From the coast of Haifa in Israel to the waters of the Balearic Islands, the **Mediterranean Sea** is experiencing an **accelerated transformation** driven by **climate and human factors**.
**Global warming**, the **expansion of the Suez Canal**, and the **growth of international trade** have turned this sea into a critical point, with temperatures rising twice as fast as the global average.
The consequences are visible:
– Tropical fish replacing native species.
– Asian algae displacing oceanic seagrass.
– Giant jellyfish forcing beach closures.
## The impact of invasive species in the Mediterranean Sea
One of the major factors of change is the arrival of **exotic species** that alter the ecosystem’s balance.
### The rabbitfish and marine deforestation
Two species of **rabbitfish**, **Siganus rivulatus** and **Siganus luridus**, entered the Mediterranean through the **Suez Canal** and have proliferated massively.
These fish, which form large schools, have eliminated extensive areas of native algae, reducing the **complexity and biodiversity** of the ecosystem.
A study on **Greek and Turkish coasts** revealed that in areas where these fish abound, marine vegetation has decreased by **65%**, while **species richness** has been reduced by **40%**.
### The spread of the Asian alga Rugulopteryx okamurae
On the Spanish coasts, the invasion of **Rugulopteryx okamurae**, an **algae of Japanese origin**, has caused enormous economic and ecological impacts.
Accidentally introduced in **France** with the importation of Pacific oysters, the species has spread through the **Strait of Gibraltar**, reaching **Almería and Catalonia**, blocking fishing nets and generating **millions in costs** for beach cleaning.
## The role of the Suez Canal in the ecological crisis
The expansion of the **Suez Canal** in **2015** has enhanced the arrival of invasive species in the Mediterranean.
Each dredging increases the amount of **water and organisms** migrating from the **Red Sea**, bringing with it **millions of larvae and eggs**.
This phenomenon, combined with the **rise in temperatures** and the lack of environmental regulation in regions such as **Turkey, Egypt, and Lebanon**, contributes to the vulnerability of the Mediterranean.
## New invasive species recorded in the Mediterranean Sea
According to marine biologist **Alan Deidun**, the arrival of exotic species is unstoppable.
So far in **2025**, **three new species** have been documented in Maltese waters, including **pufferfish and lizardfish**.
To date, there are **over 100 invasive species** recorded in the Mediterranean, originating from the **Atlantic and the Red Sea**.
### Health risk and toxic species
Some invasive species not only affect **biodiversity** but also pose a danger to human health.
For example, the **pufferfish Lagocephalus sceleratus** contains a **lethal neurotoxin**, which has caused **fatal cases in the eastern Mediterranean**.
The **jellyfish Rhopilema nomadica**, present on **Israeli beaches**, has led to hospitalizations due to **severe burns**.
## An unprecedented environmental crisis
The spread of **invasive exotic species** is one of the main causes of **biodiversity loss** worldwide.
The **Mediterranean** is now one of the most affected seas, with species such as **lionfish, blue crab, and Manila clam** deeply altering the ecosystem.
Experts warn that the transformation of the Mediterranean **will not stop**, and that it is essential to **strengthen conservation policies and biological control** to mitigate the impact of this environmental crisis.
*Cover photo: E. Ballesteros*



