Production and Life

Textbook HW read p214-221Answer 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 C6H12O6 aka_ glucose

Photosynthesis

• Fixes carbon into glucose using the energy of sunlight

• 6CO2 + 6H2O + sunlight C6H12O6 + 6O2

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

• C6H12O6 + 6O2 6CO2 + 6H2O + 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 TowPlankton 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

Bio

mas

s

Sta

nding C

rop

Com

pensa

tion

depth

Photo

synth

esis

27.8%

0.0%

55.6%

16.7%

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

Bio

mas

s

Sta

nding C

rop

Com

pensa

tion

Depth

Wat

er C

olum

n Sta

bility

21.1%15.8%

0.0%

63.2%

1. Biomass

2. Standing Crop

3. Compensation Depth

4. Water Column Stability

More Productivity in the Nertic Zones is a result of

Nutri

ent R

unoff

More

Lig

ht

Les

s Bac

teria

Les

s Lig

ht

47.4%

15.8%

5.3%

31.6%

1. Nutrient Runoff

2. More Light

3. Less Bacteria

4. Less Light

At Compensation Depth Net Productivity will be

90%

10% 1%

0

5.3%

47.4%

15.8%

31.6%

1. 90%

2. 10%

3. 1%

4. 0

What percentage of water column productivity is measured in Satellite

Imaging

100% 99

% 1% 0%

5.3%0.0%

78.9%

15.8%

1. 100%

2. 99%

3. 1%

4. 0%

Carbon fixing results in the production of

Car

bon Dio

xide

Met

hane

Glu

cose

Nitr

ates

44.4%

0.0%

38.9%

16.7%

1. Carbon Dioxide

2. Methane

3. Glucose

4. Nitrates

Fastest Responders (in seconds)

3.89 Francesca Gonzales

5.09 Jane Newman

6.8 Shqiprie Dreshaj

9.93 Jessica Colantuono

10.25 Christian 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

Nitrogen Amino acids

Proteins

Nitrate, nitrite, ammonia

Phosphate NRG molecules

Cell membrane

Nucleic acids

Phosphate

Silica Tests – e.g. diatoms

Silica dioxide

Iron Affects nutrient

uptake

Generalized cycle

Available Nutrients

Producers

Consumers

Decomposition

Nitrogen cycle (Again)

Bacteria heavily involved

Ammonia nitrite nitrate for use by producers

N2 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: 1Carbon: Nitrogen : Phosphorus (This is molar ratio.)

Nutrient Profile versus distance from shore

shore open ocean

more

less

nu

trie

nts

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

Nutri

ents

Incr

ease

Nutri

ents

dec

reas

e

Nutri

ents

rem

ain

the.

..

0.0% 0.0%0.0%

1. Nutrients Increase

2. Nutrients decrease

3. Nutrients remain the same

The three elements in the Redfield ratio are

Car

bon Hyd

rogen

O...

Car

bon Hyd

rogen

an.

..

Car

bon Nitr

ogen a

n...

Car

bon Nitr

ogen a

n...

0.0% 0.0%0.0%0.0%

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

Gro

wth N

utrien

t

Runni

ng N

utrien

t

Sta

ndard N

utrie

nt

Lim

iting N

utrie

nt

0.0% 0.0%0.0%0.0%

1. Growth Nutrient

2. Running Nutrient

3. Standard Nutrient

4. Limiting Nutrient

The limiting Nutrient for most primary producers is

Nitr

ogen

Phosp

horus

Iron

Car

bon

0.0% 0.0%0.0%0.0%

1. Nitrogen

2. Phosphorus

3. Iron

4. Carbon

Which is NOT a factor that would affect primary productivity

Lig

ht

Nutri

ents

Wat

er C

olum

n Sta

bility

Fis

h po

pulatio

n

0% 0%0%0%

1. Light

2. Nutrients

3. Water Column Stability

4. Fish population

Which factor most limits Polar productivity

0%

0%

0%

0% 1. Nutrients

2. Light

3. Water Column Stability

4. Temperature

Which factor limits productivity in the tropic regions?

Lig

ht

Wat

er S

tabili

ty

Nutri

ents

Tem

perat

ure

0% 0%0%0%

1. Light

2. Water Stability

3. Nutrients

4. Temperature

Fastest Responders (in seconds)

0 Participant 1

0 Participant 2

0 Participant 3

0 Participant 4

0 Participant 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