Early Succession Patterns of Benthic Assemblages on Artificial Reefs in the Oligotrophic Eastern Mediterranean Basin

The colonization of artificial structures by benthic organisms in the marine realm is known to be affected by the general trophic patterns of the biogeographical zone and the prevailing environmental traits at the local scale. The present work aims to present quantitative data on the early settlement progress of macrofaunal benthic assemblages developing on artificial reefs (ARs) deployed at the Underwater Biotechnological Park of Crete (UBPC) in the oligotrophic Eastern Mediterranean. Visual census and subsequent image analysis combined with scraped quadrats were used to describe the establishment of the communities and their development over three consecutive campaigns, span-ning 5 years post-deployment. Macroalgae consistently dominated in terms of coverage, while sessile invertebrates displayed different patterns over the years. Polychaeta and Bryozoa were gradually replaced by Cnidaria, while Porifera and Mollusca displayed an increasing trend over the years. Motile benthos was mainly represented by Mollusca, while the abundance of Polychaeta increased in contrast to that of Crustacea. For both sessile and motile assemblages, significant differences were observed among the years. The results of this study indicate that ecological succession is still ongoing, and further improvement in the monitoring methodology can assist towards a more accurate assessment of the community composition in complex AR structures.European Union MIS 5002670, MIS 502740

Monitoring Extreme Impacts of Rugulopteryx okamurae (Dictyotales, Ochrophyta) in El Estrecho Natural Park (Biosphere Reserve). Showing Radical Changes in the Underwater Seascape

The invasive macroalga Rugulopteryx okamurae represents an unprecedented case of bioinvasion by marine macroalgae facing the European coasts. Since the first apparition of the species in the Strait of Gibraltar in 2015, its fast dispersion along the introduced habitats constitutes a real challenge to develop monitoring strategies that ahead of its impacts. The present study uses three different approaches to address impacts on the benthic ecosystems, at the same time offers relevant data for future management actions in El Estrecho Natural Park (PNE). Information obtained by monitoring permanent sentinel stations revealed a significant loss in resident species coverage after the moment of maximum growth in 2017. Thus, despite coverage of R. okamurae did not strongly varied in the latter years, impacts generated remain high in the habitats studied. Estimations of the invasive species coverage by combining cartographic image analysis and in situ data predicted a major occupation (over 85% coverage) between 10 and 30 m, coinciding with the maximum rocky surface areas (m2) mapped on the PNE. Furthermore, a Citizen Science research collaboration evidenced impacts on the benthic seascape through an ad hoc exploration of images that allowed a “before” and “after” comparison of the invasion process in the same geographic locations. This has made it possible to graphically demonstrate severe changes in the underwater seascape and, therefore, the general impact of this new biological invasion. The spatial colonization estimations combined with the impacts reported by both scientific [Sessile Bioindicators in Permanent Quadrats (SBPQ) sentinel stations] and civilian (Citizen Science) monitoring methodologies claim the urgent development of further studies that allow the design of monitoring strategies against R. okamurae expansion across the Mediterranean and Atlantic waters

Coexistiendo con una invasora en el estrecho de Gibraltar: la integración de Rugulopteryx okamurae en la fauna y flora residente

Se presenta una revisión del estado actual del conocimiento de la interacción de Rugulopteryx okamurae con la biota marina del estrecho de Gibraltar, así como una discusión global sobre el papel de estas últimas en el proceso invasor. Tanto los hábitats más perturbados como los altamente diversos y presuntamente estables del Campo de Gibraltar han sufrido una homogeneización generalizada fruto de la superioridad competitiva de la invasora. Los efectos de la sustitución biótica se han transmitido de forma directa a las comunidades biológicas sésiles por competencia espacial e indirectamente a estas y otras comunidades asociadas que cumplen un papel fundamental en la estructura taxonómica y funcional del ecosistema marino.A review of the current state of knowledge of the interaction of Rugulopteryx okamurae with the marine biota of the Strait of Gibraltar is presented, as well as a global discussion on the role of the latter in the invasive process. Both the most disturbed and the highly diverse and presumably stable habitats of the Campo de Gibraltar have suffered a generalised homogenisation as a result of the competitive superiority of the invader. The effects of biotic substitution have been transmitted directly to spatially competitive sessile biological communities and indirectly to these and other associated communities that play a fundamental role in the taxonomic and functional structure of the marine ecosystem

