Production and Life

Textbook HW read p Answer the following questions 1.Why is Detritus important ? 2.Explain Nutrient Regeneration? 3.How is primary production measured? 4.What types of bacteria perform nitrogen fixation? 5.What is a tertiary consumer?

Homework The Oceans Primary Productivity Study questions 1-14 Page 4-13

Productivity Definitions

Primary Productivity The rate of carbon fixation under a square meter of sea surface in a unit of time Which means how much glucose is made in a set area during a set time.

What is Carbon Fixing Mean??? Carbon is “fixed” (built into an organic molecule) through the process of photosynthesis Carbon is added to hydrogen and oxygen to produce C 6 H 12 O 6 aka_ glucose

Photosynthesis Fixes carbon into glucose using the energy of sunlight 6CO 2 + 6H 2 O + sunlight  C 6 H 12 O 6 + 6O 2

Chemosynthesis Fixes carbon into glucose using energy from chemical compounds found at hydrothermal vents (especially hydrogen sulfide) Base of food chain that doesn’t require sunlight

Respiration The breakdown of glucose in the presence of oxygen to release Energy for life processes C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O + energy

Gross primary productivity – total primary production (carbon fixed) Net primary productivity – amount of primary production minus the amount used by respiration = amount available to support other trophic levels Trophic level a feeding level

Biomass and Standing Crop Biomass = the organic matter that is produced…Many times expressed as a weight Standing crop = the total amount of plant biomass present in a given volume of water at a given instant This helps us determine how much life can the area support –Remember Carrying Capacity?

Figure 14.1

Figure 14.4 Water column stability = less nutrients therefore less BIOMASS Note: Plenty of solar energy little nutrients – tropical location

How to measure primary productivity

Plankton Net A fine mesh net used to collect samples of microscope Plankton Make a Plankton Net – 20 points

Plankton Net in Tow Plankton net is towed in water. Volume of water is calculated Plankton is collected in tube and is counted. How do they count it? Amount of plankton found in one ml or cc is compared with volume of water

Measure standing crop 3 ways –Filtration of cells – plankton tow –Chlorophyll extraction –Chlorophyll fluorescence – satellite imagery Drawbacks –Patchy distribution

Satellite Imagery One way to measure productivity Measures chlorophyll concentration per square meter of sea surface Only measures top meter of water Limited because blue light penetrates 100 m. That means ONLY1% of possible water column production is measured

Production is highest off of the land masses …WHY?

What time of year is this in NY?

Compensation depth Depth where the rate of respiration = the rate of photosynthesis Net productivity will be ZERO

Figure 14.8

Compensation depth decreases with phytoplankton growth More Production! Result = reservoir of nutrients below compensation depth

The area in the water column where production equals consumption 1.Biomass 2.Standing Crop 3.Compensation depth 4.Photosynthesis

The total amount of plant biomass present in a given volume of water at a given instant 1.Biomass 2.Standing Crop 3.Compensation Depth 4.Water Column Stability

More Productivity in the Nertic Zones is a result of 1.Nutrient Runoff 2.More Light 3.Less Bacteria 4.Less Light

At Compensation Depth Net Productivity will be 1.90% 2.10% 3.1% 4.0

What percentage of water column productivity is measured in Satellite Imaging 1.100% 2.99% 3.1% 4.0%

Carbon fixing results in the production of 1.Carbon Dioxide 2.Methane 3.Glucose 4.Nitrates

Fastest Responders (in seconds) 3.89Francesca Gonzales 5.09Jane Newman 6.8Shqiprie Dreshaj 9.93Jessica Colantuono 10.25Christian Caja

Factors that affect primary productivity Light Nutrient availability Water column stability

Nutrients are brought by Runoff (from land) OR WITHIN THE WATER COLUMN THROUGH: Upwelling (bottom water wells up as surface water moves away) Overturn (denser sinks, less dense rises) Mixing (wind stirs up water column)

How to access deep nutrient reservoir Overturn –But strong winds may mix plankton too deep for photosynthesis Upwelling –Ekman spiral –Divergence zones

Nutrient cycling returns nutrients to the food chain

Nutrients NitrogenAmino acids Proteins Nitrate, nitrite, ammonia PhosphateNRG molecules Cell membrane Nucleic acids Phosphate SilicaTests – e.g. diatoms Silica dioxide IronAffects nutrient uptake

