47 research outputs found
Sobre les causes del descens de les poblacions de Callista chione (Linnaeus, 1758) a la costa del Maresme, Catalunya
Trabajo final de carrera presentado por Enric Real García para obtener el Grado en Ciencias Ambientales por la Facultad de Biología de la Universitat de Barcelona (UB), realizado bajo la dirección del Dr. Franz Peters del Institut de Ciències del Mar (ICM-CSIC).-- 20 pages, 8 figures, 3 tablesThe populations of the bivalve Callista chione (L.), have experimented a severe decline in recent years in the Maresme coast, Catalonia, (Spain), where it has a considerable commercial interest. This trend is framed within a general decline of most other fisheries and tends to be attributed to overfishing. We have addressed other possible causes such as changes in the quality of coastal waters in terms of chemical nutrient or chlorophyll concentrations or the effect of sand extraction for beach nourishment, but have failed to establish general relationships with catch per unit effortPeer Reviewe
Costes y beneficios de tres métodos de estudio de comunidades en el bentos rocoso mediterráneo
Here we compare the applicability, the information provided and the cost-benefit of three sampling methods usually used in the study of rocky benthic assemblages. For comparative purposes, sampling was performed seasonally and along a depth gradient (0-50 m) in the Cabrera Archipelago (western Mediterranean). The destructive scraping (collection) method was the least cost-effective but provided the best qualitative and quantitative information. The in situ visual method was the most time-effective but provided low levels of taxonomic resolution and its accuracy decreased with depth due to the increasing difficulty of recognizing species in situ due to nitrogen narcosis, reduced light and cold. The photoquadrat method showed intermediate values of cost-effectiveness and information but was not suitable for multilayered assemblages, as it only accounted for the overstory. A canonical correspondence analysis showed that depth was highlighted as the main environmental gradient (16.0% of variance) by the three methods. However, differences due to the sampling method (7.9% of variance) were greater than differences due to temporal variability (5.8% of variance), suggesting that the three methods are valid but their selection has to be carefully assessed in relation to the targeted assemblages and the specific goals of each study.Este trabajo compara la aplicabilidad, la calidad de la información, los costes y los beneficios de tres métodos de muestreo usados habitualmente en el estudio de comunidades en el bentos rocoso mediterráneo. Para fines comparativos, el muestreo se realizó estacionalmente y a lo largo de un gradiente de profundidad (0-50 m) en el Archipiélago de Cabrera (Mediterráneo Occidental). El método destructivo de raspado (recolección) tuvo altos costes, pero proporcionó la información de mejor calidad, tanto a nivel cualitativo como cuantitativo. El método visual in situ fue el más eficiente en cuanto a la obtención de información, pero proporcionó una baja resolución taxonómica y su exactitud decreció con la profundidad debido a la dificultad de reconocer especies in situ bajo condiciones de narcosis, falta de luz y frío. El método fotográfico obtuvo valores intermedios de coste-beneficio, pero no fue adecuado para caracterizar comunidades estratificadas ya que solo tuvo en cuenta el estrato superior. Un análisis CCA mostró que el principal gradiente ambiental resaltado en todos los métodos era la profundidad (16.0% de la varianza). Sin embargo, las diferencias debidas al método de muestreo (7.9% de la varianza) fueron más grandes que las debidas a la variabilidad estacional (5.8% de la varianza). En consecuencia, los tres métodos son válidos para el muestreo de comunidades rocosas mediterráneas, pero su selección debe basarse en un análisis minucioso de las comunidades a caracterizar y en los objetivos específicos de cada estudio
Discard-ban policies can help improve our understanding of the ecological role of food availability to seabirds
ACKNOWLEDGEMENTS Funds for this study were supplied by the Spanish Ministry of Economy and by the European Social Fund (grant ref.: CGL2013-42203-R). The study also received funding from the European Commission’s Horizon 2020 Research and Innovation Programme under Grant Agreement no. 634495 for the project Science, Technology, and Society Initiative to Minimize Unwanted Catches in European Fisheries (MINOUW). MG and ASA are supported by postdoctoral contracts co-funded by the Regional Government of the Balearic Islands and the European Social Fund. Two reviewers helped to improve the manuscript.Peer reviewedPublisher PD
Interspecific synchrony on breeding performance and the role of anthropogenic food subsidies
