Biohuts
How can marinas have a positive impact on resident marine life?
The following article is based on the “Coastal Restoration” chapter of the “Coastal Habitat Restoration” book cited below.
The coastal fringe is home to numerous essential ecosystem functions such as the so-called nursery zones, which are vital for the renewal of populations of many coastal marine organisms, especially fish, crustaceans, and molluscs.
For many years, multiple efforts have been made to improve water quality and to reduce pollution in shallow coastal areas of the Mediterranean basin. Although coastal development within these regions increased threefold since 1975, strong policy action has led to a decade of stabilisation. However, all the existing port and marina zones have degraded habitats, with low complexity and relief (smooth surface), compromising ecological functions such as nurseries and spawning grounds.
Challenged by increasing ecological pressures such as habitat loss, pollution, and the impacts of climate change, conservation efforts alone are no longer sufficient; consequently, ecological restoration offers a vital pathway to actively enhance biodiversity.
Port and marina authorities have recently demonstrated greater commitment to and receptiveness for leading ecological restoration projects. In 2025, in France alone, 40+ marinas are equipped with artificial fish nurseries. In Europe, Denmark has equipped 10 marinas, with Spain and Portugal also starting to get involved.
One of the main initiatives aimed at countering the disappearance of coastal juvenile habitats in marina zones is the creation of artificial fish nurseries (e.g., Biohut®). This solution can mimic the ecological function of a nursery by protecting the early life history (ELH) stage, as well as shielding the juveniles from predators, and ensuring the necessary food chain thanks to the abundant mobile fauna that develop within the oyster shell substrate. Scientific monitoring by visual counting has shown that the presence of Biohut has a positive effect on the fish assemblage in marinas, with a higher average diversity compared with the rest of the marina. According to studies, the Biohut seems to have a positive influence on certain species, in particular seabream and red grouper. In addition, Biohut can also serve as a support for environmental education and raising awareness about the importance of marine conservation.
Today, Ecocean has 100+ sites equipped with its Biohut® patented solution in 16 different countries. In 2024, the Biohut solution received the “Monaco sustainable marina” award as well as the Port du Future-Infrastructure category prize from the Ministry of Environment-CEREMA.
Ecological restoration practices are being increasingly considered to assist in the recovery of damaged ecosystems. But the implementation of an active and operational ecological restoration initiative requires the five following prerequisites:
- Availability of scientifically proven technical solutions that address a particular problem (e.g.: nursery function).
- A commitment to restore degraded environments and to use existing technical solutions made in recycled and recyclable material.
- Adequate financial resources to implement all aspects of the project.
- An administrative and regulatory authority to implement the project backed by good and transparent governance.
- Robust monitoring to enable a comprehensive evaluation of the restoration project.
Contacts
contact@ecocean.fr
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