Coastal engineering infrastructure impacts Blue Carbon habitats distribution and ecosystem functions

Unidad de excelencia María de Maeztu CEX2019-000940-MAltres ajuts: EU LIFE Programme (LIFE18 CCA/ES/001160)Intertidal estuarine habitats (e.g., saltmarshes and tidal flats) provide important ecosystem services to society, including coastal protection, food provision and C sequestration. Yet, estuaries and estuarine habitats have been subjected to intense human pressure, such as land-use change and artificialization of the shoreline to support economic activities and uses. Construction of engineering infrastructures (e.g., piers, bridges) in these areas alters estuary-wide hydromorphological conditions and thus sedimentation patterns at the estuarine scale, which are key drivers of habitats distribution and ecosystem structure, processes and functions. Most of the research on the impact of civil engineering structures on coastal habitats has focused on the biological communities that colonize them or the bottoms where they are placed, whereas their indirect impacts on adjacent habitats has been largely unexplored. Understanding the influence of man-made infrastructures on the distribution of estuarine habitats and functions is critical, particularly considering that shoreline armoring is expected to increase as a way to protect coastal areas from hazards derived from climate change. Shifts in habitat distribution and functions occur in several years or decades and relating them with the occurrence of past historical events is challenging when no monitoring data is available. By examining historical aerial photographs and different biogeochemical properties along a saltmarsh soil record, this study demonstrates that the construction of an infrastructure (i.e. bridge) caused a rapid transformation (~ 30 years) of a bare sandflat into a high marsh community and to significant changes in sediment biogeochemical properties, including the decrease in sediment accretion rate and C burial rates since then. This study contributes to increase the knowledge on the impact that the construction in coastal areas of civil engineering infrastructures can cause in intertidal habitats distribution and the ecological functions they provide for climate change adaption and mitigation

Drivers of variability in Blue Carbon stocks and burial rates across European estuarine habitats

The implementation of climate change mitigation strategies based on the conservation and restoration of Blue Carbon ecosystems requires a deep understanding of the magnitude and variability in organic carbon (Corg) storage across and within these ecosystems. This study explored the variability in soil Corg stocks and burial rates across and within intertidal estuarine habitats of the Atlantic European coast and its relation to biotic and abiotic drivers. A total of 136 soil cores were collected across saltmarshes located at different tidal zones (high marsh, N = 45; low marsh, N = 30), seagrass meadows (N = 17) and tidal flats (N = 44), and from the inner to the outer sections of five estuaries characterized by different basin land uses. Soil Corg stocks were higher in high-marsh communities (65 ± 3 Mg ha−1) than in low-marsh communities (38 ± 3 Mg ha−1), seagrass meadows (40 ± 5 Mg ha−1) and unvegetated tidal flats (46 ± 3 Mg ha−1) whereas Corg burial rates also tended to be higher in high marshes (62 ± 13 g m−2 y−1) compared to low marshes (43 ± 15 g m−2 y−1) and tidal flats (35 ± 9 g m−2 y−1). Soil Corg stocks and burial rates decreased from inner to outer estuarine sections in most estuaries reflecting the decrease in the river influence towards the estuary mouth. Higher soil Corg stocks were related to higher content of silt and clay and higher proportion of forest and natural land within the river basin, pointing at new opportunities for protecting coastal natural carbon sinks based on the conservation and restoration of upland ecosystems. Our study contributes to the global inventory of Blue Carbon by adding data from unexplored regions and habitats in Europe, and by identifying drivers of variability across and within estuaries

Species traits and geomorphic setting as drivers of global soil carbon stocks in seagrass meadows

