slide1
Download
Skip this Video
Download Presentation
Reminder: Midterm 1 is one week from today on Friday February 1st

Loading in 2 Seconds...

play fullscreen
1 / 11

Reminder: Midterm 1 is one week from today on Friday February 1st - PowerPoint PPT Presentation


  • 126 Views
  • Uploaded on

Big!!. Reminder: Midterm 1 is one week from today on Friday February 1st. Midterm 1 is 15% of your final grade It covers all lectures through Monday January 28th It covers all reading assigned for weeks 1-4 (up to and including “Ecology of Water Columns)

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about ' Reminder: Midterm 1 is one week from today on Friday February 1st' - elgin


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
slide1

Big!!

Reminder: Midterm 1 is one week from today on Friday February 1st

  • Midterm 1 is 15% of your final grade
  • It covers all lectures through Monday January 28th
  • It covers all reading assigned for weeks 1-4 (up to and including “Ecology of Water Columns)
  • It will be short answer comprehensive based upon understanding of content, not problem solving.

Extended office hours next week for Professor Prézelin

Monday 11AM-1PM

Wednesday 10AM-NOON

Phyto Story: The monster diatom Coscinodiscus wailessi

Common Indo-Pacific Ocean species, invaded English Channelin 1977 when likely introduced by ballast waters of ships or exotic shellfish (oysters) transplanted to European coastal mariculture facilities. Invasion spread rapidly to Atlantic coast of France by 1978 & Norway by 1979.

Effects on the environment: They bloom & produce copious mucilage that glue particles in water together & sink to blanket the seabed in mucilage, affecting gas & nutrient exchange at sediment/water column interface.

Effects on commercial interests: Fishing trawls become clogged or broken by heavy grey slime.

Regular sized diatoms

slide2

Light-inhibited PP and m

Light saturated PP and m

at ~60 % Pmax, cell division rates become maximal, eg. m =mmax

Light limited PP but Light saturated m

Light limited PP & Growth rates (m )

No PP, No growth, possible Senescence (decay, death, ), formation Resting stages,

Pmax

slide3

slopes

b, beta

a, alpha

Ik

It

a

b

= Ps rate/ PFD

Ik = Pmax/alpha

It = Pmax/beta

Parameters of Photosynthesis-Irradiance curves

without photoinhibition,Ps = Pmax . tanh (I/Ik)

with photoinhibition,Ps = [Pmax . tanh (I/Ik)] minus [ eq. describing shape of beta] Beta varies from a linear to exponential decline

slide4

Comparison of P-I curves for different algae under different growth conditions

P-I relationships are a “signature” of the

photo-physiological state of the phytoplankton

cell, population, and mixed community

  • Which has the highest Pmax?
  • Which has the highest alpha?
  • Which has the lowest Ik?
  • At 50 mEin m-2 s-1, which has the greatest rates of Ps?
  • At 200 mEin m-2 s-1, which has the greatest rates of Ps?
  • Above what QPAR does Ceratophylum

Ps rates exceed those of Hydrilla?

One mole of hv = one Einstein of hv = one Ein

= 6.02 x 10 23 molecules

slide5

Chl biomass as f(x) of depth (z)

hv

PP

Can predict in situ Ps rates if

Chl distribution or QPAR profiles change

In situ bottle measurements provide estimtew ofin situ rates of PP for one t,z but has no predictive value

P-I approach allows for estimating and predicting in situ PP for any t,z where light &Chl are known

  • NB: this FW experiment measured O2 changes in bottles, which is why respiration values are reported
  • marine PP studies use C14 uptake bottles similarly deployed; do not get respiration rates and PP measurement is something between NPP and GPP
  • Problem with C14 bottles,

some of uptake C14 gets respired during long incubations & bacteria accumulate & community biology changes

Photoinhibition and/or photorespiration

Light saturated photosynthesis, Pmax

Light-limited (alpha portion of P-I curve)

IF water column was well mixed, Chl was constant as a function of depth, & just one P-I Curve could describe phytoplankton photophysiology throughout the water column, then the depth-dependent PP could be viewed as

slide6

P-I sampling strategies for determination of in situ rates of primary productivity, PP

For determinations of instantaneous in situ PP at one place (z) and time (t)

PPz,t, expressed as mg C/m3/hr or mgC/mg Chl/hr

need to measure (Qpar)z,t and (Chl a)z,t and experimentally determine (P-I)z,t,

using (P-I)z,t, could estimate PP for other conditions (Qpar)z,t and (Chl a)z,t although the accuracy would depend on the P-I response remaining constant

i.e. Daily rates of PP at same location

(PP)z, expressed as mg C/m3/day or mgC/mg Chl/day

i.e. Integrated water column PP

(SPP)t, expressed as mg C/m2/hr or mgC/mg Chl/hr)

i.e. Daily integrated water column PP

SPP, expressed as mg C/m2/day or mgC/mg Chl/day)

Accuracy increases with knowledge of how P-I, Chl a, and Qpar vary as f(x) of t,z.

slide7

Lecture 10: FYI for readings on waters in or near the Santa Barbara Channel (SBC)

SBC resides in northern portion of the Southern California Bight (not Bite)

California Current (CC): cool, nutrient rich, flows south along the outer edge of the Continental Shelf (1000 m).

Southern California CounterCurrent (SCCC):warmer, lower nutrient waters of the northerly flow of the hugs the coastline until encountering the SBC which block much of the flow and divert it seward to mix with the CC.

Episodic upwelling north of Pt. Conception produces cold, nutrient rich water which mixes with the CC waterforming sharpfrontal boundaries as it encounters the SCCC.

Subtropical oligotrophic waters flow north along the coast in summer months, more so in El Nino years

Marked gradients in the physical, chemical, biological and optical properties of the upper water column (0 to 160 m) are observed across the SBC coastal region.

SST

slide8

The abundance, composition and photosynthetic capabilities of phytoplankton communities vary widely across the frontal boundaries in SBC and extending seaward

Surface Pmax/vol

Surface Chl /vol

Surface water temperature, SST

From your reading P et al 1987

slide9

SBC, fig. From P et al. 1987.

Note differences in pigment concentration range for cold, front, warm waters

slide10

expressed as mg C/m3/hr

Synechococcus

Diatom-dominated

??

slide11

Net phytoplankton feed the linear food via larger zooplankton

Nano- and pico-phytoplankton feed the microbial loop

Comment on phytoplankton size and food chain dynamics

ad