BIOL 311 Flashcards
surface of the Earth covered by ocean
71%
average depth of the ocean
3700m
Number of oceans
5
Arctic, Pacific, Atlantic, Indian, Southern
Abiotic environment
solar radiation temperature salinity density pressure ocean currents
solar radiation lost to upper atmosphere
50%
solar radiation that makes it to the ocean
5% of remaining reflected
50% of remaining IR and UV - heat
50% of remaining visible spectrum
PAR
photosynthetic active radiation
spectral range of solar radiation- 400-700 nm- that photosynthetic organisms are able to use in photosynthesis
UV effect in the ocean
only upper 5-10m
lines of constant T
isotherms
Temperature regulated by
solar energy input
water mixing
temperature gradients
large latitudinal gradient
increasing up to the equator from N and S
maximal seasonal temperature changes
mid-latitudes
Influence of solar radiation on marine life
Photosynthesis E source T changes of the ocean Animal vision Physiological rhythms Depression of biological activity Damage by UV Controls vertical distribution of photosyn. organisms
Effect of solar radiation on physiological rhythms
Migration (e.g. salmon, turtles)
Movement to/from feeding grounds
Adjustment of position in intertidal
How solar radiation affects biological activity
high light deactivates proteins and DNA
Mixed layer
c.a 150m
increased temperature
increased productivity
decreased nutrients
disrupt equilibrium
stressful to system
Influence of temperature on marine life
Controls rate of chemical rxn’s and biological properties
Affects density of seawater
Influences dissolution of gases
Example of biological properties influenced by temperature
metabolism
growth
Important gasses influenced by T
CO2, O2
lower T = more gases
Latitudinal distributions of animals
summer migration b/c isotherms move up
Extremes of temperature regulation
Homeotherms
Poikilotherm
Homeotherm
maintains Tb at a constant level, usually above that of the environment - mammals, birds
Examples of intermediate temperature regulation
strong swimming fish retain heat from muscular action (Tuna)
Intertidal animals lower Tb by evap./circulation of body fluids
Extremes of temperature tolerance
Eurythermic
Stenothermic
Poikilotherm
internal temperature varies considerably- most fish, subtotal inverts.
Can withstand large ranges of temperatures
Eurythermic
salinity of open ocean
33-37
average 35
salinity units
we don't use units to describe salinity anymore (previously ppt) # of g per kg of seawater
salinity is measured in
conductivity
positive linear relationship with salt
Major constituents of seawater
Na, Cl, SO4, Mg, Ca, K
conservative elements
Organisms restricted to narrow temperature range
Stenothermic
e.g. corals
max salinity
mid latitudes
lines of constant salinity
isohalines
controls on salinity
precipitation
evaporation
runoff to a smaller degree
high salinity
evaporation > precipitation
latitude vs salinity graph
low at 60º N/S
high at 30º N/S
low at 0º N/S
very low at 90ºS
low salinity
precipitation > evaporation
near mouths of rivers
glacial melt
Influences of salinity on marine life
Osmosis
Diffusion
density changes (indirect)
affect of salinity on organisms in neritic environment
very affected
e.g. intertidal, tidal pools, enclosed marginal seas
affect of salinity on nekton
in smaller ways
fish drink water to compensate for osmotic loss, excrete salts in urine through gills
extremes of salinity tolerance
Euryhaline
Stenohaline
Euryhaline
adapt to a wide range of salinities
secondary thermocline
may form in the summer due to increased heating, decreased mixing
T-S diagram
Temperature vs. Salinity
curved lines across box = isopycnals(?)
latitude vs evap-precip
same shape as lat. vs. salinity but more extreme lows
low at 60ºN/S = p > e
high at 30ºN/S = e > p
very low at equator = e
density is a measure of
mass per unit volume
density is influenced by
Temperature
Salinity
how salinity affects density
increased salinity = increased density
what defines water masses
temperature
salinity
density
how temperature affects density
increased temperature = decreased density
latitude - density map
highest at high/low lats.
decreased down to equator - U/valley shaped
c.a. opposite of lat.-T map
a function of T and S
deep water formation
Antarctic bottom water
North Atlantic Deep Water
basic vertical structure of the water column
mixed layer
-clines
deep water
depth vs salinity graphs
high lats. = low at surface, increase in halocline, c.a. 35 at depth
low lats. = high at surface, decrease through halocline, c.a. 35 at depth
depth vs T graph
high at surface
decreases through thermocline
near 0 at depth
depth vs pycnocline
low at surface (lightest water mass)
increase through pycnocline
densest at depth (heaviest)
pressure is a measure of
the weight of the overlying water column per unit area at a particular depth
pressure changes with depth
increases nearly linearly
1 atm per 10m depth
pressure units
1 atm = 1 bar = 10 dbar
stenohaline
restricted to very narrow ranges of salinity
Thermohaline basics
circulation of the world oceans
caused by differences in density of water masses
regulates global T’s
Influence of density on marine life
affects floatation/sinking
how to measure depth
pressure
Influence of pressure on marine life
can be exposed to great pressure
biological effects not well understood
deep sea organisms don’t have gas filled organs
pressure faced by deep sea organisms
1000atm
why are pressure affects on deep sea organisms not well known
difficulties associated with collecting deep sea organisms
extremes of pressure tolerance
Eurybathic
Stenobathic
Average depth of the ocean
3700m
average pressure of the ocean
370atm
adapted to a wide range of pressures
Eurybathic - mostly shelf organisms with vertical migrations
creates/maintains surface currents
Earths rotation
Presence of continents
Wind/Weather
example of the affect of continents on ocean surface circulation
around Antarctica - no continents in the way, steady, fast current that is well maintained (Antarctic circumpolar current)
Affects of current on marine life
affect PP - upwelling/downwelling (ex. Peruvian west coast, extremely productive)
Upwelling (and downwelling) is a function of
Corialis force
Eckman transport
BC upwelling zone
not permanent because we are between two surface currents and the boundary moves seasonally
BC surface currents
California current
Alaska current
Ocean divisions based on light
Euphotic c.a. 100m