Unidad de excelencia María de Maeztu CEX2019-000940-MOur knowledge of the factors that can influence the stock of organic carbon (OC) that is stored in the soil of seagrass meadows is evolving, and several causal effects have been used to explain the variation of stocks observed at local to national scales. To gain a global-scale appreciation of the drivers that cause variation in soil OC stocks, we compiled data on published species-specific traits and OC stocks from monospecific and mixed meadows at multiple geomorphological settings. Species identity was recognized as an influential driver of soil OC stocks, despite their large intraspecific variation. The most important seagrass species traits associated with OC stocks were the number of leaves per seagrass shoot, belowground biomass, leaf lifespan, aboveground biomass, leaf lignin, leaf breaking force and leaf OC plus the coastal geomorphology of the area, particularly for lagoon environments. A revised estimate of the global average soil OC stock to 20 cm depth of 15.4 Mg C ha−1 is lower than previously reported. The largest stocks were still recorded in Mediterranean seagrass meadows. Our results specifically identify Posidonia oceanica from the Mediterranean and, more generally, large and persistent species as key in providing climate regulation services, and as priority species for conservation for this specific ecosystem service

Factors Determining Seagrass Blue Carbon Across Bioregions and Geomorphologies

Este artículo contiene 15 páginas, 6 figuras, 1 tabla.Seagrass meadows rank among the most significant organic carbon (Corg) sinks on earth. We examined the variability in seagrass soil Corg stocks and composition across Australia and identified the main drivers of variability, applying a spatially hierarchical approach that incorporates bioregions and geomorphic settings. Top 30 cm soil Corg stocks were similar across bioregions and geomorphic settings (min-max: 20–26 Mg Corg ha−1), but meadows formed by large species (i.e., Amphibolis spp. and Posidonia spp.) showed higher stocks (24–29 Mg Corg ha−1) than those formed by smaller species (e.g., Halodule, Halophila, Ruppia, Zostera, Cymodocea, and Syringodium; 12–21 Mg Corg ha−1). In temperate coastal meadows dominated by large species, soil Corg stocks mainly derived from seagrass Corg (72 ± 2%), while allochthonous Corg dominated soil Corg stocks in meadows formed by small species in temperate and tropical estuarine meadows (64 ± 5%). In temperate coastal meadows, soil Corg stocks were enhanced by low hydrodynamic exposure associated with high mud and seagrass Corg contents. In temperate estuarine meadows, soil Corg stocks were enhanced by high contributions of seagrass Corg, low to moderate solar radiation, and low human pressure. In tropical estuarine meadows formed by small species, large soil Corg stocks were mainly associated with low hydrodynamic energy, low rainfall, and high solar radiation. These results showcase that bioregion and geomorphic setting are not necessarily good predictors of soil Corg stocks and that site-specific estimates based on local environmental factors are needed for Blue Carbon projects and greenhouse gases accounting purposes.This study was delivered as part of the Pilot Projects program of the Land Restoration Fund, supported by the Queensland Government, Deakin University, The University of Queensland, James Cook University, CSIRO, HSBC, Qantas, Australian Government Department of Industry, Science, Energy and Resources, NQ Dry Tropics, Great Barrier Reef Foundation and Greencollar. We are thankful for the funding provided by Deakin University (to PIM and MDPC), Qantas (to PIM and MDPC) and HSBC (to PIM and MDPC). MR, PY, PIM were supported through ARC Linkage grant LP160100492, and PIM and CEL were supported through ARC Linkage grant LP160100242. NJW is funded through Australian Government National Environment Science Program (Tropical Water Quality Hub). MFA was funded through an Advance Queensland Industry Research Fellowship, Queensland Government. CS was funded by ECU Higher Degree by Research ScholarshipPeer reviewe

Carbon skins in seagrass meadows: rates, control, vulnerability, and the role of carbonate

