Iberian Coast Research Articles

Sea slug night fever: 39 new records of elusive heterobranchs in the western Mediterranean (Mollusca: Gastropoda)

ABSTRACT Citizen (or community) science has provided copious and valuable information about charismatic marine taxa such as heterobranch gastropods, thus contributing enormously to the known geographic distribution of many sea slug species. This study reports new records of elusive sea slugs in the coastal western Mediterranean (especially on the Catalan and French Mediterranean coasts) and contributes to new ecological information regarding their phenology, diet and behaviour. Out of 39 species reported here, 23 are new records for the Catalan coast (NE Spain), three are new records of pelagic pteropods for the Spanish Iberian coast, and eight are new records for the French Mediterranean coast. With 25 species found active at night, this study highlights the importance of sampling at night and in shallow, often under-sampled waters with high species diversity. Shallow waters usually have less diving activity and are harder to survey with heavy scuba equipment. We believe that the high-quality photos herein and the related species information will enable researchers, divers and the community to find and recognise these rare species in the Mediterranean basin.

This is what we know: Assessing the stock status of the data-poor common sole on the Iberian coast

In the Iberian Coast region, the common sole (Solea solea) is considered a very relevant species due to its high commercial value. Despite its importance, the current status of this stock is still poorly known due to the scarcity of available data to apply formal assessment methods. In data-poor situations length-based methods have been widely applied to estimate biological parameters and to understand the dynamics of marine stocks. In this study we evaluate the status of common sole in the Iberian Coast region using the following three different length-based methods: (1) the length-based indicators, (2) the length-based spawning potential ratio and (3) the mean length-based mortality estimators. Overall, the three methods agree that this stock appears to be exploited at the maximum sustainable yield level, the immatures are well preserved whereas the proportion of large mature individuals is relatively low, although it has been increased in the last years. Assessing the status of this valuable stock through data-limited methods is the first step towards designing and implementing effective management measures.

Evaluation of SMOS L4 Sea Surface Salinity Product in the Western Iberian Coast

Salinity is one of the oldest parameters being measured in oceanography and one of the most important to study in the context of climate change. However, its quantification by satellite remote sensing has been a relatively recent achievement. Currently, after over ten years of data gathering, there are still many challenges in quantifying salinity from space, especially when it is intended for coastal environments study. That is mainly due to the spatial resolution of the available products. Recently, a new higher resolution (5 km) L4 SMOS sea surface salinity (SSS) product was developed by the Barcelona Expert Center (BEC). In this study, the quality of this product was tested along the Western Iberian Coast through its comparison with in situ observations and modelled salinity estimates (CMEMS IBI Ocean Reanalysis system). Moreover, several parameters such as the temperature and depth of in situ measurements were tested to identify the variables or processes that induced higher errors in the product or influenced its performance. Lastly, a seasonal and interannual analysis was conducted considering data between 2011 to 2019 to test the product as a potential tool for long-term studies. The results obtained in the present analysis showed a high potential of using the L4 BEC SSS SMOS product in extended temporal and spatial analyses along the Portuguese coast. A good correlation between the satellite and the in situ datasets was observed, and the satellite dataset showed lower errors in retrieving coastal salinities than the oceanic model. Overall, the distance to the coast and the closest rivers were the factors that most influenced the quality of the product. The present analysis showed that great progress has been made in deriving coastal salinity over the years and that the SMOS SSS product is a valuable contribution to worldwide climatological studies. In addition, these results reinforce the need to continue developing satellite remote sensing products as a global and cost-effective methodology for long-term studies.

Caves and Ritual in Medieval Europe AD 500–1500, ed. Knut Andreas Bergsvik and Marion Dowd (Oxford and Philadelphia: Oxbow Books, 2018; rpt. 2022), vi, 314 pages, color and b/w ill.

