The Primary Producers & Consumers Unit 10: Marine Life The Primary Producers & Consumers

Seaweeds are larger marine plants more obvious Phytoplankton, for the most part, are single celled plant-like organisms that drift near the ocean surface They are NOT plants!!!! Account for between 90 - 98% of ocean carbohydrate production. Almost invisible to the naked eye, but they are much more important to marine productivity than the larger and more conspicuous seaweeds. Seaweeds are larger marine plants more obvious Contribute only 2-10% of the ocean’s primary productivity. Chemosynthesis accounts for less than 1%. Biomass is the mass of living tissue in the area.

Factors that limit Productivity Limiting factor is a physical or biological necessity whose presence in inappropriate amounts limits the normal actions of an organism. Photosynthetic autotrophs require 4 things: 1. water 2. inorganic nutrients 3. carbon dioxide 4. sunlight

Ocean ---- water is not a limiting factor CO2 dissolves readily ---- not a limiting factor Potential limiting factors of primary productivity are nutrients and light. Inorganic nutrients are used to construct the larger organic molecules for primary productivity and to construct their skeleton and or shells. Nonconservative nutrients - nutrients that change in concentration with biological activity.

After a period of rapid phytoplankton growth (a phenomenon known as plankton bloom), the ocean surface is often drained of nonconservative nutrients (phosphates, nitrates and silicates). They become part of the producer or part of the animals that have eaten the producer. Lack of nutrients is the most common factor limiting primary productivity. If adequate nutrients are present, productivity depends on illumination.

Too little light limits productivity Too much light can slow and eliminate photosynthesis. Accessory pigments are light absorbing compounds closely associated with chlorophyll. Colors: brown, tan, olive, green, and red They will absorb light then transfer the energy to the chlorophyll when necessary.

Plankton Planktos = wandering Phytoplankton – plant-like members of the plankton community. Zooplankton – animal-like members of the plankton community. Plankton drifts or swims weakly Go where the ocean goes Unable to move consistently against waves or currents.

Only thing in common between various species…. The only feature common to all plankton is their inability to make consistent lateral headway, although many will move vertically in the water column.

Plankton Facts Many are in the 1-2 centimeter range. The largest drifters are the giant jellyfish, with a bell diameter of 3.5 meters. All plankton larger than about 1 centimeter across is called macroplankton The plankton that spends their lives within the plankton community are called holoplankton Some of the planktonic animals are the juvenile stages of crabs, barnacles, clams, seastars other organisms that will later adopt a benthic life style. These temporary visitors are Meroplankton

Plankton The diversity of plankton organisms is astonishing. It can contain: a. giant drifting jellyfish (8meters) b. arrowworms c. single-celled creatures d. mollusks with slowly beating flaps e. crustaceans f. algae

Plankton will contain many different plant-like species and almost every different type of animal category. Members of the plankton community are referred to as plankters and do interact with each other (grazing, predators, parasites, and competition)

Algae Simple plantlike autotroph First plants on earth (900 million years old) Non-vascular Cell wall Lack roots, stems and leaves Must live in or near water Three Phyla Chlorophyta Green algae Rhodophyta Red algae Phaeophyta Brown algae

Chlorophyta Green algae Main pigment – chlorophyll Symbiotic with lichens and fungi Store food as starch 7,000 species Most diverse group of algae

Rhodophyta Red algae Main pigment – phycoerythrin Length reaches greatest depth out of all algae 6,500-10,000 species (only 200 freshwater) Used in foods Ice cream, frosting, chocolate milk, dressing

Phaeophyta Brown alage Main pigment – fucoxanthin Found in tropics Eels lay eggs Includes kelp

Phytoplankton Autotrophic plankton - phytoplankton (phyto = plant). Autotrophic plankton is mostly single celled. Live in marine and freshwater It is critical to all life on earth because of the great contribution to food webs its generation of large amounts of atmospheric oxygen through photosynthesis. 80% of the oxygen on earth There are 8 types of phytoplankton. The most important are: dinoflagellates diatoms coccolithophores

Dinoflagellates

Dinoflagellates Single cell autotrophs Some live within the tissues of other organisms Majority live free in the water – solitary Most have 2 whip-like flagella (one for movement forward and one to make it spin) Outside “shell” of cellulose Reproduces by simple fission once a day Grow into large numbers Because of red accessory pigment, when they reproduce in large numbers, they cause a red tide (23 million/gal of water)

Bioluminescence - Dinoflagellates will take excess oxygen and combine it with enzymes and other proteins (Lucifer) to produce a glow. Some species synthesize an effective poison.

Diatoms Most dominant photosynthetic organisms in the plankton community Most biochemically sophisticated Their abundance and photosynthetic efficiency further increased the proportion of free oxygen in the earth’s atmosphere. More than 5,000 species Rigid cell wall called a frustule consisting of silica. They are penetrated by perforations through the frustule (dia= through, tomos = to cut) They are round, elongated, branched or triangular.

For the most effective light absorption, chlorophyll is accompanied in diatoms by accessory pigments called xanthophylls. Xanthophylls are yellow or brown pigments and give most diatoms a yellow-green or tan appearance. Diatoms store energy as fatty acids and lipids. These are lighter than their equivalent volume of water which helps the diatoms to float.

Coccolithophores Single celled Covered with discs of calcium carbonate Live near the ocean surface in brightly lighted areas The calcium carbonate layer is translucent and acts as a sunshade They can collect in such a number as to turn the water white or chalky The white cliffs of Dover are deposits of Coccolithophores They are referred to as nanoplankton due to their small size.

White Cliffs of Dover

The Primary Consumers Zooplankton

Zooplankton Heterotrophic plankton Most numerous of the primary consumers of the ocean The most numerous of zooplankters are the Copepods Crustaceans, a group that contains the crabs, lobsters and shrimp. Not all zooplankters are small.