Disphotic c.a. 100-1000m
Aphotic c.a. max depth
Ocean divisions based on nearness to shore
Neritic - to edge of outer continental shelf
Pelagic - continental slope and beyond
Divisions of the pelagic zone (with depth)
epipelagic - to top of continental slope, c.a. 200m, euphotic in upper half
mesopelagic 200-1000m
bathypelagic 1000-4000
Abyssopelagic 4000- max depth
supralittoral
above high tide line
divisions of the continental shelf
littoral - high tide, low tide
sublittoral - inner, outer shelf
Euphotic zone
layer closer to the surface that receives enough light for photosynthesis to occur
down to 1% light
150-200m in clear water
disphotic zone
also twilight zone
light enough to see but not enough for photosynthesis
subdivisions of the bottom of the ocean
littoral sublittoral bathyal abyssal hadal
sublittoral
region of the ocean bottom between the low tide line and the edge of the continental shelf
euphotic zone in Saanich inlet
20m
what are plankton
floaters that drift with ocean currents
main groups of plankton
bacterioplankton
phytoplankton
zooplankton
plankton are characterized by
size
plankton sizes
Megaplankton (200-2000mm) Macroplankton (20-200mm) Mesoplankton (.2-20mm) Microplankton (.02-.2mm) Nanoplankton (.002-.02mm) Picoplankton (.2-2µm) Femtoplankton (.02-.2µm)
megaplankton
jellies
siphonophore and slap colonies
Macroplankton
krill
gelatinous zooplankton
mesoplankton
adult zooplankton
larval fish
microplankton
diatoms
dinoflagellates
invert. larvae
nanoplankton
cyanophytes
coccolithophores
silicoflagelates
picoplankton
cyanobacteria
femtoplankton
viruses
Nekton
swimmers
movement independent of ocean currents
some capable of long migration
nekton distribution controlled by
salinity temperature density pressure food availability
Nekton examples
adult fish
squid
marine mammals
marine reptiles
majority of oceans plankton are controlled in what size group
nanoplankton
microplankton
Benthic organisms
bottom dwellers
# decrease with depth
biomass decreases with depth
types of benthic organisms
epifauna
infauna
nektobenthos
nektobenthos
on the bottom
capable of swimming over seafloor
zooplankton feeding behaviours
herbivores
carnivores
omnivores
zooplankton size
Less than 1 mm to greater than 1 m
mm - m
zooplankton taxa
protozoans
invertebrates - cnidarians, ctenophores, Chaetognaths, arthropods, annelids, molluscs, echinoderms
vertebrates- urochordates, chordates
zooplankton key roles in marine food webs
primary consumers
primary link in energy transfer between base of food web and higher trophic levels
main grazers of phytoplankton
zooplankton
zooplankton trophic level
can occupy numerous levels
depends on length of food chain
zooplankton are a direct resource for
fish
seabirds
marine mammals
zooplankton that spend whole life cycle in plankton
holoplankton
shorter food chains
more efficient energy transfer
meroplankton
organisms that spend part of life cycle in plankton
many benthic and nektonic species
may be months - days
benefit to having planktonic larvae
provides sessile species means of dispersal
main reason marine populations are open and ‘connected’
squid life cycle
unique planktonic life cycle
adults and larvae are planktonic
only eggs are benthic
planktonic protozoan characteristics
single celled eukaryote usually solitary (some colonial) few µm's - 3mm diverse taxonomically key component of microbial loop
Ecologically important groups of planktonic protozoans
ciliates
foraminiferans
radiolarians
protozoans feed on
heterotrophic
bateria
detritus
small phytoplankton
protozoans important for
microbial loop
prey source for larger zooplankton
ciliates
some of largest free-living protists
up to 2mm long
ciliate structure
cell surface covered with short, dense cilia
cilia function
beat to propel organism through water and/or draw in food particles
eukaryote
contain nuclease and membrane enclosed organelles
foraminifera
CaCO3 test
cold water
radiolaria
SiO2
tropical/subtropical
pseudopodia
pseudopodia function
capture bacteria, phytoplankton, detritus
heterotrophic
cannot fix carbon
utilize organic carbon
radiolarians and foraminifera
more abundant in past
form extensive sediment layers
important to geologists for dating and determining ancient ocean conditions
protozoan groups
ciliates
radiolaria
foraminifera
tintinnid
silica belt
‘belt’ of silicious ooze around Antarctica (radiolarians and diatoms)
silica deposits used for
cleaners, toothpaste, bug repellant, cosmetic
gelatinous zooplankton
‘jellies’
Cnidarians, Ctenophores, primitive chordates
primitive chordates
pelagic tunicates:
Sales, Appendicularians
Cnidarians
‘true jellyfish’
have nematocysts
can inject very potent toxins
nematocyst
specialized cells may be barbed may 'sting' subdue prey capture stick
Ctenophores
'sea gooseberries' comb jellies capture small zooplankton w/ tentacles have colloblasts feed on zooplankton or some on other ctenophores
colloblasts
specialized cells
sticky cells on tentacles
Salps
pelagic tunicate filter feeder form dense patches cylindrical, gelatinous body w/ opening at each end unusual life cycle
salp locomotion/feeding
pump water through body
catch food particles on internal mucus net continuously secreted
Salp food
phytoplankton
bacteria
Salp life cycle
solitary asexual stage - forms budding chain of sexual aggregates - each aggregate produces an embryo - embryos in solitary asexual stage
Appendicularian
a.k.a larvacean primitive chordate, closely related to benthic tunicates, sea squirts resembles small tadpole 2-10mm long gelatinous/mucus house pump water
larvacean house
pump water through
sieves food particles
abandoned when filters clog
abandoned houses part of marine snow
marine snow
vector of transporting particles to deep
food source for other organisms
substrate for bacteria/protozoans
Chaetognaphs
arrow worms
small phylum
Chaetognath feeding
carnivorous raptors
attack plankton several times their size
hang motionless until prey detected
use spines and hooks to grab prey
Planktonic Molluscs
veliger larvae
pteropods
veliger larvae
planktonic larvae of most molluscs
many spend hours-months in plankton
many of the adults are benthic
pteropods
holoplanktonic molluscs
small planktonic snails
temperate/cold waters
foot evolved into paired swimming wings
Pteropod Clades
Thecosomes
Gymnosomes
Thecosomes
thin, coiled, calcareous shell, very light for floating
few mm - 30mm
sticky mucus web for feeding
e.g. Limacina spp.
