An international research, involving the participation of the Spanish National Research Council (CSIC), provides a new perspective on the jellyfish proliferation in world's oceans. This phenomenon has noticeably impacted on beaches around the world in recent years and has provoked the concerns of fishermen and bathers.

However, according to the group of experts leading this new research, there are no "conclusive evidences" that point to global increase in jellyfish population.

The news rise in Mass Media on jellyfish blooms and the discrepancies in climate and science reports have motivated the article, published in the latest issue of the BioScience magazine.

According to the experts, jellyfish population has increased in several regions but has decreased or fluctuates through decades in others. They believe that the key to solve this question relies on understanding the data obtained in the long-term.

Carlos Duarte, CSIC researcher, states: "The significance of this work lies in putting data in common from now on so we will be able to support theories with contrasting scientific data and not speculations". Duarte is one of leaders of the Global Jellyfish Group, a consortium of 30 experts in gelatinous organisms, climatology, oceanography and socioeconomics.

Global database
In order to monitor the evolution of jellyfish populations, the scientists are already working on a global database with the information compiled since 1750. This future catalogue will comprise about 500.000 data.

The Global Jellyfish Group's initiative develops within the framework of the National Center for Ecological Analysis and Synthesis, associated to the University of California, in Santa Barbara (USA).

The analysis of this repository will enable scientist to evaluate key aspects such as the relation between human activity and jellyfish blooms, knowing if these are caused by natural causes, or finding out if more attention is paid to this phenomenon due to its direct impact on sectors such as fishing or tourism.

Duarte adds: "it is fundamental to get the right answer in order to make decisions about tourism, fishing and marine ecosystems management".