Abstract European medievalists know that in the past caves, cut-rock enclosures, and catacombs could become churches, places of monastic retreat, burial sites, and loci of saintly power. Perhaps too commonly, however, we have little memory of caves and their medieval uses inside Europe, recalling more easily the use of caves outside of Europe, for instance in Egypt or the Middle East, or on Europe’s periphery, as in Anatolia or the southern Iberian coast. One reason that so few examples come to mind of medieval Europeans putting caves to use has to do with archeological priorities. As the editors of this volume assert in page one of their opening remarks “cave archeology has become synonymous with the Paleolithic” and “of all archeological periods, it could be argued that the medieval usage of caves has been the most overlooked.” In this splendid collection of essays, twenty-four researchers, mostly archeologists but also historians, art historians, anthropologists and others, offer the successful beginnings of a remedy to the paucity of studies on the uses of caves and rock shelters in medieval Europe.

Applying length-based assessment methods to fishery resources in the Bay of Biscay and Iberian Coast ecoregion: Stock status and parameter sensitivity

Length-based methods have been widely applied to estimate biological parameters and understand the dynamics of marine resource populations within data-limited stocks. However, to date few studies have tested the sensitivity of parameters in length-based methods examining stocks with different traits and fishery contexts. In the Bay of Biscay and the Iberian Coast ecoregion, SE Europe (International Council for the Exploration of the Sea - ICES, Divisions 8 and 9a), many commercial resources are considered data-limited, and either little is known about their fisheries stock statuses or gaps remain in currently available assessments. Therefore, this study focuses on two of the most used length-based methods, which ICES considers to be the most appropriate to evaluate data-limited stocks, namely length-based indicators (LBI) and the length-based spawning potential ratio (LBSPR). Both methods have been applied to assess the stock statuses of various relevant species in the study area, such as: the small-spotted catshark (Scyliorhinus canicula), European anchovy (Engraulis encrasicolus), blackspot seabream (Pagellus bogaraveo), pouting (Trisopterus luscus), pollack (Pollachius pollachius), and Norway lobster (Nephrops norvegicus). For each stock, model results were compared with available knowledge on their current status. Furthermore, this paper discusses whether unexpected results are related to violations of the main model assumptions (constant total mortality and recruitment, and logistic selectivity) or to a lack of representativeness of stock length composition. A sensitivity analysis was conducted on the two most important input parameters: L∞ (von Bertalanffy asymptotic average maximum body size) and M/k (ratio of natural mortality to von Bertalanffy growth rate). This analysis concluded that the variation/misspecification of both parameters (M/k and L∞) had a considerable impact on the results given by both methods, and that this effect is more significant in the case of the L∞ parameter, thus highlighting the importance of its accuracy in a given assessment. Furthermore, the sensitivity analysis indicated that, among the LBI and LBSPR indicators, the least robust indicator was the LBI Pmega indicator. The remaining LBI method indicators can be considered more robust than the LBSPR indicators when there is uncertainty in the life history input parameters (M/k and L∞). Among LBSPR indicators, SPR is more affected than F/M (relative fishing mortality) by the variation/misspecification of parameter L∞, whereas under the variation of M/k both indicators perform similarly. However, it is important to consider that LBI indicators are very rough measures of stock statuses, whereas LBSPR measures describe stock statuses more explicitly. Thus, both measures can be used together to obtain more precision in estimating stock status. Nevertheless, when critical parameters are uncertain (e.g., L∞) and the results of both methods contradict one another, LBI method indicators, with the exception of Pmega, are more trustworthy than LBSPR indicators.

