Autotrophs

primary producers

certain bacteria, algae, and green plants

self-nourishment

able to make their own food by photosynthesis or chemosynthesis

photosynthetic and chemosynthetic organisms

Chlorophyll Pigment

traps light energy in primary producers

transforms light energy into chemical bond energy

Carbohydrates:

How are they formed?

chemical bond energy, formed from light energy, manufactures carbohydrate food molecules

are used by plants for chemical synthesis, growth, and reproduction

Photosynthesis

Process by which autotrophs bind light energy into chemical bonds for food with the aid of chlorophyll and nutrients

Uses carbon dioxide and water as raw materials

Produces carbohydrates and oxygen

Process where light energy is used to synthesize/make organic molecules rich in stored energy

The primary method of primary production

Photosynthesis Equation

                                                  sunlight

6CO₂  +  6H₂O  ¾¾_YIELDS¾¾®  C₆H₁₂O₆  +  6O₂ ↑

                                                                                ^(glucose)

– larger molecules formed from smaller ones

– oxygen (O₂) is the by-product (↑) of the reaction

Respiration

The release of stored energy from chemical bonds

– carbohydrates broken down

– oxygen consumption

Carbon dioxide and water are formed as by-products

All organisms (plants and animals) carry out ________.

Respiration Equation

C₆H₁₂O₆ + 6O₂  ¾¾¾®  6CO₂ + 6H₂O + chemical energy ↑

– large molecules being broken down

– energy liberated and used for metabolism

Chemosynthesis

Releases the energy held in the chemical bonds of hydrogen and sulfur containing compounds in order to construct glucose from carbon dioxide

→IOW: Constructs glucose from carbon dioxide by releasing the energy held in the chemical bonds of compounds containing hydrogen and sulfur

→IOW: Energy from inorganic compounds

Does not require sunlight to form carbohydrates

(unlike photosynthesis)

Glucose

Immediate organic material produced from inorganic substances

C₆H₁₂O₆

Heterotroph

An organism that derives food from other organisms because it is unable to synthesize its own food molecules

Incapable of self-nourishment

Trophic Level

– A feeding step within a trophic pyramid

– The mass of consumerse decreases as trophic level increases

The 10% Rule

 Each trophic level roughly equals 1/10 the mass of the trophic level directly below

1kg of Tuna = 10kg of Medium Fish = 100kg of Small Fish

About 10% of consumed energy is stored in the consumer's flesh

The remaining energy is lost as heat and work by organisms

Food Web

Group of organisms linked together by complex feeding relationships in which the lfow of energy can be followed from primary producers through consumers

Measuring Primary Productivity

Is expressed in grams carbon bound into organic material per square meter of ocean surface area per year

g C/m²/yr

Productivity of Primary Producers

Phytoplankton

90-96%

Seaweeds

2-5%

Chemosynthetic Organisms

2-5%

Total Ocean Productivity

75-150 g C/m²/yr

(1) Total Marine Productivity

and

(2) Total Terrestrial Productivity

are approximately equal to each other

Productivity (1)

35-50 billion metric tons of C/yr

Productivity (2)

50-70 billion metric tons of C/yr

Plant Biomass Productivity:

(1) Oceans

(2) Land

Productivity (1)

1-2 billion metric tons

Productivity (2)

600-1,000 billion metric tons

Factors Limiting Productivity

1. Lack of nutrients

(most common factor)

2. Inorganic nutrients

(nitrogen, phosphorus, iron, etc.)

3. Sunlight

too little is limiting, usually below depth of 300ft (100m)

too much is also problematic

Limiting Nutrients

(to productivity)

– Nitrogen

– Phosphorus

– Iron

Not Limiting:

– Carbon

– Water

Accessory Pigment

Present in various photosynthetic plants

Assist in light uptake and the transfer of its energy to chlorophyll

Marine plants can live in depths of over 250m because their ________ absorb the dim blue light at depth and transfer energy to adjacent chlorophyll molecules

aka: "masking pigments"

can be brown, tan, olive green, or red

Planktonic Organisms

drift in water columns or swim weakly in the ocean

go where the ocean currents go

unable to move consistently against waves or current flow

can move vertically but not laterally

Phytoplankton

are plant-like autotrophs

mostly single-celled drifting photosynthesizers

account for about 40% of the food made by photosynthesis on Earth 

Main Types of Phytoplankton

 
1. Diatoms
2. Dinoflagellates
3. Zooxanthellae
4. Coccolithophores
5. Silicoflagellates
6. Nanoplankton (dwarf)
7. Picoplankton

