INVESTIGADORES
ACHA eduardo marcelo
congresos y reuniones científicas
Título:
El Viejo, El Niño and jellyfishes: dramatic environmental-driven changes in jellyfish abundances off Peru.
Autor/es:
QUIÑONES DÁVILA J.; MIANZAN H. W.; ACHA E.M.; PURCA S.; GRAHAM W.
Lugar:
Mar del Plata, Argentina
Reunión:
Simposio; 3rd International Jellyfish Blooms Symposium,; 2010
Resumen:
There is a general concern on that jellyfish populations are increasing worldwide, mainly due to environmental (i.e. global warming) and/or anthropogenic influences (i.e. overfishing). However for the Peruvian coast, jellyfish abundances remained at very low values during the last 20 years, in spite of being this one of the most heavily fished ecosystems in the world. On the basis of research cruises information, we constructed a 38 year-long abundances time series for the Scyphomedusae Chrysaora plocamia. To study climate driven effects, this information was cross-related with the Peruvian Oscillation Index (POI), which best represents ENSO pulses in coastal waters. We found that during 1970’s and 1980’s C. plocamia abundances were extremely high and then a dramatic fall down was registered since 1990’s until now. This pattern matches interdecadal warm – cold fluctuations respectively known as El Viejo and La Vieja regimes. At a shorter time scale, within the high medusae abundances El Viejo regime, strong jellyfish fluctuations were also observed, being higher abundance peaks related to EN phenomenon and other local warm events. We cannot discard some effect of overfishing  but our results show that climate-driven variability seems to be enough to explain jellyfish abundances oscillations at the Peruvian ecosystem.