Gymnosomes
naked (shell-less)
elongate
feed exclusively on thecosomes
e.g. Clione spp.
most diverse group of eukaryotes on Earth
Arthropods
Arthropods are characterized by
segmentation
paired, jointed appendages
hard, external skeleton
most important marine arthropods
crustaceans
Benthic arthropods
crabs, lobsters, etc.
usually have usually have meroplanktonic larvae
crustacean larvae
nauplius
Planktonic arthropods
nauplius larvae
Euphausiids
Amphipods
Copepods
Euphausiids
'krill' among largest zooplankton 1-10cm long shrimp like appearance stalked eyes multi-yr life cycle - up to 5 major food source to fish, whales
Euphausiid feeding
generally omnivorous
filter phyto. and zoop.
commercial krill
Euphausia pacifica
500 tonnes/yr in Strait of Georgia
others spp. 10^5 tonnes/yr in Antarctic
Krill migration
diel vertical migration
each night go up in water column to feed (dawn ascent), come back down in day (dawn descent)
visualizing diel vertical migrations
acoustic backscatter (can be seen by VENIS mooring)
UTC
coordinated universal time
BC time
Pacific Time Zone
UTC -08:00
Amphipods
laterally compressed c/w krill
almost exclusively carnivorous
direct development (no nauplius)
often live commensally w/ jellies
Most abundant zooplankton by far
copepod
usually >80%
Copepoda
c.a. 2000 spp. main phyto. grazers vertical migration 100s of µm - 10mm major prey of young fish key link to higher trophic levels
Copepod feeding
often consume >1/2 body weight in phyto./ day
some are carnivorous or omnivorous
Autotroph
producer
produce complex organic compounds
plankton sampling net
SCOR net
60cm diameter
250µm mesh
how to tell how much water has gone through plankton sampling net
flow meter
4 dials that turn opposite direction sequentially
write down #’s to start and at end
what we do with samples once retrieved
use splitter to split in half
freeze half for biomass measurement
preserve half in formalin for ID
how plankton sampling net works
tow up from bottom
send messenger down to hit release mechanism
hard holding top of net is let go
net is folded over
copepod morphology
straight body, antennae as long as body, 5 pairs swim legs, 1-5mm long, 3 body sections, no eyes
copepod body sections
prosome - ‘head’ + first body segment
metasome- posterior 1/2 of body
urosome - narrow posterior, looks like tail
copepod cephalasome
prosome + metasome
most common type of planktonic copepods
calanoid copepods
copepod taxonomy
Phylum Crustacea Subclass Copepoda
amphipod morphology
half-moon shaped, shorter antennae, 7 prs. walking legs, 2-50mm, laterally compressed, humpbacked, unstalked black eyes
amphipod body segments
head/thorax- head, antennae, body, walking legs
abdomen- posterior section of body, pleopods, uropods
determine plankton abundance
take pipette sample - count - extrapolate to size of sample - x2 (b/c half is frozen) - / volume of water filtered by net
how to find out volume of water filtered by net
flow meter or
V = pie * r^2 * h
x by efficiency
Euphausiid taxonomy
Phylum Curstacea
Order Euphausiacea
Euphausiid morphological characteristics
krill, curved body shrimp-like body prominent, stalked eyes 2 main body sections not laterally compressed usually largest crustacean zoop., 10-60mm 5 pairs of swimming legs
Euphausiid behaviour characteristics
form huge swarms
strong vertical migrators
Euphausiid body segments
anterior fused carapace
posterior segmented abdomen
Pteropod taxonomy
Phylum Mollusca
Order Pteropoda
Pteropods
sea butterflies
pelagic swimming gastropods
wing-like structures adapted from molluscan foot
shelled or shell-less
local pteropod genus
Limacina
most common shell-less pteropod genus
Clione
local Clione species feeds exclusively on Limacina
common local Euphausiids
Euphausia pacifica
Thysanoessa spinifera
Larvacean taxonomy
Phylum Chordata
Class Larvacea
Larvacean characteristics
not invertebrates
head, long tail, notochord
5-25mm
mucus house
Phylum Chaetognatha characteristics
arrow worms elongate arrow-shape 3 paired fins 1-10cm c.a. 60spp. do not have clearly differentiated head eyespots grasping spines on head
common local Chaetognath
Sagitta
Chaetognath feeding
exclusively carnivorous
prey on other zoop. and larval
Ostracod
segmented crustacean w/ head, thorax, abdomen all enclosed in hinged carapace which is held shut by strong muscles
most species
UTC
Coordinated Universal Time
PDT +7 hours
7 hours ahead of BC
why would organisms want to undergo diel vertical migration
avoid predation expenditure of energy (cooler waters at bottom during day)
phytoplankton size
<2µm - 2mm
most <100 µm
chains = several mm
phytoplankton coverings
SiO2
CaCO3
cellulose
ornamented
phytoplankton are
unicellular microscopic algae mostly individual (some chains) floaters (or weak swimmers)
Phytoplankton role in marine ecosystem
primary producer - photoautotroph
link abiotic and biotic environments
produce organic material
Phytoplankton photosynthetic pigments
chlorophyll a
accessory pigments
Photosynthesis
H2O + CO2 + E – CH2O + O2
Ecologically important phytoplankton groups
cyanobacteria (prokaryote)
Diatoms (eukaryote)
Coccolithophore (e)
Dinoflagellates (e)
why do diel migrations not go all the way to the bottom in Saanich Inlet?
anoxic layer!
depth of diel migration is probably the o-a boundary
Diel
a 24 hour cycle
Best time to sample for phytoplankton based on acoustic backscatter?
