Using catenas for GIS-based mapping of NW Mediterranean littoral habitats

Studies aimed at describing habitats and mapping their distributions are pivotal to implementing management plans and to effectively guide conservation measures. We developed a novel approach of data collection and entry (CAT-LIT) to establish a detailed cartography of the littoral habitats found along the Catalan coast (Spain). Field data were recorded using coded, two-digit hierarchical lists (e.g. Aa, Ab, etc.) of horizons found at each point along the coast, called catenas. The horizons were either dominated by species (on the rocky bottoms) or sediment types (on the beaches) and corresponded to LPRE, EUNIS and CORINE habitats. Catenas were transferred into a database and calculations about the extent of bottom types, habitats, and catenas themselves along the coast were carried out with GIS tools. In addition, habitat link richness was calculated and represented using network analysis programs. The application of CAT-LIT to the Catalan coast showed that the habitats dominated by the lichen Verrucaria amphibia and the flattened barnacle Euraphia depressa and those dominated by the barnacle Chthamalus spp. were almost ubiquitous. Those dominated by the red alga Corallina elongata, the mussel Mytilus galloprovincialis and the red alga Rissoella verruculosa were also common. Because of the frequency of their connections, those habitats formed a huge hub of links in the networks. By using catenas, the habitats can be viewed using GIS based programs keeping the catena as the main informational and ecological unit. The catenas allow maximum compactness when vertically distributed habitats are to be shown on a 2D map. The complete cartography and dataset on the spatial distribution of the littoral habitats from Catalonia is valuable for coastal management and conservation to study changes in the habitat distribution and relate such changes to anthropogenic pressures. Furthermore, the CAT-LIT can be easily adapted to shores of other seas and oceans to obtain accurate cartographies of the spatially-reduced and highly vulnerable littoral habitats.Financial support came from the projects “Cartografia dels Hàbitats Litorals a Catalunya” (Departament de Territori i Sosteniblitat and Institut Cartogràfic, Generalitat de Catalunya) and INTRAMURAL CSIC 201330E065. This study is also a contribution of GRACCIE (C5D2007-00067) and CoCoNET (FP7 Grant Agreement: 287844) projects

Vertical zonation is the main distribution pattern of littoral assemblages on rocky shores at a regional scale

Vertical variation in the distribution of rocky shore assemblages is greater than horizontal variation, as shown by univariate and multivariate analysis performed with data obtained along 1000 km of shoreline and covering from the upper supralittoral to the upper infralittoral zone (−1 m). Consequently, vertical littoral zonation is a consistent pattern at a regional scale within the same biogeographical zone. While their distribution varies at the same shore height, marine species and assemblages from rocky shores show a specific vertical sequence known as zonation. A key question in ecology is how consistent is zonation along large spatial scales. The aim of this study is to show distribution patterns of littoral assemblages at a regional scale and to identify the most relevant abiotic factors associated to such patterns. The study is based on a detailed and extensive survey at a regional scale on a tideless rocky shore. Benthic macroflora and macrofauna of 750 relevés were described along the vertical axis of 143 transects distributed across the shoreline of Catalonia (NW Mediterranean). The Detrended Correspondence Analysis (DCA) first axis is highly related to the height on the shore: species, relevés, and assemblages grade from lower to upper height (infralittoral to supralittoral). As observed in nature, different assemblages co-occur at the same height at different sites, which is shown along DCA second axis. The abiotic variables that best explain the assemblage distribution patterns are: height (75% of the model inertia), longitude (14.6%), latitude (7.2%) and transect slope (2.9%). The Canonical Correspondence Analysis (CCA) first axis is related to height on the shore and explains four times more variance than CCA second axis, which is related to the horizontal gradient. Generalized Lineal Model (GLM) results show that height on the shore is the factor explaining most of the variance in species presence. Most studied species show distribution patterns related to latitude and longitude, but always in a much smaller proportion than to height.Financial support for this work was provided by projects “Cartography of the littoral habitats of Catalonia” (Departament de Medi Ambient & Institut Cartogràfic, Generalitat de Catalunya), GRACCIE (C5D2007-00067), CoCoNET (FP7 Grant Agreement: 287844) and INTRAMURAL CSIC 201330E065