A perfect storm: An anomalous offshore phytoplankton bloom event in the NE Atlantic (March 2009)

While primary productivity is more stable in oceanic regions, it may vary to a great extent with the proximity to coasts, where mesoscale processes may intertwine and shape phytoplankton community composition and biomass. Sometimes, this may lead to the development of anomalous phytoplankton blooms (i.e., episodic blooms that exceed several times the average phytoplankton biomass). A massive bloom observed off the Western Iberian Coast (SW Europe) during March 2009 prompted a full investigation on its spatial and temporal extent, its causes, and its potential impact on the ecosystem. Results revealed that the March 2009 bloom was both novel in terms of biomass in a regional context and one of the largest anomalous blooms until now described in terms of relative magnitude. Its causes were due to a concurrence of long-term (deep winter MLD) and short-term factors (coastal upwelling, sudden changes in the water column, consistent offshore water transport). Its impact on the regional ecosystem is difficult to gauge, although the high concentrations of particulate organic carbon at surface during the bloom period suggests that it may have had a significant local impact. Since climate change is expected to increase the frequency and intensity of extreme weather events, it is possible that anomalous blooms will also become more frequent, expanding their role in shaping carbon export and food webs. These results are crucial for the monitoring of the Western Iberian Coast and are applicable to other complex coastal upwelling regions where phytoplankton biomass and variability have a crucial link to fisheries.

Response of Food-Webs Indicators to Human Pressures, in the Scope of the Marine Strategy Framework Directive

Understanding food webs environmental condition is a challenging task since evaluations are limited by data on key ecosystem elements, by the availability of indicators that incorporate relevant guilds and by the difficulty in establishing cause-effect relations between pressures and health status, as multiple overlapping pressures can affect taxonomic elements differently. The present work aims to investigate food webs assessment under the Marine Strategy Framework Directive (MSFD), revealing gaps and future research needs in the North Eastern Atlantic. To understand reporting patterns, information on the criteria employed and the resulting assessment trends of Descriptor 4—Food webs were surveyed from the MSFD reports. A multivariate analysis was applied to food webs assessment status and spatially overlapping anthropogenic pressures to understand if the assessment was detecting pressures, considering fish elements. Results revealed that reporting strategies varied between Member States. High reporting effort was exhibited by the United Kingdom in opposition to Ireland or France. Reporting of other groups other than fish and plankton was limited to the United Kingdom due to the availability of monitoring programs and data. The analysis applied to criteria considering fish elements reinforced that reporting strategies and trends differed between countries, although some similarities were found for the Bay of Biscay and Iberian coast and the Celtic Seas. Food webs assessment trends for fish were variable in Spain and were stable or increased in Portugal and the United Kingdom. Anthropogenic drivers significantly influencing food web trends for fish elements were fishing, and climate anomalies in the southern Bay of Biscay and Iberian coast, while eutrophication and chemical contamination had effects on trends in the Celtic Sea and the North Sea. Results allowed to establish a relation between anthropogenic effects and food web patterns, however, these were limited since food webs assessment is incongruent in terms of criteria used and data is still limited at relevant scales. This study reinforced the necessity to increase Member States harmonization and calibration to improve our understanding of food webs environmental status.

Coupled modelling of the interaction between dissolved substances emitted by Minho and Lima estuarine outflows (Portugal)

The Minho and Lima estuaries comprise important and sensitive protected areas valuable for species and habitats conservation, constituting a reference for ecotoxicological and water quality studies. These estuaries, separated only by 20 km, are very productive systems with high metabolic rates that strongly influence the cycle of nutrients and the ecology of NW Iberian coast. This study aims to understand the propagation of Minho and Lima estuarine plumes in order to investigate the effects of buoyancy on the interaction between dissolved substances emitted by their outflows and its impacts on regional productivity. Using the Delft3D model, a deeper analysis of the intrusion and dynamics of outflows of these adjacent estuaries was performed, through the simulation of trajectories of passive tracers emitted in each estuary, considering river discharges and wind stress. The results show an interaction between these estuaries, both during the summer and the winter seasons. Both estuarine outflows tend to move southward in response to the predominant north wind in the summer season, while in winter the opposite is observed. The northward outflows tend to be transported very close to the coastline, while the southward and westward is diverted offshore. The estuarine outflows interaction promotes exchanges of physical-chemical properties and nutrients between these estuaries, generating ecological advantages for the smaller one. These results showed that the numerical model used accurately describes the dynamical processes in these estuarine systems, being essential for a proper assessment of the effects of forcing drivers and providing relevant information for coastal zone planning and management.

