Related Experiment Video
Updated: Aug 26, 2025
05:04
Author Spotlight: Understanding Riverine Nitrogen Impacts and Primary Productivity for Effective Nutrient Management
Published on: July 14, 2023
463
A nutrient relay sustains subtropical ocean productivity.
Mukund Gupta1,2, Richard G Williams3, Jonathan M Lauderdale1
1Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139.
Summary
Subtropical ocean gyres rely on mesoscale eddies and particle remineralization for nutrient replenishment. This nutrient relay sustains ocean productivity and carbon export in these vital marine ecosystems.
Area of Science:
- Oceanography
- Biogeochemistry
- Climate Science
Background:
- Subtropical ocean gyres are crucial for global carbon export.
- Nutrient replenishment in subeuphotic layers of gyres is poorly understood.
- Surface productivity depletes nutrients, necessitating resupply mechanisms.
Purpose of the Study:
- To quantify nutrient resupply mechanisms in subtropical ocean gyres.
- To investigate the role of mesoscale eddies in nutrient transport.
- To understand the pathways sustaining gyre productivity.
Main Methods:
- Utilized a global, eddy-permitting ocean physics and biogeochemistry simulation.
- Quantified nutrient fluxes along and across density surfaces.
- Assessed the contribution of mesoscale eddies (10-100 km) to nutrient transport.
Main Results:
- Mesoscale eddies transport nutrients from gyre flanks into the interior.
- Nutrient resupply to subeuphotic layers is equally driven by eddy transport and particle remineralization.
- Eddy-driven nutrient supply is significant in the lower thermocline and dominant within gyre interiors.
Conclusions:
- Subtropical gyre productivity is sustained by a nutrient relay system.
- Lateral nutrient transport by eddies is critical for thermocline resupply.
- This process supports surface biological production and carbon export.
Related Concept Videos
01:06Primary Production
23.8K
The total amount of energy acquired by primary producers in an ecosystem is called gross primary production (GPP). However, of this energy, producers use some for metabolic processes, and some is lost as heat, decreasing the amount of energy available to the next trophic level. The remaining usable amount of energy is called the net primary productivity (NPP). In terrestrial ecosystems, NPP is driven by climate, while light penetration and nutrient availability drive NPP in aquatic ecosystems.
23.8K
01:19Absorption of Nutrients
947
Absorption refers to taking dietary nutrients from the intestinal lumen for transportation throughout the body. After digestion in the small intestine, carbohydrates, proteins, and fats are broken down into simpler forms. These essential macronutrients and other vital substances, such as vitamins, minerals, and water, are then prepared for absorption into the bloodstream.
Enterocytes, which are specialized polar epithelial cells, line the mucosa of the small intestinal walls. These cells...
Enterocytes, which are specialized polar epithelial cells, line the mucosa of the small intestinal walls. These cells...
947
02:12Short-distance Transport of Resources
16.3K
Short-distance transport refers to transport that occurs over a distance of just 2-3 cells, crossing the plasma membrane in the process. Small uncharged molecules, such as oxygen, carbon dioxide, and water, can diffuse across the plasma membrane on their own. In contrast, ions and larger molecules require the assistance of transport proteins due to their charge or size. Transport across membranes also occurs within individual cells, playing a variety of essential roles for the plant as a whole.
16.3K
00:46Trophic Efficiency
21.2K
Trophic level transfer efficiency (TLTE) is a measure of the total energy transfer from one trophic level to the next. Due to extensive energy loss as metabolic heat, an average of only 10% of the original energy obtained is passed on to the next level. This pattern of energy loss severely limits the possible number of trophic levels in a food chain.
21.2K
01:26Oxygenic Photosynthesis
108
Oxygenic photosynthesis is a fundamental process in which light energy is harnessed to drive the oxidation of water, leading to the production of molecular oxygen (O₂), adenosine triphosphate (ATP), and nicotinamide adenine dinucleotide phosphate (NADPH). This process is essential for sustaining aerobic life on Earth and is primarily carried out by cyanobacteria, algae, and plants. The core of oxygenic photosynthesis lies in the thylakoid membranes, where chlorophyll pigments facilitate...
108
01:22Inorganic Nitrogen Assimilation
81
Nitrogen is an essential element in biological systems, forming a crucial component of proteins, nucleic acids, and other cellular constituents. Many bacteria and archaea acquire nitrogen in the form of nitrate (NO₃⁻) or ammonia (NH₃), which are then assimilated into biomolecules through specific enzymatic pathways.Assimilatory Nitrate ReductionWhen nitrate enters the cell, it undergoes a two-step reduction process known as assimilatory nitrate reduction. Initially, the enzyme...
81