Phytoplankton Succession

Differences between aquatic and terrestrial ecosystems

There are more autotrophs, detrital production, detritus, and decomposers in terrestrial ecosystems but more herbivores in marine ecosystems

What does light availability depend on in marine ecosystems

Season and mixing

What do nutrient concentrations depend on in marine ecosystems

Mixing and also on recycling (terrestrial sources)

What is the Margalef Mandala

It is a model that illustrates how succession and r and k selection functions in ecosystems with varying levels of nutrients and turbulence. The diagonal shows main succession from nutrient rich, turbulent waters to calm, nutrient poor waters

Phytoplankton dynamics in eutrophic vs oligotrophic lakes

Physical factor — same between the two

Grazing — More grazing in eutrophic lakes especially in spring

Nutrient limitation — Much more nutrient limitation in oligotrophic lakes and almost none in eutrophic lakes

Zooplankton dynamics in eutrophic vs oligotrophic lakes

Physical factor — Same between the two

Feeding by fish — very similar but more in eutrophic lakes

food limitation — eutrophic lakes have food limitation in spring and summer and none the rest of the time while oligotrophic lakes have food limitation the entire year except spring into summer

What does carbon export largely depend on

Depends on phytoplankton species composition. Large, heavy species sink faster, toxic species get eaten less, sticky or spiny species form larger heavy aggregates (sink faster)

Characteristics of cyanobacteria bloom

Increase — PH, chlorophyll-a, phytoplankton richness, phytoplankton RUE

Decrease — Water transparency, Zooplankton richness, Zooplankton RUE

Characteristics of Dinophyta blooms

Increasing — Water transparency, phytoplankton RUE, Zooplankton richness

Decreasing — Zooplankton RUE, Phytoplankton richness

Characteristics of chlorophyta blooms

Increasing — Water transparency, Phytoplankton RUE

Decreasing — PH, chlorophyll-a, phosphorus, zooplankton richness, zooplankton RUE

Characteristics of Mixed blooms

Increasing — PH, chlorophyll-a, phosphorus, phytoplankton RUE

Decreasing — Water transparency, zooplankton richness, zooplankton RUE

Describe annual biomass of phytoplankton globally

Looks very low across the entire globe with some activity at the northern polar regions

Describe annual maximum biomass globally

Most activity is at higher latitudes and not in temperate or tropical regions due to mixing conditions

Describe total divisions from minimum-to-maximum for phytoplankton globally

Much more activity visible near and along the equator

Describe light availability seasonally

Light availability increases in spring supporting the spring bloom. Light levels remain high during summer, but biomass is low (grazing by zooplankton) meaning that light is not a limiting factor. Light availability drops off in autumn

What factor influences light availability

Mixing (surface mixing allows more light and deeper mixing reduces light because plankton are transported deeper)

Describe how nutrients change throughout the seasons and impact phytoplankton biomass

There are new (mainly inorganic), nutrients brought up through mixing in spring which supports spring bloom. During summer there are more organic nutrients because they are recycled. In fall there is more upwelling of inorganic nutrients due to seasonal storms and mixing which supports the second fall bloom

In calm nutrient poor areas what phytoplankton are present

more k selective

In turbulent nutrient rich areas what phytoplankton are present

More r selective

What is an example of an early successional phytoplankton species

Diatoms

What is an example of a late successional phytoplankton species

Dinoflagellates

Describe dynamics between large and small phytoplankton in eutrophic lakes

The first bloom in spring is almost entirely made up of small phytoplankton and gets grazed down by zooplankton. In summer the large phytoplankton dominate (represents a later large scale successional state), zooplankton populations also rise in summer. There is another small bloom in autumn that is dominated by small phytoplankton again

Describe dynamics between large and small zooplankton in eutrophic lakes

In spring large zooplankton dominate and graze away the first phytoplankton bloom. Summer is dominated by small zooplankton (this is because large zooplankton don’t have enough time to react after the spring bloom crashes).

What is the big takeaway from the comparison of eutrophic and oligotrophic lakes

That adding nutrients to a system doesn’t just increase biomass but completely changes the successional cycle and the way that phytoplankton and zooplankton function

How do marine heatwaves impact phytoplankton communities

Increased temperature alters phytoplankton communities. Increases in Syndiniales sp. (parasitic dinoflagellates) They can kill phytoplankton efficiently.

Life cycle of Syndiniales

Dinospore infects host, grows (multiplies) until host bursts, releases the vermiform (many dinospores clustered together), spores break apart and infect new hosts

Alkalinity enhancement method

Where you add material that are proton acceptors (alkalinity enhancers) that bind carbonic acid (thus binding CO2) in the stable form of bicarbonate. Kills two birds with one stone because it diffuses carbon from atmosphere and also increases PH thus reducing ocean acidification

Describe the method of PH enhancement

Mimics the natural process of mineral weathering but speeds it up. Grind minerals such as olivine or quicklime into a very fine powder to maximize surface area and increase the speed of the reaction

Different places where ocean alkalinity enhancement can be used

Directly dropped into ocean by boat, put into ocean through water treatment plants, added to land so it is washed into ocean