[spa] Los ecosistemas costeros vegetados (manglares, marismas y praderas de fanerógamas marinas) se encuentran entre los sumideros de carbono más importantes del planeta gracias a una elevada capacidad de absorber y atrapar carbono y enterrarlo en el sedimento a largo plazo. Sin embargo, los ecosistemas de “Carbono Azul”, como se les conoce, se encuentran entre los más amenazados a nivel global y su declive implica la pérdida de todos los servicios ecosistémicos que proveen, incluido el de sumidero de carbono. La protección de estos ecosistemas podría ser considerada como una medida de mitigación del cambio climático dentro de las estrategias ya existentes, dirigidas a promover, mediante incentivos económicos, la conservación de los sumideros naturales de carbono terrestres, como los bosques (ej.: programa REDD+). Sin embargo, el conocimiento sobre la capacidad como sumidero de carbono de los ecosistemas costeros, en especial de las praderas submarinas, era todavía muy limitado cuando esta tesis se planteó. El objetivo de esta tesis es contribuir al conocimiento de los procesos que determinan la capacidad como sumideros de carbono de las praderas submarinas así como la vulnerabilidad de esta función. Se han evaluado distintos aspectos claves, incluyendo la variabilidad espacial y temporal (~ último siglo), el efecto de factores ambientales y de la presión antrópica, la vulnerabilidad de los depósitos a ser remineralizados cuando las praderas se degradan y el papel de las praderas como depósitos de carbonato (CaCO3) así como sus implicaciones en la función de sumidero de carbono. En base al estudio del sedimento de praderas de Posidonia oceanica de las Islas Baleares, esta tesis identifica importantes diferencias en los depósitos y tasas de enterramiento de carbono orgánico (Corg) en el sedimento que se explican mejor por el distinto nivel de presión antrópica que por los factores ambientales considerados (profundidad de las praderas y exposición al oleaje). Una alta presión antrópica ha dado lugar a mayores tasas de enterramiento tanto espacial como temporalmente, como muestra su incremento hacia el presente coincidiendo con el aumento de la presión antrópica en la región en los 60’s asociado con el desarrollo del turismo; y también a una mayor contribución de carbono derivado de seston. Estos resultados apuntan al incremento en la eutrofización del agua, derivado de la incidencia humana, como la explicación más parsimoniosa a las tendencias que se observan, indicando que la presión antrópica es un factor determinante en los sumidero de carbono de las praderas submarinas. La vulnerabilidad de los depósitos de Corg a ser remineralizados y emitidos en forma de CO2 queda demostrada, por primera vez, en esta tesis. El riesgo a ser remineralizados depende de características biogeoquímicas, siendo mayor en sedimentos ricos en nitrógeno y en materia orgánica de origen sestónico y menor cuanto mayor es la concentración de carbonato en el sedimento. Por tanto, un enriquecimiento del sedimento de las praderas con aportes sestónicos, posiblemente favorecido por un incremento en la presión antrópica, como el observado en las Islas Baleares, da lugar a un debilitamiento de los sumideros de carbono que se vuelven más vulnerables a ser remineralizados. Esta tesis también demuestra que los sedimentos de las praderas submarinas son un importante reservorio de carbonato a escala global y que, aunque su precipitación da lugar a la emisión de CO2, el CaCO3 inhibe la remineralización de la materia orgánica e incrementa la eficiencia en el enterramiento de Corg en el sedimento de las praderas. Por tanto, la investigación presentada en esta tesis contribuye significativamente al conocimiento sobre el papel de las praderas submarinas como sumideros de carbono, evaluando diferentes aspectos que, hasta la fecha, habían sido poco o nada explorados.[eng] Coastal vegetated ecosystems (i.e. mangroves, saltmarshes and seagrasses) have been recognized as being among the most significant natural carbon sinks on Earth due to a high capacity of absorbing and trapping carbon that gets buried and stored in the sediment compartment for a long-term. Yet “Blue Carbon” ecosystems, as they are usually referred to, rank among the most threatened globally and their decline implies the loss of all the ecosystem services they provide including that of carbon sink. Hence, the protection of these ecosystems has been proposed as a suitable way to mitigate climate change to be considered within the current, or similar, strategies addressed to enhance the protection of terrestrial carbon sinks (i.e. forests) through economic incentives (i.e. REDD+ programs). However, the knowledge on the carbon sink capacity of these ecosystems, especially seagrass meadows, was very weak at the time this thesis was planned and certain gaps of knowledge needed to be urgently addressed. This thesis was planned with the aim to contribute to the understanding of the processes that govern the carbon sink capacity in seagrass meadows and its vulnerability. Different key questions were examined including the spatial and temporal (~last century) variability in the sediment organic carbon (Corg) sinks (stocks and burial rates), the effect of environmental factors and human pressure, the vulnerability of the Corg deposits to be remineralized when seagrass meadows are lost, and the role seagrass meadows play as carbonate (i.e. CaCO3) sedimentary reservoirs as well as the implications of carbonate in seagrass meadows efficiency as carbon sinks. Based on Posidonia oceanica meadows around the Balearic Islands, this thesis identifies significant differences in the sediment Corg stocks and burial rates among meadows that could be better explained by