Genetic and oceanographic tools reveal high population connectivity and diversity in the endangered pen shell Pinna nobilis

For marine meta-populations with source-sink dynamics knowledge about genetic connectivity is important to conserve biodiversity and design marine protected areas (MPAs). We evaluate connectivity of a Mediterranean sessile species, Pinna nobilis. To address a large geographical scale, partial sequences of cytochrome oxidase I (COI, 590 bp) were used to evaluate phylogeographical patterns in the Western Mediterranean, and in the whole basin using overlapping sequences from the literature (243 bp). Additionally, we combined (1) larval trajectories based on oceanographic currents and early life-history traits and (2) 10 highly polymorphic microsatellite loci collected in the Western Mediterranean. COI results provided evidence for high diversity and low inter-population differentiation. Microsatellite genotypes showed increasing genetic differentiation with oceanographic transport time (isolation by oceanographic distance (IBD) set by marine currents). Genetic differentiation was detected between Banyuls and Murcia and between Murcia and Mallorca. However, no genetic break was detected between the Balearic populations and the mainland. Migration rates together with numerical Lagrangian simulations showed that (i) the Ebro Delta is a larval source for the Balearic populations (ii) Alicante is a sink population, accumulating allelic diversity from nearby populations. The inferred connectivity can be applied in the development of MPA networks in the Western MediterraneanProject MEDEICG funded by the Spanish Ministry of Economy and Competitiveness (CTM2009-07013)IEH was supported by Ramon y Cajal Fellowship RYC2014-14970Spanish Ministry of Economy, Industry and Competitiveness IFCT Investigator Programme-Career Development (IF/00998/2014)MGW and AHE was supported by FCT fellowships SFRH/BPD/63703/2009 and SFRH/BPD/107878/2015National Science Foundation (OCE-1419450)CCMAR team via excellence research line EXCL/AAG-GLO/0661/2012Ciencias del Ma

Evaluating the extent and impact of the extreme Storm Gloria on Posidonia oceanica seagrass meadows

Extreme storms can trigger abrupt and often lasting changes in ecosystems by affecting foundational (habitat-forming) species. While the frequency and intensity of extreme events are projected to increase under climate change, its impacts on seagrass ecosystems remain poorly documented. In January 2020, the Spanish Mediterranean coast was hit by Storm Gloria, one of the most devastating recent climate events in terms of intensity and duration. We conducted rapid surveys of 42 Posidonia oceanica meadows across the region to evaluate the extent and type of impact (burial, unburial and uprooting). We investigated the significance of oceanographic (wave impact model), geomorphological (latitude, depth, exposure), and structural (patchiness) factors in predicting impact extent and intensity. The predominant impact of Storm Gloria was shoot unburial. More than half of the surveyed sites revealed recent unburial, with up to 40 cm of sediment removed, affecting over 50 % of the meadow. Burial, although less extensive, was still significant, with 10–80 % of meadow cover being buried under 7 cm of sediment, which is considered a survival threshold for P. oceanica. In addition, we observed evident signs of recently dead matte in some meadows and large amounts of detached drifting shoots on the sea bottom or accumulated as debris on the beaches. Crucially, exposed and patchy meadows were much more vulnerable to the overall impact than sheltered or continuous meadows. Given how slow P. oceanica is able to recover after disturbances, we state that it could take from decades to centuries for it to recoup its losses. Seagrass ecosystems play a vital role as coastal ecological infrastructure. Protecting vulnerable meadows from anthropogenic fragmentation is crucial for ensuring the resilience of these ecosystems in the face of the climate crisis.This study was funded by the CSIC project “Effects of storm Gloria on the western Mediterranean meadows (202030E052) and “Storms of change: as phenomena extreme weather alters Mediterranean coastal ecosystems, their services and their perception by society" (PID2020-113745RB-I00), state program of I+D+I Oriented to the Challenges of the Society and within the framework of the activities of the Spanish Government through the "Maria de Maeztu Centre of Excellence” accreditation to IMEDEA (CSIC-UIB) (CEX2021-001198). We want to thank the SPAS (Society of Fishing and Underwater Activities of Mataró) and the Mataró City Council, which has financed 25 years of the Alguer de Mataró project

The effect of temperature on the expansion of marine exotic macrophyte in the Mediterranean sea