Estructura de los hábitats y patrones de zonación en playas del Mediterráneo noroccidental

We studied the habitat structure (macrofaunal assemblages and bottom types) and zonation patterns of 29 unvegetated shoreline strands along the 900-km coast of Catalonia (NW Mediterranean Sea). Organisms were sampled with grabs, pitfall traps, sticky traps, clam nets and spades to ensure capture of the different proportions of macrofaunal assemblages from the supra-, medio- and infralittoral levels. We collected 211 taxa: 194 animals and 17 algae. The most abundant and dominant organisms collected with van Veen grabs were Nematoda, Oligochaeta and Collembola at the supralittoral level; the polychaetes Saccocirrus spp. and Pisione remota, the amphipod Corophium orientale, Nematoda, and Turbellaria at the mediolittoral level; and Nematoda at the upper infralittoral level. SIMPER analysis revealed great dissimilarity between the organisms inhabiting the supralittoral and the other littoral levels. Regarding the epifauna, the sticky traps used at the supralittoral level mainly collected Collembola, which were nearly absent in pitfall traps. The qualitative study performed with a clam net and a small spade revealed that Nematoda, Saccocirrus spp., Turbellaria, Nemertea and the polychaete P. remota were the most abundant animals at both the medio- and the infralittoral levels and no differences were found between these levels. Different qualitative sampling methodologies showed that in fine sediments the bivalves Donax trunculus and D. semistriatus determined more than 97% of dissimilarity from coarse-sand sites. Richness increased in protected sandy and cobble shores. Littoral level and bottom-type features were only to a certain extent valid indicators of specific biotic components for a specific habitat.Se ha estudiado la estructura de los hábitats (comunidades de macrofauna y tipos de sedimento) y los patrones de zonación de 29 playas desprovistas de vegetación a lo largo de los 900 km de la costa de Cataluña (Mediterráneo noroccidental). El muestreo de los organismos se realizó mediante dragas, trampas de caída, trampas adhesivas, redes de marisqueo y palas para asegurar una captura exhaustiva de los organismos presentes en las comunidades de macrofauna de los niveles supralitoral, mediolitoral e infralitoral. Se colectaron 211 taxones: 194 animales y 17 algas. Los organismos más abundantes y dominantes recolectados con dragas van Veen fueron: Nematodos, Oligoquetos y Colémbolos en el nivel supralitoral; los poliquetos Saccocirrus spp. y Pisione remota, el anfípodo Corophium orientale, Nematodos y Turbelarios en el nivel mediolitoral; y Nematodos en la parte menos profunda del nivel infralitoral. Los análisis SIMPER detectaron grandes diferencias entre los organismos del nivel supralitoral y los de los otros niveles. Respecto a la epifauna, las trampas adhesivas usadas en el nivel supralitoral capturaron principalmente Colémbolos, los cuales estaban ausentes en las trampas de caida. El estudio cualitativo realizado con una red de marisqueo y una pala pequeña reveló que Nematodos, los poliquetos Saccocirrus spp. y Pisione remota, Turbelarios y Nemertinos eran los animales más abundantes tanto en el nivel mediolitoral como en el nivel infralitoral y que no había diferencias entre ambos niveles. Diferentes métodos cualitativos de muestreo revelaron que en los sedimentos finos los bivalvos Donax trunculus y D. semistriatus determinaban más del 97% de la disimilitud con los sedimentos gruesos. La riqueza en especies aumentaba en playas mixtas de arenas y cantos. El nivel y el tipo de sedimento fueron solo hasta cierto punto indicadores válidos de la composición de especies para cada hábitat concreto.Financial support came from the projects “Cartografia dels Hàbitats Litorals a Catalunya” (Departament de Territori i Sosteniblitat and Institut Cartogràfic, Generalitat de Catalunya) and INTRAMURAL CSIC 201330E065