Open Access via the PLOS Flat Fee Agreement Funding: This work has been partially supported by Balearic Government, Ministry of Education (FPU2012-000869), Ministry of Economy (IBISES-CGL2013-42203-R and RESET-CGL2017-85210-P) and EU project MINOW (H2020-634495). It was partially funded by the EU FEDER regional funds. ASA was supported by a Ramón y Cajal contract (RYC-2017- 22796) funded by the Ministerio de Ciencia, Innovación y Universidades, the Agencia Estatal de Investigación and the ESF. MG was supported by a postdoctoral contract co-funded by the Regional Government of the BI and the ESF (PD/023/2015). There was no additional external funding received for this study. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD
It’s not all abundance: Detectability and accessibility of food also explain breeding investment in long-lived marine animals
Large-scale climatic indices are extensively used as predictors of ecological processes, but the mechanisms and the spatio-temporal scales at which climatic indices influence these processes are often speculative. Here, we use long-term data to evaluate how a measure of individual breeding investment (the egg volume) of three long-lived and long-distance-migrating seabirds is influenced by i) a large-scale climatic index (the North Atlantic Oscillation) and ii) local-scale variables (food abundance, foraging conditions, and competition). Winter values of the North Atlantic Oscillation did not correlate with local-scale variables measured in spring, but surprisingly, both had a high predictive power of the temporal variability of the egg volume in the three study species, even though they have different life-history strategies. The importance of the winter North Atlantic Oscillation suggests carry-over effects of winter conditions on subsequent breeding investment. Interestingly, the most important local-scale variables measured in spring were associated with food detectability (foraging conditions) and the factors influencing its accessibility (foraging conditions and competition by density-dependence). Large-scale climatic indices may work better as predictors of foraging conditions when organisms perform long distance migrations, while local-scale variables are more appropriate when foraging areas are more restricted (e.g. during the breeding season). Contrary to what is commonly assumed, food abundance does not directly translate into food intake and its detectability and accessibility should be considered in the study of food-related ecological processes.En prensa4,41
Monitoring the complex benthic habitat on semi-dark underwater marine caves using photogrammetry-based 3D reconstructions
Marine caves are dark environments considered a priority habitat for conservation included
in the EU Habitats Directive (H8330). They harbor fragile benthic communities and
represent a major reservoir of marine biodiversity. However, there is a lack of knowledge of
these habitats due to the difficulties of creating detailed benthic maps and characterizing
the biodiversity, structure, and dynamics of their communities. The uniqueness of marine
caves fosters their popularity among recreational divers, who can cause disturbances
through abrasion of the biota, resuspension of sediment, and accumulation of exhaled air
bubbles in the caves' ceilings. This study aims to build a monitoring framework to
characterize the structure and temporal dynamics of this complex habitat using Structurefrom-
Motion (SfM) photogrammetry. SfM is a novel, non-invasive technique that allows a
major advancement in the monitoring of changes in the cave’s community assemblages. This
method relies on images acquired by 4K video footage to build fine-scaled 3D digital models
of the substrate using overlapping imagery. For this study, we combined SfM
photogrammetry and photo quadrats extracted from the video recordings. We evaluate the
effectiveness of this methodology in a marine cave highly frequented by divers, located in
Illa de l’Aire (Balearic Islands, Spain), and carried out two surveys before and after the
diving season (2019-2021). As a result, we found a loss of 25 colonies of bryozoans with
fragile skeletons, like Schizoretepora sp., and 8 individual sponges with globose
morphotypes. Our results indicate that this methodology enables accurate and efficient
monitoring of benthic communities in underwater caves that allow us to better understand
their dynamics and, therefore, to develop the need management measures
MAPPING COMMUNITY INTEREST HABITATS IN THE COLUMBRETES ARCHIPELAGO, AN EXTRAORDINARY HOT SPOT OF BIODIVERSITY
The Columbretes Archipelago and their submerged surroundings are part of an unusual,
Pleistocene volcanic field located in the Western Mediterranean designated as a Site of
Community Importance (SCI) of the Natura 2000 Network. In the present study, 4 benthic
habitats of community interest (1110, 1170, 1180 and 8330) have been identified by analyzing
several sources of information. Generalized additive models (GAMs) have been used to model
the potential distribution of reefs (1170) and maërl beds (1110). Our results highlight the
diversity and extent of these habitats and allow comparisons to other marine SCIs of Spain. This
can be attributed to the variability of the environment of this site. The Columbretes Islands
combine a relatively shallow environment with volcanic structures, hydrothermalism with active
degassing, current-driven sedimentary lobes and the influence of inland flows. Understanding
