Introduction to upwelling, its importance in coastal ecosystem productivity and support to Aquatic diversity. Recent studies on upwelling

1. Importance of upwelling for Coastal
Aquatic productivity and Fisheries
By:
Bhukya Bhaskar
Fisheries
(Ref: Satar, et al.2023)

2. Introduction
• When the wind blows parallel to a coastline, surface waters are
pushed offshore and water is drawn from below to replace the
water that has been pushed away.
• The upward movement of this deep, colder water is called
upwelling.
• The deeper water that rises to the surface during upwelling is rich
in nutrients.
• These nutrients “fertilize” surface waters, encouraging the growth
of plant life, including phytoplankton.
• These phytoplankton serve as the ultimate energy base in the ocean
for large animal populations higher in the food chain, providing
food for fish, marine mammals, seabirds, and other critters.
• Coastal upwelling ecosystems, such as along the west coast of the
United States, are some of the most productive ecosystems in the
world and support many of the world's most important fisheries.
• coastal upwelling regions of the world account for only 1% of
the ocean surface, they contribute roughly 50 % of the world's
fish catch landings.

3. Cont...
• Upwelling can also play an important role in the movement of marine animals.
• Most marine fish and invertebrates produce microscopic larvae which, depending on
the species, may drift in the water for weeks or months as they develop.
• For adult marine creatures that live in shallow waters nearshore, upwelling that
moves surface water offshore can potentially move drifting larvae long distances
away from their natural habitat, thus reducing chances for survival.
• In some ways, upwelling can be a mixed blessing to coastal ecosystems.
• It can infuse coastal waters with critical nutrients that fuel dramatic productivity, but
it can also rob coastal ecosystems of offspring required to replenish coastal
populations.
• Indonesia itself has a type of coastal upwelling which is strongly influenced by the
change of seasons.
• In the southern hemisphere, upwelling is strongly influenced by the southeast
monsoon, on the contrary in the northern hemisphere, such as waters in the Aceh
Sea, northern Natuna, northern Banggai and Sulawesi Sea.
• In addition, as mentioned above, ENSO, IOD and some long waves such as Kelvin
and Rossby waves play an important role in modulating the upwelling
phenomenon.
• Knowledge of the upwelling characteristics of various places from different
latitudes with different seasons that characterize the difference in wind direction
and speed makes an important contribution to the development of better fisheries
management, planning actions, strategies and protection, of fishery resources and
the coastal environment.

4. • The mass of nutrient-rich water raised to the surface
stimulates the growth and reproduction of primary
producers (phytoplankton).
• Due to the phytoplankton-biomass and the presence of
cold water, upwelling could be identified from SST and
Chlorophyll-a.
• Not all of the world's coastal waters experience the
upwelling phenomenon, only certain water areas are
supported by several factors, including the position of
the land to the ocean, wind direction and speed,
bottom topography of the waters and the Coriolis
effect which are working in the area.
• In addition, upwelling can occur in the equatorial zone,
eddy processes, ridges or sills in the bottom of the sea
and the presence of the capes.

5. Source: NOAA
• Upwelling occurs when winds push surface water
away from the shore and deeper water rises to fill
the gap.

6. Cont...
• Upwelling in the current climate off a southern hemisphere coast.
• Wind is parallel to the coast, and water is deflected to the left of the wind by the
Coriolis force.
• Surface water is pushed offshore and is replaced by cool, nutrient-rich water from
depth.
• Upwelling and downwelling describe mass movements of the ocean, which affect
both surface and deep currents.
• These movements are essential in stirring the ocean, delivering oxygen to depth,
distributing heat, and bringing nutrients to the surface.
• Phytoplankton are responsible for almost 80% of the oxygen
contribution to the atmosphere. Thus, ocean upwelling becomes essential in
multiplying more rapidly.
Downwelling: occurs when surface waters converge (come together), pushing the
surface water downwards.
• Regions of downwelling have low productivity because of the nutrients get used up
and are not continuously resupplied by the cold, nutrient-rich water from below the
surface.
• Downwelling is a kind of reverse upwelling. Instead of deeper water rising up,
warm surface water sinks down.
• Upwelling and downwelling patterns often alternate seasonally.
• The West Coast of the United States, for example, experiences summer upwelling
and winter downwelling, as the winds change directions with the seasons.