Dawn - zooplankton have undergone vertical migration (down) and will not be grazing/in the way
First photosynthetic organisms
cyanobacteria
c.a. 3.5bya
free oxygen in atmosphere
c.a. 2 bya
possible origin of photosynthetic organisms
purple sulfur bacteria
reduce C to carbs
photosyn. but no O2 release
use H2S not H2O
Prokaryotic phytoplankton
Cyanobacteria
2 groups of cyanobacteria
Coccoid cyanobacteria (Synechococcus) Prochlorophythes (Prochlorococcus)
why are we only concerned with 2 groups of cyanobacteria
they are ubiquitous and represent a large fraction of phytoplankton biomass and productivity in the oceans
discovery of Synechococcus
1980’s by its intense orange phycoerythrin fluorescence
largest group of zooplankton
copepods, by far
smallest known photoautotroph
Prochlorococcus (prochlorophythes)
single cell
thrives in oligotrophic regions
Prochlorococcus discovery
late 1980s
dim red fluorescence detected
Synechococcus
solitary cells or clusters/pairs
accidental discovery
other cyanobacteria group
Trichodesmium
diazotroph
bacteria/archaea that fix atmos. N gas into a more usable form such as ammonia
-water must be calm, warm
Best known planktonic diazotroph
Trichodesmium
colonial or free-living
Diatoms
single cell or chains
two types of cells
frustule
Diatom cell types
centric (radial)
pennate (bilateral)
diatom frustule
SiO2 or Opal Epitheca (top) Hypotheca (bottom) Cingulum (girdle bands, overlap) pores Pseudoseptum, septum in epitheca
chain-forming diatom cell type
pennate and centrics
diatom productivity is highest
in areas of upwelling
west coasts
coccolithophore
unicell or colony
may be flagellated
body scales
affect climate
coccolithophore scales
coccoliths
CaCO3
coccolithophore impacts
produce CO2 during calcification
produce DMS - cloud formation
produce biogenic sediments
calcification
2HCO3- + Ca 2+ — CaCO3 + CO2 + H2O
coccolithophore sediments
calcareous ooze
chalk/limestone (lithified ooze)
diatom sediments
siliceous ooze diatomaceous earth (lithified ooze)
Dinoflagellates
unicells, chains 2 flagella (sometimes) rotary swimming theca may bioluminesce may produce toxins
difference between cyanobacteria and other bacteria
cyano. - autotrophic
other bacteria - heterotrophic
how cyanobacteria are unique compared with other photosynthesizers
have accessory pigments to cover more of spectrum - allows success in various habitats
theca
dinoflagellate covering
cellulose plates
prokaryote photosynthesizer
cyanobacteria
Cingulum
area where diatom thecae overlap
expands w/ cell growth
Centric diatoms
predominantly planktonic
Diatom covering
organic layer outside of frustule to prevent dissolution
frustule studies
lots of concern over how they’re formed and used
nanotechnology, medical, space, neuro
HAB
harmful algal bloom
aggregation of dinof.
harmful effects to humans and marine environment
some contain poisonous toxins
most abundant element on Earth
Si
HAB in coastal BC waters
Alexandium catenella
saxitoxin
PSP
saxitoxin
neurotoxin
Na channel blocker
PSP
paralytic shellfish poisoning
Adaptations for planktonic existence
small size spines chain forming ionic regulation of cell lipids/oil drops gas vesicles carbohydrate ballast flagella
planktonic adaptation, small size
staying afloat
planktonic adaptations, spines
increase SA:V
increase drag
planktonic adaptations, chain forming
reduce sinking
planktonic adaptations, ionic regulation
actively release heavier ions
makes them lighter (diatoms)
planktonic adaptations, lipids/oil
increase buoyancy
nutrient storage
planktonic adaptations, gas vesicles
internal tubes filled with air to move up
increase buoyancy
(cyanobacteria)
planktonic adaptations, carbohydrate ballast
create carbs to fill tubes and reduce air in them move down
sinking for nutrients
(cyanobacteria)
planktonic adaptation, flagella
locomotion
Importance of phytoplankton
PP - food chain base Form extensive blooms Influence atmospheric/aquatic chemistry Form oil, siliceous, and limestone deposits Impact global climate Geochemical cycle
Phytoplankton chemistry changes
Produce O2
Drawdown CO2
Sink carbon
Contribute to cloud formation
Control of Si levels in surface waters
Si cycle controlled by diatoms
Planktoniella sol
mucogenic extensions (like a sun) parachute that helps float
Pennate diatom environment
predominantly benthic
Problem with chain forming/colonial diatoms
can be harmful to farmed fish - Si sharp, tear up gills
farm fish can’t leave area
first plankton to bloom in spring
diatoms
abundant in cool, nutrient rich waters
why are nutrients high in deep waters
not being used
accumulate -sinking of unused particles/detritus
remineralized back in to useable forms by heterotrophic bacteria
Area between nutrient high deep waters and nutrient low surface
Nutricline
Pseudo-nitzschia
pennate, stick together at ends, produce neurotoxin (demoic acid)
Coccolithophore impact on carbon system
variable depending on shell formation and sink
in surface water approx. equal
long term = sink
Emiliania
abundant coccolith that produces DMS - cloud nuclei
phytoplankton reproduction
asexual
up to 1 daughter/ day
exponential growth in #s
Effects of ocean acidification
lowers shell integrity, dissolves
decreases ability for plate formation
Red tides
HAB
mostly dinoflagellates
(not always red)
First true oceanographic research cruise
Challenger Expedition
Challenger expedition
1872 - 1876 Atlantic, Pacific, Southern oceans physical, chemical, bio sampling deep sea currents discovery of Marianas Trench
Considerations for choice of sampling methods and design
target - organisms? fish, viruses? who how many - abundance? how often -spatially/temporally what do they do - productivity, movement
Sampling considerations, target
size
age-structure
whole community
Sampling considerations, how many, how often
Numeric abundance (individuals / m3)
Biomass (mg chla/m3)
spatial/temporal trends in abundance (within or between)
Sampling considerations, what do they do
Movement - vertical migration
Productivity - rate of population growth
Sampling considerations, physical data
CTD probe
irradiance (PAR)
[O2]
chlorophyll fluorescence
Light absorbed by chl a
use in photosynthesis
dissipated as heat
re-emitted as fluorescent red light (5%)
Measuring chlorophyll fluorescence in vivo
excite seawater sample w/ blue light - chl absorbed by chl - chl fluoresces – measure red light produced
mechanisms for measuring chl in vivo
sample tube blue LED red filter photo diode detector volt meter
Water sampling
Traditional - Niskin bottle suspended from a wire
Modern Method - CTD-Rosette
water sampling, traditional method
discrete depth measurements
bottles ‘tripped’ close with ‘messengers’ (weights)
water sampling, modern method
up to 36 niskins in a frame
CTD, fluorometer
real-time data
computer controlled firing
Niskin bottles used for
quantitative sampling: phytoplankton, bacteria, virusis
Phytoplankton sampling (biomass)
usually estimated with [Chl]
Qualitative phytoplankton sampling
fine mesh net (less than 20µm)
not used often - too fine, tears easily
Counting/Identifying bacteria, phytoplankton
Inverted light/epifluorescence microscopy
Flow cytometer
Cell/particle counter (mainly phyto.)
submersible flow cytometer (mainly phyto.)
Imaging particle analysis (phyto. and zoo.)
