Description: Transparent exopolymer particles (TEP) and Coomassie stainable particles (CSP) are gel-like particles, ubiquitous in the ocean, that affect important biogeochemical processes including organic carbon cycling by planktonic food webs. Despite much research on both groups of particles (especially TEP) over many years, whether they exist as distinctly stainable fractions of the same particles or as independent particles, each with different driving factors, remains unclear. To address this question, we examined the temporal dynamics of TEP and CSP over 2 complete seasonal cycles at 2 coastal sites in the Northwestern Mediterranean Sea, the Blanes Bay Microbial Observatory (BBMO) and the L’Estartit Oceanographic Station (EOS), as well as their spatial distribution along a coast-to-offshore transect. Biological, chemical, and physical variables were measured in parallel. Surface concentrations (mean ± standard deviation [SD]) of TEP were 36.7 ± 21.5 µg Xanthan Gum (XG) eq L–1 at BBMO and 36.6 ± 28.3 µg XG eq L–1 at EOS; for CSP, they were 11.9 ± 6.1 µg BSA eq L–1 at BBMO and 13.0 ± 5.9 µg BSA eq L–1 at EOS. Seasonal variability was more evident at EOS, where surface TEP and CSP concentrations peaked in summer and spring, respectively, and less predictable at the shore-most station, BBMO. Vertical distributions between surface and 80 m, monitored at EOS, showed highest TEP concentrations within the surface mixed layer during the stratification period, whereas CSP concentrations were highest before the onset of summer stratification. Phytoplankton were the main drivers of TEP and CSP distributions, although nutrient limitation and saturating irradiance also appeared to play important roles. The dynamics and distribution of TEP and CSP were uncoupled both in the coastal sites and along the transect, suggesting that they are different types of particles produced and consumed differently in response to environmental variability.

Description: Down core marine sediment samples from ODP Site 1240 have been used for the analysis of the C28 and C30 1,14-diols, the C37:2 and C37:3 long chain ketones (alkenones) and the 24-methylcholesta-5,22-dien-3β-ol (brassicasterol) as proxies of primary productivity. Alkenones were also used to infer past sea surface temperatures through the unsaturation index UK'37. The C29 n-alkane was measured to obtain information on continental material inputs. δD of C37-alkenones and δ¹⁸O-seawater of Globigerinoides ruber were used as indicators of relative salinity changes. This data has been used for the study of the period between 150 and 110 ka (sediment depth from ca. 13 to 17 m), according to the age model from Rippert et al. (2017).

Description: Over the last deglaciation there were two transient intervals of pronounced atmospheric CO2 rise; Heinrich Stadial 1 (17.5-15 kyr) and the Younger Dryas (12.9-11.5 kyr). Leading hypotheses accounting for the increased accumulation of CO2 in the atmosphere at these times invoke deep ocean carbon being released from the Southern Ocean and an associated decline in the global efficiency of the biological carbon pump. From core ODP1090 we present new G. bulloidies carbon and oxygen isotope records. These stable isotopic analyses were performed on a Thermo Finnigan MAT253 coupled with a Kiel IV carbonate device at the University of Southampton.

Description: Over the last deglaciation there were two transient intervals of pronounced atmospheric CO2 rise; Heinrich Stadial 1 (17.5-15 kyr) and the Younger Dryas (12.9-11.5 kyr). Leading hypotheses accounting for the increased accumulation of CO2 in the atmosphere at these times invoke deep ocean carbon being released from the Southern Ocean and an associated decline in the global efficiency of the biological carbon pump. From core TAN1106-28 we present new G. bulloidies boron isotope and Mg/Ca derived sea surface pH and pCO2 concentrations. Trace element analysis was performed on a ThermoScientific Element 2 ICP-MS at the University of Southampton using the method described by Henehan et al. (2015). Isotopic analysis was performed on a ThermoScientific Neptune MC-ICPMS at the University of Southampton following the methods of Foster (2008) and Foster et al. (2013).

Description: Over the last deglaciation there were two transient intervals of pronounced atmospheric CO2 rise; Heinrich Stadial 1 (17.5-15 kyr) and the Younger Dryas (12.9-11.5 kyr). Leading hypotheses accounting for the increased accumulation of CO2 in the atmosphere at these times invoke deep ocean carbon being released from the Southern Ocean and an associated decline in the global efficiency of the biological carbon pump. From core ODP1090 we present new G. bulloidies boron isotope and Mg/Ca derived sea surface pH and pCO2 concentrations. Trace element analysis was performed on a ThermoScientific Element 2 ICP-MS at the University of Southampton using the method described by Henehan et al. (2015). Isotopic analysis was performed on a ThermoScientific Neptune MC-ICPMS at the University of Southampton following the methods of Foster (2008; doi:10.1016/j.epsl.2008.04.015) and Foster et al. (2013; doi:10.1016/j.chemgeo.2013.08.027).

Description: Over the last deglaciation there were two transient intervals of pronounced atmospheric CO2 rise; Heinrich Stadial 1 (17.5-15 kyr) and the Younger Dryas (12.9-11.5 kyr). Leading hypotheses accounting for the increased accumulation of CO2 in the atmosphere at these times invoke deep ocean carbon being released from the Southern Ocean and an associated decline in the global efficiency of the biological carbon pump. From core TAN1106-28 we present new deglacial alkenone and n-alkane records. Analysis and characterization of total lipid content were performed at Institut de Ciències del Mar in Barcelona following published methods (Villanueva et al., 1997; doi:10.1016/S0021-9673(96)00669-3, Calvo et al., 2003; doi:10.1016/S0021-9673(03)00119-5, Kornilova and Rosell-Melé, 2003; doi:10.1016/S0146-6380(03)00155-4) on an Agilent 7890 Gas Chromatograph with a flame ionization detector equipped with a HP-1 capillary column (60 m, 0.25 mm I.D. and 0.25 µm film thickness).

Description: Predicting the potential for species adaption to climate change is challenged by the need to identify the physiological mechanisms that underpin species vulnerability. Here we investigated the sensitivity to ocean acidification in marine mussels during early development, and specifically the trochophore stage. Using RNA and DNA sequencing and in situ RNA hybridization, we identified developmental processes associated with abnormal development and rapid adaptation to low pH. Trochophores exposed to low pH seawater exhibited 43 differentially expressed genes. Gene annotation and in situ hybridization of differentially expressed genes point to pH sensitivity of (1) shell field development and (2) cellular stress response. Five genes within these two processes exhibited shifts in allele frequencies indicative of a potential for rapid adaptation. This case study contributes direct evidence that protecting species' existing genetic diversity is a critical management action to facilitate species resilience to climate change.