BLUE SEASON JUST GOT THE BLUES: Can blue jellyfish change policies for environmental protection in the Mediterranean?

7 août 2020

Par Nadia Ben Ammar

Oh how sweet it is to be in Tunisia during the “blue season”! Local and international tourists, children and adults alike are rushing toward the beautiful white sand beaches to enjoy some very well-deserved post-COVID-19 time off. But wait a minute, why are we seeing big blue jellyfish on all the holiday pictures and Instagram vacation posts? Articles started to appear on this new phenomenon in the media. Locals know the patterns of jellyfish behavior. There are well-known times when they appear during the summer season and people usually adapt their vacation slots to the presence and absence of these beautiful sea creatures which are considered as a nuisance for swimmers. But this year there is a strange phenomenon noticed: hundred and thousands of blue jelly fish (rhizostoma pulmo) are washed off on many Tunisian shores. Scientists finally broke the silence when Mosaique FM, local radio invited Sami Mhanni, Chief Engineer in marine science; environment protection activist and revealed the truth behind this strange and mysterious occurrence. UNDP Tunisia Accelerator Lab team, in the context of UNDP’s work on costal resilience, has generated a few learnings and hypotheses and identified some emerging opportunities related to environment protection.

A blue Alert: What are the blue jelly fish telling us about our own behavior and about the planet?

According to Mhanni, the marine ecosystem has been turned upside down by various factors. So what exactly does the presence of these blue creatures mean?

When the Tuna’s away, the jelly will play

Tuna is an important part of Tunisian diet. Tunisian eat tuna in pasta, salad, on pizza, from cans, grilled fresh steaks, in sandwiches or as an entrée with some chilly paste and olive oil (literally every restaurant in the country will serve you this when you enter). Our Tuna is also appreciated in other countries. The Japanese who are fond of red tuna fish, have licenses allowing them to fish Tuna in Tunisian seas. The price of tuna fish can reach over a million USD at the auction in Japan. This creates

a high demand for this variety of blue fish. Tuna also happens to be one of the main predators of jelly fish.

When sea turtles are threatened, so are the beaches

Sea turtles are major jelly fish predators. Their presence in the Mediterranean waters is however threatened by many factors such as overfishing, people’s presence on shores during nesting periods as well as black rat (Rattus rattus species) infestation around beaches. An before you go and blame things on these poor rats, you should know they only managed to prosper due to the presence of food waste in coastal areas (Feng and Himsworth 2013) (that’s humans alright). Sea turtles decreasing in proportions in the Mediterranean means jelly fish are less hunted and therefore live long and prosper.

Warmer waters make them grow, like, bigger!

What? You can’t blame this one on climate change, too can you? Well, yes you can, actually. Heat makes jellyfish grow faster and bigger as they thrive in hot waters with less oxygen (Brodeur et al., 2008). But then really, what can be done directly about it and what proof do we have this is actually caused by human behavior, right (being the devil’s advocate here).

Pollution: a nightmare for some, an opportunity for…well, plankton

Pollution caused by domestic and industrial waste, or in the case of Tunisia, by hotel waste and directly discharged into the sea (yeah that’s illegal I know) makes certain tiny marine creatures thrive. Certain varieties of plankton which constitute the main pray of jelly fish proliferate in dirty waters due to the presence of phosphorus and nitrogen. Increased presence of plankton also means lower oxygen levels and remember who prospers with less oxygen? (hint: look above)

So, what is actually being done about the above issues?

All the stories told by the blue jelly fish are well-established and well-known threats to the marine ecosystem in particular. Protection of biodiversity in general is part of the strategic of the ministry of agriculture. There is a number of public policies on protection of biodiversity in the Mediterranean. The operationalization of these policies is more problematic as translation into laws and regulations constitutes a real gap. Application of the was has also been an issue, due to lack of adequate control mechanisms and corruption issues which are generalized in the country.

Can jelly fish presence entice the government and people to change their ways?

Effect on environment protection policies

Marine life protection policies matter, but in time of socio-economic hardship and amidst a real political crisis, marine ecosystems might not constitute a national priority. Efforts of thegovernment are directed towards creating a sustainable economic model and steering the country away from the economic crisis iceberg. In this journey, the creation of new jobs and increasing domestic revenues is what fuels the ship.

But what if jellyfish proliferation means less coastal tourism, what if it means we are threatening many people’s sources of seasonal revenues. Will the government then start looking into the root causes of the increased presence of jellyfish on the shores and near the coasts.

We know that for the first time ever in Tunisia, the municipality of Monastir, a coastal area has just voted for the implementation of a substantial fine for sea turtle fishing in order to prevent the proliferation of jellyfish in coastal areas. So, things are moving in the right direction at the local and micro-local level. How many more jellyfish will need to wash out on our shores for the government to take action against pollution, waste disposal in the sea, over fishing of Tuna and Sea Turtles?

Effect on people’s behavior

While public policies and strategies can be slow to put in place, behavioral changes can take much less time. This is given, of course, that people make a clear link between their own behavior and the presence of these marine creatures on the shores. We are ready to take action for our environment when this starts to actual affect our daily lives, provided we understand of course how our behavior can have an impact on these threats to our comfort and well-being.


The increased presence of blue jellyfish on our shores might create a real chain of reactions in the direction of environment protection both at local and national level and both for policies and people’s behaviors but how many more jellyfish will need to play kamikaze on our shores in order for us to actually start a behavioral chain of reactions.


Brodeur, Richard D., et al. "Rise and fall of jellyfish in the eastern Bering Sea in relation to climate regime shifts." Progress in Oceanography 77.2-3 (2008): 103-111.

Fontaine, Nick. "Rat Infestation: An Analysis of the Black Rat (Rattus rattus) Outbreak around Kamloops, BC." Proceedings of the Annual Thompson Rivers University Undergraduate Research and Innovation Conference. Vol. 12. No. 1. 2018.