Which Organisms Make Up The Majority Of The Primary Productivity Of The Oceans?

Productivity is crucial for life in the ocean, driving its chemical cycles and reducing atmospheric carbon dioxide. Nutrient uptake and export interact with circulation to produce distinct ocean regimes. Primary production, the biological transformation of dissolved inorganic carbon to organic carbon during photosynthesis, is a fundamental process in the ocean. Net marine primary productivity is the amount of organic material available to support herbivores and carnivores. Organisms responsible for oceanic primary production include a wide diversity of marine plants and algae.

Phytoplankton, which are microscopic in size compared to marine plants and macroalgae like seaweeds and seagrasses, account for by far the majority of oceanic primary production. Most marine primary production is generated by a diverse collection of marine microorganisms called algae and cyanobacteria, which form the principal group. Over 90% of the world’s food (carbohydrates) comes from phytoplankton, which is the single most important process for life and energy.

Ocean productivity is the primary production of single-celled phytoplankton suspended in the ocean, which supply organic matter to heterotrophs. Most primary productivity is carried out by pelagic phytoplankton, not benthic plants. Marine phytoplankton are the major source of organic matter in the oceans through photosynthesis, but their contribution is not necessarily related to the overall productivity.

Which ecosystem having the highest primary productivity is ocean?

Ecosystems are diverse and can be classified into four types: Ocean Ecosystem, Pond Ecosystem, Desert Ecosystem, and Forest Ecosystem. Ocean ecosystems produce organic matter through phytoplankton and zooplankton, while pond ecosystems include microorganisms and phytoplankton. Desert ecosystems have low primary productivity due to low rainfall and high temperatures. Forest ecosystems have the highest primary productivity. Primary productivity is the energy stored at the producer level, followed by secondary productivity and tertiary productivity.

Ecosystems can be divided into four types: lentic, which occurs on still bodies like ponds, lakes, and rivers, lotic, which occurs on moving water bodies like springs and streams, artificial ecosystems, and terrestrial ecosystems. Primary productivity is the amount of energy stored at the producer level, followed by secondary productivity and tertiary productivity.

Where in the ocean is productivity highest?

Ocean productivity is primarily attributed to the production of organic matter by phytoplankton, which are photoautotrophs that convert inorganic to organic carbon. These phytoplankton supply this organic carbon to diverse heterotrophs, such as bacteria, zooplankton, nekton, and benthos.

There are several nested cycles of carbon associated with ocean productivity, including gross primary production (GPP), net primary production (NPP), secondary production (SP), and net ecosystem production (NEP). Gross primary production (GPP) refers to the total rate of organic carbon production by autotrophs, while respiration (RP) refers to the energy-yielding oxidation of organic carbon back to carbon dioxide. Net primary production (NPP) is GPP minus the autotrophs’ own rate of respiration, indicating the rate at which the full metabolism of phytoplankton produces biomass.

Secondary production (SP) typically refers to the growth rate of heterotrophic biomass, with only a small fraction of the organic matter used to grow, the majority being respired back to dissolved inorganic carbon and nutrients that can be reused by autotrophs. Fisheries rely on SP and depend on both NPP and the efficiency with which organic matter is transferred up the foodweb. Net ecosystem production (NEP) is GPP minus the respiration by all organisms in the ecosystem, with the value depending on the boundaries defined for the ecosystem.

Productivity in the surface ocean is connected to nutrient cycling, with the blue cycle representing net ecosystem production (NEP), the red cycle representing the fate of most organic matter produced in the surface ocean, and the green cycle representing the internal respiration of phytoplankton themselves. These nested cycles combine to yield gross primary production (GPP) representing gross photosynthesis and net primary production (NPP) representing phytoplankton biomass production that forms the basis of the food web plus a much smaller rate of organic matter export from the surface.

What are the factors that limit primary productivity in the ocean?

The presence of a thin buoyant surface layer and other processes in the ocean contribute to nutrient limitation, limiting ocean productivity. The export of organic matter to depth depletes the surface ocean of nutrients, causing them to accumulate in deep waters where there is no light available for photosynthesis. Ocean circulation can only slowly reintroduce dissolved nutrients to the euphotic zone, driving nutrients out of sunlit, buoyant surface waters.

This limits ocean productivity. Phytoplankton growth limitation is traditionally interpreted in the context of Liebig’s Law of the Minimum, which states that plant growth will be as great as allowed by the least available resource, the “limiting nutrient”. However, interactions among nutrients and between nutrients and light can also control productivity. In polar regions, higher iron supply can increase the efficiency of phytoplankton in capturing light energy. Generally, phytoplankton should seek co-limitation by all the chemicals they require, including trace metal nutrients.

Which organisms perform most of the primary production carried out in the open ocean?

Ocean productivity is primarily the production of organic matter by phytoplankton, which are photoautotrophs that convert inorganic to organic carbon. These plants supply this organic carbon to diverse heterotrophs, such as bacteria, zooplankton, nekton, and benthos. Ocean productivity is characterized by various nested cycles of carbon, including gross primary
production (GPP), net primary production (NPP), secondary production (SP), and net ecosystem production (NEP).

GPP refers to the total rate of organic carbon production by autotrophs, while respiration refers to the energy-yielding oxidation of organic carbon back to carbon dioxide. Net primary production (NPP) is GPP minus the autotrophs’ own rate of respiration, indicating the rate at which the full metabolism of phytoplankton produces biomass. Secondary production (SP) typically refers to the growth rate of heterotrophic biomass, with only a small fraction of organic matter used for growth. Fisheries rely on SP and depend on both NPP and the efficiency of organic matter transfer up the foodweb.