Sediment traps (settling material)
zooplankton sampling
net
net system
computer-assisted counting technology
high-frequency acoustics (biomass)
zooplankton net size
70µm - greater than 1mm
types of zooplankton nets
ring net
closing net
bongo net
tucker trawl
multiple zooplankton net system
MOCNESS
Multiple Opening/Closing Net and Environmental Sensing System
how in situ fluorescence measurement works
Blue light in – red light out in a manner proportional to amount of chl
bottom of euphotic zone
irradiance less than 1%
computer assisted zooplankton counter
Optical Plankton Counter
Vertically stratified sampling
determine differences in depth distribution (#s, biomass)
using basic nets - tow up from bottom - another sample from mid - another from surface - use subtraction to find different depths
needs many samples
Net sampling problems
nets don’t catch everything
patchiness
get clogged
logistics - sample processing
epifluorescence microscope
put organisms in, let them settle (~24hrs), shines specific wavelengths – small to large range of cells
Flow Cam
larger cells, similar to flow cytometer, laser, takes picture when laser hits a particle
Submersible flow cytometer
characterize light signatures, also takes pictures
velocity of water in front of plankton net
increases closer to net
Organisms that can sense hydrodynamic disturbance can avoid the net
sediment trap
understand C transfers measure ‘raining’ of particles/marine snow mesh top (to keep fish out) – funnel – tube (on a timer so it moves to the next tube)
Sediment traps
long lines moored to bottom different depths tethered to surface free drifting (acoustic release and recovery)
Ring net
zooplankton sampling of large portion of water column not multiple specific depth samples
velocity through net mouth vs time
measured for flowmeter in middle and out to side of net, difference between the two gives an idea of how clogged net is getting
CPR
Continuous (Zoo) Plankton Recorder
CPR used when
towed by ships of opportunity
how CPR works
water flow – filtering silk– silk rolled into storage tank w/ formalin
later id’d, counted
‘greenness’ = weak indicator
CPR coverage
greatest along major shipping routes
optical counting methods
count and size zoop. automatically
can’t ID
VPR
Video Plankton Recorder
collects underway video images of zooplankton
BIOMAPER II
comines VPR w/ CTD, bioacoustics, fluorometer, etc.
Bioacoustics measurements
high frequency (200kHz) pulse emitted from hull-mounted echosounder (or installed on platforms)
how bioacoustics works
ping every 2s, record vertical, temporal variations in [organism] in water column
reflects off zooplankton (and fish)
used to measure diel vertical migration
ZAP measures
concentrations and patterns throughout the year
problems with ZAP
acoustic backscatter
background noise masks acoustic scatter
no ID - requires direct sampling for verification
acoustic dead zone - difficult to measure benthic
information collected on event logs
date, station name, physical conditions, event #, event type, time, lat/long., bottom depth, cast depth, extra notes
Graphing, figure caption
figure numbered sequentially specific, concise what, where, when date, organization, data handling details of legend
Graphing, lines
continuous data = solid line
discrete data = dotted/dashed line
Graphing, colour mixing
avoid using red/green together
don’t use colours close in hue
avoid grayscale
Graphing, font and details
leading zeros on decimals
significant fig.’s only
capital letters for parts (A.)
At least 9pt. and bold
Plankton distribution
not homogenous
differences due to light, nutrients
In vivo fluorescence data
not very accurate
needs to be quantified w/ physical samples
over-interpreting discrete data
actual trend may differ significantly from estimated trend line
can cause misleading conclusions
be cautious when interpreting
combination plot
multiple x-axes
useful for comparisons and co-varying trends
graph dimensions
oceanographic graphs are usually taller than wide
waterfall plot
multiple profiles on same graph
add constant to successive plots to spread them out for visual ease
plotting zooplankton data
stacked bar graph
abundance vs station
stacks are the taxa
our sampling boat
MSV John Strickland
Sampling we did
CTD
Niskin
Net tow
Sampling we did, CTD
salinity temperature density PAR fluorescence dissolved oxygen
Sampling we did, Niskins
Dissolved nutrients (Nitrate, Phosphate, Silicic acid) Phytoplankton biomass (chl a)
Sampling we did, zooplankton nets
taxonomy
biomass
How CTD measurements are taken
lower through water column 1m/s
type of CTD we use
SeaBird SBE19
SBE43 Oxygen sensor
WetLabs Wetstar fluorometer
Biospherical PAR
How we measured Chl
glass fibre filter (0.7µm) into filtration funnel base - measure some water - draw through filter with vacuum (5mm Hg) - rinse w/ FSW - freeze - dry - weigh
Our zooplankton net
60cm diameter SCOR net
250µm mesh
closing attachment
flow meter
How the net is towed
1m/s up (I think we did 0.5m/s)
faster = net damage
Net retrieval
carefully bring weights on to deck
wash down so plankton goes in to cod-end (keep it up straight)
never grab by the net
pour into splitter, wash with FSW, freeze half, preserve half
role of phytoplankton in the ocean
fix CO2 into organic matter
pass Corg from producers – consumers and the deep
Return C to seawater
how carbon is returned to seawater
respiration bacterial decomposition (remineralization, decay)
Where carbon ends up in ocean
returned to seawater or ‘locked away’ in sediments
How satellites measure phytoplankton
reflectance of light (at certain wavelengths) is altered by algae
PB
phytoplankton biomass
standing stock
total phytoplankton in a given area or volume of water
PP
Primary productivity
RATE at which organic matter is produced by PP’s via photosynthesis
Phytoplankton ‘bloom’
accumulation of biomass in a particular area, typically from increase PP/cell division
productivity is
a change with TIME
PB measured as
cells/L m^2 or m^3
g C or N/L or /m^2
g Chlorophyll a/L m^2 m^3
PB #cells measured how
counted with microscope or particle counter
PB g C measured how
elemental analyzer
PB g Chlorophyll measured how
fluorescence
most common way to measure PB
fluorescence
(g Chl a / area or volume
Methods for measuring Chl
In vivo fluorescence
In vitro fluorescence
