When the oceans help us 🐳🌏♻️
For our first episode of the Marine Odysseys, it seemed obvious to start by answering the question: ‘Why are the oceans important?
Because they provide us with a number of ecosystem services on which we humans depend.
In this blog post, we’re going to paint a broad picture of these services. We’ll come back to some of these services in more detail in future Odysseys.
Enjoy reading, and discover thousands of talents of our oceans!
The ocean is sometimes seen as an immense mass of cold, inert water, with just over a billion cubic kilometers [1]… (and a cubic kilometer is just over 300,000 Olympic-sized swimming pools). And yet…
…it’s fair to say that it keeps well its secrets.
If we go back in time, we remember that the oceans were the cradle of life some 4 billion years ago. Without oceans, there is no life.
Here are a few milestones in the history of life on Earth (or rather life on our blue planet). These include:
- No species appeared directly on the continents; the origin of all life on Earth was in the oceans.
- The ‘conquest of continents’ by complex organisms began just under 500 million years ago, which is very recent on a global scale.
- We had to wait for the first pollinators to see a real boom in terrestrial species.
So, if the ocean was the beginning of life on Earth, what services does it provide in concrete terms today?
Just like the diversity of ecosystems and habitats it comprises – deep oceans, coastlines, mangrove swamps, sea grass beds, foreshores [2], etc. – the ocean provides us with a wide and varied range of services.
We have therefore decided to draw up an overview of these services, the benefits that nature (in this case, the oceans) provides to humans [3]. These services include so-called “ecosystem services”, i.e. benefits linked to ecosystems. They are often grouped into different categories, and in this article we will use one of the most common classifications. It should be borne in mind, however, that a large proportion of these services are probably still unknown or poorly understood. Services are not limited to those provided by ecosystems: the oceans also provide other benefits, such as non-renewable resources (minerals, fossil fuels, etc.).
Provisioning services:
Provisionning services are often the ones we think of first: the resources and products obtained from ecosystems. These include
▶️ We think directly of food resources such as fish, crustaceans, molluscs and algae, for both human and animal consumption.
- The FAO has estimated that by 2022, nearly 100 million tonnes of wild fish will have been caught worldwide.
- According to WWF, over 800 million people worldwide depend on fishing for their livelihood.
But the ocean is also a supplier of other, lesser-known resources:
▶️ Raw materials, whether biosourced (derived from living organisms) or mineral: sand, siliceous and calcareous gravel, coralligenous algae, etc. [4]. Or even salts (and not just table salt!), metals (resources that are sometimes very limited on the continents), diamonds, or just simply water (for desalination, cooling systems, aquaculture, etc.) [5].
▶️ Biochemical and genetic resources:
- Molecules: bioplastics produced by bacterias, carrageenans produced by red algae and used as gelling and thickening agents by the food industry, enzymes, etc.
- Genetic resources in all marine species, a reservoir of potentially useful genetic information for research. For example, the Hemarina laboratory has discovered a universal hemoglobin in a marine worm that binds 40 times more oxygen than human hemoglobin, making it possible to improve the quality of life of patients suffering from various diseases, and to better preserve organs prior to transplantation [6]. AZT, a substance used to treat AIDS in drugs such as Retrovir, was originally isolated from herring sperm [7].
▶️ Energy resources, including renewables:
- Subsea hydrocarbons exploited on off-shore platforms
- Tidal current turbines, powered by ocean currents
- Tidal turbines, powered by tidal power and the difference in water height between consecutive high and low tides. Harnessing this energy requires the installation of quite heavy infrastructure, such as a dam. The Rance plant in France is the only one of its kind in France, and the 2nd largest tidal power plant in the world [8].
- Offshore wind power
- Ocean thermal energy (temperature difference between shallow and deep waters) or osmotic energy based on the difference in salinity between seawater and freshwater.
Regulating services:
▶️ A historic role in climate regulation [9]:
- The ocean has played a crucial role in the natural regulation of the Earth’s climate for millions of years. Its exceptional heat capacity, around a thousand times greater than that of the atmosphere, enables it to absorb and store enormous quantities of thermal energy. This process is characterized by very slow warming and cooling, helping to stabilize the global climate.
- Ocean currents are essential to this regulation, redistributing thermal energy across the planet. Warm surface water masses transport heat from the tropics to the poles, reducing temperature differences. At the same time, cold currents flow at depth in the opposite direction, creating an oceanic “conveyor belt” that balances out global thermal distribution.
- Certain marine micro and macro-organisms bind greenhouse gases naturally produced in the oceans (e.g. methane released from hydrothermal vents), preventing them from entering the water column and ultimately the atmosphere.
▶️ Mitigating anthropogenic global warming [9]:
- While the oceans have always played a role in balancing the climate, they are now taking on an additional function: that of moderating the warming caused by man-made greenhouse gas emissions.
- The excess heat generated by human activities via greenhouse gases is mostly absorbed by the oceans, which have a moderating effect on the climate and its changes
- The oceans absorb large quantities of CO₂: as atmospheric carbon dioxide naturally dissolves on the ocean surface, micro-organisms such as phytoplankton produce primary organic matter from this CO₂ and light (this is photosynthesis). This primary organic matter is then used by the entire trophic chain of marine species and transferred to the deep layers of the ocean in the form of particles (dead organisms, excrement, etc.).
▶️ Marine and coastal environments play an active role in regulating erosion and natural hazards:
- Seagrass beds (Posidonia in the Mediterranean, eelgrass in the Atlantic) attenuate swell and limit erosion by stabilizing the seabed and reducing the speed of currents [10].
