The effect of long-term brine discharge from desalination plants on benthic foraminifera.

Desalination plants along the Mediterranean Israeli coastline currently provide ~587 million m3 drinking water/year, and their production is planned to increase gradually. Production of drinking water is accompanied by a nearly equivalent volume of brine discharge with a salinity of ~80 that is twice the normal, which can potentially impact marine ecosystems. The goal of this study was to examine whether benthic foraminifera, a known sensitive marine bio-indicator, are affected by this brine-discharge. For that, we investigated the seasonal and cumulative effect of brine discharges of three operating desalination facilities along the Israeli coast. Those facilities are located in Ashkelon, Hadera, and Sorek. The brine-discharge in the first two desalination plants is associated with thermal pollution, while the Sorek facility entails increased salinity but no thermal pollution. In four seasonal cruises during one year, we collected surface sediment samples in triplicates by grabs from the outfall (near the discharge site), and from a non-impacted control station adjacent to each study site. Our results highlight that the most robust responses were observed at two out of three desalination shallow sites (Ashkelon and Hadera), where the brine was discharged directly from a coastal outfall and was accompanied with thermal pollution from the nearby power plants. The total foraminiferal abundance and diversity were, generally, lower near the outfalls, and increased towards the control stations. Moreover, changes in the relative abundances of selected species indicate their sensitivity to the brine discharge. The most noticeable response to exclusively elevated salinity was detected at Sorek discharge site, where we observed a sharp decline in organic-cemented agglutinated benthic foraminifera, suggesting that these are particularly sensitive to elevated salinity. The herein study contribute new insights into the effect of brine discharge from desalination plants, on benthic foraminifera, and propose a scientifically-based ecological monitoring tool that can help stakeholders

Influences of Temperature and Secondary Environmental Parameters on Planktonic Foraminiferal Mg/Ca : A New Core-Top Calibration

The accuracy of the Mg/Ca paleothermometer is contested over the influences of secondary environmental parameters such as salinity and pH. Recent calibrations based on compiled sediment trap and laboratory culture data suggest moderate influences from salinity and pH. Core tops are the best analogues to downcore samples used for paleoceanographic reconstruction with well-constrained environmental parameters and thus can be used to validate sediment trap and laboratory culture calibrations. Here, we calibrate new core-top Mg/Ca data in Globigerinoides ruber (white) and Trilobatus sacculifer (without final sac-like chamber) with sea surface temperature, salinity, and pH. Part of these coretops were previously used to argue for a large salinity effect on G. ruber (w) Mg/Ca (Arbuszewski et al., 2010, http://10.0.3.248/j.epsl.2010.10.035). Our new G. ruber (w) Mg/Ca data are on average 12% lower than the previous results. Our calibrations yield Mg/Ca-temperature sensitivities of 8.1 ± 0.7%/°C for G. ruber (w) and 6.6 ± 0.8%/°C for T. sacculifer (w/o sac), and Mg/Ca salinity effects of 4.7 ± 2.4%/‰ for G. ruber (w) and 5.5 ± 2.3%/‰ for T. sacculifer (w/o sac). These results agree well with culture experiments but discount the large salinity effects reported in previous core-top studies. Our data reveal insignificant pH effects on Mg/Ca in both species. Overall, our core-top calibrations for G. ruber (w) and T. sacculifer (w/o sac) lend strong support to previous calibrations, strengthening our confidence in the use of planktonic Mg/Ca as a reliable proxy for sea surface temperature reconstructions

Influences of Temperature and Secondary Environmental Parameters on Planktonic Foraminiferal Mg/Ca: A New Core-Top Calibration

The accuracy of the Mg/Ca paleothermometer is contested over the influences of secondary environmental parameters such as salinity and pH. Recent calibrations based on compiled sediment trap and laboratory culture data suggest moderate influences from salinity and pH. Core tops are the best analogues to downcore samples used for paleoceanographic reconstruction with well‐constrained environmental parameters and thus can be used to validate sediment trap and laboratory culture calibrations. Here, we calibrate new core‐top Mg/Ca data in Globigerinoides ruber (white) and Trilobatus sacculifer (without final sac‐like chamber) with sea surface temperature, salinity, and pH. Part of these coretops were previously used to argue for a large salinity effect on G. ruber (w) Mg/Ca (Arbuszewski et al., 2010, http://10.0.3.248/j.epsl.2010.10.035). Our new G. ruber (w) Mg/Ca data are on average 12% lower than the previous results. Our calibrations yield Mg/Ca‐temperature sensitivities of 8.1 ± 0.7%/°C for G. ruber (w) and 6.6 ± 0.8%/°C for T. sacculifer (w/o sac), and Mg/Ca salinity effects of 4.7 ± 2.4%/‰ for G. ruber (w) and 5.5 ± 2.3%/‰ for T. sacculifer (w/o sac). These results agree well with culture experiments but discount the large salinity effects reported in previous core‐top studies. Our data reveal insignificant pH effects on Mg/Ca in both species. Overall, our core‐top calibrations for G. ruber (w) and T. sacculifer (w/o sac) lend strong support to previous calibrations, strengthening our confidence in the use of planktonic Mg/Ca as a reliable proxy for sea surface temperature reconstructions.This research is supported by ARC Future Fellowship (FT140100993), Discovery Projects (DP140101393 and DP190100894), and NSFC (41676026) to J. Y. New data generated in this study are archived on Pangaea (https://doi.pangaea.de/ 10.1594/PANGAEA.905128)

