What are underwater biotopes and why are they important for marine life?

Types of Biotopes: Production, Protection, and Attraction

Production Biotopes

Specifically designed to become new underwater habitats, these structures have openings, chambers, and hiding places that allow various marine species to seek refuge, establish themselves, and reproduce.
They are built with neutral materials, meaning they do not chemically alter the marine environment or its ecological balance. Their function is to promote natural colonization by marine organisms, from invertebrates to larger fish.

Protection Biotopes

These do not so much seek to attract marine life as to protect vulnerable seabeds, such as Posidonia meadows or areas of high ecological value.
They have star-shaped or other structures that prevent the passage of trawl nets, acting as physical barriers against destructive fishing practices.
Breakwaters and groynes are also considered protection biotopes, as they reduce coastal erosion and serve as refuge for many species.

Biotopes of Attraction: Wrecks or Sunken Ships

Undoubtedly, the most popular among divers are wrecks, i.e., sunken ships.
Some are accidentally submerged (shipwrecks), but others are deliberately submerged after a cleaning and adaptation process, converting them into tourist attractions and diving spots that also offer new habitats for marine fauna.

What happens when a new biotope is created?

1. Stabilization

Once placed on the seabed, the biotope needs time to settle. Factors such as the type of sediment, currents, or the inclination of the relief can modify its initial position. This initial stage is crucial, as it will determine what type of life can establish itself later.

2. Colonization

When the biotope begins to stabilize, the process of biological colonization begins.

Some fish, especially the less territorial ones, use it as a temporary refuge.
Ocean currents carry larvae and microorganisms that adhere to surfaces, forming the first sessile communities.
Over time, the new habitat becomes more complex, stable, and diverse.

3. Ecosystem Development

As the environment matures, the biotope develops into a true underwater ecosystem, with its own food chains, dynamics, and balances.
Each structure will eventually favor the presence of certain species:

• Conger eels and moray eels, which seek hiding places.
• Lobsters and crustaceans that colonize crevices.
• Groupers, territorial fish that patrol rocky areas.
• Schools of small fish, attracted by the protection.
• Pelagic migratory fish, which use the area as a feeding ground.
• Sessile species such as sponges, anemones, and bryozoans.
• Each biotope develops a unique community, creating different underwater landscapes depending on its shape, location, and depth.

Conclusion: Creating life where none existed before

Artificial biotopes represent an effective tool in the restoration and management of the marine environment. They can mitigate human impacts, attract sustainable diving tourism, and enhance biodiversity in degraded or ecologically poor areas.

However, their design, installation, and monitoring must be carried out with scientific criteria and rigorous planning. A poorly managed biotope can become a problem, while a well-executed one can become an underwater oasis teeming with life.

Have you ever dived on a wreck or in an area with artificial biotopes? Come to a Greendiving center, we'll take you there and tell you much more about them.