Resumen del trabajo presentado a la EGU General Assembly, celebrada en modalidad virtual del 19 al 30 de abril de 2021.Peer reviewe

Aquecimento ameaça impulsionar a expansão da exótica erva-marinha Halophila stipulacea

The spread of exotic species to new areas can be magnified when favored by future climatic conditions. Forecasting future ranges using species distribution models (SDMs) could be improved by considering physiological thresholds, because models solely based on occurrence data cannot account for plasticity due to acclimation of individuals to local conditions over their life-time or to adaptation due to selection within local populations. This is particularly relevant for the exotic seagrass Halophila stipulacea, which colonized the Mediterranean Sea a century ago and shifted its thermal niche, coping with a colder regime. Here, we used two hybrid models combining correlative SDMs with the thermal limits for growth of native and exotic H. stipulacea populations to predict the distribution of the species in its native (Indian Ocean and Red Sea) and exotic ranges (Mediterranean Sea and Caribbean Sea) under two scenarios forecasting limited (RCP 2.6) and severe (RCP 8.5) future climate changes by 2050 and 2100. Then, we assessed the differences between hybrid models based on native Red Sea thermal limits (niche conservatism: 17–36◦C) and on exotic Mediterranean thermal limits (local adaptation: 14–36◦C). At the Mediterranean exotic range, the local adaptation hybrid model accurately agreed with the present distribution of the species while the niche conservatism-based hybrid model failed to predict 87% of the current occurrences of the species. By contrast, both hybrid models predicted similar species distributions for the native range and exotic Caribbean range at present and projected that H. stipulacea will maintain its current worldwide under all future greenhouse gas emission scenarios. The hybrid model based on Mediterranean thermal limits projected the expansion of H. stipulacea through the western Mediterranean basin (except the gulf of Leon) under the most severe scenario (RCP 8.5) by 2100, increasing its distribution by 50% in the Mediterranean. The future expansion of H. stipulacea is related to its capacity to cope with warm waters and it may become a relevant species in the future, particularly under the projected decline of native Mediterranean seagrasses, resulting in important shifts in seagrass communities and overall ecosystem functions.info:eu-repo/semantics/publishedVersio

Marine macrophytes as carbon sinks: Comparison between seagrasses and the non-native alga Halimeda incrassata in the western Mediterranean (Mallorca)

Seagrass species play a critical role in the mitigation of climate change by acting as valuable carbon sinks and storage sites. Another important ecosystem service of this coastal vegetation is nutrient removal. However, coastal ecosystems are under increasing pressure of global warming and associated establishment of invasive species. To elucidate the respective contributions of seagrass species Posidonia oceanica and Cymodocea nodosa and the non-native macroalga Halimeda incrassata as primary producers and nutrient sinks in coastal habitats we conducted in-situ incubations in the North-western Mediterranean Sea. Measured metabolic activity and nutrient removal as well as calcification rates in these habitats over a 24 h period in spring and summer confirmed that the endemic seagrass P. oceanica represents a valuable ecosystem with high O2 production and considerable carbon capture. The documented regression of P. oceanica meadows with higher temperatures and decline in autotrophy as measured here causes concern for the continuity of ecosystem services rendered by this habitat throughout the Mediterranean Sea with progressing climate warming. In contrast, the enhanced performance of C. nodosa and the calcifying alga H. incrassata with increasing temperatures, under expected rates of future warming is uncertain to mitigate loss of productivity in case of a potential shift in marine vegetation. This could ultimately lead to a decline in ecosystem services, decreased carbon storage and mitigation of climate change. Furthermore, this study provides a first estimate for the growth rate of H. incrassata in the Mediterranean Sea, supporting evidence for the mechanism of its rapid extension.Funding was provided by projects PRD2018/18, from the Conselleria d’Innovació, Recerca i Turisme of Mallorca (Spain) and RTI2018-095441-B-C21 (SUMAECO) from the Spanish Ministry of Science, Innovation and Universities. SF was supported by a “Margalida Comas” postdoctoral scholarship, funded by the Balearic Islands Government.Peer reviewe

Geographic occurrences and sea surface temperature data of non-native macrophytes in the Mediterranean Sea across both native and non-native ranges [Dataset]