the level of human pressure than by the environmental factors considered (water depth and wave exposure). High human pressure surprisingly led to higher Corg burial rates both spatially and temporally, as the rate of Corg burial increased towards the present, coinciding with the increase in anthropogenic pressure in the region of study that took place around the 60’s (following tourism industry development), and led to a higher contribution of seston derived organic carbon to the sediment deposits. The enhanced eutrophication of coastal waters derived from an increasing human pressure is suggested as the most parsimonious explanation to the trends observed, indicating that anthropogenic pressure is a relevant factor conditioning the carbon sink capacity in seagrass meadows. The vulnerability of seagrass Corg deposits to remineralization and to be lost as CO2 is proved, for the first time, in this thesis. The risk of remineralization is however variable and depends on sediment biogeochemical characteristics, being enhanced in sediments rich in nitrogen and sestonic organic matter and prevented as sediment carbonate content increases. Therefore, an enrichment of seagrass sediments with sestonic inputs enhanced by the increase in anthropogenic pressure, as the observed in the Balearic Islands, leads to a “weakening” of the sedimentary carbon sinks since they become more vulnerable to remineralization. This thesis also demonstrates that seagrass sediments are a globally significant CaCO3 reservoir and that, despite the precipitation of carbonate leading to CO2 emissions, sedimentary carbonate prevents organic matter remineralization and enhances Corg burial efficiency in seagrass sediments. Hence, the research presented in this dissertation significantly contributes to the knowledge on the role seagrass meadows play as carbon sinks by examining different aspects that, until now, had been largely unexplored or not considered.[cat] Els ecosistemes costaners vegetats (manglars, maresmes i praderies de fanerògames marines) es troben entre els embornals de carboni més importants del planeta gràcies a una elevada capacitat d'absorbir i atrapar carboni, i d’enterrar-lo en el sediment a llarg termini. No obstant, els ecosistemes de "Carboni Blau", com se'ls coneix, es troben entre els més amenaçats a nivell global i el seu declivi implica la pèrdua de tots els serveis ecosistèmics que proveeixen, inclòs el d'embornal de carboni. La protecció d'aquests ecosistemes podria ser considerada com una mesura de mitigació del canvi climàtic dins de les estratègies ja existents, dirigides a promoure, mitjançant incentius econòmics, la conservació dels embornals naturals de carboni terrestres (per exemple, boscos) (programa REDD+). No obstant, el coneixement sobre la capacitat com a embornal de carboni dels ecosistemes costaners, especialment de les praderies submarines, era encara molt limitat quan aquesta tesi es va plantejar. L'objectiu d'aquesta tesi és contribuir al coneixement dels processos que determinen la capacitat de les praderies submarines com a embornals de carboni, així com la vulnerabilitat d'aquesta funció. S'han avaluat diferents aspectes claus, incloent la variabilitat espacial i temporal (~ últim segle), l'efecte de factors ambientals i de la pressió antròpica, la vulnerabilitat dels dipòsits a ser remineralitzats quan les praderies es degraden i el paper de les praderies com dipòsits de carbonat (CaCO3), així com les seves implicacions en la funció d'embornal de carboni. En base a l'estudi del sediment de praderies de Posidonia oceanica de les Illes Balears, aquesta tesi identifica importants diferències en els dipòsits i taxes d'enterrament de carboni orgànic (Corg) en el sediment, les quals s'expliquen millor pel diferent nivell de pressió antròpica que per els factors ambientals considerats (profunditat de les praderies i exposició a l'onatge). Una alta pressió antròpica ha donat lloc a majors taxes d'enterrament tant espacial com temporalment; com a mostra, el seu increment cap al present coincidint amb l'augment de la pressió antròpica a la regió en els anys 60 associat amb el desenvolupament del turisme, i també a una major contribució de carboni derivat de sèston. Aquests resultats apunten a l'increment en l'eutrofització de l'aigua, derivada de la pressió antròpica, com l'explicació més parsimoniosa a les tendències que s'observen, indicant que la pressió antròpica és un factor determinant en els embornal de carboni de les praderies submarines. La vulnerabilitat dels dipòsits de Corg a ser remineralitzats i emesos en forma de CO2 queda demostrada, per primera vegada, en aquesta tesi. El risc a ser remineralitzats depèn de característiques biogeoquímiques, sent major en sediments rics en nitrogen i en matèria orgànica d'origen sestònic i menor com més gran és la concentració de carbonat en el sediment. Per tant, un enriquiment del sediment de les praderies amb aportacions sestòniques, possiblement afavorit per un increment en la pressió antròpica, com l'observat a les Illes Balears, dóna lloc a un debilitament dels embornals de carboni que es tornen més vulnerables a ser remineralitzats. Aquesta tesi també demostra que els sediments de les praderies submarines són un important reservori de carbonat a escala global i que, encara que la seva precipitació dóna lloc a l'emissió de CO2, el CaCO3 inhibeix la remineralització de la matèria orgànica i incrementa l'eficiència en l'enterrament de Corg en el sediment de les praderies. Per tant, la investigació presentada en aquesta tesi contribueix significativament al coneixement sobre el paper de les praderies submarines com a embornals de carboni, avaluant diferents aspectes que, fins ara, havien estat poc o gens explorats