Assessing the expansion and success of a restored population of Gongolaria barbata (Stackhouse) Kuntze (Fucales, Phaeophyceae) using high-precision positioning tools and size distribution frequencies

Ongoing human pressures over recent decades have caused the loss and ensuing impoverishment of the complexity and diversity of Mediterranean habitats dominated by algal species of the order Fucales. Gongolaria barbata, a habitat-forming Fucales species that has disappeared in several places across the Mediterranean, was reintroduced in a cove (Cala Teulera, Maó Bay, Menorca) where it was known to have been locally extinct for more than 40 years. Reintroduction was performed in 2011 using innovative non-destructive techniques. Here we describe the expansion patterns of the population ten years after its reintroduction, and we look at the size-structure distribution of the restored population compared to one of the only natural populations known in Spain (Fornells Bay, Menorca). Newly settled individuals exhibit a progressive dispersal pattern from restoration sites, favouring rocky substrates at the shallowest level parallel to the shore. The area occupied by G. barbata has increased by almost three orders of magnitude in ten years, from approximately 3.6 m2 of the initially restored area to a current restored area of 2093 m2. Recruits and juveniles dominate the restored population but some individuals have reached large size classes, the overall size distribution resembling the reference population. The high-resolution cartography included in our study enables an accurate mid to long-term assessment of the expansion of G. barbata. Incorporating such tools in restored marine forests would facilitate the implementation of efficient management policies that will help reinforce their conservation.Funding was provided by IEO (“Mola-Menorca Dos Project”, financed by the Direcció General de Recerca del Govern de les Illes Balears through the European Regional Development Fund)

Life on the boundary: Environmental factors as drivers of habitat distribution in the littoral zone

The boundary between land and sea, i.e. the littoral zone, is home to a large number of habitats whose distribution is primarily driven by the distance to the sea level but also by other environmental factors such as littoral's geomorphological features, wave exposure, water temperature or orientation. Here we explore the relative importance of those major environmental factors that drive the presence of littoral rocky habitats along 1100 Km of Catalonia's shoreline (Spain, NW Mediterranean) by using Geographic Information Systems and Generalized Linear Models. The distribution of mediolittoral and upper infralittoral habitats responded to different environmental factors. Mediolittoral habitats showed regional differences drawn by sea-water temperature and substrate type. Wave exposure (hydrodynamism), slope and geological features were only relevant to those mediolittoral habitats with specific environmental needs. We did not find any regional pattern of distribution in upper infralittoral habitats, and selected factors only played a moderate role in habitat distribution at the local scale. This study shows for the first time that environmental factors determining habitat distribution differ within the mediolittoral and the upper infralittoral zones and provides the basis for further development of models oriented at predicting the distribution of littoral marine habitats.Financial support for this work was provided by projects INTRAMURAL CSIC 0065 “Estudios para la implementación de las Directivas Europeas Hábitats, Marco del Agua y Estrategia Marina en el Mediterráneo Español”. This study is also a contribution of GRACCIE (C5D2007-00067) and CoCoNET (FP7 Grant Agreement: 287844) projects

The optimal sampling design for littoral habitats modelling: A case study from the north-western Mediterranean

Species distribution models (SDMs) have been used to predict potential distributions of habitats and to model the effects of environmental changes. Despite their usefulness, currently there is no standardized sampling strategy that provides suitable and sufficiently representative predictive models for littoral marine benthic habitats. Here we aim to establish the best performing and most cost-effective sample design to predict the distribution of littoral habitats in unexplored areas. We also study how environmental variability, sample size, and habitat prevalence may influence the accuracy and performance of spatial predictions. For first time, a large database of littoral habitats (16,098 points over 562,895 km of coastline) is used to build up, evaluate, and validate logistic predictive models according to a variety of sampling strategies. A regularly interspaced strategy with a sample of 20% of the coastline provided the best compromise between usefulness (in terms of sampling cost and effort) and accuracy. However, model performance was strongly depen upon habitat characteristics. The proposed sampling strategy may help to predict the presence or absence of target species or habitats thus improving extensive cartographies, detect high biodiversity areas, and, lastly, develop (the best) environmental management plans, especially in littoral environments.This study was supported by INTRAMURAL CSIC (0065) and the European Union’s Horizon 2020 (689518) MERCES

