Microsatellite genotyping of Mediterranean population of Ircinia fasciculata and Ircinia variabilis

Recent episodes of mass mortalities in the Mediterranean Sea have been reported for the closely related marine sponges Ircinia fasciculata and I. variabilis, which live in sympatry. In this context, the assessment of the genetic diversity, bottlenecks and connectivity of these sponges has become urgent in order to evaluate the potential effects of mass mortalities on their latitudinal range. Our study aims to establish 1.) the genetic structure, connectivity, and signs of bottlenecks across the populations of I. fasciculata, and 2.) the hybridization levels between I. fasciculata and I. variabilis. To accomplish the first objective, 194 individuals of I. fasciculata from 12 locations across the Mediterranean were genotyped at 14 microsatellite loci. For the second objective, mitochondrial cytochrome c oxidase subunit I sequences of 16 individuals from both species were analyzed along with genotypes at 12 microsatellite loci of 40 individuals coexisting in 3 Mediterranean populations. We detected strong genetic structure along the Mediterranean for I. fasciculata, with high levels of inbreeding in all locations and bottleneck signs in most locations. Oceanographic barriers like the Almeria-Oran front, North-Balearic front, and the Ligurian-Thyrrenian barrier seem to be impeding gene flow for I. fasciculata, adding population divergence to the pattern of isolation by distance derived from the low dispersal abilities of sponge larvae. Hybridization between both species occurred in some populations, which might be increasing genetic diversity and somewhat palliating the genetic loss caused by population decimation in I. fasciculata

Compilation of maximum ingestion and maximum clearance rate data for marine pelagic organisms

The metabolic rate of organisms may either be viewed as a basic property from which other vital rates and many ecological patterns emerge and that follows a universal allometric mass scaling law; or it may be considered a property of the organism that emerges as a result of the organism's adaptation to the environment, with consequently less universal mass scaling properties. Data on body mass, maximum ingestion and clearance rates, respiration rates and maximum growth rates of animals living in the ocean epipelagic were compiled from the literature, mainly from original papers but also from previous compilations by other authors. Data were read from tables or digitized from graphs. Only measurements made on individuals of know size, or groups of individuals of similar and known size were included. We show that clearance and respiration rates have life-form-dependent allometries that have similar scaling but different elevations, such that the mass-specific rates converge on a rather narrow size-independent range. In contrast, ingestion and growth rates follow a near-universal taxa-independent ~3/4 mass scaling power law. We argue that the declining mass-specific clearance rates with size within taxa is related to the inherent decrease in feeding efficiency of any particular feeding mode. The transitions between feeding mode and simultaneous transitions in clearance and respiration rates may then represent adaptations to the food environment and be the result of the optimization of tradeoffs that allow sufficient feeding and growth rates to balance mortality.

Georeferenced standardized apparent wave power along the coastline of Cabrera National Park for analysis of essential habitats of littoral species

Wind- induced exposure is one of the major forces shaping the geomorphology and biota in coastal areas. The effect of wave exposure on littoral biota is well known in marine environments (Ekebon et al., 2003; Burrows et al., 2008). In the Cabrera Archipelago National Park wave exposure has demostrated to have an effect on the spatial distribution of different stages of E.marginatus (Alvarez et al., 2010). Standarized average wave exposures during 2008 along the Cabrera Archipelago National park coast line were calculated to be applied in studies of littoral species distribution within the archipelago. Average wave exposure (or apparent wave power) was calculated for points located 50 m equidistant on the coastline following the EXA methodology (EXposure estimates for fragmented Archipelagos) (Ekebon et al., 2003). The average wave exposures were standardized from 1 to 100 (minimum and maximum in the area), showing coastal areas with different levels of mea wave exposure during the year. Input wind data (direction and intensity) from 2008 was registered at the Cabrera mooring located north of Cabrera Archipelago. Data were provided by IMEDEA (CSIC-UIB, TMMOS http://www.imedea.uib-csic.es/tmoos/boyas/). This cartography has been developed under the framework of the project EPIMHAR, funded by the National Park's Network (Spanish Ministry of Environment, Maritime and Rural Affairs, reference: 012/2007 ). Part of this work has been developed under the research programs funded by "Fons de Garantia Agrària i Pesquera de les Illes Balears (FOGAIBA)".

(Table 3) Mediterranean core-top d18O values for various planktonic foraminiferal species

A box model is presented to simulate changes in Mediterranean long-term average salinity and d18O over the past 20,000 years. Simulations are validated by comparison with observations. Sensitivity tests illustrate robustness with respect to the main assumptions and uncertainties. The results show that relative humidity over the Mediterranean remained relatively constant around 70%, apparently narrowly constrained to the lower end of the range observed globally over sea surfaces by the basin's land-locked character. Isotopic depletion in run off, relative to the present, is identified as the main potential cause of depletions in the Mediterranean d18O record. Also, slight increases in relative humidity (of the order of 5%) might have caused very pronounced isotopic depletions, such as that in sapropel S5 of the penultimate interglacial maximum. The model shows distinctly non proportional responses of d18O and salinity to environmental change, which argues against the use of isotope residuals in Mediterranean paleosalinity reconstructions.

Late Pleistocene sedimentation in the Western Mediterranean Sea

Sediment cores from the Western Mediterranean Sea (WMS) have been analyzed for their bulk element composition, delta18O values of planktic foraminiferal tests, and 87Sr/86Sr and 143Nd/144Nd ratios of their bulk lithogenic components. The investigated time interval comprises the last 215 kyr. Si/Al and Ti/Al ratios as well as radiogenic isotope compositions indicate changes in the provenance of the lithogenic components between glacial intervals and interglacial phases. Comparison with modern data indicates that detrital input from the northwestern and northeastern Sahara may have dominated during interglacial phases. In contrast, during glacial periods the accumulation rate of terrigenous sediment is high and changes in the sediment source areas are evident that may be related to changes in the prevailing atmospheric circulation over the basin and its source areas. A productivity reconstruction based on bio-mediated barium accumulation rates reveals increased surface productivity during glacial phases. Intervals time-equivalent to sapropel formation in the Eastern Mediterranean Sea (EMS) show no changes in surface productivity compared to the intervening intervals. Comparison of the productivity patterns between the WMS and EMS suggests a decoupling during Late Pleistocene sapropel formation and highlights the importance of more localized factors such as the freshwater drainage basin.

Real-time surface current data in the Ibiza Channel from January to October 2016

The data set consists of maps of total velocity of surface currents in the Ibiza Channel, derived from HF radar measurements.