Remote sensing w/ Satellites
In vivo fluorescence
flow-through fluorometer emits blue light causing organisms to fluoresce red light which is measured and converted to a Chl estimate
In vitro fluorescence
sample sw at various depths collect samples filter known volume extract Chl from filter put in acetone (24hr) measure in fluorometer
Remote sensing with satellites
converts ocean color measurement to Chl a
benefit of satellite measuring chlorophyll
ability to examine global patterns
Satellites can measure how much
5-25m depth
Important ocean color satellites
Coastal Zone Color Scanner (CZCS, 1978-1986)
Sea-viewing Wide Field-of-view Sensor (SeaWiFS, 1997-2010)
MERIS (Europe, 2002-2012)
MODIS (NASA, since 2000)
GPP
Gross PP = total PP
total org. matter produced by phyto. / unit time
NPP
Net PP = GPP - respiration
amount of org. matter produced by phyto. that is available to primary consumers / unit time
Is PP proportional to Biomass
sometimes
not always
Methods for measuring PP
integrate over temporal/spatial scales Satellite (months, globally) O2 mass balance (weeks, mixed layer) Incubations (days, specific depth) FRRF (minutes, single cells)
FRRF
fast repetition rate flourometry – how fast can a single cell grow
Incubation methods for measuring primary productivity
Measure the evolution of O2
Measure the uptake of CO2 (14C/13C)
Measure the uptake of N or Si (15N, 32Si)
how incubations are conducted
incubate seawater samples in light and dark bottles (at different light intensities) for several hours
O2 technique for measuring primary productivity
leave light and dark bottles in water column (different depths) for period of time
measure O2 given off by photosynthesis and utilized during respiration
what is incubations
tracking the different components of productivity (evolution of O2…) using isotopes to trace movement of component in to cells
processes that occur in light bottles
photosynthesis
respiration
processes that occur in dark bottles
respiration
Measurement taken from light bottle
NPP
PP - Respiration
measurement taken from dark bottle
Respiration
Calculating GPP
light bottle + dark bottle
NPP + R
Factors that regulate PP
Light quantity and quality
Nutrient availability
Grazing Pressure
Temperature (to a lesser degree)
Why is temperature not as important of a regulator on PP as the others
because organisms adapt
rapid changes in T are more of a factor than T itself
Light that reaches ocean surface
50% of insolation reaches surface
1/2 of that is absorbed/scattered in first few m’s
1/2 of remaining light is visible spectrum and penetrate water
The 1/8 of light that penetrates the ocean in the visible spectrum
PAR
photosynthetically active radiation
UV spectrum
400 - 700nm
1/4 of light that is absorbed in the first few m’s of the ocean
UV radiation (380nm) scattered IR radiation converted to heat
Depth to which visible light can penetrate the water column is a function of
Wavelength of light
Clarity of the water
Penetration of light as a function of wavelength
Blue - deeper
Red - shallower
Penetration of light as a function of water clarity
more particulate/dissolved matter = more rapid absorption/scattering
light penetration, open ocean
deeper relative to coastal due to less particulates
why isn’t max PP at 0m?
TOO much UV
photo inhibition
compensation depth
NPP = 0 GPP = R
Determine NPP, GPP, compensation depth from graph
depth vs. PP
NPP and GPP have same shape curve with GPP being a fixed constant larger - that constant is R
comp. depth is where NPP curve goes to 0
Net efficiency
takes in to account that not the whole ‘cylinder’ of water passes through the net due to the net clogging
80% was determined experimentally
What happens below compensation depth
productivity may still occur but is lower than productivity
Transmittance vs wavelength
high and low wavelengths have low transmittance, and it decreases with lower clarity of water
Low transmittance =
high absorption
particle rich waters
Energy vs wavelength
low E at 400, 700 nm
highest E 500nm
E curve is lower in more turbid waters
Coastal waters - E barely rises
Light intensity decay
exponential with depth
Light Intensity, I_D
I_o * e^(-k*d) I_D = radiation at depth I_o = radiation at surface k = light extinction coefficient D = depth (exponential equation)
Light intensity vs depth
max at surface, drops off exponentially
clear ocean water curve is to the right of turbid coastal water
How to find the bottom of the euphotic zone
use sensor
calculate I_D
determining k
Radiometer
Secchi disk
Radiometer
records light intensity directly
Secchi disk
depth at which it ‘disappears’ is called Secchi disk depth D_s
K = 1.7 / D_s
Gravimetric determination of zooplankton biomass
filter on petri dish - weigh - put filter paper in filtration funnel - pour sample into funnel - rinse - suction water through filter - filter back on petri - dry in oven (60ºC 24-48hrs) - weigh - / volume of water through net * efficiency * 2 (sample was split in 1/2)
zooplankton abundance determination
measure amount of water in an jar w/ same amount of liquid as sample - take 10/20mL of sample - put in Bogorov tray - ID and count
SCOR
Scientific Committee on Oceanic Research
Dominant type of zooplankton in our samples
copepod
what does copepod morphology say about it’s lifestyle
no eyes - lives in dark
cephalic sensory organs + appendages - motile
oil/lipids - buoyancy, floating
role of phytoplankton in the oceans
fix CO2 into org matter
pass OM from prod. - cons.
return C to seawater where deposition ‘locks it away’
Carbon is returned to seawater through
respiration
bacterial decomp
How do phytoplankton deal with variability in light quality
use accessory pigments to harvest additional light energy
carotenoids
How do phytoplankton deal with variability in high quantity
photosynthesis vs irradiance
relationship differed based on water mass and species
light intensity decay dependent on
particles in water column
disphotic zone in turbid waters
higher
depth of the euphotic zone
compensation depth
1% irradiance
photosynthesis and light intensity
proportional until P_max
P_max
maximum photosynthesis value
P_gross =
Pmax * I / K_I + I
I = ambient PAR
K_I = half saturation constant
K_I
I when P = Pmax/2
P_max response to
environmental changes which affect dark rxn’s of photosyn.
