Mnemiopsis leidy : Ecology Modelling and Observation (MEMO)
The proliferation of the gelatinous plankton has important socio-economic effects that concern particularly tourism, fishing, pisciculture and has also consequences on the structuring of the pelagic ecosystem. Certain highly invasive species had been observed to cause irremediable damages to indigenous fauna. This is particularly the case of the cténaire Mnemiopsis leidyi. This species is a gelatinous plankton able to form highly dense patches and can cause disastrous consequences on commercial fish stocks and aquaculture resources as it feeds on fish eggs and larvae and other zooplankton. We wish to focus on this species which has been recently observed at the North Sea eastern coast. In 2009, it has also been observed in the harbours of Zeebrugge, Dunkirk and Calais as well as on the monitoring site of the Gravelines nuclear plant. We propose in this project, to study the inter- and intra-annual spatial variability of this species along the English Channel and the south of the North Sea and how environmental parameters affect these variations. The strong proliferation potential of this species relies on its fast growth rate capacity and on its high tolerance to water salinity and temperature variations. This work will also consist in estimating various prey ingestion rates by M. leidyi and their physiological respiration response (i.e., oxygen consumption) and excretion (i.e., ammonium and phosphate production) under various water temperature and salinity conditions. In the context of mussel aquaculture development in the Nord-Pas de Calais area, the impact of M. leidyi on the larval stages of mussels will be also studied based on targeted grazing experiments. Several scenarii of climate changes will be also tested. The importance of this species in terms of impact on particulate matter, dissolved substances remineralisation, pelagic ecosystem structuring and the significance in the study area could then be better evaluated.
1. Origin of Mnemiopsis leidyi invasion and the seasonal distribution of gelatinous zooplankton
2. Physiological and ecological characteristics of Mnemiopsis leidyi
3. Applicability of the model of the planktonic ecosystem and potential impact of Mnemiopsis leidyi on it
By courtesy of Dr Otto Oliveira.
Contact: Elvire ANTAJAN, Ifremer Boulogne-sur-Mer