A worrying arrival: the first record of brown macroalga Rugulopteryx okamurae in Madeira Island and its invasive risk

The brown macroalgae Rugulopteryx okamurae is described as one of the most severe and threatening invasive marine macroalgae in European waters. This study reports the first record of R. okamurae in the Madeira archipelago, which represents a new southern distribution limit of this species in NE Atlantic European waters. Morphological and molecular characters were used to confirm the species' identity, and its potential invasion risk in Madeiran waters was screened using the standard risk assessment tool AS-ISK. Results show that R. okamurae has a medium-high risk of becoming invasive in Madeira Island under present and future climate scenarios. The greater risk of impact involves suppressing local species growth and the modification and degradation of local habitats, including trophic cascade effects. However, environmental and commercial impacts could also occur in case of an explosion of the invasive populations. This new introduction in Madeira coastal waters emphasises the need for regular monitoring of R. okamurae, particularly to assess population dynamics to avoid establishing and further expansions. Finally, we recommend the evaluation of the possible derived impacts affecting rocky coastal communities and adopting the necessary mitigation measures and policies.MIMAR+ MAC2/4.6.d/249Fundo Azul FA_06_2017_067Madeira 14-20 M1420-09-5369-FSE-000002Ministerio de Ciencia e Innovación CGL 2017-82739-PFundação para a Ciência e a Tecnologia UIDB/04292/2020, CEECINST/00098/201

Assessing environmental pollution levels in marinas

Despite the growing interest in recreational boating and the increasing number of marinas along the world's coastlines, environmental knowledge of these ecosystems is still very scarce. Detailed data of pollutants in marinas are necessary to provide a global approach of environmental risks in the context of international management strategies. In the present study, a set of 64 variables (30 in seawater and 34 in sediments) were measured to compare marinas from the Southern Iberian Peninsula (SIP). Uni and multivariate analyses showed significant differences among marinas, evidencing the importance of management on a local scale. The most relevant variables determining these differences were turbidity and the biocide Irgarol 1051 in seawater, and granulometry, hydrocarbons and faecal coliforms in sediment. The use of normalization techniques with Al or Fe, and the suitability of different methodologies to measure Total Organic Matter in marinas were also discussed. Additionally, we perform a comprehensive literature review of worldwide marina stressors and develop a simple and straightforward method for assessing environmental quality. The method was tested using SIP marinas and was based on the comparison of 15 selected sediment stressors with background values, concentrations of worldwide sediment quality guidelines (SQGs), and reference conditions/security thresholds established by the programme of coastal waters in port areas (ROM 5.1). A global score was assigned using a new proposed index, Marinas Environmental Pollution Index (MEPI), ranging from 0 to 150 points according to the environmental quality (120: good). MEPI of marinas from SIP ranged from 60 to 110 points indicating bad or moderate levels of pollution. Environmental quality is one of the decisive factors for awarding eco-labels or eco-certifications, such as Blue Flags in marinas. Therefore, pollution baseline information and environmental tools are mandatory for correct assignation of these awards and necessary for assessing the efficiency of management actions.We are very grateful to the staff in charge of the marinas for all support and facilities and to Dr. Pilar Burgos from IRNAS (Instituto de Recursos Naturales y Agrobiología de Sevilla) for her valuable contribution to the chemical analyses. Thanks are also due to two anonymous reviewers for their valuable and constructive comments and to Clara Gavira O'Neill for English revision of the manuscript. Financial support for this study was provided by the Ministerio de Ciencia, Innovación y Universidades (Project CGL2017-82739-P co-financed by the Agencia Estatal de Investigación -AEI- and Fondo Europeo de Desarrollo Regional -FEDER-).Departamento de Química "Profesor José Carlos Vílchez Martín