Planktonic foraminiferal Mg/Ca ratios from top of different sediment cores from the Atlantic

The accuracy of the Mg/Ca paleothermometer is contested over the influences of secondary environmental parameters such as salinity and pH. Recent calibrations based on compiled sediment trap and laboratory culture data suggest moderate influences from salinity and pH. Core-tops are the best analogues to downcore samples used for paleoceanographic reconstruction with well-constrained environmental parameters and thus can be used to validate sediment trap and laboratory culture calibrations. Here, we calibrate new core-top Mg/Ca data in Globigerinoides* ruber* (white) and *Trilobatus sacculifer *(without final sac-like chamber) with sea surface temperature, salinity, and pH. Part of these core-tops were previously used to argue for a large salinity effect on G. ruber (w) Mg/Ca [Arbuszewski et al., 2010]. Our new G. ruber (w) Mg/Ca data are on average 12% lower than the previous results. Our calibrations yield Mg/Ca-temperature sensitivities of 8.1 ± 0.7 %/°C for G. **ruber (w) and 6.6 ± 0.8 %/°C for *T. sacculifer *(w/o sac), and Mg/Ca-salinity effects of 4.7 ± 2.4 %/‰ for G. **ruber (w) and 5.5 ± 2.3 %/‰ for *T. sacculifer *(w/o sac). These results agree well with culture experiments but discount the large salinity effects reported in previous core-top studies. Our data reveal insignificant pH effects on Mg/Ca in both species. Overall, our core-top calibrations for G. **ruber (w) and *T. sacculifer *(w/o sac) lend strong support to previous calibrations, strengthening our confidence in the use of planktonic Mg/Ca as a reliable proxy for sea surface temperature reconstructions

Testing foraminiferal environmental quality indices along a well-defined organic matter gradient in the Eastern Mediterranean

International audienc

Molecular evidence for Lessepsian invasion of soritids (larger symbiont bearing benthic foraminifera).

The Mediterranean Sea is considered as one of the hotspots of marine bioinvasions, largely due to the influx of tropical species migrating through the Suez Canal, so-called Lessepsian migrants. Several cases of Lessepsian migration have been documented recently, however, little is known about the ecological characteristics of the migrating species and their aptitude to colonize the new areas. This study focused on Red Sea soritids, larger symbiont-bearing benthic foraminifera (LBF) that are indicative of tropical and subtropical environments and were recently found in the Israeli coast of the Eastern Mediterranean. We combined molecular phylogenetic analyses of soritids and their algal symbionts as well as network analysis of Sorites orbiculus Forskål to compare populations from the Gulf of Elat (northern Red Sea) and from a known hotspot in Shikmona (northern Israel) that consists of a single population of S. orbiculus. Our phylogenetic analyses show that all specimens found in Shikmona are genetically identical to a population of S. orbiculus living on a similar shallow water pebbles habitat in the Gulf of Elat. Our analyses also show that the symbionts found in Shikmona and Elat soritids belong to the Symbiodinium clade F5, which is common in the Red Sea and also present in the Indian Ocean and Caribbean Sea. Our study therefore provides the first genetic and ecological evidences that indicate that modern population of soritids found on the Mediterranean coast of Israel is probably Lessepsian, and is less likely the descendant of a native ancient Mediterranean species

Molecular Phylogeny and Ecology of Textularia agglutinans d'Orbigny from the Mediterranean Coast of Israel: A Case of a Successful New Incumbent.

Textularia agglutinans d'Orbigny is a non-symbiont bearing and comparatively large benthic foraminiferal species with a widespread distribution across all oceans. In recent years, its populations have considerably expanded along the Israeli Mediterranean coast of the eastern Levantine basin. Despite its exceptionally widespread occurrence, no molecular data have yet been obtained. This study provides the first ribosomal DNA sequences of T. agglutinans complemented with morphological and ecological characterization, which are based on material collected during environmental monitoring of the hard bottom habitats along the Israeli Mediterranean coast, and from the Gulf of Elat (northern Red Sea). Our phylogenetic analyses reveal that all specimens from both provinces belong to the same genetic population, regardless their morphological variability. These results indicate that modern population of T. agglutinans found on the Mediterranean coast of Israel is probably Lessepsian. Our study also reveals that T. agglutinans has an epiphytic life mode, which probably enabled its successful colonization of the hard bottom habitats, at the Mediterranean coast of Israel, which consist of a diverse community of macroalgae. Our study further indicates that the species does not tolerate high SST (> 35°C), which will probably prevent its future expansion in the easternmost Mediterranean in light of the expected rise in temperatures