Marine life: the plankton Production & Energy Transfer Part of Chapter 12, Chapter 13 (review) Organization of life Prokaryotes (usually no nucleus simple life forms) Domain Archaea: : most are extremophiles (prefer environments with high temp/pressure); hard livin bacteria Domain Bacteria: : regular bacteria; no nucleus or organelles Eukaryotes (has nucleus complex organisms) Domain Eukarya: : all complex organisms with nucleus, organelles; includes plants, animals, fungi, protists (simple cells) 1
(review) Organization of life 3 Domains 5 Kingdoms Kingdom Monera (bacteria) Kingdom Protoctista (algae and protozoa) Kingdom Fungi (mold and lichens) Kingdom Plantae (multi-celled plants) Kingdom Animalia (sponges to humans) Organization of life Eukarya Bacteria Archaea 2
Bacteria Very important in the grand scheme of things Can live anywhere on anything Bacteria in the deepest darkest reaches of the Earth Some make their own food (autotrophic), some do not (heterotrophic) Plankton Kingdoms Monera,Protoctista Plankton = organisms (both plant and animal) that cannot swim against a current ( floaters( floaters ; drifters) Phytoplankton = plant-like drifters Zooplankton = animal-like drifters 3
Lifestyles of the small and feeble Holoplankton: : plankton that spend their whole lives within the water column e.g. jellyfish, krill, copepods Meroplankton: : plankton that spend some portion of their lives on the bottom (usually juvenile or postlarval stages) e.g. sea urchins, sea stars, octopi, lobsters Sunlight Drives the Oceans (?) Let s s Review: The oceans are stratified The surface is warm and well-lit Biological elements (nutrients) are generally low Most of the ocean is deep, dark, and cold So why is sunlight so important? 4
Sunlight changes color with depth. Sunlight also disappears REALLY fast! 5
6
http://www.lifesci.ucsb.edu/~biolum/ 7
Sunlight Drives the Oceans (?) Let s s Review: The oceans are stratified The surface is warm and well-lit Biological elements (nutrients) are generally low Most of the ocean is deep, dark, and cold So why is sunlight so important? Huge Change--Mass Extinction! 8
Primary production Autotrophs make their own food via Photosynthesis (plants) Using H 2 O, CO 2, light, and nutrients to make organic material (Equation of Life) Most ecosystems based on photosynthesis (99.9% of oceans s biomass relies on photoysnthesis-supplied organic matter!) Chemosynthesis (bacteria) Using chemical energy to make organic material Hydrothermal vents The secret of photosynthesis A phytoplankton cell is like a potato--it s s full of starch, oils, and other energy storing compounds that let the cell survive when it s not in sunlight. 9
Hydrothermal Vent: Chemosynthesis Production Autotrophs called Primary Producers Primary production - rate how fast they grow g C / m 2 / yr Biomass - an amount or standing stock g C / m 2 Heterotrophs called Secondary Producers cannot make own food Must eat. 10
Needs of phytoplankton Need light and nutrients Must stay within sunlit layer (for photosynthesis) Must have nutrients in environment for growth Must be able to TAKE IN these nutrients efficiently Must expel wastes Primary producers: who are they? 11
Ocean Primary Production Algae (not same as vascular plants) Microalgae - phytoplankton, single-cell, tiny (µm) Macroalgae - seaweeds All have photosynthetic pigments Chlorophyll - absorbs blue, reflects green Phycoerythrin - absorbs blue, reflects red Fucoxanthin - absorbs blue, reflects yellow 12
Global Phytoplankton Biomass Microalgae: : Diatoms 13
Microalgae: : Dinoflagellates Macroalgae: : Green Seaweeds Ulva lactuca Chlorophyta Sea Lettuce 14
Macroalgae: : Red Seaweeds Porphyra sp. Rhodophyta Nori (mmm ) Macroalgae: : Brown Seaweeds Macrocystis pyrifera Phaeophyta Kelp 15
Primary Production Photosynthesis Energy IN (Sun) (High E molecules) CH 2 O + O 2 (sugar) CO 2 + H 2 O (Low E molecules) Respiration Energy OUT Primary Production: building biomass What about lipids, proteins, etc.? Use ATP $ Adenosine Triphosphate P (phosphorous) is key Other nutrients? 16
Primary Production Chemical Composition of typical algae 1. The Major Elements % tissue Limiting? Oxygen ~60 No Carbon ~20 No Hydrogen ~10 No 2. The Minor Elements Macro-nutrients Nitrogen 1-5 Often Phosphorous 1-5 Often Micro-nutrients (Na, Cl, Mg, Zn, Si, Co, Fe ) <0.05 Perhaps Primary Production So our Equation of Life Photosynthesis 2 + 6H 2O! C6H12O6 6 6CO + O Respiration is really more complicated CO 2 + PO 4 + NO 3 + H 2 O CH 2 O,P,N + O 2 carbon dioxide + phosphate + nitrate + water becomes organic tissue + oxygen 2 17
Primary Production CO 2 + PO 4 + NO 3 + H 2 O CH 2 O,P,N + O 2 Redfield Ratio (C:N:P = 106:16:1) Approx. concentration of elements in phytoplankton each in relation to each other; nearly constant ratios C 106 N 16 P 1 (by atoms) C 106 N 16 Si 16 P 1 (diatoms) - Add (Fe,Cu,Mn,Zn) 0.01 (expanded) 18
Primary Production Simply describes the transformation of inorganic compounds into organic compounds Photosynthesis uses sunlight, but other types exist, such as chemosynthesis at vents Primary Production Principle of Limiting Factors (aka Liebig s s Law: one missing nutrient stunts phytoplankton growth) Macronutrients (N, P) usually the limitation P - comes from rock weathering As PO = 4 (phosphate) Recycled within cells quickly (ATP - ADP - ATP, etc.) NOT a structural component N - plenty in atm (N 2 ), but not available to plants or animals, which need inorganic nitrogen (NO( 3-, NO 2-, NH + 4 ) N is most often the main limiting factor for algal growth N-Cycle is a bit more complicated 19
Global Phytoplankton Biomass Only primary producers have chlorophyll, so we can use chlorophyll to measure biomass Biomass is NOT primary production! Production is the rate of change of the biomass--so how do we measure it? 20
Measuring Primary Production We can measure the rate (growth) by tracking any parameter associated with photosynthesis. - Carbon uptake - Oxygen production - Change in biomass - Uptake of any other nutrient, if we assume Redfield proportions Global Primary Production (g C/m 2 yr) We can even estimate growth (primary production) from satellites! 21
Ocean Primary Production Average Productivity (gc/m2/yr) Percent Ocean Area Percent Total Ocean Production Upwelling 300 0.1 0.5 Coastal 100 9.9 18 Open Ocean 50 90 81.5 Global Primary Production Average Productivity (gc/m2/yr) Fraction Earth s Surface Total Production (tons C /yr) Land 160 28% 26 B Ocean 50 72% 25 B About equal 22