Comparing P_max and K_I
to determine species dominance
measure light intensity
PAR
light sensor
radiometer
K =
ln (I_o) - ln(I_D) / D
I_O = light at surface
I_D = light at depth
what if K is known but I is not
calculate depth a % of light intensity is at
I_D = I_0 * e(-k * d)
0.5 = 1.0 * e(-k * d)
beyond P_max
photo inhibition
too much light
saturation
D_cr
critical depth
depth above which total production = total respiration in the water column
Ī_D
average light intensity
=[ I_o / (kD) ] [ 1 - e ^ -kD]
D_cr =
I_o / k *I_c
GPP_w = R_w
GPP _w - R_w = 0
depth of mixing > D_cr
no phytoplankton bloom
GPP_w < R_w
NPP_w < 0
mixing depth > D_cr
no bloom
D_c controlled by
transparency of water
seasons
why does critical depth affect bloom
if cells mixed below D_cr they will be using products faster than producing them
what are nutrients
chemical substances
support life
dissolved salts
precursors for synthesis of OM
N use
proteins
nucleic acids
P use
nucleic acids
teeth, bones, shells
Na use
body fluid
osmotic regulation
Mg use
osmotic balance
Chl production
S use
proteins
cell division
Cl use
nerve discharge
osmotic regulation
ATP
K use
nerve discharge
osmotic regulation
enzyme activation
Ca use
shells
bones
coral
teeth
mixing depth < D_cr
phytoplankton bloom
can achieve surplus of products
Si use
tests and other support structures
Fe use
e- transport
GPP_w > R_w
NPP_w > 0
bloom
nutrient requirements
different organisms have different requirements, availability can contribute to changes in community composition, succession
nutrients and PP
can regulate PP when light is abundant
limiting resource
Essential phytoplankton growth elements
C, N, H, P, O, Fe, Cu, Mg, Mn, Mo, Zn
Also most require S, K, Ca
nutrients essential for some phytoplankton
Na, Si, Cl, Co, Se, B, I
Vitamins
required by most phytoplankton
Vitamin B12, Vit B1, Biotin
Vitamin B12
cyanocobalamine
cobalamine
Vitamin B1
thiamine
phytoplankton and vitamins
since most don’t produce vitamins they are actually auxotrophic (produce their own organics)
Macronutrient
present in µM’s
C, N, P, H, O, Si
micronutrients
trace elements
present in nM’s
Fe, Zn, Cu, Mn
nutrients that are never limiting
Na, K, Ca, Mg, Cl, SO4, H2O, CO2
nutrients that are limiting
N, P, Si, Fe, organics, vitamins
short supply
bio-limiting
Bio-limiting nutrient
depleted in surface water by biological uptake in photosynthesis
returned at depth from bacterial degradation
bio-limiting profile
typical low in surface, increase to bottom of euphotic, stabilize with depth
Redfield ratio
linear regression of dissolved [Nitrate] vs [Phosphate]
106C : 16N : 1P (mol/mol)
variations in bio-limiting profiles between regions
same overall shape
difference []s at depth due to thermohaline circulation (Pacific > Atlantic)
critical depth is calculated based on
properties of the water column
e.g. transparency
independent of mixing
D_c, D_cr
D_cr > D_c always
CDT (theory)
Critical depth theory Gran, Broarud (1935), Sverdrup (1953) relationship btw light and productivity underrepresented grazing does not apply to every region
why does CDT not always apply
grazing pressures and other limiting factors that affect productivity of the water column
biogeochemical cycles
nutrient cycles
mineral cycles
flow of nutrients btw ocean, atmosphere, land
nutrient biogeochemical cycle
inorganic material – OM —- up food web — microbial loop — back to photosyn. zone – IM —
biogeochemical cycle controls
biotic and abiotic processes
affect form and physical state
biotic processes, biogeochemical cycle
Inorganics - Organics by phytopl.
CO2, Si(OH)4, NO3
decomp. of OM by bacteria
return inorg to water
abiotic processes
wind mixing upwelling river discharge sewage outfall atmosphere- ocean diffusion atmospheric input (dust) add nutrients to water
common PP, PB limiting factor
N
Nitrogen cycle, components
N2 (gas), NO3 (nitrate), NO2 (nitrite), NH4 (ammonium), NH3 (ammonia), CO(NH2)2 (urea), Amino acids, other DIN
DIN
N2, NO3-, NO2-, NH4+, NH3
most abundant N species
N2 (780µM)
NO3 (0-40µM)
all else 0-3 µM
N2 (g) use
only by cyanobacteria, must fix in to useable form
DON
Urea, Amino acids, others
preferred N forms for PP
NO3, NH4
dictates preference for any species of a nutrient
lowest Energy requirement
N used for
aa's enzymes, proteins nucleotides, nucleic acids ATP chl
To use N as NO3, NO2, urea, etc.
must first reduce it to NH4, requires ATP + enzymes
this is why NH4 is preferred (but is low in abidance)
processes that bring N to surface waters
runoff gas exchange upwelling deep/winter mixing denitrification??
processes that contribute to loss of N from surface ocean
nitrification
fixation
??
limiting factor in modern ocean system
nitrogen
New production
portion of PP that results from utilization of ‘new nitrogen’
mainly NO3, N2
regenerated production
portion of PP resulting from ‘regenerated nitrogen’
mainly NH4, urea
new production
ca. = export production
Processes that bring Si to surface ocean
Upwelling of nutrient rich H2O river/groundwater discharge Aeolian Hydrothermal processes Seafloor weathering weathering of silicate minerals
Processes that contribute to loss of Si from surface ocean
Sedimentation of diatoms, radiolarians, silicoflagellates
“Lost” particulate Si eventually recycled back (dissolution)
Production and dissolution of biogenic bSiO2
kinetics of nutrient uptake
depend on transport mechanism
passive diffusion
facilitated diffusion
passive diffusion
V proportional to S
V = uptake rate
S = external concentration of nutrient (substrate)
active transport
saturation of carriers as S increases
rectangular hyperbola, Michaelis Menten uptake
K_s and molecular diffusion
lower K_s = higher affinity of carrier site for molecule
in limiting nutrient scenarios, K_s
low K_s species out-compete and dominate
paradox of the plankton
different species, different needs, coexisting?
gradients, mixing, many factors constantly changing
contemporaneous disequilibrium
each species has different nutrient requirements, K_s, K_I, etc.., will dominate in some time and space but conditions will change and favour another species. ever changing balance
what is the redfield ratio
atomic ratio of carbon, nitrogen and phosphorus found in phytoplankton and throughout the deep oceans
most N is in the form
N2 - not utilized by most plankton
N most commonly used by plankton
NO3
aminoacid formation
need NH4, must reduce
NO3 - NO2 - NH4
typical plankton cycle
spring bloom - use up NO3 - NO3 replenished by winter mixing
HNLC
High Nitrate Low Chlorophyll regions
3 large regions - 1/3 of oceans
no spring bloom
surplus NO3
HNLC regions of the world
subarctic Pacific Ocean
eastern equatorial Pacific Ocean
Southern Ocean
Fe in the ocean
dissolved [Fe] very low
ppm - ppt
less than 0.2 nM
average 0.07nM
Fe in the ocean
dissolved [Fe] very low
ppm - ppt
less than 0.2 nM
average 0.07nM
Fe profile
nutrient-like profile
limiting in surface
open ocean Fe sources
upwelling
Aeolian (dust, ash)
coastal eddies
hydrothermal vents
Coastal Fe sources
rivers
continental runoff
resuspension of bottom sed.
