The Ocean's Primary Productivity

The Importance of Primary Productivity in the Ocean

• Primary productivity in the ocean represents 9% of the ocean's biomass, supporting all marine life.

• Photosynthetic organisms at the ocean's surface, such as single-celled algae, play a crucial role in sustaining marine life through the process of photosynthesis.

• The cyclical and complementary processes of photosynthesis and respiration are fundamental to the ocean's ecosystem, with phytoplankton being essential primary producers.

• Methods of measuring primary productivity include using planktonic nets and measuring radioactive carbon in seawater.

• Satellite monitoring of ocean color, affected by chlorophyll in phytoplankton, provides data on primary productivity distribution.

• The most important factors affecting primary productivity are sunlight and nutrient availability, such as nitrate, phosphorus, iron, and silica.

• Nutrient delivery to oceans primarily occurs via runoff from rivers, leading to high productivity in coastal waters.

• Eutrophication, caused by runoff of fertilizers, can lead to excessive algal blooms and oxygen depletion, negatively impacting marine life.

• Solar radiation, with blue wavelengths penetrating the deepest, affects the depth and extent of the ocean's photosynthetic zone.

• Ocean color varies due to factors such as turbidity, chlorophyll content, and coastal upwelling, influencing primary productivity.

• Coastal margins are rich in life due to nutrient availability and sunlight, despite facing challenges such as temperature and salinity variations.

• Upwelling of nutrient-rich deep water towards the surface, particularly on western continental margins, greatly enhances primary productivity and supports diverse marine ecosystems.Marine Photosynthetic Organisms

• Trade winds push surficial water, bringing nutrients and sunlight to the surface, promoting biological activity.

• Anthophyta are seed-bearing plants found in shallow coastal areas, such as eelgrass and surf grass.

• Anthophyta play a vital role as a food and protection source for marine animals in coastal environments.

• Macroscopic algae, or seaweeds, are typically found in shallow waters along ocean margins and are classified based on their pigments.

• Green algae are common in freshwater environments and grow in intertidal waters or shallow bays.

• Red algae are the most abundant and widespread macroscopic algae, adapting to receive less sunlight in deeper waters.

• Red algae have been documented to grow into depths of 330 feet and are specially adapted to photosynthesize in very diffuse light.

• Brown algae, or seaweeds, are the largest attached marine algae and produce food for about 99% of all marine organisms.

• Diatoms, a type of golden algae, make their shells out of silica and their shells become diatomaceous earth when they die and rain down to the sea floor.

• Dinoflagellates possess flagella for locomotion, photosynthesize, and are known to cause red tides.

• Dinoflagellates' tests are made of cellulose and they are considered plankton.

• Dinoflagellates are important as they cause red tides.