Ecophysiological effects of mercury bioaccumulation and biochemical stress in the deep-water mesopredator Etmopterus spinax (Elasmobranchii; Etmopteridae)

Mercury (Hg) is a non-essential metal that can have toxic effects on the fitness of organisms and tends to bioaccumulate with age and to biomagnify in higher trophic levels. Few studies have assessed oxidative stress and neurotoxicity in deep-water sharks. This study evaluated early ontogenetic changes and physiological effects (antioxidant defences, oxidative damage, aerobic metabolism and neurotransmission functions) of Hg accumulation in the white muscle and brain tissues of the velvet belly lantern shark Etmopterus spinax from the southern Iberian coast (NE Atlantic). Results suggested that the low mercury concentrations observed may induce acute effects in E. spinax before they reach sexual maturity. We found different Hg concentrations in E. spinax: [Hg] males > [Hg] females; [Hg] muscle > [Hg] brain. Females appeared to have higher redox capability translated into higher activities and levels of antioxidant defences than males. However, higher levels of oxidative damage were also observed in females. Whilst the mechanisms underlying these effects remain unknown, these results suggest differences in mercury accumulation between tissues and sex, and potentially deleterious effects on oxidative stress status and neurophysiology of E. spinax, potentially impairing swimming performance and reproduction, which could subsequently impact on the health of both individuals and population.

Tsunami generation potential of a strike-slip fault tip in the westernmost Mediterranean

Tsunamis are triggered by sudden seafloor displacements, and usually originate from seismic activity at faults. Nevertheless, strike-slip faults are usually disregarded as major triggers, as they are thought to be capable of generating only moderate seafloor deformation; accordingly, the tsunamigenic potential of the vertical throw at the tips of strike-slip faults is not thought to be significant. We found the active dextral NW–SE Averroes Fault in the central Alboran Sea (westernmost Mediterranean) has a historical vertical throw of up to 5.4 m at its northwestern tip corresponding to an earthquake of Mw 7.0. We modelled the tsunamigenic potential of this seafloor deformation by Tsunami-HySEA software using the Coulomb 3.3 code. Waves propagating on two main branches reach highly populated sectors of the Iberian coast with maximum arrival heights of 6 m within 21 and 35 min, which is too quick for current early-warning systems to operate successfully. These findings suggest that the tsunamigenic potential of strike-slip faults is more important than previously thought, and should be taken into account for the re-evaluation of tsunami early-warning systems.

Spatial variability of elemental fingerprints of sea lettuce (Ulva spp.) and its potential use to trace geographic origin

Seaweeds are an important marine resource and are currently used in a wide range of applications, such as food, feed, pharmaceuticals, cosmetics, nutraceuticals, and biomaterials. Seaweeds uptake a multitude of chemical elements from the environment, which can turn them into high-quality food products or pose a threat to human health. Therefore, knowing the elemental fingerprint of seaweeds, as well as their geographic origin, is of utmost importance for their valorization and to safeguard public health. In the present study, the elemental fingerprint of the green seaweed Ulva spp., popularly known as sea lettuce, was determined. Different samples were sourced from nine different locations over the western and southwestern Iberian coast, and elemental fingerprints targeted three major elements (Ca, K and Na) and seven trace elements (Al, Ba, Cu, Fe, Mn, Pb and Zn). The elemental fingerprints of Ulva spp. differed significantly among the different places of origin, confirming the potential of this biogeochemical tool to trace the geographic origin of seaweeds. Origin certification can contribute towards the valorization of premium Ulva spp. biomass and enhance safety standards for high-end uses of this green seaweed.