high biodiversity spots is crucial as they offer natural laboratories to describe how ecosystems
respond to the effects of global change. The knowledge obtained will be of paramount
importance for the conservation of species and habitats. Furthermore, it will establish a
baseline for future monitoring and assist in the development of effective management plans
Database of spatial distribution of non indigenous species in Spanish marine waters
Research in marine Spanish waters are focused on several actions to achieve an effectively management on protected areas, with the active participation of the stakeholders and research as basic tools for decision-making. Among these actions, there is one about the knowledge and control on NIS. One of its objectives is the creation of NIS factsheets, which are going to be added to the National Marine Biodiversity Geographical System (GIS) providing complementary information about taxonomic classification, common names, taxonomic synonyms, species illustrations, identification morphological characters, habitat in the native and introduced regions, biological and ecological traits, GenBank DNA sequences, world distribution, first record and evolution in the introduced areas, likely pathways of introduction, effects in the habitats and interaction with native species, and potential management measures to apply. The database will also provide data for (1) the European online platforms, (2) the environmental assessment for the Descriptor 2 (D2-NIS) of the EU Marine Strategy Framework Directive (MSFD), as well as (3) supporting decisions made by stakeholders. It is the result of extensive collaboration among scientist, manager’s and citizen science in the Spanish North-Atlantic, South-Atlantic, Gibraltar Strait-Alboran, Levantine-Balearic and Canary Islands marine divisions, providing an updated overview of the spatial distribution of relevant extended and invasive NIS of recent and established NIS introduced by maritime transport and aquaculture pathways, as well as on cryptogenic or native species in expansion due to the climatic water warming trend
Determinació de l'edat i el creixement, durant tot el cicle de vida, del mictòfid Ceratoscopelus maderensis (Lowe, 1939), del Mediterrani Occidental
Treball final presentat per Enric Real Garcia pel Màster en Oceanografia i Gestió del Medi Marí de la Universitat de Barcelona (UB), realitzat sota la direcció de la Dra. Mª Pilar Olivar Buera de l'Institut de Ciències del Mar (ICM-CSIC).-- 31 pages, 19 figures, 8 tables, 1 annexL'edat i el creixement de Ceratoscopelus maderensis al llarg de tot el seu cicle de vida (larves, transforming, juvenils i adults), han sigut descrits a partir de l'anàlisi d'otòlits. S'han comptat els increments dels otòlits (saggita) de 59 individus (longitud estàndard = 3.5-64 mm) capturats en el Mediterrani Occidental, durant el mes de desembre de 2009. S'han identificat fins a tres zones característiques dels otòlits d'aquesta espècie, a les quals ens hem referit com a zona larvària, zona metamòrfica i zona juvenil-adulta. Assumint com a diària la periodicitat dels increments, els individus analitzats tindrien entre 7-332 dies. El número d'anells de creixement en funció de la talla, s'han ajustat a un model de creixement de von Bertalanffy, obtenint l'equació: L = 70.5899 * (1 - exp (-0.05005(t+2.6705))), on >L> és la longitud estàndard i >t> el temps en dies. El creixement de C. maderensis al Mediterrani s'assimila molt als resultats reportats per Linkowski et al., 1993, amb individus de C. maderensis de l'Atlàntic. Les taxes de creixement, tot i no mostrar diferències significatives, suggereixen un creixement més ràpid per part dels individus del Mediterrani, que assolirien una mida de 60 mm en 361 dies, mentre que els de l'Atlàntic necessitarien 394 dies. Això podria ser degut a les diferències en el règim de temperatura, més altes al MediterraniAquest treball s'ha realitzat en el departament de Recursos Marins Renovables de l'Institut de Ciències del Mar dins del marc del projecte IDEADOS (CTM2008-04489-C03-02)Peer Reviewe
Extracción de características para la clasificación de estados cognitivos a partir de imágenes FMRI
L’estudi de les funcions cerebrals humanes s’ha incrementat enormement durant els últims anys donada l’aparició de les imatges funcionals de ressonància magnètica (FMRI). Mentre que la tècnica s’ha emprat principalment en la localització de diferents funcions cerebrals, el problema de classificació d’estats cognitius ha estat poc explorat. L’estudi d’aquest problemaés important perquè pot servir com a eina per a detectar i seguir processoscognitius (seqüències d’estats cognitius) amb la finalitat de diagnosticarproblemes en el moment d’executar una tasca complexa.En aquest treball s’investiguen diferents aproximacions per a detectar l’estat cognitiu d’una persona prenent com a base la seva imatge de ressonància magnètica. En particular, s’han investigat varis mecanismes de sel·lecció de característiques així com mètodes d’aprenentatge automàtic pelproblema de la discriminació d’estats cognitius procedents d’estimuls auditius.Es presenten els resultats d’un estudi sobre estímuls musicals