAPTER 25.6ADAPTATIONS TO FLOWING WATER

AQUATIC ECOSYSTEMS

• A streamlined form offers less resistance to water current.

• Sticky undersurfaces help snails and planarians cling tightly

• flattened bodies and broad, flat limbs (black-fly larva)

• construct protective cases of sand or small pebbles (Caddisfly)

The Flowing Water-Ecosystem is a

Continuum of Changing Environments

Headwater Streams

Swift, cold, and in shaded forested

regions.

Headwater StreamsPrimary productivity in

these streams is typically low and they depend

heavily on the input of detritus from terrestrial streamside vegetation.

Headwater Streams

Dominant organisms are shredders,

processing large-sized litter and feeding on

CPOM, and collectors, processors of FPOM.

Headwater StreamsAccumulators,

processors, and transporters of

particulate organic matter of terrestrial

origin.

Rivers Flow Into the Sea, Forming

Estuaries

Estuary

The place where freshwater joins

saltwater.

EstuarySemi-enclosed parts of

the coastal ocean where seawater is diluted and partially mixed with the freshwater coming from

the land.

Mixing waters of different salinities and temperatures creates a counterflow that works

as a nutrient trap.

Inflowing river waters most often impoverish rather than fertilize the estuary. Instead,

nutrients and oxygen are carried into the estuary by

tides.

Problems Organisms Inhabiting

The Estuary Face2

Maintaining their position

Adjusting to changing salinity

Most estuarine organisms are benthic.

Salinity dictates the distribution of life in

the estuary.

Benthos is a World of its OwnEarl Judd C SullanoBSED – 3 Biological Sciences

Benthic Benthos

Refers to the plants and

animals that live there.

Refers to the floor of the sea.

In a world of darkness, no photosynthesis takes place, so the

bottom community is strictly

Heterotrophic Organisms that cannot produce their own food.

They rely on food that comes from other organisms.

Despite the darkness in depth….

benthic communities support a high diversity of species.

Polychaete Worms

Pericarid Crustaceans

Important organisms in the benthic food chain are the

bacteria of the sediments. o Commonly found where large

quantities of organic matter are present.

o Bacteria synthesize protein from dissolved nutrients and in turn become a source of protein, fat and oils for other organisms.

Hydrothermal Ventso Form when cold seawater flows down

through the fissures and cracks in the basaltic lava floor deep into the underlying crust.

o The water, heated to a high temperature, re-emerges through mineralized chimneys rising up to 13 m above the sea floor.

White smokers Black smokers

Narrower chimneys rich in copper

sulfides, issue jets of clear water from 300 °C to more 450

°C that are soon blackened by

precipitation of fine-grained sulfur-

mineral particles

Rich in zinc sulfides issue a milky fluid

with a temperature of

under 300°C

Associated with these vents is a rich diversity of unique deep-sea life, confined to within a

few meters of the vent system.

The primary producers are chemosynthetic bacteria

o Oxidize reduced sulfur compounds such as hydrogen sulfide to release energy used to form organic matter from carbon dioxide.

The primary consumers include giant clams, mussels, and

polychaete worms

o Filter bacteria from water and graze on bacterial film on rocks

Coral Reefs Are Complex Ecosystems Built by Colonies of Coral Animals

Coral Reefs

Lying in the warm, shallow waters about tropical islands and continental landmasses.

Unique accumulation of dead skeletal material built up by

carbonate secreting organisms

Coral Reefs

Coral Reefs

Reef-building corals are generally found at depths of less

than 45 m.

Coral Reefs

Reef-building corals have symbiotic relationship with algal cells, their

distribution is limited to depths where sufficient solar radiation is available to

support photosynthesis.

Coral Reefs

This precipitation occurs when water temperature and salinity

are high and carbon dioxide concentrations are low.

3 Basic Types of Coral Reefs

Fringing Reefs

Grow seaward from the rocky shores of islands and continents

Barrier Reefs

Parallel shorelines of continents and islands and are separated from land by shallow lagoons.

Atolls

Rings of coral reefs and islands surrounding a lagoon, formed when

a volcanic mountain subsides beneath the surface.

Corals are modular animals, anemone-like cylindrical polyps,

with prey capturing tentacles surrounding the opening mouth.

Also associated with coral growth are mollusks, echinoderms, crustaceans, polychaete worms, sponges, diverse array of fishes, both herbivorous and

predatory.

PRODUCTIVITY OF THE OCEANS IS

GOVERNED BY LIGHT AND NUTRIENTS

CONCEPT 25.13

BY PAULA MARIE M. LLIDO

PROCESSES THAT RETURNED THE

RATE OF NUTRIENTS TO THE

SURFACE2

Upwelling of deeper nutrient-rich waters

To the surface

Seasonal breakdown of the thermocline and subsequent turnoverUpwelling of deeper nutrient-rich waters to the surface

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COASTAL REGION HIGH PRIMARY PRODUCTIVITY

OPEN WATERS LOW PRIMARY PRODUCTIVITY

TROPICAL OCEAN

Highest production of open waters of tropical

oceans occurs in EQUATORIAL REGION

where upwelling occurs as surface current

diverge

OPEN WATERS

PRIMARY PRODUCTIVITY

ANTARTICREGION HIGH PRIMARY PRODUCTIVITY

ARCTIC REGION LOW PRIMARY PRODUCTIVITY

POLAR

OCEAN

ANTARCTICREGION HIGH PRIMARY PRODUCTIVITY

ARCTIC REGION LOW PRIMARY PRODUCTIVITY

POLAR

OCEAN

TEMPERATE OCEAN=Seasonal variation in nutrient supply driven by the seasonal dynamics of the thermocline

• TROPICAL OCEANCoastal region = productivityOcean waters = productivity

(except in equatorial region)• POLAR OCEANAntarctic region = productivityArctic Region = productivity

• TEMPERATE OCEANS = Seasonal dynamics

of thermocline

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SUMMARYAQUATIC ECOSYSTEM VARY FROM LAKE, RIVER, SWAMP,

ESTUARY, AND OCEAN ENVIRONMENTS AND EACH HAVE UNIQUE AND DIVERSE SPECIES

LIVING IN IT.