Assessing the use of surrogate species for a more cost-effective traceability of geographic origin using elemental fingerprints of bivalve shells

Illegal, unreported and unregulated (IUU) fishing is a major threat to marine ecosystems and their living resources. IUU fishing promotes fraudulent mislabeling of seafood, which can pose serious risks to consumers’ health if specimens being traded originate from contaminated areas. The development and optimization of reliable tools to confirm the geographic origin of seafood is therefore of utmost importance under these scenarios. These tools are usually based in reference models of a given species that allows to trace the geographic origin of conspecifics. However, to date, the accuracy of such reference models requires the sampling of specimens of the species being surveyed, an issue that may impair the generalized use of this approach by authorities under real-case scenarios. A potential way to overcome this constraint is to apply a model built for a given species (working as surrogate) to trace the geographic origin of another one. The present study evaluated the effect of species-specific and spatial variability associated with the elemental fingerprints (EF) of shells of three commercially important bivalve species (Cerastoderma edule, Ruditapes decussatus and R. philippinarum) from five different locations over the northwestern and western Iberian coast and tested if a reference model based on one of this species could be used to reliably trace the geographic origin of specimens from the two other species. The EF of shells of the three species were significantly different within each location, as well as among different locations within each species. The reference models of the three species presented high cross-validation accuracy (ranging from 95.3% to 99.3%). The tests to infer if these models could reliably trace the geographic origin of samples from another species presented an overall accuracy ranging between 50% and 82.3%. Based on these results, and other requirements that a surrogate species must fulfil, it is possible to conclude that the three species hold the potential to be used as surrogates of each other, although C. edule is the one that better fulfills the requirements of a surrogate species. The optimization proposed in this study improves the cost-efficiency of using EF of bivalve shells as a tool to trace and confirm the geographic origin of bivalves, while also allowing to deliver a prompter reply to authorities.

Differential responses of trailing-edge populations of a foundation alga to thermal stress

ABSTRACT Populations within the same species range edge may experience contrasting local conditions and exhibit diverse levels of environmental tolerance. This heterogeneity within a range boundary has seldom been considered in studies forecasting the impact of anthropogenic habitat alteration and climate change on species distributions. Moreover, any ecological prediction under changing environmental conditions requires a good understanding of the combined responses of organisms to multiple stressors, in particular the effects on key life cycle stages of species. The intertidal seaweed Fucus serratus is a dominant species on northern Atlantic shores and whose southern limit is in the NW Iberian Peninsula. We examined how early developmental stages of southern-edge populations of this foundation alga responded to the combined effects of environmental stressors, including salinity and aerial and seawater temperature. Four populations from two different areas of the NW Iberian coast were considered: two populations from open shores on the northern coast and two populations from the western rias on the Atlantic coast. The study findings revealed inter-population variability in the response to heat stress, with greater survival of germlings from the northern populations than those from western rias. Environmental conditions are still more benign within western rias, under the influence of strong summer upwelling events. The results also suggest the key role of aerial thermal stress in determining the southern limit of distribution of the target species. The future of these heterogeneous edge populations from NW Iberian Peninsula depends on trends in climate change and the ability of populations to cope with these. Environmental changes may already be occurring at rates that exceed the plastic and adaptive potential of edge populations in N Spain, while the future of western rias as climate refugia for this and other foundation alga is also uncertain.

Contrasting impacts of climate change on connectivity and larval recruitment to estuarine nursery areas

