Artificial downwelling
Artificial downwelling (AD) is an idea to pump upper layer water deeper down into the ocean.
Oceans & marine
Re-oxygenating the Baltic
The deep waters in the Baltic are severely deoxygenated. Although the causes of the current state are complex, this is mainly a result of increased eutrophication from sewage and agricultural runoff from surrounding lands, which leads to extreme bioproductivity (Rolff et al. 2022). Some species manage to survive in the upper water layers, but many organisms living on the seafloor are severely impacted by the hypoxia, thereby influencing the health of a wide network of ecosystems and biochemical processes. There are attempts to reduce nutrient runoff into the Baltic (see for example: https://helcom.fi/baltic-sea-action-plan/). However, some argue these will be insufficient and argue for engineering solutions to the issue.
Artificial upwelling
Artificial upwelling (AU) is an idea to increase carbon uptake of upper ocean layers by fertilizing it with pumped-up colder nutrient-rich waters from the deep, which would encourage the biological sequestration of carbon through photosynthesis (NASEM 2022).
Improved fishing practices and management
Fisheries contribute to global CO2 emissions by the extraction of fish, disturbance of coastal and oceanic blue carbon ecosystems, and the use of fossil fuels as their main energy source. Fishing vessels are moreover a major source of short-lived climate forcers like black carbon (McKuin and Campbell 2016), which can have a major effect in Arctic and Northern regions (see Black carbon reduction).
Enhancing oceanic light availability below the photic layer
Ocean bioproductivity through photosynthesis stops beyond the photic layer as no more energy from the sun can penetrate beyond that point.
