Acoustic identification of krill (Nyctiphanes couchii & Nematoscelis megalops) in the Spanish Mediterranean Sea

During the 2015 routine acoustic survey for stock assessment carried out in the Spanish Mediterranean continental shelf, krill swarms were localized in two different places using an EK60 scientific echosounder, operating at multiple frequencies. Biological identification was performed by mean of a plankton net (bongo 90) equipped with two different mesh sizes (500 to 2000 microns). Although krill frequency response was similar in both localizations, samples analysis revealed the presence of two different species: Nyctiphanes couchii (Bell, 1853) and Nematoscelis megalops (Sars, 1883)

Relationship between anchovy (Engraulis encrasicolus) recruits and anchovy spawners estimated from acoustic surveys in Northwestern Mediterranean Sea

In this study we present the abundance and biomass of European anchovy (Engraulis encrasicolus) estimated by acoustic methods in the Northwestern Mediterranean Sea (GSA06). during two different seasons, winter, the anchovy recruitment season and summer, when the majority of the anchovy stock belongs to the spawner fraction of one year-old. Four standardized acoustic surveys carried out covering the study area during two consecutive years (every six months), two of them during the peak of anchovy recruitment and the other two during the peak of anchovy spawn, allow to observe changes in the anchovy stock abundance and biomass in this area. Acoustic data from summer and winter echo-surveys were analyzed in an effort to better understand the life cycle of anchovy in relation to the survival during its first year of life

Acoustic assessment and distribution of the main pelagic fish species in the ICES Subdivision IXa South during the ECOCADIZ 0813 Spanish survey (August 2013).

The present working document summarises the main results from the Spanish (pelagic ecosystem‐) acoustic survey conducted by IEO between 2nd and 13th August 2013 in the Portuguese and Spanish shelf waters (20‐200 m isobaths) off the Gulf of Cadiz onboard the R/V “Cornide de Saavedra”. The survey dates were somewhat delayed in relation to the usual ones and to the anchovy (Engraulis encrasicolus) peak spawning as well. Abundance and biomass estimates are given for all the mid‐sized and small pelagic fish species susceptible of being acoustically assessed according to their occurrence and abundance levels in the study area. The distribution of these species is also shown from the mapping of their back‐scattering energies. The bulk of the anchovy population was concentrated in the Spanish shelf, with a residual nucleus to the west of Cape Santa Maria. A delay of the usual survey dates may be the reason of a higher relative importance of smaller anchovies in the population as a probable consequence of the incorporation of the first waves of recently recruited juveniles to the adult population. The total biomass estimated for anchovy was 8.5 thousand tonnes (609 million fish), the lowest estimate in its series. Sardine showed a distribution pattern almost complementary to that described for anchovy, with higher densities occurring over the inner‐middle shelf of both extremes of the surveyed area, mainly west to Cape Santa Maria, and in shallower waters than anchovy. Sardine yielded a total of 9.7 thousand tonnes (232 million fish). The 2013 sardine estimate was also the lowest one in its series and corroborates a clear recent decline in the population which has also been evidenced by the PELAGO surveys. Chub mackerel was present all over the surveyed area although showed a more “oceanic” distribution in the westernmost waters. The species was the most important in terms of assessed biomass, rendering estimates of 31.3 thousand tonnes (333 million fish). Acoustic estimates for jack and horse‐mackerel species (Trachurus spp.), and bogue (Boops boops) are also given in the WD. No acoustic estimates either for mackerel S. scombrus or round sardinella (Sardinella aurita) were computed because their incidental occurrence in the study area during the survey

Krill spatial distribution in the Spanish Mediterranean Sea in summer time

We documented krill distribution in the Spanish Mediterranean Sea for the first time using acoustic methods, highlighting the method’s suitability to study marine communities restricted to specific areas with patchy aggregation behavior. The 2009–2017 acoustic time series analysis revealed that krill distribution, mainly located on the continental shelf edge, was driven by the presence of fronts and submarine canyons. On the other hand, areas of persistent krill distribution included from Cape La Nao to the eastern part of Almeria Bay, although an interannual northwards increase of krill presence had been detected in 2015–2017 likely related to the position of the Balearic front. We provide information on the aggregation characteristics and biological parameters of three krill species, Nyctiphanes couchii, Nematoscelis megalops and Meganyctiphanes norvegica. N. couchii and N. megalops formed patchy pelagic aggregations in the neritic and oceanic zone, respectively, and they were the most common species in the net tows. By contrast, M. norvegica formed a large demersal aggregation on the continental shelf edge and was only found in 2017; nevertheless, its 861-kg catch represented a unique milestone in the Mediterranean. Finally, krill species shared distribution area with Maurolicus muelleri; thus, coexistence between them are also described

CLytA-DAAO, free and immobilized in magnetic nanoparticles, induces cell death in human cancer cells

Depto. de Bioquímica y Biología MolecularFac. de Ciencias QuímicasTRUEpu