Net ecosystem production (NEP) is GPP minus respiration by all organisms in the ecosystem, with the value depending on the boundaries defined for the ecosystem. For example, NEP for the entire ocean is roughly equivalent to the slow burial of organic matter in sediments minus the rate of organic matter entering from the continents.

Productivity in the surface ocean is connected to nutrient cycling, with the blue cycle representing net ecosystem production (NEP), the red cycle representing the fate of organic matter produced in the surface ocean, and the green cycle representing internal respiration of phytoplankton. These nested cycles result in gross primary production (GPP) representing gross photosynthesis and net primary production (NPP) representing phytoplankton biomass production, which forms the basis of the food web. While new nutrient supply and export production are ultimately linked by mass balance, there may be imbalances on small scales of space and time, allowing for brief accumulations of biomass.

What is the most productive ecosystem in the ocean?

Coral reefs are highly productive ecosystems, with primary producers at the base of the food chain supporting their complex food webs. Charles Darwin’s 1842 work, “Darwin’s paradox”, raised questions about how reefs thrive in nutrient- barren tropical oceans. Scott Reef, a largely pristine open-ocean atoll reef, presents an ideal case study to investigate the mechanisms by which ocean processes support reef productivity. The health and function of this ecosystem are highly dependent on the region’s oceanography.

Researchers have successfully deployed instruments to characterize the circulation of the whole Scott Reef lagoon system, measuring currents and waves along the shallow reef rim using Falkor’s workboats at over 20 sites. The deployment of instruments within north Scott complements instruments deployed in the south, helping to understand the overall circulation of Scott Reef and how both shallow and deep regions are connected to the surrounding ocean. This full array of instrumentation will help researchers understand the overall circulation of Scott Reef and how both shallow and deep regions are connected to the surrounding ocean.

Which part of the ocean contains most of the ocean’s primary productivity?

The majority of net primary production in the ocean takes place in the epipelagic zone, with the greatest concentrations occurring in the neritic zone in proximity to the shoreline.

What is the most primary producer in the ocean?

Microscopic phytoplankton represent the largest primary producer in the ocean and a significant source of oxygen. They are found in the dark depths of the ocean, where sunlight cannot reach the ocean floor, and thus represent the largest primary producers.

What are 95% of primary producers in the ocean?

Phytoplankton, comprising diatoms and dinoflagellates, are responsible for 50% of the oxygen present in the atmosphere, and account for 95% of primary production in the ocean, including bacteria and protists.

Where is ocean productivity highest?

The coastal upwelling areas in the eastern Pacific and Atlantic Ocean, which occupy less than 2% of the oceans, are among the most biologically productive marine areas globally. These areas support a large biodiversity and provide 20% of the world’s fish harvest, posing significant societal and economic importance for neighboring countries and the global food supply. However, the Federal Ministry of Education and Research is supporting three joint projects under the theme “Importance of climate change in coastal upwelling areas” to investigate these areas in the north- and south-eastern Atlantic and the south-eastern Pacific.

The projects, which will receive funding of 8. 7 million euros over three years, aim to better understand the sensitivities of these areas to climate change and identify possible consequences at an early stage. The coastal upwelling areas are characterized by major ocean currents flowing parallel to the coast, such as the Benguela Current in the south-eastern Atlantic, the Canary Current in the north-eastern Atlantic, and the Humboldt Current in the south-eastern Pacific.

What is the primary productivity of the ocean?

Marine primary production is primarily generated by algae and cyanobacteria, which form the primary producers at the base of the ocean food chain and produce half of the world’s oxygen. These microorganisms underpin almost all marine animal life by generating oxygen and food. Some marine primary producers also serve as ecosystem engineers, altering the environment and providing habitats for other marine life.

Primary production in the ocean is mainly from cyanobacteria and algae, while on land it comes mainly from vascular plants. Marine algae includes unicellular microalgae, which form ocean phytoplankton, and larger, more visible macroalgae called seaweed. Seaweeds are found along coastal areas, living on the floor of continental shelves and washed up in intertidal zones.

In the Silurian, phytoplankton evolved into red, brown, and green algae, which invaded land and evolved into land plants. Later, these land plants returned to the sea as mangroves and seagrasses, found along coasts in intertidal regions and in the brackish water of estuaries. Seagrasses can be found at depths up to 50 meters on both soft and hard bottoms of the continental shelf.

What organisms are primary producers in the ocean?

Primary producers, such as bacteria, phytoplankton, and algae, form the lowest trophic level of the aquatic food web and synthesize their own energy without needing to eat. They can use photosynthesis to build carbohydrates or chemosynthesis to metabolize chemicals from hydrothermal vents and methane seeps. Seraina Rioult-Pedotti, a 2022 Hollings scholar, studied Pacific halibut and black rockfish diets at the Kachemak Bay National Estuarine Research Reserve in Alaska, which are both environmentally and economically important species. Understanding these predators’ dietary preferences can help fisheries managers unders
tand how fishing activity affects ecosystems.

Consumers, such as copepods, rotifers, and larval stages of fish and invertebrates, graze on phytoplankton, while larger animals, like marine snails, fish, reptiles, and mammals, graze on algae. Filter feeders strain their food directly from the water, including bivalves, tube worms, sponges, and even large animals like baleen whales and manta rays.