THE CLIMATE CHANGE EFFECT IN THE MEDITERRANEAN
Form 3 students. Foley’s school. Limassol (Cyprus)
WHAT IS HAPPENING TO OUR OCEANS?
Climate change is the single greatest threat we face as a species – and in the Mediterranean, temperatures are going up 20% faster than the global average. This is already having real and serious consequences across the basin, and they’ll increase over the upcoming decades, with sea level rises expected to exceed one metre by 2100, impacting one third of the population in the region. Urgent and far-reaching action is needed, both to mitigate further greenhouse gas emissions, and to adapt to the new reality of a warming sea. We need to collectively make tremendous efforts in order to guarantee a future free from fossil fuels; greenhouse pollution; our growing issue – global warming; and rising sea levels.
HIGHLY DESTRUCTIVE INVASIVE SPECIES – SKULKING ACROSS THE MEDITERRANEAN’S WARM WATERS, DEVASTATING NATIVE ECOSYSTEMS
The Mediterranean holds one particularly unwelcome distinction: it’s the most invaded sea in the world. In recent decades there’s been an explosion in the numbers of alien species as almost 1000 invasive species have migrated into the Mediterranean, establishing themselves across the basin, with catastrophic consequences for native biodiversity – interaction with the new arrivals is completely disrupting stable ecosystems.
A few decades ago, the waters would have been too cold for species such as Rabbitfish and Lionfish to survive. Now, they’re not only surviving but positively thriving at the expense of native species, expanding their numbers rapidly, and establishing a new community. Lionfish in particular, began feeding on large quantities of small native fish and crustaceans which led to their stomachs being able to expand up to 30 times its original volume to accommodate them. Experience from other parts of the world show just how much damage it can do: in the Bahamas, a 40% increase in lionfish numbers. Additionally, to put this in perspective, a study of more than 1,000km of Greek and Turkish coastline found that where rabbitfish were abundant, there was a 65% reduction in large seaweeds; a 60% reduction in algae and other invertebrates; and a 40% reduction in the overall number of species present. Meanwhile fishers in Kas, Turkey, report that rabbitfish make up 80% of their catches making the issue of whether Rabbitfish should be there or not, quite controversial. Personally, as a group we believe that even though Rabbitfish are out of place and are considered invasive, they do have a positive impact towards the citizens of the surrounding areas, which for us cancels out their slightly odd presence. Unfortunately though, we still can’t ignore that a 40% reduction in numbers of native species was caused in some areas, due to their irregular presence and invasive behaviour.
Climate change means it will likely be impossible to stop the continued spread of lionfish, rabbitfish, and other potentially destructive invaders across the Mediterranean. But in a region where so much depends on healthy, diverse marine ecosystems – fishing, tourism, recreational diving etc. – the need to at least attempt to control the numbers of these alien species is obvious.
JELLYFISH DOMINATE THE MEDITERRANEAN EACH YEAR, DISRUPTING FISHERIES AND OVERWHELMING TOURIST BEACHES
Jellyfish have been around since before the time of the dinosaurs. While they’re undeniably strange creatures – 96% water, with no brains, no bones, and no blood – they’re common in all oceans and are an important part of a balanced marine ecosystem. When the ecosystem gets out of balance though, jellyfish can become a problem. Since around 2003 that’s what’s been happening in the warming Mediterranean, jellyfish blooms – where populations breed and rapidly increase – used to be occasional events that took place every few years, but in southern waters today they’re happening annually and lasting longer. The increased blooms have led to an explosion in jellyfish numbers which is radically altering regional ecosystems, with serious knock-on effects for fisheries and tourism. As jellyfish fill up fishing nets across the Mediterranean, gear is damaged and efficiency reduced, and crews waste hours dealing with them instead of catching the fish that support their livelihoods. In Tunisia’s Gulf of Gabes some fishers report they can catch more jellyfish than fish! Furthermore, Jellyfish can be venomous, therefore fishers are frequently stung when clearing their gear, and this is a growing problem in Mediterranean tourist destinations too: a swimming beach filled with stinging jellyfish swiftly loses its appeal, and if visitor numbers drop local communities take an immediate economic hit.
Think about it, would you like to be stung by a jellyfish on your vacation?
The rising sea temperatures lengthen the duration of jellyfish blooms, increase winter breeding in some species and make the environment more welcoming for invasive jellyfish species. So, what can we, as a community do to prevent the sea temperatures from rising? Years of overfishing have destroyed many of the stocks that used to compete with jellyfish for food, including many of the sharks, tunas and other larger fish that are sometimes their natural predators. Since they prey on fish larvae and compete with them too, it’s the jellyfish themselves that are becoming the new top predators in the Mediterranean – a future ecosystem dominated by jellyfish is a genuine possibility, and the ‘jellification’ of the sea is becoming a reality.
It’s time to act.
Solving the jellyfish problem is a complex challenge and will require coordinated action on several fronts, thus Increasing competition by reducing overfishing on key fish species is critical. There’s little you can do alone as an individual. For the time being we have to face this reality and accept the changes around us. Tourist operators are already taking the simple step of installing nets around popular beaches to keep out the jellyfish, whilst In Tunisia, fishers are starting to try to sell their unwelcome catch, looking for inspiration to Asia where jellyfish have long been a source of food. There’s also rising global demand for collagen for the cosmetics industry – this can be extracted from jellyfish, although the technology is still in its infancy.
CONFRONTING THE MEDITERRANEAN’S CLIMATE CHANGE REALITIES: IMPLICATIONS AND IMPERATIVES
Confronting the Mediterranean’s climate change realities requires enormous effort – with rising temperatures, shifting precipitation patterns, and heightened frequency of extreme weather events, the delicate balance of the Mediterranean ecosystem and the livelihoods of its inhabitants are under threat. It’s crucial that urgent action is taken from both local and global cooperation to apply precaution measures and lessen further climate disruption. Our mission as a whole should be to conserve nature and reduce the most pressing threats to the diversity of life on earth! More than ever, people are aware that our climate and our ocean are in danger – and they are two sides of the same coin. As these cases clearly show, while climate change has serious impacts on the ocean, and a depleted ocean further exacerbates the effects of climate change, we also know that by protecting the ocean we contribute to the fight against climate change, and by fighting against climate change we contribute to protecting the ocean.
Embrace change and join our mission to save our ocean.
