# Invasive species expansion in the Mediterranean Sea

> Live situation record from CLSTR: https://clstr.news/situations/invasive-species-expansion-in-the-mediterranean-sea
> Updated: 2026-09-13T03:25:41.000Z. Sources: 11. Developments: 2.

The Mediterranean and Adriatic Sea ecosystems are experiencing significant changes due to rising sea temperatures and the arrival of invasive species. Over the last thirty years, more than 40 new species have been recorded in the Adriatic region.

A primary concern is the expansion of the lionfish (Pterois miles), an invasive predator from the Indo-Pacific. Experts describe it as a “voracious predator” that feeds on juvenile fish and poses risks to humans via its venomous spines. Other invasive species, such as the stargazer and the toxic silver pufferfish, are also impacting local biodiversity and fish populations.

Recent data indicates that climate change is further altering these ecosystems. In the Bay of Kotor, water temperatures have reached up to 29 degrees Celsius, leading to decreased oxygen concentrations and the arrival of additional tropical species, including the blue crab. While some species like the dentex are becoming more abundant and accessible to fishermen, the influx of new predators continues to threaten indigenous populations.

In response to these ecological and economic risks, Italy and Malta have initiated cross-border cooperation projects focusing on monitoring, scientific research, and early warning protocols to manage the spread of non-native organisms and protect the fishing industry.

## Timeline

### 2026-09-13: Adriatic Sea ecosystem faces threats from warming and invasive species

Climate change is driving rising temperatures and invasive species in the Adriatic Sea, while studies link hydroelectric operations to mass fish kills in the Neretva River.

9 sources. https://clstr.news/cluster/adriatic-sea-ecosystem-changes-due-to-rising-sea-temperatures

### 2026-08-24: Mediterranean lionfish expansion triggers Italy and Malta cooperation

Italy and Malta are enhancing cooperation and monitoring efforts to combat the spread of the invasive lionfish in the Mediterranean, which threatens marine ecosystems and local fishing industries.

2 sources. https://clstr.news/cluster/mediterranean-lionfish-expansion-triggers-italy-and-malta-cooperation

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Cite as: Invasive species expansion in the Mediterranean Sea. CLSTR, https://clstr.news/situations/invasive-species-expansion-in-the-mediterranean-sea