Marine primary production

Global ocean chlorophyll concentration October 2019

Error creating thumbnail:

Cyanobacteria guerrero negro

Prochlorococcus marinus (cropped)

Error creating thumbnail:

Cyanobacteria

Marine primary production is the process by which carbon dioxide is converted into organic matter in the ocean. This process is fundamental to the marine food web, as it forms the base of the ocean's food chain and is a crucial component of the global carbon cycle. Marine primary production is carried out by photosynthesis in phytoplankton, microalgae, and cyanobacteria, as well as by chemosynthesis in some marine environments.

Types of Marine Primary Production

Marine primary production can be divided into two main types based on the energy source used for the production of organic matter: photosynthetic and chemosynthetic.

Photosynthetic Primary Production

Photosynthetic primary production is the most widespread form of primary production in the ocean. It is carried out by phytoplankton, microalgae, seagrasses, and kelp. These organisms use sunlight to convert carbon dioxide and water into glucose and oxygen through the process of photosynthesis. This type of primary production is predominant in the epipelagic zone (sunlit zone) of the ocean, where sunlight penetrates the water.

Chemosynthetic Primary Production

Chemosynthetic primary production occurs in environments where sunlight is not available, such as in deep-sea hydrothermal vents, cold seeps, and anoxic zones. In these environments, chemoautotrophic bacteria and archaea use the energy derived from the oxidation of inorganic molecules, such as hydrogen sulfide or methane, to fix carbon dioxide into organic matter. This form of primary production supports unique ecosystems, including those found at hydrothermal vents.

Factors Influencing Marine Primary Production

Several factors influence the rate of marine primary production, including:

• Light availability: Essential for photosynthesis, light availability decreases with depth in the ocean.
• Nutrient availability: Key nutrients include nitrogen, phosphorus, and iron. Their availability can limit primary production, especially in oligotrophic (nutrient-poor) waters.
• Water temperature: Affects the metabolic rates of primary producers.
• CO2 concentration: Higher concentrations of carbon dioxide can enhance photosynthetic rates up to a certain point.

Importance of Marine Primary Production

Marine primary production is crucial for several reasons:

• It is the primary source of organic matter in the ocean, which is essential for the survival of most marine organisms.
• It plays a significant role in the global carbon cycle by absorbing carbon dioxide from the atmosphere.
• It influences global climate patterns by affecting the concentration of carbon dioxide in the atmosphere.
• It supports the vast majority of marine fisheries, either directly or indirectly.

Challenges and Future Research

Understanding and predicting changes in marine primary production is critical in the context of global climate change. Factors such as ocean acidification, rising sea temperatures, and changes in nutrient inputs due to human activities can significantly impact marine primary production. Future research is focused on improving models of primary production and understanding how these changes will affect marine ecosystems and human societies reliant on marine resources.

Marine primary production Resources
Latest articles Most recent articles Ongoing trials	Wikipedia