The Mediterranean Sea has undergone significant changes due to climate change. Scientists attribute this primarily to the burning of fossil fuels such as oil, coal, and gas. These activities have increased sea temperatures, allowing invasive fish species to thrive and compete with native populations.
Irreversible Changes in the Mediterranean
According to Ernesto Azzuro, a marine biologist with Italy’s National Research Council, the traditional Mediterranean ecosystem is disappearing. These transformations are largely irreversible. The warming sea has been identified as a climate change “hot spot,” with predictions of a 2 to 6 degrees Celsius rise by 2100. The sea’s enclosed nature prevents the dissipation of heat, which exacerbates this trend.
Invasive Species Impact on Biodiversity
Rising temperatures have introduced species like the spotted puffer fish, notorious for its predatory nature. These species entered through the Suez Canal and spread rapidly, diminishing native populations. The lionfish, recorded in the region since 2012, is now prevalent. This shift is particularly detrimental to the eastern Mediterranean, where local species struggle to survive.
Cyprus was among the first to experience these impacts. Native stocks like red mullet are declining. Rabbitfish, another invasive species, damage habitats by consuming sea algae. Efforts to curb fossil fuel usage are urgent, but solutions require global cooperation.
Documented Invasive Species
Approximately 1,000 invasive species now inhabit the Mediterranean, with 800 well-established. Notably, 93% of mollusks in the eastern Mediterranean have vanished. The once-plentiful mussel populations along the Adriatic coast are almost extinct due to extreme sea temperature increases.
The die-off was spectacular. The future of mussels is grim unless resilient populations emerge.
Azzuro’s institute has launched awareness campaigns about the dangers of invasive species, such as the toxic puffer fish and the harmful lionfish spikes.
Possible Mitigation Strategies
Experts assert that reversing the spread of invasive species is too late. However, strategies to manage the impact include commercializing edible invasives and compensating fishers for catching inedible species. For example, the lionfish is valued in some markets, yet the dusky spinefoot remains underutilized despite its proliferation.
To minimize further migration, international treaties should enforce treatment of ballast waters in incoming ships, preventing species transport. This could decrease new alien species by up to 99%. Additionally, applying specific paint to ship hulls can deter attachment of unwanted species.
Adjustments in fishing policies can help native species recover. Encouraging the growth of mollusks resistant to alien species like the blue crab is one approach. The future challenge will be finding ways to restore the Mediterranean environment.