- Mangroves, ecosystems at the interface between land and sea, reduce the capacity of waves to erode sediment. The entanglement of roots and branches reduces the height and energy of waves, thus limiting the impact of extreme phenomena such as tsunamis [11].
▶️ Water purification :
- Certain marine organisms help regulate water quality through their filtration capacity (bivalve molluscs, bacteria, etc.). This process is particularly effective in certain coastal ecosystems such as mangroves.
- The oceans also regulate the concentration of nutrients in the water, notably via phytoplankton, which absorb nutrients such as nitrogen and phosphorus.
Supporting services:
Supporting ecosystem services are the fundamental services required for the production of all other services. They create the basic conditions essential to the development of life on Earth. Their effects are indirect and often manifest over the long term.
▶️ Participation in the Earth’s natural biogeochemical cycles:
- The ocean is a major player in the water cycle, as a major reservoir of water and a site of evaporation. Ocean currents also contribute to global heat redistribution [12].
- Participation in the carbon cycle (see section on regulating services)
- Participation in other biogeochemical cycles, such as the oxygen cycle and the cycle of certain nutrients such as phosphorus. In particular, the ocean is a major producer of oxygen for us, even more important than the forests we call the lungs of the planet.
▶️ Soil formation and stabilization:
- Marine sedimentation of mineral and biological particles deposited on the ocean floor forms sedimentary layers that can become soils.
- Some marine organisms, such as calcareous algae and corals, are involved in soil formation.
- Some coastal ecosystems play a crucial role in soil stabilization. This is the case of the seagrass beds and mangroves mentioned in the regulation services section, as well as salt marshes, which slow down the erosion of soils.
▶️ Habitats
- The oceans offer a wide variety of habitats that are ideal for the proliferation of many marine and terrestrial species.
- Mangroves, for example, are veritable nurseries for a wide variety of fish species, but are also a habitat for many species of birds, reptiles, crustaceans, etc.
▶️ Transport support
- The oceans have enabled us to transport people and goods for thousands of years. Today, maritime transport plays a major role in world trade (90% of all trade, according to the Musée de la Marine).
- Via undersea cables, the oceans play a key role in telecommunications. 98% of Internet traffic is routed via undersea cables [13].
- Gas and oil pipelines also transport raw materials.
Cultural services:
Cultural ecosystem services are non-material benefits that human beings derive from ecosystems.
▶️ Recreation and tourism:
- The oceans support a wide range of activities, including scuba diving, fishing and swimming.
- Seaside tourism, cruises
▶️ Aesthetic, artistic, heritage and spiritual values:
- The oceans are a source of inspiration for the fine arts and other forms of artistic expression such as music, cinema, etc.
- The beauty of marine and coastal landscapes and ecosystems contributes to the cultural identity of communities.
▶️ Educational and scientific values:
- The oceans offer opportunities for scientific learning and discovery.
- Underwater archaeology enables historical discoveries to be made thanks to conservation.
Conclusion
Marine ecosystem services play a crucial role in our existence, well-being and economy. Often overlooked, these services encompass a range of vital functions from oxygen production and carbon sequestration to food production and coastal erosion regulation.
These ecosystem services are based on dynamic balances and multiple interactions, forming a puzzle whose pieces are not yet fully understood.
When we try to pick out anything by itself, we find it hitched to everything else in the Universe. John Muir [14]
Increasing anthropogenic pressure on marine ecosystems (pollution, unsustainable resource exploitation, climate change) threatens the ability of these ecosystems to continue providing these essential services.
Preserving these ecosystems means investing in the future: the health of the oceans is intimately linked to our own.
At Sayari, we aim for a holistic approach to the impacts of human activities on biodiversity, and particularly marine biodiversity. We address the 5 pressures identified by IPBES: land and sea use change, wildlife exploitation, climate change, pollution and invasive species. Our assessments cover the entire value chain. Please take a look at our offer on this subject.
For seafood products, whether from fishing or aquaculture, we can help you measure your specific impacts and build your biodiversity strategy.
Want to find out more about marine biodiversity? We recommend taking part in an Océane fresk [15]!
Sources
[1] https://oceanservice.noaa.gov/facts/oceanwater.html
[2] Part of the land next to the sea that is between the limits reached by high and low tide
[3] https://www.eib.org/fr/stories/ecosystem-service-nature
[4] https://www.mineralinfo.fr/sites/default/files/documents/2021-02/geosciences_brgm_augris-simplet.pdf
[5] https://www.techniques-ingenieur.fr/actualite/articles/31250-31250/
[6] https://www.hemarina.com/
[7] https://www.centrescientifique.mc/uploads/documents/fr_2009-04.pdf
[8] https://www.edf.fr/usine-maremotrice-rance/produire-de-lelectricite
[9] ocean-climate.org
[10] https://www.ofb.gouv.fr/les-herbiers-de-posidonies
[11] https://www.unesco.org/fr/articles/les-mangroves-un-bouclier-naturel-contre-les-aleas-cotiers-dans-la-reserve-de-biosphere-de-savegre
[12] https://ocean-climate.org/sensibilisation/le-role-de-locean-dans-le-climat/
[13] https://warm.2050now.com/mers-oceans/sous-les-mers-la-guerre-des-cables-sintensifie-553/
[14] My First Summer in the Sierra (Boston: Houghton Mifflin, 1911) (https://vault.sierraclub.org/john_muir_exhibit/writings/misquotes.aspx)
[15] https://www.fresqueoceane.org/
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