Diatoms

Dominant type and best studied with 5,600 species

Most are round, some elongated, branched, or triangular

"to cut through" refers to their perforation patterns

55% of sun energy to carbohydrate chemical bonds

Contain chlorophyll and accessory pigments for effective light absorption

Reproduces by dividing in half and drifting apart, and auxospores

Dinoflagellates

Majority are autotrophs and are widely distributed

Have two whip-like projections

One to move forward

One to rotate through water

Responsible for "red tide"

Produce toxins to filter feeders

Zooxanthellae

single-celled Dinoflagellate Phytoplankton

are symbiotic with coral

(live within coral)

Coccolithophores

single-celled autotrophs covered with disks of calcium carbonates

Silicoflagellates

internal support structures made of silica

Euphotic Zone

"good light"

the upper layer of the photic zone in which net photosynthesis gain occurs

carbohydrate production exceeds carbohydrate uptake

photosynthesis exceeds respiration in the euphotic zone, but not always in the photic zone

zone is classified by light level

Dysphotic Zone

the lower part of the photic zone

insufficient light for plant photosynthesis

zone is classified by light level

Compensation Depth

is for phytoplankton, not zooplankton

always below depth of greatest productivity

Neritic Zone

nearshore or coastal waters

part of the Pelagic Zone, but not the Benthic Zone

important to Louisiana

Global Distribution of Plankton Productivity:

Nearshore Production

is nearly always higher than open ocean

nutrient levels are highest near the continent's coastal upwelling and land runoff

plankton most abundant in quantity and production in nearshore

Global Distribution of Plankton Productivity:

Open Water - TROPICS

water is generally deficient in surface nutrients

these oceans are away from land

are nearly devoid of visible plankton due to strong thermocline, which discourages vertical mixing necessary to bring up nutrients from the depths

tropical coral reefs are the exception to the general rule of low tropical productivity

Global Distribution of Plankton Productivity:

Open Water - Temperate and Sub-Polar Zones

greatest productivity of any open ocean area

productivity due to dependable light and moderate nutrient supply

has northern spring and fall blooms

(1) Northern Spring Bloom

vs.

(2) Northern Fall Bloom

(1) caused by increasing illumination

higher of the two

(2) caused by nutrients moving toward the surface

Phytoplankton Bloom

period of rapid phytoplankton growth where nonconservative nutrients (nitrates, phosphates, iron, silicates) are consumed and depleted

Global Distribution of Plankton Productivity

Open Water - Polar Regions

winter months have weeks or months of darkness which severely limit productivity

summer months have 24hr daylight and upwelling nutrients, which lead to plankton blooms but does not last because nutrients are rapidly removed

Antarctic Ocean is more productive than the Arctic Ocean because Arctic has landmasses that interfere with water circulation and nutrient upwelling

Zooplankton

heterotroph (animal) members of the plankton community

most numerous primary consumers of the ocean

graze on phytoplankton

most range from 1-2cm

(1) Copepods

and

(2) Macroplankton

(1) most abundant zooplankton

account for 70% of individuals

tiny shrimp-like animals about .5mm long

type of crustacean

(2) larger than 1cm

a type of zooplankton

Algae

collective term for nonvascular plants possessing chlorophyll and capable of photosynthesis

lack vessels to conduct sap

unicellular are diatoms and dinoflagellates

multicellular are large seaweed reaching 62m in length

Structure of Seaweed:

Nonvascular

blades (fronds)

stipes

holdfast

gas bladder - helps plant reach up to more light

Structure of Seaweed:

Vascular

leaves

stem

root

Seaweed Classification:

Chlorophyta 

green algae

live near surface

zonation: surface to 10m

Seaweed Classification:

Phaeophyta

kelps

brown algae

live at greater depths

(but not the greatest)

zonation: surface to 35m

Seaweed Classification and Zonation:

Rhodophyta

largest division of algae

red algae

lives at the greatest depth with dim light  

(accessory pigments)

zonation: surface to 268m

Marine Angiosperms

 type of seaweed

reproduce with flowers and seeds

Sea-grasses

most common type of seaweed

eelgrass

Mangroves

type of seaweed

tangled masses of trees

grow in water nearshore

estuaries

(Florida)

"Plants use sunlight as a source of energy to...

...fix carbon dioxide and nitrogen.

Inorganic compounds are converted to organic compounds."