ESS Exam 2

Richness

Total number of species found in an area

Evenness

How equally represented is each species

α diversity

β diversity: between habitat diversity

Shannon vs Simpson

Shannon: strongly influenced by species richness and by rare species

Simpson: gives more weight to evenness

Types of Algae

• Cyanobacteria

• Green algae (chlorophyta)

• Diatoms

• Dinoflagellates

• Chrysophytes

• Euglenoids

Phytoplankton Identification is Based on morphology and physiology including:

• Pigments

• Locomotion

• Size

• Unique Biology

Cyanobacteria

• No nucleus

• (Usually) heterocysts

Green algae (chlorophyta)

Can be…

• Unicellular

• Colonial

• Filamentous

• Branching

Diatoms

• Key features:

• Silica cell walls (“frustules”)

• Two dominant shapes: centric or pennate

Dinoflagellates

• Key features

• Unicellular

• Have flagella (various lengths)

Chrysophytes

• Key features:

• Golden in color

• 1 or 2 flagella

Euglenoids

• Key features:

• Flagella

• Thrives in high nutrient environments

If it has heterocysts…

Cyanobacteria

If it is pretty

Diatom

If it looks like the Eifel tower…

Dinoflagellates

If it looks like a seed

Chrysophytes

If it has rounded edges

Euglenoids

If you can’t figure out what else it could be…

Green algae

Relative Abundance=

(# of individuals in a specific species/ total number of individuals of all species)*100%

Soft water

low concentrations of major ions

Hard water

High concentration of major ions

Dominate surface waters cations:

CA⁺⁺, Mg⁺⁺, Na⁺, K⁺

Major Surface waters anions:

HCO₃^-, CO_3^-, SO_4^-, Cl-

Salinity

total concentration of major cations and anions

Salinity of surface water range:

1-100,000mg L^-1

Conductivity

measure current carrying capacity of water

total dissolved solids

evaporate water to dryness, measure mass

weathering:

breakdown of rocks and mineral through physical and chemical processes

What is pH

pH=-log[H+]

Why should we care about pH?

H+ ions are extremely reactive

H+ and OH- have important effects on chemical reactions that occur in solution

Aquatic system pH is determined by

pH of inputs and alkalinity and acid neuralization capacity (ANC)

ANC is determined by

cations present in the system which is a function of parent material

a lakes pH is

a combination of acid inputs balanced by ANC

ANC =

Acid Neutralizing Capacity

Nekton

organisms like fish and mammals that swim actively

Seston

all particals

plankton

organisms that cant fight a current

tripton

dead particles

Relationship between fish and ph:

between 4 and 6 pH, fish have a positive growth relationship. after 6 pH there is obvious relationship. Lower pH binds sediment to gills of fish, suffocating them

Eukarya

Ubiquitous, possess a cell nucleus and organelles, metabolically constrained

Archaea –

Ubiquitous, metabolically diverse with undifferentiated cells

Bacteria

Ubiquitous, highly important in biogeochemical cycles. Include heterotrophs and autotrophs

Considering these evolutionary relationships, what then are phytoplankton or algae?

• NOT a genetic unit – Protista & Bacteria (although cyanobacteria are not “algae”).

• NOT a single habitat – meroplanktonic (both planktonic and benthic life stages), epiphytic (grows attached to plants), epilithic (grows attached to

rocks), etc.

• Includes unicellular, colonial and multicellular forms. Some quite large (macrophytes). NOT based purely on structure.

• ALL (almost!) are autotrophs or have autotrophic capabilities, but some can switch autotrophy on and off and some are mixotrophic.

• ALL are nonvascular (lacking specialized cells to transport water and nutrients)

Major groups of phytoplankton

• Bacterial

  • Cyanobacteria

• Eukaryotic

• Chlorophyta

• Cryptophyta

• Chrysophyta

  • Bacillariophyta

• Dinophyta

• Euglenophyta

Compensation irradiance

is the light level where Gross Photosynthesis equals respiration, or where NPP = 0.

Adaptations to stay planktonic

• cell size

• cell shape

  • Filamentous

  • Forming chains

  • Horns, spines and setae

  • Coloniality

• Density adjustments

  • Oil inclusions

  • Gas Vacuoles

• Flagella

principal primary producers in most aquatic ecosystems

Algea

phytoplankton dominate production in

lentic ecosystems

in lotic ecosystems

attached (epilithon, epiphyton) dominate

Plankton can adjust their sinking rates through

modification of cell shape and composition

Most common aquatic phototrophs are

eukaryotic with the exception of cyanobacteria

Local geology determines

the number and kind of dissolved ions in solutions

Ionic composition determines

ANC

ANC can mitigate

pH inputs making a system more

or less sensitive to low pH inputs (e.g. acid rain)