The dataset provides data of geographic occurrences of non-native marine macrophytes in the Mediterranean Sea over 200 years. It includes occurrences in their native biogeographical range, along with sea surface temperature data for both the Mediterranean Sea and the native range. Additionally, it provides measures of spread, such as least coastal distances and the number of invaded grid cells, aiding in the calculation of linear spread rates, accumulated, and new invaded areas by non-native macrophytes in the Mediterranean Sea, as outlined in Wesselmann et al., 2024.Peer reviewe

Mediterranean seagrasses as carbon sinks: methodological and regional differences

The increasing rates of CO2 due to anthropogenic activities are causing important potential climate threats for the Mediterranean Sea: ocean acidification and warming. In this region, two seagrass species, Posidonia oceanica and Cymodocea nodosa, can play a crucial role in climate change mitigation. Seagrasses can act as carbon sinks, buffer lowering pH values during the day and storing carbon in the sediment underneath their meadows. However, available data documenting these processes are scattered and collected using different methodologies, which makes its interpretation and generalization very challenging. In this study, we analyzed published and unpublished data (collected for this study) on seagrass community metabolism to compare two methodologies, benthic chambers and multiparametric sensors, and evaluate trends through time for these two species. Furthermore, we analyzed seasonal trends of both seagrass species' metabolic rates and their variation between the eastern and western Mediterranean basins. Most evaluated meadows, 80.9 %, were autotrophic. Calculated metabolic rates differ between methodologies, with multiparametric sensors estimating rates almost an order of magnitude higher, 143.22±28.21 (SE) mmol O2 m-2 d-1 for net community production (NCP) compared to an average of 18.75±3.80 (SE) mmol O2 m-2 d-1 for measurements with benthic chambers. However, sensors are not able to differentiate between habitats and only useful to assess seagrass metabolism at a broader community level, whereas benthic chambers are capable of evaluating rates at the species level and confirm that P. oceanica is more productive compared to C. nodosa. We found similar metabolic rates in the eastern and western Mediterranean regions for P. oceanica with the benthic-chamber technique and higher NCP in the west based on sensor measurements.This work was funded by the Spanish Ministry of Economy and Competitiveness (MEDSHIFT, grant no. CGL2015-71809-P) and the Spanish Ministry of Science, Universities and Innovation (project SUMAECO, grant no. RTI2018-095441-B-C21). Susana Flecha was supported by a Margalida Comas postdoctoral scholarship, funded by the government of the Balearic Islands. We acknowledge support of the publication fee by the CSIC Open Access Publication Support Initiative through its Unit of Information Resources for Research (URICI)

Mediterranean seagrasses as carbon sinks: Methodological and regional differences

The increasing rates of CO2 due to anthropogenic activities are causing important potential climate threats for the Mediterranean Sea: ocean acidification and warming. In this region, two seagrass species, Posidonia oceanica and Cymodocea nodosa can play a crucial role in climate change mitigation. Through their metabolic activity, they can act as carbon sinks; buffer lowering pH values during the day and store carbon in the sediment underneath their meadows. In this study we analyse the metabolism synthesized from published data on seagrass community metabolism and from own results to evaluate trends through time of these two species comparing two methodologies: benthic chambers and multiparametric sensors. Furthermore, we analysed seasonal trends of both seagrass species´ metabolic rates and their variation between the Eastern and Western Mediterranean basins, with no significant results despite the clear visual trends. Our analysis revealed that there are significant differences between methodologies, with multiparametric sensors estimating higher rates, but unable to differentiate between habitats and useful to assess seagrass metabolism at a community level whereas benthic chambers are capable to evaluate rates at a seagrass species level. We found significant differences between the two Mediterranean regions for both methodologies, with highest rates of Net Community Production found in the Easter basin. At a species level, we found that Posidonia was more productive compared to Cymodocea. Furthermore, 86.7 % of the metabolic values reflected that the meadows were acting as carbon sinks in the Western basin.This work was funded by the Spanish Ministry of Economy and Competitiveness (Project MEDSHIFT, CGL2015-71809-P) and Project RTI2018-095441-B-C21 (SUMAECO) from the Spanish Ministry of Science, Universities and Innovation.Peer reviewe