Connectivity between spawning grounds and recruitment areas of marine fish species drives population structure and dynamics, and may be affected by climate-induced changes in oceanographic processes. We analysed the variability in recruitment success of larvae to estuarine nursery areas along the Iberian Atlantic coast of four fish species with distinct spawning grounds and periods (Solea solea, Solea senegalensis, Platichthys flesus and Dicentrarchus labrax). Concomitantly, we explored the variations in connectivity patterns between “cold” and “warm” year archetypes. We used a three-dimensional Lagrangian transport particle-tracking model integrating time series of velocity, temperature and salinity fields archived from the Regional Ocean Modelling System. We simulated individual larval dispersal, over extended spawning periods, from multiple coastal spawning areas to estuarine recruitment areas over 20 years (1989–2008). Overall, high inter- and intra-annual variation were found for all species. Nonetheless, highest overall average recruitment estimates were obtained for S. solea and D. labrax (with 7.3% and 5.7% of the particles released in spawning areas reaching a recruitment area, respectively) compared to S. senegalensis and P. flesus (3.4% and 1.7%, respectively). Recruitment estimates were overall higher at earlier spawning dates but peak values occurred at later spawning events. Regarding spawning origin, particles that recruited to the northern part of the Iberian coast were mainly from southern source areas. For estuarine systems located in southern Portugal, the relative contributions of northern and southern coastal spawning areas were more balanced, or with a preponderance of northern spawning areas (namely for S. senegalensis and D. labrax). Recruitment was higher in “warm” years compared to “cold” years, except for P. flesus for which nil recruitment was registered in the southern Iberian coast during “warm” years. Larvae also travelled farther in “warm” years compared to “cold” years. Ultimately, understanding how oceanographic conditions govern larval recruitment to estuarine nursery areas is pivotal to forecast the potential impacts of climate change on species with segregated life histories, and will underpin long term management and safeguarding of estuarine nursery role.

Influence of oceanic and climate conditions on the early life history of European seabass Dicentrarchus labrax

Understanding how marine fish early-life history is affected in the long-term by environmental and oceanographic factors is fundamental given its importance to population dynamics and connectivity. This work aimed at determining the influence of these processes on the interannual variability in hatch day and early-life growth patterns of European seabass, over a seven-year period (2011–2017) in the Atlantic Iberian coast. To accomplish this, otolith microstructure analysis was used to determine seabass hatch day and to develop early-growth correlations. In most years, hatching occurred from February to April, with two exceptions: in 2012, hatching started in early-January, and in 2016 an exceptionally long hatching period was registered. Using generalized additive models (GAM), we observed that sea surface temperature (SST), the North Atlantic Oscillation index (NAOi) and Chlorophyll-a (Chla) were the main drivers behind the inter-annual variability in seabass hatch day. Analysis of correlations between growth increments allowed assessing important periods of seabass growth and how future growth is affected. Since seawater temperature is among the main drivers for seabass recruitment and growth, its life cycle may be hampered due to ocean warming and an increasingly unstable climate, with consequences for the natural marine stocks and their harvest.

River Freshwater Contribution in Operational Ocean Models along the European Atlantic Façade: Impact of a New River Discharge Forcing Data on the CMEMS IBI Regional Model Solution

River freshwater contribution in the European Atlantic margin and its influence on the sea salinity field are analyzed. The impacts of using a new river discharge database as part of the freshwater forcing in a regional ocean model are assessed. Ocean model scenarios, based on the CMEMS (Copernicus Marine Environment Monitoring Service) operational IBI-MFC (Iberia Biscay Ireland Monitoring Forecasting Centre) model set-up, are run to test different (observed, modeled and climatological) river and coastal freshwater forcing configurations throughout 2018. The modelled salinity fields are validated, using as a reference all known available in-situ observational data sources. The IBI model application is proven to adequately simulate the regional salinity, and the scenarios showcase the effects of varying imposed river outflows. Some model improvement is achieved using the new forcing (i.e., better capture of salinity variability and more realistic simulation of baroclinic frontal structures linked to coastal and river freshwater buoyancy plumes). Major impacts are identified in areas with bigger river discharges (i.e., the French shelf or the northwestern Iberian coast). Instead, the Portuguese shelf or the Gulf of Cadiz are less impacted by changes in the imposed river inflows, and other dynamical factors in these areas play a major role in the configuration of the regional salinity.

Economic Feasibility of Floating Offshore Wind Farms Considering Near Future Wind Resources: Case Study of Iberian Coast and Bay of Biscay.