7. Importance And Benefits of Ocean Upwelling
• a. Brings the nutrient-rich ocean waters to the
surface
• b. Results in marine bloom
• c. Upwelling is significant for ocean life
• d. Supports the fish industry
• e. Benefitting the human life

8. A .Upwelling brings the nutrient-rich ocean waters to the surface
• Not only does ocean upwelling bring the cold and
deep ocean waters to the surface of the coast, but it
also brings the water to the coastlines that are rich
in nutrients.
• This happens due to the blowing winds and the
rotation of the Earth on its axis.
• As a combined effect of these two motions, the
waters are churned, and the nutrients are mixed.
• Even a topcarbon sequestration company looks out
for such areas where the trapped carbon dioxide
from the depths of the ocean waters can be
churned to put to better use by the phytoplankton
along with the rich nutrients during photosynthesis.

9. B. Results in marine bloom
• Deep ocean water is nutritionally richer than surface water.
• This is because things like nutrients, plankton, and fish carcasses in
the ocean, sink to the depths of the oceans.
• With the process of upwelling, it returns the lost and the sunk
nutrients to the surface.
• Thus, resulting in “blooms” of algae and zooplankton that feed on
those nutrients.
• These blooms subsequently serve as a feeding ground for
plankton feeders, fish, and so on, supporting ocean life at the
surface.
C. Upwelling is significant for ocean life
• Upwelling and downwelling are ocean mass movements that
affect surface and underwater currents.
• These movements are critical in stimulating the ocean water,
transporting oxygen to depths of the seas, spreading heat, and
bringing nutrients to the ocean’s top layers.

10. D. Supports the fish industry
• Coastal upwelling occurs where winds blow parallel to the shore and
towards the equator.
• Upwelling brings higher quantities of dissolved nutrients to the ocean
surface, boosting the growth of plankton, which in turn supports large
numbers of fish and other marine species to thrive.
• Thus, these are where carbon removal companies usually have their work in
progress and try to put their artificial upwelling pumps to mix the deeper
waters to bring up the nutrient-rich waters.
E. Benefitting the human life
• Water that rises to the surface due to upwelling is often colder and richer in
nutrients.
• Because these nutrients “fertilize” surface waters, they frequently have high
biological productivity.
• Since fish love colder waters, they tend to breed at large in these waters.
• As a result, good fishing grounds are frequently found in areas with
extensive upwelling.

11. Effects of Upwelling
Biodiversity and productivity
Because the deep water brought to the surface is often rich in nutrients, coastal upwelling supports the
growth of seaweed and plankton. These, in turn, provide food for fish, marine mammals, and birds.
• Upwelling generates some of the world’s most fertile ecosystems.
• A 25,900-square-kilometer (10,000-square-mile) region off the west coast of Peru, for example,
undergoes continual coastal upwelling and is among the richest fishing grounds in the world.
• During El Niño, a weather phenomenon that typically occurs every three to seven years, the Pacific
Ocean’s climate changes dramatically.
• The transition zone between warm surface water and cold deep water deepens. Trade winds are also weak
during El Niño.
• The combination of weak winds and deeper water transition zone limits upwelling.
• The reduction in nutrient-rich water leads to a lower fish population in the area, and therefore to a
smaller fish crop.
Animal movement
• Upwelling affects the movement of animal life in the area. Tiny larvae—the developing forms of many
fish and invertebrates—can drift around in ocean currents for long periods of time.
• A strong upwelling event can wash the larvae far offshore, endangering their survival.
Coastal climate
The cold water welling up to the surface cools the air in the region, this promotes the development of
sea fog.
• The city of San Francisco, California, is famous for its chilly, foggy summers, brought on by seasonal
upwelling in the area.

12. • Several places in the Southeast Asia experienced high
intensities of upwelling when El Nino events such as in South
of Java, East Coast of Malaysia Peninsula and in Vietnam
Coastal area.
• The most intensive and productive upwelling in the world is
South American waters and Banguela Upwelling System (BUS)
in the African Coast.
• Several other areas also show intensive and high productivity
of upwelling, such as off the southern coast of Java Island in
Indonesia and the Banda Sea and its surroundings.
• It is found that upwelling with stronger intensity can result in
increase of mortality of certain organisms such as scallops.
• Increase of nutrients in a waters is often accompanied by an
increase in several species of toxic algae that are harmful to
the local fishery system (harmful algae blooms, HABs).

