Exploring Marine Primary Productivity

Factors Affecting Primary Productivity in the Oceans

• 9% of the ocean's biomass depends directly on photosynthetic organisms.

• Primary producers, such as single-celled algae, hold up the entire marine life in the world's oceans.

• Photosynthesis and respiration are cyclical and complementary processes that are fundamental on Earth.

• Photosynthesis converts carbon dioxide, water, and sunlight into sugar and oxygen.

• Phytoplankton, a type of primary producer, photosynthesize and create oxygen as a byproduct.

• Nutrient availability, sunlight, and the Redfield ratio (C:N:P) are key factors affecting primary productivity.

• Primary productivity can be measured directly using planktonic nets or by measuring radioactive carbon in seawater.

• Satellite monitoring of ocean color can indicate areas of high primary productivity, with green indicating higher levels.

• Nutrients needed for primary productivity are delivered to the oceans via runoff from rivers.

• Runoff of fertilizers from farms can cause eutrophication, leading to excessive algal growth and reduced oxygen levels.

• Solar radiation, especially blue wavelengths, penetrates the ocean surface and affects primary productivity.

• Ocean margins are rich in life due to nutrient availability and sunlight, despite greater temperature and salinity variations.Types of Photosynthetic Marine Organisms

• Wind and trade winds push surficial water, bringing nutrients and sunlight to the surface, leading to biological activity.

• Phylum Anthophyta includes seed-bearing plants found in shallow coastal areas, like eelgrass and surf grass.

• Anthophyta plants provide food and protection for marine animals in coastal environments.

• Macroscopic algae, known as seaweeds, are found in shallow waters along ocean margins.

• Seaweeds are classified based on pigment and can be green, red, or brown.

• Green algae is common in freshwater and grows in intertidal waters or shallow bays.

• Red algae is the most abundant and widespread macroscopic algae, often attached to the sea floor.

• Red algae are adapted to receive less sunlight in deeper waters and can grow as deep as 100 meters.

• Brown algae, or seaweeds, are the largest members of marine algae and range in color from light brown to black.

• Brown algae are found in mid-latitudes and colder waters.

• Diatoms, a type of golden algae, produce food for 99% of all marine organisms and their shells become diatomaceous earth.

• Dinoflagellates are plankton that possess flagella for locomotion and have cellulose tests.