Biogeochemical variables along the soil profile of three saltmarsh cores sampled in an estuary of the Gulf of Biscay

This database contains data on different biogeochemical variables measured in three soil cores (32-39 cm long) sampled in a saltmarsh community of the Bay of Santander (Gulf of Biscay). Soil cores were extracted in June 2019 within an area of 25 m2 in a high marsh community located at the mouth of the Miera estuary, within the Bay of Santander (43.452136°/ -3.748134°) by manually hammering a PVC tube (60 cm L * 7 cm Ø). Compression was measured during sampling of each of the cores. The cores were preserved frozen until processing. The longest core (BS2A1, 39 cm) was sliced every 1 cm, whereas the other two cores (BSA2, BS2A3) were sliced every 2 cm for the top 20 cm and every 5 cm for the deeper layers. Each sediment slice was measured for wet volume and dried at 60 ºC for a minimum of 72 h. The dry weight of each slice was measured and used together with wet volume to estimate sediment dry bulk density (DBD in g·cm-3). Soil organic carbon content (Corg % DW) was measured every two or three slices along the sediment depth profile of each core. Corg was analyzed in the IHLab Bio laboratory of the IHCantabria using a TC analyzer (Shimadzu TOC-L + SSM-5000A). Grain size analysis was performed every other sample at the Universitat de Barcelona with a Beckman Coulter LS GB500. Organic Corg isotopic signature (δ13Corg) (in pre-acidified subsamples) was measured using an Elemental Analyzer Flash IRMS coupled with an Isotope Ratio Mass Spectrometry (DeltaV A) at the Universidad de la Coruña. The years of sediment accumulation were estimated from concentration profiles of 210Pb, determined by alpha spectrometry through the measurement of its granddaughter 210Po, assuming radioactive equilibrium between both radionuclides. About 100–200 mg aliquots of each sample were spiked with 209Po and microwave digested with a mixture of concentrated HNO3 and HF. Boric acid was then added to complex fluorides. The resulting solutions were evaporated and diluted to 100 mL 1M HCl and Po isotopes were auto plated onto pure silver disks. Polonium emissions were measured by alpha spectrometry using PIPS detectors (CANBERRA, Mod.PD-450.18 A.M). Reagent blanks were comparable to the detector backgrounds. Analyses of replicate samples and reference materials were carried out systematically to ensure the accuracy and the precision of the results. The supported 210Pb was estimated as the average 210Pb concentration of the deepest layers once 210Pb reached constant values. Then, excess 210Pb (210Pbxs) concentrations were obtained by subtracting the supported 210Pb from the total 210Pb. Age model of the sediment depth profile records was obtained by modeling the 210Pbxs concentration profiles along the accumulated mass at each site. The model age of the sediment record was estimated using the Constant Flux: Constant Sedimentation model (CF:CS, 76). In order to assess the impact of the bridge construction on the biogeochemical properties of the saltmarsh soil, we compare all biogeochemical properties across two sections of the core, divided based on the results of 210Pb dating: sediments accumulated before and after the building of the bridge (i.e., before vs. after 1978).concentration profiles of 210Pb and applying the Constant Flux: Constant Sedimentation model (CF:CS, Krishnaswamy et al. 1971).This database contains biogeochemical data on different biogeochemical variables measured in three soil cores sampled in a saltmarsh community of the Bay of Santander (Gulf of Biscay).These data were compiled with the contribution of the LIFE Programme of the European Union to the Project ADAPTA BLUES (ref. LIFE18 CCA/ ES/001160). This document reflects only the author’s view and the Agency/ Commission is not responsible for any use that may be made of the information it contains.Authors acknowledges the financial support from the Government of Cantabria through the Fénix Programme. The authors want to thank the support of the Generalitat de Catalunya to MERS (2017 SGR-1588) and the Spanish Government for the “Maria de Maeztu” program for Units of Excellence to ICTA (grant no. CEX2019-000940-M).-Infrastructure impact_Data.xlsx: the Database to be published. -Variables Database.xlsxPeer reviewe