Wind energy resources are subject to changes in climate, so the use of wind energy density projections in the near future is essential to determine the viability and profitability of wind farms at particular locations. Thus, a step forward in determining the economic assessment of floating offshore wind farms was taken by considering current and near-future wind energy resources in assessing the main parameters that determine the economic viability (net present value, internal rate of return, and levelized cost of energy) of wind farms. This study was carried out along the Atlantic coast from Brest to Cape St. Vincent. Results show that the future reduction in wind energy density (2%–6%) mainly affects the net present value (NPV) of the farm and has little influence on the levelized cost of energy (LCOE). This study provides a good estimate of the economic viability of OWFs (Offshore Wind Farms) by taking into account how wind resources can vary due to climate change over the lifetime of the farm.

Wedge clam (Donax trunculus Linnaeus, 1758) reproduction: reproductive traits and environmental influence in the NW Iberian coast and contrast across Atlantic and Mediterranean waters

Production of wedge clam (Donax trunculus) has experienced a widespread decrease. Environmental conditions have been postulated as an important agent though the effects on reproduction are poorly understood. We here review the reproductive cycle and evaluate the influence of environmental conditions in Galicia (NW Iberian coast). We further contrast the variability of reproductive traits across the distribution range. Reproductive individuals dominate size classes between 20 and 30 mm, and spawning spans from April to July with a subsequent inactive period from September onwards. Length at first maturity (L50) was established at 19 mm. Oocyte size was unrelated to shell size or gonad occupancy, and realized fecundity averaged 8 × 105 eggs per female. Environmental conditions had significant effects on the gonadosomatic index and flesh yield which were lower in less productive waters. Furthermore, the interannual proportion of fully mature individuals during the spawning period maximized at high and low levels of coastal upwelling and continental runoff, respectively. Across the distribution range, water temperature and chlorophyll concentration defined the geographical differences on reproductive traits with lower L50 and longer spawning period occurring in warmer waters and the central month of spawning taking place earlier in the year in more productive waters.

Assessing Phytoplankton Bloom Phenology in Upwelling-Influenced Regions Using Ocean Color Remote Sensing

Phytoplankton bloom phenology studies are fundamental for the understanding of marine ecosystems. Mismatches between fish spawning and plankton peak biomass will become more frequent with climate change, highlighting the need for thorough phenology studies in coastal areas. This study was the first to assess phytoplankton bloom phenology in the Western Iberian Coast (WIC), a complex coastal region in SW Europe, using a multisensor long-term ocean color remote sensing dataset with daily resolution. Using surface chlorophyll a (chl-a) and biogeophysical datasets, five phenoregions (i.e., areas with coherent phenology patterns) were defined. Oceanic phytoplankton communities were seen to form long, low-biomass spring blooms, mainly influenced by atmospheric phenomena and water column conditions. Blooms in northern waters are more akin to the classical spring bloom, while blooms in southern waters typically initiate in late autumn and terminate in late spring. Coastal phytoplankton are characterized by short, high-biomass, highly heterogeneous blooms, as nutrients, sea surface height, and horizontal water transport are essential in shaping phenology. Wind-driven upwelling and riverine input were major factors influencing bloom phenology in the coastal areas. This work is expected to contribute to the management of the WIC and other upwelling systems, particularly under the threat of climate change.

Molecular and morphological validation of the species of the genus Actinia (Actiniaria: Actiniidae) along the Atlantic Iberian Peninsula

The discrimination between the several species of the genus Actinia occurring in the Northeastern Atlantic and Mediterranean has been made analyzing morphological characters, with emphasis on external coloration patterns and morphology of cnidom structures. In Iberia, the occurrence of more than two species of Actinia has been suggested, but its validity is yet to be confirmed. In this paper, the identity of the species of the genus Actinia occurring along the Atlantic Iberian coast is investigated, analyzing morphological and molecular procedures. For this purpose, genetic data was collected from 140 individuals and two genetic markers were amplified and sequenced (the nuclear 28S and the mitochondrial 16S ribosomal genes). The genetic identification was corroborated by morphological analysis of individuals representing each of the genetic groups found. This procedure led to the identification of three species occurring in the studied area – Actinia equina (L.), A. fragacea Tugwell and A. schmidti Monteiro, Sole-Cava & Thorpe.