13. Location of significant coastal upwelling regions in
the world ocean

14. • The area where upwelling occurs is always
identically with water productivity because it is rich
in nutrients (nitrates, phosphates and silicates)
carried by the water mass from the bottom of the
water.
• Therefore, this area is rich in pelagic fishery
resources, both small and large.
• In addition to the positive impact of this upwelling
phenomenon, it is not uncommon for negative
impacts such as blooming of certain algal species to
occur which can cause anoxic conditions and cause
massive death of several fish species

15. • The characteristics of upwelling phenomena are different from one place to another
area in the world.
• In the Southeast Asia, upwelling generally triggered by south-easterly wind during
dry season (June to November).
• Another side of Asia such as South China Sea, the upwelling induced by jet eddy
system as occurs at the western of this area during summer period.
• Upwelling also modulated by ENSO, IOD and Kelvin Wave in several parts in the
world particularly in the Southeast Asia and South China Sea.
• In Europe, some upwelling occurred during the winter time which provided high
rich nutrients to the surface waters like in the North Estonian Coast, Gulf of Finland,
Baltic Sea.
• Humboldt Current System (HCS) in South America, Banguela Upwelling System
(BUS) in Africa, off the coast of Java Island, and Banda Sea are categorized as the
most productive upwelling area in the world.
• It is uniquely that was found upwelling caused by the amplitude of internal wave
that occurred along the coast of the Tahiti Islands, French Polynesia.

16. Several locations of Upwelling based on seasonality
(Ref: Satar, et al.2023)
Fig: All the upwelling locations
analyzed, the red line indicates the
upwelling in EBUS areas, and the
green line indicates all the other
upwelling in marginal seas/small
scale upwelling areas.

19. Effects of Wind-Driven Lateral Upwelling on Estuarine
Carbonate Chemistry

20. Extracellular enzyme activity in the coastal upwelling system
off Peru: a mesocosm experiment (Kristian et al. 2023)

21. Artificial Upwelling
• Scientists and businesses are working to create
areas of "artificial upwelling" to pump cold water to
the surface.
• Researchers hope artificial upwelling will increase
fish crops from the Gulf of Mexico to southwest
Australia.
• Artificial upwelling involves complex technology
using the motion of waves to bring cold, nutrient-
rich water from the deep ocean to the surface.
• Experiments in artificial upwelling have been tried
in the Pacific Ocean near the Hawaiian Islands.

22. Nutrient composition (Si:N) as driver of plankton communities during
artificial upwelling

23. Scientists support Somali fisheries to
navigate the effects of climate change
• Scientists from the National Oceanography Centre (NOC) have
developed a new method to monitor the effects of climate change on
coastal upwelling to support the growth of local fisheries in Somalia.
• As part of the NOC’s SOLSTICE project, the new methodology uses
machine learning systems to automatically detect coastal upwelling in
the Somali Current, one of the strongest upwelling systems in the Indian
Ocean. Prior to this, fisheries have had to rely on traditional fishing
practices, but the new method will enable them to see when the
highest levels of fish productivity are likely to take place, helping to
form a sector-wide strategy that increases the efficiency of operations
within the fishing community.
• By using a machine learning approach, NOC scientists were able to
propose an ‘Upwelling Watch’ analysis, which will produce updates and
alerts on upwelling presence and extremes to form the basis for
appropriate management of fisheries along the coast of Somalia. Up
until now, there has been limited data available to assess how to
navigate these changes whilst still operating a thriving fisheries sector.
• Over 100 million people in the Western Indian Ocean region live within
100km of the coast, with over one million working in the fisheries
sector. This region is highly dependent on the ocean for economic
stability, food security, and social cohesion. In recent years, the region
has seen dramatic reductions in key fisheries, with two of the causes
being climate change, and natural ecosystem variability.
• Source: Dr Matthew Hammond, 2022. Satellite Oceanographer at the
National Oceanography Centre.

24. References
• https://oceanexplorer.noaa.gov/facts/upwelling.html#:~:text=The%20upward%20movement%20of%20this,of%20plant
%20life%2C%20including%20phytoplankton.
• https://www.redmap.org.au/article/upwelling-and-downwelling-in-the-ocean/
• https://ocean-based.com/ocean-upwelling-its-meaning-importance-benefits/
• https://education.nationalgeographic.org/resource/upwelling/
• H Umasangaji and Y Ramili, 2004. Mini review: Characteristics of upwelling in several coastal areas in the world: IOP
Conference Series: Earth and Environmental Science : https://iopscience.iop.org/article/10.1088/1755-
1315/890/1/012004/pdf
• https://doi.org/10.1038/s41467-023-36992-1
• DOI 10.3389/fmars.2022.1015188 frontier in marine science
• doi: 10.3389/fmars.2020.588465
• Satar, M.N.; Akhir, M.F.; Zainol, Z.; Chung, J.X. Upwelling in Marginal Seas and Its Association
• with Climate Change Scenario—A Comparative Review. Climate 2023, 11, 151. https://doi.org/10.3390/ cli11070151
• https://noc.ac.uk/news/scientists-support-somali-fisheries-navigate-effects-climate-change
• https://www.researchgate.net/figure/The-range-of-coastal-fisheries-activities-in-the-tropical-Pacific-and-the-habitats-
that_fig5_275328681

25. Ref: Johann D. Bell et al. 2011)
Thank you for your time B