Global unbalance in seaweed production, research effort and biotechnology markets

Exploitation of the world's oceans is rapidly growing as evidenced by a booming patent market of marine products including seaweed, a resource that is easily accessible without sophisticated bioprospecting technology and that has a high level of domestication globally. The investment in research effort on seaweed aquaculture has recently been identified to be the main force for the development of a biotechnology market of seaweed-derived products and is a more important driver than the capacity of seaweed production. Here, we examined seaweed patent registrations between 1980 and 2009 to assess the growth rate of seaweed biotechnology, its geographic distribution and the types of applications patented. We compare this growth with scientific investment in seaweed aquaculture and with the market of seaweed production. We found that both the seaweed patenting market and the rate of scientific publications are rapidly growing (11% and 16.8% per year respectively) since 1990. The patent market is highly geographically skewed (95% of all registrations belonging to ten countries and the top two holding 65% of the total) compared to the distribution of scientific output among countries (60% of all scientific publications belonging to ten countries and the top two countries holding a 21%), but more homogeneously distributed than the production market (with a 99.8% belonging to the top ten countries, and a 71% to the top two). Food industry was the dominant application for both the patent registrations (37.7%) and the scientific publications (21%) followed in both cases by agriculture and aquaculture applications. This result is consistent with the seaweed taxa most represented. Kelp, which was the target taxa for 47% of the patent registrations, is a traditional ingredient in Asian food and Gracilaria and Ulva, which were the focus of 15% and 13% of the scientific publications respectively, that are also used in more sophisticated applications such as cosmetics, chemical industry or bioremediation. Our analyses indicate a recent interest of non-seaweed producing countries to play a part in the seaweed patenting market focusing on more sophisticated products, while developing countries still have a limited share in this booming market. We suggest that this trend could be reverted by promoting partnerships for R and D to connect on-going efforts in aquaculture production with the emerging opportunities for new biotech applications of seaweed products. © 2014 Elsevier Inc.This research was funded by a grant from the Food and Aquaculture Organization (FAO) of the UN. I.M. was supported by a Ph.D. grant from the Balearic government, E.M. was supported by a grant from the JAE-predoc programme of CSIC, and Y.S.O. was supported by the Marie Curie programme of the European Union Seventh Framework Programme (grant agreement n° PIEF-GA-2009-254297)Peer Reviewe

