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Announcements

• Third problem site due November 27

– Review calculations

• Fourth problem set (new but short) due Dec. 6th

• A week from Tuesday– quiz on Kirchman reading

(microbes)

• Moving from physical to biological oceanography

• Reading: Ch 13, 325-335, Ch 14?

Primary Fields of Oceanography

Geology Chemistry

Physics Biology

Upwelling

mixed-layer depth

Light attenuation

Bottom topography

Organic C

production &

degradation

Nutrients

Contaminants

Nutrients, light... Phytoplankton Zooplankton

Benthos

Life in the Ocean: Lecture topics and conceptual models

Fish, Birds,

Mammals

Ecosystem Structure and Function:

Function: Organic-matter production, energy flow,

biogeochemical cycles

Structure: Spatial and temporal patterns of organism abundance,

community composition, and species diversity

Food-web model (or energy-flow, bottom-up view):

Microbes

Microzooplankton

DOC

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Topics for today:

I. Important organisms in Puget Sound

A. Nutrients and phytoplankton

B. Zooplankton

C. Microbes

D. Fish, mammals

E. Benthos

II. Primary productivity

A. Definitions

B. Measurement

C. Primary production limiting factors

Organisms and ecosystem function:

What factors limit abundance and

productivity of marine organisms?

Phytoplankton:

Light, nutrients, temperature,

salinity, (also pH, pressure)

Heterotrophs:

Food, temperature, salinity, etc.

Algae

Density

De

pth

Density

De

pth

Density

De

pth

Light

De

pth

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Structure: Ways of classifying marine organisms:

Plankton - drifts (phytoplankton, zooplankton)

Nekton - swims (fish, mammals)

Benthos - remains on the bottom (benthic algae, animals)

Taxonomy

Phytoplankton - protista

Zooplankton - protista, animalia (arthropoda, cnidaria, mollusca)

Nekton - animalia (vertebrata, arthropoda)

Microbes – protista, bacteria, archaea

Benthos - protista, plantae, animalia (many, many phyla)

1. Base of the oceanic food web

2. >half O2 in atm. from phytoplankton.

3. 1 gallon gasoline ≈ 1 metric tonne of plankton biomass.

4. Ecological Indicators of ecosystem health. (monitored by King Cty)

5. Toothpaste, aquarium filters, and SoftScrub®.

6. POISON: Red Tides or Harmful

Algal Blooms

Initiates contaminant biomagnification

Plankton - Greek: πλαγκτός

“that which is made to wander and drift”

Why do we care?

What are the major groups of

phytoplankton?• Diatoms

• Cell wall (frustule) made of silica

• Perhaps 12,000 to 30,000 species

• Two groups (orders:

– Centric (shaped like a petri dish)

– Pennate (shaped like a pen)

• Size ~0.1 mm (0.002 to 0.2 mm)

What are the major groups of

phytoplankton?• Dinoflagellates

“whirling whips”

• Two flagella for locomotion

• Very primitive protists

• ~ ½ photosynthetic and ~ ½

heterotrophic (some mixotrophic)

• Perhaps 2,000 species

• Size ~0.5 mm (0.005 to 1 mm)

• Many species produce toxins

• A few species form chains

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What are the major groups of

phytoplankton?

• Cyanobacteria

• Photosynthetic bacteria!

• Tiny (0.00005-0.04 mm)

• Probably the first photosynthetic

organisms

• Created earth’s oxygen ~ 2 bya

• Very diverse group with 9 major

divisions and three important genera

– Synecococcus

– Trichodesmium

– Prochlorococcus

• Number of species?

What are the major groups of

phytoplankton?

• Microflagellates

• Many other groups of flagellated

phytoplankton

• Size: ~0.01 mm (0.0002 to 0.03 mm)

• Important groups

– Silicoflagellates

– Coccolithophores

– Phaeocystis

Studying phytoplankton

• “Net” plankton

• Bottle collection

• Laboratory cultures

• Mapping biomass

from space

• Molecular

investigations

May

Plankton in Puget Sound

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Phytoplankton of Puget Sound

Diatoms:

Skeletonema costatumChaetoceros debilis

Chaetoceros convolutus

Thalassiosira

aestivalis

Phytoplankton of Puget Sound

Dinoflagellates:

Ceratium fusus

Noctiluca miliaris

Protoperidinium

divergens

Alexandrium

catenella

Phytoplankton of Puget Sound

Other flagellates:

Dictyocha Heterosigma agawashio

Phaeocystis

Cyanobacteria

• major form

– Synechococcus

• In Hood Canal: >70% of cells and ~20% spring biomass is Synechococcus

• In open ocean cyanobacteria can dominate biomass

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Zooplankton of Puget Sound

Copepods: Calanus Pseudocalanus

Acartia

Euchaeta

Zooplankton of Puget Sound

Gelatinous plankton:

Aequorea victoria Pleurobranchia

Oikopleura

Zooplankton of Puget Sound

Chaetognaths

Sagitta elegans

Zooplankton of Puget Sound

Meroplankton:

Crab larvae Cod larva

Urchin larva

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Benthos:

Greek for deep

“benqos”

Hard-bottom intertidal benthos

Soft-bottom benthos

Fish

Size ranges of organisms

of Puget Sound

Summary: Marine organisms and ecosystem function

Primary production:

Removes CO2, nutrients (N, P, Fe, etc.), metals

Converts dissolved CO2 to particulate organic carbon,

which sinks (“Biological Pump”)

Produces oxygen

Respiration:

Releases CO2, nutrients

Uses oxygen

Organic-matter consumption: sends energy throughout food web

Organic-matter production and consumption drives nearly all of the

other biogeochemical cycles

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Diagram by David Karl