What is an ecosystem? đ§Ź
An ecosystem consists of a habitat and the living organisms that inhabit it. More specifically, a âmarine ecosystemâ refers to an ecological system comprising a biocoenosis â made up of marine organisms â and a biotope, consisting of salt water and the shores of seas and oceans. Marine organisms constantly interact with one another (reproduction, food chain, etc.) and with the biotope.
Every component of an ecosystem is interconnected, forming a network of energy and material exchange. For example, a plant produces oxygen by absorbing carbon dioxide; this oxygen is used by animals, which release COâ, thus completing the cycle.
A delicate balance
If a key component is lost or the balance is disruptedâsuch as the extinction of a keystone species or the introduction of a new speciesâthe entire ecosystem can collapse.
If the temperature of this ecosystem is altered over the long term, the entire ecosystem may change, and the organisms living there may even be endangered.
That is why it is crucial to understand and protect these complex systems.
Marine ecosystems: a fascinating diversity đđ
Marine ecosystems encompass a wide range of environments, each unique in its physical, chemical, and biological characteristics. Here are the main types:
Coral reefs
- Distribution: shallow tropical waters (Caribbean, Indian Ocean, Pacific).
- Ecological role: habitat for 25% of marine species, natural barrier against coastal erosion.
- Threats: coral bleaching, pollution, overfishing.
Les mangroves
- Location: tropical coastlines where land meets sea.
- Ecological role: breeding grounds for many species, protection against storms.
- Threats: deforestation, urbanization.
Seagrass beds
- Habitat: shallow seabeds in temperate and tropical waters.
- Ecological role: water filtration, carbon sequestration, shelter for young fish.
- Threats: dredging, anchoring of boats.
Pelagic zones (open sea)
- Location: open waters, far from the coast.
- Ecological role: climate regulation, habitat for large predators (tuna, sharks).
- Threats: overfishing, plastic pollution.
The Depths
- Location: deep sea (deeper than 2,000 m).
- Ecological role: decomposition of organic matter, carbon cycle.
- Threats: mining, chemical pollution.
A central role for the entire planet đ
Marine ecosystems do more than just provide habitats:
- Thanks to phytoplankton, they produce more than 50% of the oxygen we breathe.
- They absorb about 30% of the COâ emitted by human activities.
- They are a vital food source for billions of people.
These services, known as âecosystem services,â demonstrate just how much our survival depends on the health of the oceans.
Les Ă©cosystĂšmes marins ne sont pas quâun dĂ©cor naturel : ils sont le moteur de la vie sur Terre. Les comprendre, câest le premier pas pour mieux les protĂ©ger.
Educational activity for the classroom
A/ Mapping Marine Ecosystems đ Cycle 3
Objective: To introduce students to the diversity of marine ecosystems and their geographic distribution.
Equipment:
- A blank map of the oceans.
- Colored markers.
- Fact sheets on various marine ecosystems.
Steps:
- Divide the class into groups, with each group focusing on a different type of marine ecosystem.
- Students identify where this ecosystem is located on the map.
- They describe its characteristics and the challenges involved in its preservation.
B/ Collect data from aquatic environments (Cycles 2, 3, and 4)
Participants collect water samples to analyze their quality using the âMeasure Your Science!â kit. They measure temperature and turbidity using a Secchi disk, and plankton concentration using a net. Then, they compare the results to standard benchmarks. The activity highlights the impacts of the measured parameters on aquatic biodiversity and raises awareness of the importance of preserving these ecosystems.
Sow my Dream invites you to download the âMeasure Your Science!â kit: a free activity booklet that includes experiments, along with explanatory sheets and analysis tools to enhance learning.