BIOL 208: Lecture 5 - Aquatic Biomes

****How are Aquatic biomes Classified (2)

1. Salt

2. Fresh

****What are the further classifications of FRESH water?

1. Lotic = Moving (rivers + streams)

2. Lentic = Still (ponds, lakes + wetlands)

Define LIMNOLOGY?

The study of INLAND AQUATIC SYSTEMS

• eg. rivers, lakes, ponds, wetlands etc.

******What are the 2 BROAD VERTICAL divisions of aquatic zones for ALL aquatic systems (oceans + others)?

Pelagic: Off bottom of aquatic environment in the water

Benthic: BOTTOM of aquatic environment

****What are the 5 OCEAN VERTICAL ZONES. Place them in order from top to bottom and indicate which are PELAGIC + which are BENTHIC

Pelagic (thus all have pelagic in name)

1. Epipelagic:

2. Mesopelagic

3. Bathypelagic

Benthic

4. Abyssal

5. Hadal

****What is the EPIPELAGIC ZONE also known as?

Photic zone

• high light + temp

TRUE OR FALSE: Organisms in the EPIPELAGIC zone tend to be dull in color as they need to camouflage due to the high light that passes through the zone?

FALSE

• tend to be BRIGHT COLOR

*****What type of Water movement is ALGAE BLOOMS related to and why?

COASTAL UPWELLING: replacing water moving away from shore due to Ekman transportation when the wind is blowing parallel to the coast with DEEPER waters

• Deep waters = Nutrient rich

Are algae blooms good or bad?

Depends on:

• species + density

What are the conditions in the BATHYPELAGIC ZONE?

LOW: Light + temp

HIGH Pressure

Organisms living in the Bathypelagic zone, adapt to their environment. How do they adapt their METABOLISM?

Slow it down

****What are the 2 water sources of RIVERS?

1. Rain runoff

2. Ground water

Finish the sentence: Rivers ___ most of the landscapes of this world

DRAIN

****What are the HORIZONTAL ZONES of RIVERS? Define each zone (3)

Furthest from shore

1. Wetted channel

   • Permanently has water

2. Active channel

   • Has water at certain times of the year

3. Riparian Zone

   • Transition between water + land

Closest to shore

****What are the VERTICAL ZONES of a RIVER? List them in order. (4)

1. Water Zone

2. Benthic zone (Bottom)

3. Hyporheic Zone

4. Phreatic zone

****Define Hyporheic + Phreatic Zone and What special organism live in each?

Hyporheic = Where Surface water meets ground water

• Organism = HYPORHEOS

Phreatic zone = Ground water

• Organism = Phreatobites

*****What are some Adaptations of HYPORHEOS + PHREATOBITES and How do they differ in LIFESPAN?

Hyporheos = adapted to HIGHER O2 + SHORTER LIFE SPAN

Phreatobites = no eyes b/c no light to see + LONGER LIFE SPANS = slower metabolism?

****What are the HORIZONTAL ZONES of STILL WATER? Define each zone (2)

1. Littoral = Along lake edge

2. Limnetic = open lake (further in)

*****What are the VERTICAL ZONES of STILL WATER? (3)

1. Epilimnion: warm

2. Metalimnion

3. Hypolimnion: Dark + cold

(Limnion Like LIMNETIC)

***Define Thermocline + identify which of the 3 vertical layers in still water = the Thermocline

Metalimnion

• Thermocline = rapid decrease in temp

***What are some organisms are typically found in the Epilimnion?

Phytoplankton, fish + birds

****What is the O2 concentration at the HYPOLIMNION? Why?

LOW

• Due to Organic matter settled + accumulated at bottom, decomposers= use up the O2 present

• Also cannot dissolve more O2 from the atmosphere because it is separated from it

Define Thermal stratification

Water bodies, particularly lakes, develop separate layers due to temperature differences

• Driven by solar heating

Is hot or cold water more dense?

Cold

Is ice less or more dense than water?

Less dense

*******At what temperature is Water the MOST DENSE?

4 degrees Celsius

****In temperate lakes specifically, during WHICH SEASONS is there THERMAL STRATIFICATION or is there ALWAYS Thermal stratification? If there is thermal strat. what are the temps?

Summer: Top = 28, middle = 8, Bottom = 4

Winter: Top = 0 (ice), middle = 3, Bottom = 4

****There is NO thermal stratification During spring + fall for Temperate Lakes; what does this allow to occur within the lake?

MIXING OF LAYERS as all layers are 4 degrees = TURN OVER

****How does the MIXING of Layers affect the Lake?

Increase productivity esp. of Phytoplankton (primary prod.)