Coastal engineering infrastructure impacts Blue Carbon habitats distribution and ecosystem functions

Este artículo contiene 13 páginas, 6 figuras, 2 tablas.Intertidal estuarine habitats (e.g., saltmarshes and tidal fats) provide important ecosystem services to society, including coastal protection, food provision and Corg sequestration. Yet, estuaries and estuarine habitats have been subjected to intense human pressure, such as land-use change and artifcialization of the shoreline to support economic activities and uses. Construction of engineering infrastructures (e.g., piers, bridges) in these areas alters estuary-wide hydromorphological conditions and thus sedimentation patterns at the estuarine scale, which are key drivers of habitats distribution and ecosystem structure, processes and functions. Most of the research on the impact of civil engineering structures on coastal habitats has focused on the biological communities that colonize them or the bottoms where they are placed, whereas their indirect impacts on adjacent habitats has been largely unexplored. Understanding the infuence of man-made infrastructures on the distribution of estuarine habitats and functions is critical, particularly considering that shoreline armoring is expected to increase as a way to protect coastal areas from hazards derived from climate change. Shifts in habitat distribution and functions occur in several years or decades and relating them with the occurrence of past historical events is challenging when no monitoring data is available. By examining historical aerial photographs and diferent biogeochemical properties along a saltmarsh soil record, this study demonstrates that the construction of an infrastructure (i.e. bridge) caused a rapid transformation (~30 years) of a bare sandfat into a high marsh community and to signifcant changes in sediment biogeochemical properties, including the decrease in sediment accretion rate and Corg burial rates since then. This study contributes to increase the knowledge on the impact that the construction in coastal areas of civil engineering infrastructures can cause in intertidal habitats distribution and the ecological functions they provide for climate change adaption and mitigation.Tis research was carried out with the contribution of the LIFE Programme of the European Union to the Project ADAPTA BLUES (ref. LIFE18 CCA/ES/001160). Tis document refects only the author’s view and the Agency/ Commission is not responsible for any use that may be made of the information it contains. Authors acknowledges the fnancial support from the Government of Cantabria through the Fénix Programme. Te authors want to thank the support of the Generalitat de Catalunya to MERS (2017 SGR-1588) and the Spanish Government for the “Maria de Maeztu” program for Units of Excellence to ICTA (Grant No. CEX2019-000940-M).Peer reviewe

Rapid growth of seaweed biotechnology provides opportunities for developing nations

Peer Reviewe

Sediment organic carbon stocks were similar among four species compositions in a tropical seagrass meadow

Seagrass meadows composed of larger species are assumed to store larger sediment organic carbon (Corg) stocks, storing more Corg in their tissues and larger leaves promoting greater burial of seagrass and non-seagrass Corg. However, the influence of species composition on sediment Corg stocks remains poorly understood mainly from challenges in isolating it from confounding factors. We assessed Corg stocks in seagrass biomass and sediment of four species compositions in a tropical Caribbean meadow. We hypothesized that larger species would lead to higher sediment Corg stocks, within a limited geomorphic setting and time frame. Seagrass biomass and surficial and sediment profiles were collected to measure seagrass morphometrics, δ13C and δ15N, dry bulk density, Corg and inorganic carbon (Cinorg) stocks, and grain size. Seagrass biomass Corg stocks ranged from 0.04 to 3.7 Mg ha 1 , with higher biomass Corg stocks in compositions with larger species. Surficial sediment Corg and Cinorg stocks (to 1.5 cm) averaged 2.6 0.6 Mg Corg ha 1 and 68.8 14.6 Mg Cinorg ha 1 , respectively, and did not vary among species compositions. Isotopic analyses revealed a 50% contribution of seagrasses to surficial sediment Corg in compositions with larger species, compared to a contribution of 35% for those of smaller species. This study provides novel blue carbon data from an understudied region and contributes to understanding the role of seagrass species composition on sediment carbon storage.Universidad de Costa Rica/[808-B8-218]/UCR/Costa RicaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigación en Ciencias del Mar y Limnología (CIMAR)UCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de Biologí