The optimal sampling design for littoral habitats modelling: A case study from the north-western Mediterranean

Species distribution models (SDMs) have been used to predict potential distributions of habitats and to model the effects of environmental changes. Despite their usefulness, currently there is no standardized sampling strategy that provides suitable and sufficiently representative predictive models for littoral marine benthic habitats. Here we aim to establish the best performing and most cost-effective sample design to predict the distribution of littoral habitats in unexplored areas. We also study how environmental variability, sample size, and habitat prevalence may influence the accuracy and performance of spatial predictions. For first time, a large database of littoral habitats (16,098 points over 562,895 km of coastline) is used to build up, evaluate, and validate logistic predictive models according to a variety of sampling strategies. A regularly interspaced strategy with a sample of 20% of the coastline provided the best compromise between usefulness (in terms of sampling cost and effort) and accuracy. However, model performance was strongly depen upon habitat characteristics. The proposed sampling strategy may help to predict the presence or absence of target species or habitats thus improving extensive cartographies, detect high biodiversity areas, and, lastly, develop (the best) environmental management plans, especially in littoral environments

Scientific monitoring program of the Research Station “Jaume Ferrer”: Temporal evolution of the cover of potentially invasive alien algae

4 págs, 1 fig.[EN] We analyze the changes in the percentage of cover of five species of introduced marine algae during more than a decade in different marine habitats around the island of Menorca. Acrothamnion preissii is abundant in the rhizomes of Posidonia oceanica but its cover has been decreasing during the last ten years. Womersleyella setacea shows persistent high abundances in coralligenous outcrops and sciaphilic algal communities. Asparagopsis taxiformis has colonized almost all habitats but its cover has been low during all the study period, never displaying an invasive behavior. Lophocladia lallemandii has also colonized almost all kind of habitats but it has never reached high coverages during the study period. Finally, Caulerpa cylindracea, a very ubiquitous species, has shown strong interannual cover variability, but it is not currently performing as an invasive species.[ES] En este trabajo se analizan los cambios en el porcentaje de cobertura de cinco especies de algas introducidas desde hace más de una década en distintos hábitats marinos de la isla de Menorca. Acrothamnion preissii es abundante en hábitats de Posidonia oceanica pero su cobertura ha ido disminuyendo a lo largo de los últimos diez años. Womersleyella setacea continua siendo muy abundante en los hábitats de coralígeno y de algas esciáfilas. Asparagopsis taxiformis ha colonizado casi todos los hábitats pero ha presentado una cobertura muy baja durante todo el periodo de estudio sin presentar nunca un carácter invasor. Lophocladia lallemandii llegó a colonizar casi todos los hábitats pero nunca tuvo una cobertura importante. Finalmente, Caulerpa cylindracea, muy ubicua, ha sufrido variaciones interanuales en su cobertura pero actualmente tampoco presenta un carácter invasor.Las actividades de Seguimiento científico de la Estación de Investigación "Jaume Ferrer" están cofinanciadas por la Dirección General de Políticas Universitarias e Investigación del Gobierno de Baleares y el Centro Oceanográfico de Baleares (IEO-CSIC). Queremos hacer llegar nuestro agradecimiento a la Dirección General de Pesca y al Parque Natural de s’Albufera des Grau, para facilitarnos las autorizaciones pertinentes que nos han permitido realizar los trabajos en los espacios marinos protegidos de Menorca. También a Joan Moranta por su ayuda en los primeros muestreos.Peer reviewe

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

Distribución geográfica, predicción espacial y diversidad de los hábitats litorales en la costa Catalana

Peer reviewe