ODYSSEA to track and model jellyfish blooms across the Mediterranean

Following a summer in which coastlines across the Mediterranean region saw more jellyfish, more kinds of jellyfish, and bigger jellyfish, end-users will be happy to hear that the EU-funded ODYSSEA project’s services will include early warnings of jellyfish spatial and temporal distributions and potential stranding locations, as well as records of jellyfish sightings, as reported in the recent ODYSSEA newsletter.

“ODYSSEA will provide the necessary tools for supporting an integrated system for the prediction and research of jellyfish on the Mediterranean coast,” said ODYSSEA partner Ghada El Serafy of Deltares and her colleagues Sonja Wanke, Lorin Meszaros and Mercedes de Juan Muñoyerro. “The first and most important step is to report sightings and issue early warnings on jellyfish occurrence to the relevant end-users in the affected sectors.”

Early jellyfish bloom warnings will report on the blooms and their spatial and temporal distributions and predict potential landing locations before they reach public beaches, installations and touristic zones along the coasts, in order for local authorities and industries in affected areas to respond appropriately.

Jellyfish tracking services will be based on innovative IT solutions and numerical models, the team noted, adding that the numerical models – primarily hydrodynamics and particle tracking – will simulate the spatial and temporal variations in jellyfish distributions, including their stage of development and aspects of their behaviour. Additionally, ODYSSEA will produce maps showing the probability of encountering jellyfish in a given location. Such maps would be of particular use for planning trips of fishing vessels, for instance.

“Although an essential part of a healthy marine ecosystem, anomalies in jellyfish populations have led to undesirable consequences for societies dependent on marine resources,” the team commented, citing nuisances caused to human activities such as tourism and fishing. “When favourable conditions for jellyfish are present, they expand their population incredibly fast. … Unfortunately, swarms have been very common in recent years, and could be linked to climate change, overfishing and eutrophication.”

“Jellyfish populations are flourishing,” the team said, citing overfishing and declines in the numbers of the jellyfish’s predators as one major cause, alongside increased numbers in phytoplankton – which the jellyfish themselves feed on – due to eutrophication and heightened chlorophyll levels.

Though numerous jellyfish species are present in the Mediterranean, the region’s most prevalent native species is Pelagia noctiluca, also known as the mauve stinger. It is a holoplanktonic medusa jellyfish known for its painful sting and is found in both coastal waters and further offshore.