Fe-requiring pathways
photosynthesis
nitrogen assimilation
synthesis of chl a
nitrogen assimilation, Fe
Fe needs for synthesis of Nitrate Reductase (NR) and Nitrite Reductase (NiR)
convert NO3 - NO2 - NH4
IRON hypothesis
Dr. John Martin, 1986
phyto. growth in HNLC areas limited by Fe availability
Testing Iron hypothesis
test tubes of natural seawater spike w/ Fe
observations of Fe testing
dramatic increase in [Chl a]
decrease in [NO3]
first Fe experiment
1989
Southern ocean
Dr. Martin
criticism of Fe experiments
skeptical of results
small containers, no mixing
zooplankton removed
possibility of Fe contamination
evidence for Fe hypothesis
Ice age - less rain, dry dusty Earth - dust blowing over ocean - massive phytoplankton bloom - CO2 drawdown - aid in further climate cooling
results of further Fe testing
using ultra-clean techniques founds Fe stimulates growth and NO3 uptake in all 3 HNLC regions
why are nutrient concentrations higher in deep water
remineralization throughout water column
below nutricline nutrients not being used for photosyn.
return > use
where do we see deviations from red field ratio
fixation of N2
Fe limitation
growth and NO3 uptake from Fe experiment
mostly occurred in large size cells, diatoms
mainly >10µM
open ocean cells
generally small
size-biased response to Fe
picoplankton have lower K_s for Fe
greater SA:V
why SA:V matters in size-bias response to Fe
pico plankton are better able to absorb molecules in low concentration
IronEx 1
Oct 1993
1st ocean manipulation
single Fe pulse - 65k ^2, eastern equatorial Pacific
tracked w/ Chl a fluorescence, SF6 inert gas
results of IronEx1
2-3 days = 3X [Chl a]
4X NPP
no measurable drawdown of NO3, CO2
4 days = fertilized water subjects below pycnocline
IronExII
June 1995
64km^2 patch, 3X 1 week
tracked w/ Chl a, SF6
IronEx II results
19 days, drifted 10-100km/day 2X Phyto growth rates 25X [Chl a] 50% decrease [NO3] O-A CO2 flux decreased 60% micro, meso zooplankton biomass doubled
SOIREE
Jan-Mar 1999
Southern Ocean
Fe added repeatedly over few weeks
SOIREE results
dissolve Fe decreased photo. competency increased PB increased PP increased N decreased from surface large drawdown of atmospheric CO2 DMS increased
DMS produced by
haptophytes (Phaeocystis) large gelatinous colonies or unicellular extensive blooms in temperate ocean dominate polar phyto assemblage 10% of total global DMS flux
SERIES
July-Aug 2002 Subarctic NE Pacific nutrients decreased, chl increased diatoms dominant pseudo-nitzschia abundance at peak of bloom
common finding in mesoscale Fe experiments
all result in phytoplankton blooms
wide range of bloom signature
steep curve in active transport kinetics
lower Ks (really good at uptake) – have high affinity for that nutrient, will dominate
why shouldn’t zooplankton be removed from fe experiment
not a natural system
does help to isolate the area of interest though
why is dissolved Fe added to ocean
so that it is bioavailable
discourage sinking
Where would you expect to see Phaeocystis
higher Fe, low Si
limiting environment for diatoms
where does C go in Fe experiments
may sink out
may flux back to atmosphere
why does C flux back to atmosphere
increased productivity = increased grazing = increased respiration
LOHAFEX
Feb, Mar 2009
Indo-German, SW Alt
300km^2 inside eddy
followed 39 days
LOHAFEX results
Chl a biomass 2X in 2wks heavy grazing pressure some C sank out some CO2 flux to atmos Phaeocystis bloom
Ice ages
last ice age 30X higher dust
higher bio productivity
risks of Fe fertilization
toxic blooms (Pseudo-nitzschia)
increased heterotrophy may cause higher CO2 flux to atmos.
increased DMS
commercial interests in Fe fertilization
increased fish production
delayed mode observing system
data retrieved when instrument recovered
long term use
require batteries
may become unknowingly disrupted
autonomous marine observatory
moored buoys that provide power to seafloor instruments and satellite communication link to land, communicate in real-time
battery powered
cabled marine observatory
linked to land by summarize cables providing a limitless source of power and communications/internet connectivity
continuous data, high resolution/frequency, expensive, not battery
observatory instrumentation
continuous presence high sampling frequency co-located sensors (multiple types of sampling) interactivity (tell what to do) event detection (set thresholds)
observatory limitations
not all variables measurable - reproductive state, physiological condition, metabolism, live sampling
not being able to do live sampling limits
community dynamics
population genetics
species colonization
ESP
environmental sample processor discrete water samples concentrate microorganisms molecular probes ID microorganisms and genes
Other observatory identification tool
plankton counting and imaging using back-lit LED cameras
SCIPPS
ZAP
monitors presence/abundance of zoop. and fish by measuring acoustic backscatter
whale fall research
zombie worm, Osedax sp., digest whale by acid secretion; successional stages
Our cabled observatories
VENUS - Salish sea, 10yrs old
NEPTUNE - 800km long, Port Alberni loop, across JDF plate, spreading ridge, Endeavour vents
community observatories
open source
smaller scale, easier to maintain
shallow water
10 in Canada
Instruments in an observatory
Node (power) hydrophone array camera platform seafloor camera instrument platform
being measured by NEPTUNE
earthquake, tsunami ocean currents, waves PP C flux Ocean acidification ZOOP Biomass migration Mammal migration benthic ecology dynamics
NEPTUNE core instrumentation
CTDs ZAP ADCP Oxygen sensor Nitrate sensor CO2 sensor Fluorometer sediment traps hydrophones video cameras seismomemeters pressure reader vertical profiler
Saanich inlet
24km fjord max depth 200m 75-80m sill inverse estuary deep, wide sill weak turbulence anoxic most of year
Saanich Buoy profiling system
moored 3km S of VENUS
7m surface platform
profiling instrument package
3 pt fixed mooring
BPS instrumentation
Meterological station (Air T, barometer, relative humidity, wind) MacArtney Winch (raise/lower CTD) CTD, O2 sensor, c hl, fluorescence, optical turbidity
BPS profiling mode
4 profiling cycles a day
parked at 200m
most common way to determine amount of phytoplankton
measure amount of Chl
most common technique for measuring Chl
extract from filtered sample using acetone, measure fluorescence in fluorometer
fluorescence is
process where photosynthetic pigments absorb list at one wavelength and emit light at another; intensity is proportional to amount
phaeopigments
breakdown products of chlorophyll produced during digestion by zooplankton
correct for by reading again after acidifying with HCl