Generalized cycle Available Nutrients Producers Consumers Decomposition

Nitrogen cycle (Again) Bacteria heavily involved Ammonia  nitrite  nitrate for use by producers N 2  fixed for use by producers

Phosphate Cycling

Nitrogen Cycling

Limiting Nutrient The nutrient that runs out first and will limit growth Usually Nitrogen “N” N and P occur in similar concentrations, but producers need more N In Our fish tanks no fish = no nitrates = no algae

Redfield Ratio The elemental composition of marine organic matter (dead and living) is fairly constant. The ratios of carbon to nitrogen to phosphorus remaines the same from coastal (Neritic) to open ocean (Oceanic) regions. C :N :P = 106 : 16: 1 Carbon: Nitrogen : Phosphorus (This is molar ratio.)

Nutrient Profile versus distance from shore shoreopen ocean more less nutrients

Nutrient Profile versus water depth M nutrients Surface

Eutrophication Excess nutrients (N and P) from fertilizers, sewage, etc., cause bloom in producers. As nutrients are depleted, bloom dies all at once. Massive decomposition depletes oxygen  fish kills

Alive, healthy and Diverse Dead- Algae covered

Productivity in the World

What controls productivity by latitude? Polar – light limits – 6 months of light or darkness Mid latitudes – light and nutrients limit as they vary over the year Tropics/ subtropics – nutrients limit

Figure 14.3 Peak points of both Nutrients and Solar energy = Peak Production

Figure 14.2

Figure 14.10

High latitudes (near poles) Very productive in summer Long day length in summer Weak, constant sun plus fresh water layer at surface  plankton held above compensation depth

Figure 14.2

Middle latitudes Spring sun plus overturn from winter/spring storms/winds plus slightly stratified water column  spring bloom Mid summer heat stratifies water column  nutrient depletion Autumn sun weakens, stratification weakens, late summer storms replenish euphotic zone with nutrients

Figure 14.2

Mid Latitude Nutrient Light availability by season Stratification of water column in summer

Low Latitudes (tropics / subtropics) Not very productive, except locally (productivity reef based>phytoplankton based Consistent sun year round Upwelling and overturn not very common, and very localized

Figure 14.2

As you move from the Neritic to Oceanic Zones 1.Nutrients Increase 2.Nutrients decrease 3.Nutrients remain the same

The three elements in the Redfield ratio are 1.Carbon Hydrogen Oxygen 2.Carbon Hydrogen and Phosphorus 3.Carbon Nitrogen and Hydrogen 4.Carbon Nitrogen and Phosphorus

The nutrient which runs out first and will limit growth 1.Growth Nutrient 2.Running Nutrient 3.Standard Nutrient 4.Limiting Nutrient

The limiting Nutrient for most primary producers is 1.Nitrogen 2.Phosphorus 3.Iron 4.Carbon

Which is NOT a factor that would affect primary productivity 1.Light 2.Nutrients 3.Water Column Stability 4.Fish population

Which factor most limits Polar productivity 1.Nutrients 2.Light 3.Water Column Stability 4.Temperature

Which factor limits productivity in the tropic regions? 1.Light 2.Water Stability 3.Nutrients 4.Temperature

Fastest Responders (in seconds) 0Participant 1 0Participant 2 0Participant 3 0Participant 4 0Participant 5

Marine Food Chain A review of the food chain, food web and food pyramid Review of flow of energy and related terms

Food chain terms Autotroph –Photoautotroph- makes food using light –Chemotroph – makes food using chemical compounds Heterotroph – gets energy from other organisms Producer – makes its own food (Autotroph) Consumer – consumes producers or other consumers Herbivore- consumes plant matter Carnivore – consumes meats

Food chains and food webs show trophic (feeding) relationships between members of a community Arrows show flow of energy Food or Prey Consumer

Food Chain

Food Web

More connections means more stability Very important reason to maintain biodiversity More food choices if one runs out the organism has others and a better chance to survive

Food Web

Figure 14 p.385

Food Pyramid

Pyramid of Numbers

Pyramid of Biomass

The amount of energy transferred at each step in a food chain averages about 10% - less lost in very productive environments where little energy expended to get food

Figure 14.13