PHYTOPLANKTON

Pelagic environment is the largest marine ecosystem. More food, oxygen and biota (life) are here than anywhere else.

Spirogyra

The dominant organism in the neritic zone and oceanic zone is plankton.

Plankton are organisms that can not make a forward motion against a current of at least 1 knot.

There are 2 types of plankton: phytoplankton & zooplankton.

Volvox

Phytoplankton are photosynthetic autotrophs, who begin all marine food webs.

They produce 50-90% of all atmospheric oxygen, and are critical biomass. Meaning their production is critical to all other life in the ocean

They are adapted to a floating life style because of their:

1. Small size - diffusion is quick, frictional drag from large surface area to low volume ratio helps slow sinking

2. Structure - disks shaped or chains aid in floating

3.Low Density - light ions and lipid by-products of photosynthesis reduce density and aid floating

Remember lipids are “oil” and oil floats in water.

.

Meroplankton – Plankton for partOf their lives e.g. crustacean, fish larvae

Holoplankton – plankton for their entire life e.g. diatoms, copepods, ctenophores

Terms and Size Classes

Net Plankton

Megaplankton

Macroplankton

Mesoplankton

Microplankton

Nanoplankton

Picoplankton

“Microbial Loop”

Phytoplankton

No external skeleton of siliconMostly solitary (chains rare)Photosynthetic, parasitic, grazer, symbioticProportions increase offshore; blooms

Tropical, pelagicCaC03 plates

Coscinodiscus Chaetoceros

Ceratium Peridinium

Coccolithus

Silicon dioxide glass “pill boxes” (single & chains)Dominate coastal waters (cold waters)Planktonic & benthic

Diatoms

Dinoflagellates

Coccolithophores

Phytoplankton“blue-green algae” dominate brackish, nearshore watersoften undergo nitrogen fixation N is converted to NH4

+

unicellular and biflagellate chloroplasts, internal silica skeletonless abundant than diatoms high in Antarctic and open ocean

true green algaerare in marine watersoften dominate estuaries and lagoons

Tricodesmuim

Isochrisis

Chlamydomonas colony

The two main divisions of marine habitats are

1. Benthic and Abyssal

2. Neritic and Oceanic

3. Photic and Aphotic

4. Neritic and Benthic

Organisms which cannot swim against a current of a least 1 knot

are known as

1. Neckton

2. Plankton

3. Demersal

4. Benthic

Phytoplankton use ______ to help them to float

1. Carbohydrates

2. Proteins

3. Glucose

4. Lipids

Plankton are grouped by their

1. Shape

2. Weight

3. Color

4. Size

Fastest Responders (in seconds)

3.85

4.48 Jenna Fiore

4.99 Arlinda Hasani

5.61 Valentina Alsina

6.01 John Cacace

Fastest Responders (in seconds)

3.85

4.48 Jenna Fiore

4.99 Arlinda Hasani

5.61 Valentina Alsina

6.01 John Cacace

Homework p 312-314

1. What percentage of photosynthesis is performed by Phytoplankton?

2. Outside of dinoflagellates what else can be a cause of red tides?

3. What group is considered the vital link between primary producers and the rest of the community?

4. Which type of Zooplankton is the most abundant? (Hint: they are crustaceans)

5. What are Krill and what do they eat?

ZOOPLANKTON

Zooplankton are the primary consumers, called heterotrophic herbivores, in food webs.

They are the smallest and most numerous marine animals. Their population density depends on the availability of phytoplankton upon which they graze.

USGS

There are two groups of zooplankton:

Crab Zoe

1. Meroplankton - planktonic larvae who will become adult forms of fish, worms, Mollusks, and Crustaceans

The advantage of meroplanktonic lifestyle is reduced competition from adults for the same basic needs.

However, predation is extremely high because of their size and lack of adaptability.

2. Holoplankton - will remain plankton throughout life. They remain visible, but tiny.

Adult Daphnia

Copepods (Phylum: Arthropoda) are 95% of all zooplankton. Others are krill, foraminifera and members of Kingdom Protista, Phylum Protozoa.

Zooplankton are grouped by the way they move - either by pseudopods like the amoeba (1), flagella like euglena (2) or by cilia as in paramecium (3).

1. 2. 3.

Vertical migration is a daily pattern of phytoplankton and zooplankton changing positions like a day and night shift.

During the day phytoplankton produce lipids by photosynthesis.

Because oils are less dense than water, the products of photosynthesis increase their buoyancy.

VERTICAL MIGRATION

As the sun goes down, the phytoplankton use lipids for energy which causes them to sink in the water column.

In response to the “rain” of phytoplankton descending, the zooplankton move up in the water column to graze on them.

As the sun comes up, photosynthesis again causes more production than the organisms need at that time, the phytoplankton become lighter and begin to float upward.

The zooplankton begin their downward response to graze again and to take advantage of reduced visibility and less heat than at the surface.

These two periods of grazing protect both populations, reduces predation and distributes stress in the ecosystem.

A “bloom” is an increase in population density of phytoplankton associated with high nutrient levels. It can be the result of upwelling or excessive nutrients.

Upwelling is caused by winds and other atmospheric conditions that move surface water away from shore, pulling nutrient rich bottom water to the surface.

A change in winds direction blows surface water toward the land and prevents upwelling. Water is depleted of nutrients and fishing is poor. – an “El Nino” Event

Land

Ocean

No upwelling

Wind

Critical DepthD

epth

PhotosyntheticProduction

Critical Depth & Mixing Depth

Gulf of Mexico

Upwelling draws _________ rich water to the surface

1. Mineral

2. Oxygen

3. Nutrient

4. Energy

Zooplankton which is plankton for its entire life is called

1. Meroplankton

2. Holoplankton

3. Phytoplankton

4. Picoplankton

Zooplankton which is plankton for only the beginning of its life is

called1. Meroplankton

2. Cytoplankton

3. Holoplankton

4. Phytoplankton

Zooplankton are Primary

Consu

mer

s

Pro

ducers

Dec

ompos

ers

Pre

y

0% 0%0%0%

1. Consumers

2. Producers

3. Decomposers

4. Prey

Copepods make up _______ of all Zooplankton

50%

25%

95% 5%

0% 0%0%0%

1. 50%

2. 25%

3. 95%

4. 5%

Zooplankton are grouped by

Colo

r S

ize

Shap

e

The

way

they

move

0% 0%0%0%

1. Color

2. Size

3. Shape

4. The way they move

Phytoplankton use lipids at night for energy and float down the water

column

Tru

e

Fal

se

0%0%

1. True

2. False

Zooplankton float up at night to graze on phytoplankton

Tru

e

Fal

se

0%0%

1. True

2. False

Fastest Responders (in seconds)

3.85 Erica Wenzel

4.48 Ciara Galligan

4.99 Douglas Miller

5.61 Charles Badman

6.01 Anthony Bambach

“I will rule the world! All hail Plankton! All hail Plankton!” - Plankton