Announcements. Third problem site due November 30 Review calculations

Transcription

1 Announcements Geology Primary Fields of Oceanography Chemistry Third problem site due November 30 Review calculations Next Thursday quiz on Kirchman reading (microbes) Moving from physical to biological oceanography Physics Upwelling mixed-layer depth Light attenuation Bottom topography Organic C production & degradation Biology Nutrients Contaminants Life in the Ocean: Lecture topics and conceptual models Food-web model (or energy-flow, bottom-up view): Nutrients, light... Phytoplankton Zooplankton DOC Fish, Birds, Mammals Microbes Microzooplankton Benthos 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 1

2 Depth Depth Depth 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. Density Density Light Density Algae 2

3 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) Plankton - Greek: πλαγκτός that which is made to wander and drift Why do we care? 1. Base of the oceanic food web 2. >half O 2 in atm. from phytoplankton 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 and paralytic shellfish poisoning. Initiates contaminant biomagnification 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 3

4 What are the major groups of phytoplankton? What are the major groups of phytoplankton? Cyanobacteria Photosynthetic bacteria! Tiny ( 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? Microflagellates Many other groups of flagellated phytoplankton Size: ~0.01 mm ( to 0.03 mm) Important groups Silicoflagellates Coccolithophores Phaeocystis Studying phytoplankton Plankton in Puget Sound Net plankton Bottle collection Laboratory cultures Mapping biomass from space Molecular investigations May 4

5 Phytoplankton of Puget Sound Diatoms: Skeletonema costatum Chaetoceros debilis Phytoplankton of Puget Sound Dinoflagellates: Ceratium fusus Protoperidinium divergens Thalassiosira aestivalis Chaetoceros convolutus Noctiluca miliaris Alexandrium catenella Phytoplankton of Puget Sound Other flagellates: Dictyocha Heterosigma agawashio Cyanobacteria major form Synechococcus Phaeocystis In Hood Canal: >70% of cells and ~20% spring biomass is Synechococcus In open ocean cyanobacteria can dominate biomass 5

6 Zooplankton of Puget Sound Copepods: Calanus Pseudocalanus Zooplankton of Puget Sound Gelatinous plankton: Aequorea victoria Pleurobranchia Euchaeta Acartia Oikopleura Zooplankton of Puget Sound Chaetognaths Sagitta elegans Zooplankton of Puget Sound Meroplankton: Urchin larva Crab larvae Cod larva 6

7 Hard-bottom intertidal benthos Fish Soft-bottom benthos Benthos: Greek for deep benqos Summary: Marine organisms and ecosystem function Size ranges of organisms of Puget Sound Primary production: Removes CO 2, nutrients (N, P, Fe, etc.), metals Converts dissolved CO 2 to particulate organic carbon, which sinks ( Biological Pump ) Produces oxygen Respiration: Releases CO 2, nutrients Uses oxygen Organic-matter consumption: sends energy throughout food web Organic-matter production and consumption drives nearly all of the other biogeochemical cycles 7

8 Diagram by David Karl 8