• evenly distribute Nutrients + O2 to all layers

****What are the 3 CLASSIFICATION of LAKES by Productivity

1. Oligotrophic

2. Eutrophic

3. Dystrophic

***Define OLIGOTROPHIC lakes by their: Color, Nutrients, Primary production, O2 lvls + Diversity/organisms

Color = Clear Blue

Nutrients = Low [N] + [P]

Primary Prod = Low (bc low nutrients)

O2 lvls = HIGH

Diversity = Animals adapted to conditions eg. trout (adapted to high o2)

Why is O2 lvls high in OLIGOTROPHIC lakes?

• [O2] is affected by: ALGAE growth + Rate of die-off + Decomposition of aquatic plants = related to high demand in O2

Low nutrients = Low algae growth = Less organic matter settled at bottom of lake = less decomposer activity

More light penetration b/c clear blue color = increase phytoplankton activity

***Define EUTROPHIC lakes by their: Color, Nutrients, Primary production, O2 lvls + Diversity/organisms

Color = Green

Nutrients = HIGH [N] + [P]

Primary Prod = HIGH (bc High nutrients)

O2 lvls = VARIES

• In the summers = Low (LOTS OF ALGAE BLOOMS, block sun, use up o2 + create organic matter for decomposers)

Diversity = Animals adapted to conditions eg. cat fish

Define Eutrophication

Addition of EXCESS NUTRIENTS to a lake due to run off from farms etc. = cause algae blooms which reduce O2 concentrations

***Define DYSTROPHIC lakes by their: Color, Nutrients, Primary production, O2 lvls + Diversity/organisms

Color = Brown

Nutrients = HIGH HUMIC ACIDS

• AKA Humic Lakes

Primary Prod = LOW (bc of Low pH)

O2 lvls = LOW

• bacterial decomposition of the organic matter

Diversity = LOW

*What are the 2 Fresh water wetlands?

1. Fens

2. Bogs

*Compare + Contrast Fens + Bogs: Water source, pH, topography + Plant diversity

Water source:

• Fens = Ground water

• Bogs = Rainwater

PH

• Fens = Varies (depends on minerals)

• Bogs = ACIDIC (acid rain)

Topography

• Fens = Flat

• Bogs = Bumpy/lumpy

Plant diversity

• Fens = Grasses, sedges, mosses + vascular plants

• Bogs = Mosses, Carnivorous plants, shrubs + hardy tree species

****Define NICHE

Range of ABIOTIC conditions + BIOTIC interactions in which an organism can survive, grow + reproduce (required factors)

• Abstract concept not a specific location

*****Fundamental vs. Realized niche?

Fundamental aka. Physiological conditions:

• Physical conditions (ABIOTIC) under which a species might live in the absence of interactions w others

Realized:

• Environmental conditions under which a species might live when restricted by interactions (BIOTIC) with other species

********What is the Competitive exclusion principle?

No 2 species that depend on the same limiting factors can occupy the same realized niche (coexist) indefinitely

Evolution of Niche: Joseph Grinnell

Focused on ABIOTIC CONDITIONS

Evolution of Niche: Charles Eton

Included BIOTIC to abiotic

****Evolution of Niche: HUTCHINSONIAN NICHE

MANY factors affect niche

****What is the n-Dimensional Hypervolume?

Hutchinsonian Niche

• ALL the things that influence where something lives + allows it to live its best life GRAPHED in a HYPERVOLUME

• Where ‘n’ = the # of environmental factors important to survival

  • More factors added = harder to graph

****Why do we Characterize the niche?

To predict where species are found + encountered

*What are 4 THINGS we can PREDICT/DO by characterizing the niche?

1. Actual + potential change in geographic range of a species

2. Bring back species from brink of extinction

3. Expansion of new invasive species

4. How far + fast will range of expansion occur with a change in environmental suitability

***What are 3 Ways we characterize the niche. And 1 specific way for Invasive species?

1. Historical data on species distribution

2. Geographic Information systems (GIS)

3. Climate modeling

Invasive

• Habitat conditions found in regions of origin

***What are some Other factors used to characterize niche depending on species studies?

• Soil type (eg. plants)

• Presence of Predators + competitors (eg. Animals)

*******What did ROBERT MACARTHUR study

Competitive Exclusion Principle

• Using Warblers

  • all insectivores that live in the same type of forest/trees

****What specific activity did ROBERT MACARTHUR Observe + what was his CONCLUSION?

Observed amount of time spent in each level of tree + how it differed between species of warblers

Conclusion: Each species had a distinct FEEDING ZONE

***What type of Strategy did the Warblers apply to decrease competition?

Avoidance strategy

*****How can species avoid being excluded from the niche?

NICHE PARTITIONING

*****Define NICHE PARTITIONING

Species in a community use the same limiting factors (resources) in Different ways

• occupy different Realized niches + coexist

• Decrease direct competition

****What are the types of Resource partitioning?

Where, Which, How or when Resources/factors are used

1. Spatial (warblers)

2. Dietary (food source change)

3. Temporal