pH affects the

dominate form of CO2 in solution

and whether some metals are in solution or not and

can precipitate CaCO3 and affects a wide range of

organisms especially those with “tests” or shells

pH is a measure of

the H+ concentration

H+ is very reactive, and affects

many inorganic reactions and biological processes

Seasonal Productivity Cycles Drive

Calcite Precipitation

As pH changes

the dominant form of inorganic carbon changes, changing alkalinity

three main groups of primary producers in inland waters

phytoplankton periphyton macrophytes

Inland waters are

important processor of organic matter

Aquatic foodwebs are often supported by

allochthonous production

Most inland waters are

net heterotrophic

Inland waters are expected to

become an increasing source of CO2 to the atmosphere over the coming decades

Forms of Phosphorous

Organic vs. inorganic

Soluble (dissolved) vs. particulate

• Dissolved

• Orthophosphates

• Polyphosphates-detergents

• Colloids

• Low molecular weight esters

• Particulate

• Cells

• Minerals (including clays, carbonates and ferric hydroxide)

• Adsorbed onto particulate organic matter (POM)

PH3

Phosphine, Gaseous

Phosphorous sources

Rocks/soils (natural sources, overland runoff)

– Ca5(PO4)3: apatite (primarily igneous rocks, some

sedimentary)

–Decaying plant/animal matter in soil

–Guano

• Atmospheric

–Gaseous/particulate

• Human sources

Dissolved organic phosphorous

–Excretion of living organisms/decay of dead organisms

–Some detergents and pesticides

Dissolved inorganic phosphorous (aka “SRP”)

• Orthophosphate- PO4-3- used by plants

Particulate organic phosphorous

P in organic chemicals associated with living/dead

organisms, plant material & fecal material

Particulate inorganic phosphorous

– PO4-3 associated with particles

POP

Particulate organic phosphorous

• P in living/dead organisms, plant material & fecal material

DOP

Dissolved organic phosphorous

Excretion of living organisms/decay of dead organisms

Some detergents and pesticides

DIP

Dissolved inorganic phosphorus

Orthophosphate- PO4-3- used by plants

CP:

Colloidal phosphorous

Complexed with iron, carbonates, etc

Zooplankton and fish

Excrete organic P and phosphate

–Significant source of P for phytoplankton

–Vertical migrations influence P levels

Rooted plants

Transport phosphate from sediment to open water- uptake/

decay

Phytoplankton and Bacteria

Take up significant amounts of phosphate

–Excretion of some organic P

–Release phosphate upon decay

–Alkaline phosphatase

–Luxury consumption

Most phosphorus ends up in

the sediment

Clay content of sediment is important determinant of

P holding capacity

SEDIMENT-WATER COLUMN EXCHANGE

major component of cycle

SEDIMENT-WATER COLUMN EXCHANGE depends on

–(1) oxygen content (redox state) and

–(2) biological activity

Oxygen depletion of sediment primarily due to

bacterial decomposition of organic loading

(organisms dying and sinking to the bottom)

Most of sediment is

anoxic (all but top few cm)

The depth of O2 penetration in sediments is key to

PO4 exchange with water:

oxygenated zone acts as

• barrier for release into water

• a few mm makes a big difference in exchange rates

Oxygenated microzone can

“lock” materials in sediments

Ferrous Wheel (Top half, dissolved → sinking)

→ Fe⁺³→PO₄^-3→Fe⁺³ → FePO₄→

Ferrous Wheel (Bottom Half, solid →dissolved)

→ FePO₄→ PO_4^-3→ Fe⁺²→ PO₄^-3→ Fe⁺²→

P cycle

- no redox states, limited gaseous phase

- primarily released by weathering or mining (which

is really just human accelerated mining)

- internal nutrient loading well after nutrient inputs

stop

P is a major

element limiting primary productivity on a global scale

Very little P in is available in

the Epilimnion but

more in the Hypolimnion (generally)

Liebig’s Law of the Minimum

Growth rates or yields are limited by the single growth factor that is: in the shortest supply relative to its need

eutrophic lakes would____if phosphorus stopped being added

recover

Phosphorus release from the

sediments occurs at least 3 ways:

1. Sediment Release –anoxic hypolimnion

2. Bioturbation – stirring up/burrowing of sediment by

macroinvertebrates or fish – increases P release from

oxygenated sediments.

3. Resuspension – physical process transport sediments

back into the water column.

What causes Sediment Resuspension?

• Wind

• Boats

• Fish

Artificial Circulation

•If the lake is already stratified, mixing is only achieved above the depth of air injections

•If the lake is not stratified, injection near the surface can prevent stratification

•Involves disrupting stratification or preventing stratification using pumps and compressed air

•Air can also be used to oxygenate the hypolimnion

P has traditionally been considered to

limit primary and secondary productivity in freshwater ecosystems

More recent evidence suggests that

N and P may be regularly co-limiting