"Since 2002, these organisms have become increasingly frequently found in the north east Atlantic in winter, since winters have been warmer, and they have tended to appear earlier and spend more time in their annual cycle there", María Luz Fernández de Puelles, the only Spanish co-author of the study, and a researcher at the IEO's Balearic Oceanography Centre, tells SINC.
The study, which has been published in the journal Biology Letters, brings together 50 years of analysis and shows that warmer winters favour the entry of the surface current into the Mediterranean Sea past Gibraltar, creating ideal conditions for the jellyfish Pelagia noctiluca. This species proliferates along Spanish coasts, where there are more food resources than in oceanic areas.
"We have shown that they can reproduce rapidly if the conditions are right, and can reach large densities throughout the whole year, particularly if winters are warm", the marine biologist explains.
The international team used molecular methods to study the increase in the frequency of this group of cnidaria in the North Sea from 1958 to 2007, a period covering the general change in the hydro-climatic regime from cold to warm observed since 1980. "The records for the Mediterranean are much more recent and not as long or continuous, but they further strengthen the study", says Fernández de Puelles.
Adult Pelagia noctiluca have been recorded in various parts of the western Mediterranean, including the Balearic Islands. Their abundance was particularly striking in the autumn and winter of 2007 and in the spring of 2010, as well as in the summers.
According to existing data for the Mediterranean, these proliferations have a 12-year frequency, with most of them remaining for four years. "However, since 1998 these periods have become shorter and more frequent", explains Fernández de Puelles.
Consequences for fisheries and tourism
The increase in jellyfish over the course of the year "directly" affects fisheries, fish farming and tourism "because of the jellyfishes' toxic effects and the poison in their tentacles, and because they appear particularly in the summer, having a significant socioeconomic impact", says Fernández de Puelles.
According to the expert, the increase in the number of jellyfish and the length of time that they remain is primarily due to over-fishing, but hydroclimatic effects such as climate change and the current warming of the sea also have an impact.
Pelagia noctiluca is a jellyfish from the class of the Scyphozoa with a complex and long life cycle, a very extensive range in the warm waters of the Atlantic and Mediterranean, and which usually lives in pelagic habitats (the area of oceans closest to the surface), but also at a certain depth, which makes them difficult to study. This animal can form 'enormous blooms', which are visible from Spanish coasts and beaches.
"Jellyfish are very voracious predators at the top of the trophic network. They feed directly on fish larvae and compete with other zooplankton organisms for food, meaning that they drastically alter the trophic structure of marine ecosystems", says the scientist. "Further studies should be carried out into the impact of this", she concludes.
References: Licandro, P.; Conway, D.V.P.; Yahia, M.N. Daly; Fernández de Puelles, M.L.; Gasparini, S.; Hecq, J.H.; Tranter, P.; Kirby, R.R. "A blooming jellyfish in the northeast Atlantic and Mediterranean", Biology Letters 6(5): 688-691, 23 de octubre de 2010.
SINC | EurekAlert!
Researchers identify potentially druggable mutant p53 proteins that promote cancer growth
09.12.2016 | Cold Spring Harbor Laboratory
Plant-based substance boosts eyelash growth
09.12.2016 | Fraunhofer-Institut für Angewandte Polymerforschung IAP
Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.
Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...
In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.
Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
09.12.2016 | Life Sciences
09.12.2016 | Ecology, The Environment and Conservation
09.12.2016 | Health and Medicine