Bio 346 - Freshwater Eco. (Chpt 21) --> Phytoplankton Flashcards
How many divisions of algae are there in freshwater ecosystems?
6
Meroplankton
Planktonic algae that spend a part of their life on substrate
Benthic algae
Associate with shallow water sediments or its vegetation
How are sediments/ macrophytes resuspended?
By windy periods
What kind of algae are in rapid flushed streams?
Tycholankton
What king of algae are in slow flushed rivers?
True phytoplankton
Potamoplankton
The suspended algae of lotic systems
True phytoplankton
Are those that reproduce within the water column
What does wind speed do?
It increases mixture but does not produce more algae
What is specie richness determined by? (3 things)
- Physical environment
- Chemical environment
- Biological environment
What is abundance not a good measure of?
- Growth rate
- Importance of a species in energy flow
- Small species reproduce fast but also are removed fast
- Large species reproduce slow but are removed less frequently
What dominates the algal biomass of nutrient rich temperate lakes and slow flowing rivers?
- Large colonies
- Clusters of intertwined cells
- Single filament of cyanobacteria
–> also dominate on ice covered polar lakes and polar meltwater streams that freeze solid in winter
What dominates slow flowing rivers and lakes at lower latitudes?
Large cyanobacteria
What predominates among benthic algae of hot springs and antarctic pools?
Large cyanobacteria
What dominates oligotrophic lakes
Tiny cyanobacteria
What 7 factors determine the dominate of particular species?
- Nutrients
- Light
- Co2
- pH
- Temperature
- Turbulence
- Grazers
Where is variation in particular species is most dominant?
In high nutrient lakes because there is more P but limited by N
–> smaller algae can out compete larger algae
What forms water columns?
Dissolved nutrients
What are 3 negative effects of highly visible blue-green blooms?
- Aesthetically displeasing
- Interfere with drinking water plants
- Interfere with the production of toxins that can cause illness in humans and death in livestock and wildlife
What are sand filters used for?
Used in the plants to remove the algal particles from the water
What happens when water is affected by blue-green blooms?
Requires special and expensive treatment to make is acceptable, otherwise is causes illness or even death (due to the production of toxins)
What is the main nutrient linked to the algal blooms and toxins in water source?
P
What are the major sources of P? (3 things)
- Septic and sewage
- Storm water
- Fertilizers
Neurotoxins (alkaloids)
Cause neurodegenerative symptoms through disruption in communication between neutrons and muscles
Hepatotoxin (peptides)
Causes weakness, vomiting, diarrhea, respiratory blockages
Lipo-Polyssachrides
Cause skin irritation
What are toxins in cyanobacteria found linked to? (2 things)
- Neuro-degenerative disease
2. Hapato-degenerative disease
What re the top 3 places with toxic blooms?
- Finland
- UK
- Scandinavia
What is chl-a composed of?
- Unicellular flagellated cells
- Non-flaggellated cells
- Colonies
- Filaments
- macroscopic charophyceans
What makes a major contribution to the to the phytoplankton richness in freshwater lakes?
The microscopic green algae
Highly saline shallow lakes and wetlands are frequently dominated by what?
Green algae
What is euglenophyta characterized by?
A small number of flagellated species that normally make a very small contribution phytoplankton biomass
Where are euglenoids often abundant?
Amount the littoral zones and wetland vegetation and are sweet into rivers following storms
What do bacillariophyta (diatoms) dominate?
The species composition during spring and fall overturn with a sufficient supply of silica (to build an exoskeleton) in temperate lakes
What 2 lakes do diatoms make a major contribution to?
- Tropical lakes
2. Ultra-oligotrophic polar lakes
What does the group chrysophyta consist of?
Relatively few species of small single-celled flagellated colonies
What do chrysophyta modestly contribute to?
Species richness
- and a little to the phytoplankton biomass of eutrophic lakes
What are cryptophyta?
A second group of small or medium sized flagellates
Where do cryptophytas make their greatest proportional biomass contribution? (2 types of lakes)
- Oligotrophic polar lakes (more common)
2. Mesotrophic temperate lakes
What is an important determinant of the max growth rate over a large size range?
Cell size
What is an important determinant of the pathways of material and energy flow in aquatic systems?
Cell size
What are utermohl inverted microscopes used for?
To quantify and identify the small algae
Netplankton
The larger organisms retained by traditional plankton nets
Nanoplankton
Those too small to be quantitatively retained by the nets, but readily enumerated under the utermohl microscope
What are fluorescent dyes used for?
To allow phytoplankton as small as <1 um to be recognized
Picoplankton
Algae, bacteria and protozoa with a max dimension between 2um and 0.2um
Mictrophytes normally dominate in what kind of lakes, during what part of the year?
- Dominate in europohic lakes
- During summer periods
What happens to the doubling rate as size increases?
It decreases
Compare large organisms to small organisms (reproduction and nutrient uptake)
Larger organisms take in less nutrients and response slower compared to small organisms
What size organism dominates the primary production (large or small)?
Small
What does the close relationship between cell size and growth rate demonstrate?
It indicates that over a large size range, the influence of cell volume on growth rate is much stronger than differences in growth linked to the particular taxonomic grouping
What does the scatter around the best fit line between cell size and max growth demonstrate?
Shows that variables other than size plays a role in determining growth rates among species that differ little in size
r-selected species
Small organisms, characterized by high max growth and loss rates
k-selected species
Dominated by larger organisms with a reduced max growth rate
Why must the k-selected species experience a reduced loss rate?
To be able to maintain their abundance
What is the importance of chl-a?
Its a predictor of photosynthesis over a large (interval) scale
- can’t predict in a narrow range scale
What happens to volumetric production if chl-a increases
Increases linearly
Define the P:B ratio
Is the ratio of carbon fixed (P) to the phytoplankton biomass, expressed as carbon (B)per unit time
- It provides a useful measure of the rate at which algal carbon turns over
What are the mixed layers in an average P:B ratio?
High in transparent oligotrophic systems and is low within and among aquatic systems when the community biomass is high (eutrophic waters)
What do low ratios in entropic waters imply?
A low productivity per unit biomass of chl-a
What do low specific growth rates imply?
Loss rates must also be low to allow the high biomass to be maintained
What does a high P:B in nutrient poor transparent waters dominated by small species imply?
A rapid recycling of both organic matter and the nutrients in high demand
What is the result of self shading?
A reduced community P:B under conditions of high phytoplankton biomass is primarily attributable to a poor effective light climate
What does light limit?
Growth rates
What happens to self shading as the community P:B decreases?
Increases
What happens to the areal community production as self shading increases?
Increases with increasing nutrient richness but at a slower rate
What happens to nutrient rich lakes as nanoplankton P:B increases?
They become dominated by small algae
Eutrophication
Excess richness of nutrients in a lake or other body of water
What nutrients are responsible for the summer algal blooms in oligotrophic lakes?
N and P
What happens to Chl-a and TP as TN increases?
They both increase
What do N and/ or C do to algal biomass?
Nothing!
- They don’t increase
What is P necessary to produce?
High algal blooms
High grazers
Lower amount of biomass
Low grazers
Higher amount of biomass