Mediterranean seagrass metabolic rates

[Geographic location of data collection] Mediterranean basin, seagrass meadows of Posidonia oceanica and Cymodocea nodosa in coastal regions, max. depth 17m.[File List] datacompilation_med_seagrass_metabolic_rates_hendriks.csv, readme.txt.[Relationship between files, if important] readme provides background information for csv datafile.[Additional related data collected that was not included in the current data package] dissolved nutrients for author data (available upon request).[Description of methods used for collection/generation of data] Data on metabolic rates was extracted from the literature, through a literature search (March 2020) on SCOPUS and the Web of Science using the keywords “Posidonia”, OR “Cymodocea”, OR “Seagrass”, AND “Productivity”, OR “Metabolism” and manually screened for data on metabolism in the Mediterranean basin. This database was extended with unpublished data from the authors and data from dedicated sampling campaigns in 2016 in Mallorca (Western Mediterranean) and 2017 in the Eastern basin (Crete and Cyprus). We compiled data from multiparametric sensors, and data using the benthic chambers methodology with a temporal cover from 1982 to 2019.[Methods for processing the data] For benthic chambers, reported metabolic rates were extracted from the literature. For measurements with multiparametric sensors we used time series of dissolved oxygen (DO, in mg/L), salinity and temperature (C) measured in P. oceanica and/or C. nodosa meadows. With the time series of dissolved oxygen (DO), temperature (°C) and salinity we calculated the metabolic rates of the seagrass habitats using a modification of the model of Coloso et al., (2008) implemented in MATLAB (version 7.5. the Mathworks Inc.) explained in detail in Vaquer-Sunyer et al., (2012). Wind speed was estimated at each station for the same interval as oxygen measurements to predict k660 (air-sea gas transfer velocity for oxygen at 20º C and salinity 35) based on Kihm et al., (2010) and Cole et al., (1998). Schmidt number equations for seawater according to Wanninkhof (1992) were used for the k calculation from k660. As the cubic model equals the model proposed by Wanninkhof et al., (1999) for short-term winds this parameterization by Kihm et al., (2010) is used. Meteorological data (windspeed) for the deployment period was obtained from the Agencia Estatal de Meteorología (AEMET) for the stations in Mallorca, from the Cyprus Department of Meteorology for Cyprus sampling sites and from the Hellenic National Meteorological Service for the locations in Crete.--[Standards and calibration information] Sensors were calibrated before each deployment; oxygen sensors (Hach LDOTM) were calibrated using the water saturated air method calibration. For validation of salinity, specific conductance calibrations were performed with 50.000uS/cm buffers. For depth measurements, pressure readings were corrected for specific conductance.[Environmental/experimental conditions] Coastal seagrass meadows with max. 17m depth.[Describe any quality-assurance procedures performed on the data] Negative respiration rates (oxygen production) at night for sensor deployments, were discarded as this was interpreted as an indication for the influence of lateral advection and passing of different water masses. Therefore, we trimmed the dataset to contain only measurements where this influence was not detected. Respiration rates were notated as oxygen consumption (positive values, literature reports differ in notation).[People involved with sample collection, processing, analysis and/or submission, please specify using CREDIT roles https://casrai.org/credit/: Conceptual idea IEH and NM. Data collection in the field MW, SF, RVS, IEH, NM. Literature compilation IEH and AEM. Data curation AEM and IEH.[Data-specific information] 1. Number of variables: 21. 2. Number of cases/rows: 151. 3. Variable List: Reference, Journal, Methodology, Year, Month, Season, Site, Region, Latitude, Longitude, Species, Temperature_C, Salinity, Depth, NCP, NCP_SD, CR, CR_SD, GPP, GPP_SD, Wind_m_s. 4. Missing data codes: Empty cell. 5. Specialized formats or other abbreviations used: C (degree Celcius), SD (Standard Deviation), m_s (Meter per second). Depth in meter. Latitude and Longitude in Decimal Degrees (DD).The data is a compilation of information on metabolic rates of Mediterranean seagrasses obtained by two different methodologies (benthic incubations and multiparametric sensors) from published literature and data from the authors.The Spanish Ministry of Economy and Competitiveness (Project MEDSHIFT, CGL2015-71809-P). Project RTI2018-095441-B-C21 (SUMAECO) from the Spanish Ministry of Science, Universities and Innovation. SF was supported by a “Margalida Comas” postdoctoral scholarship, funded by the Balearic Islands Government. Also funding was received from “projectes de recerca La Caixa en àrees estratègiques” (2018) through a grant to IEH at the University of the Balearic islands.datacompilation_med_seagrass_metabolic_rates_hendriks.csv, readme.txtPeer reviewe