ECOLOGICAL STATUS AND TRAJECTORIES OF CHANGE IN TEMPERATE AND TROPICAL REEFS

Amongst marine temperate and tropical ecosystems, Mediterranean rocky reefs and Maldivian coral reefs are the most productive and diverse, providing essential ecosystem services. Unfortunately, due to several co-occurring local and global pressures, they are ranked as the most threatened marine habitat. The present work attempts to analyse their ecological status and change over time in a global warming scenario. With this purpose, different methodological approaches have been adopted. Many studies have been conducted in Marine Protected Areas (MPAs), highlighting that the constant updating of species inventory and surveillance is still necessary, also after their establishment. Monitoring of target species is a valuable tool in assessing ecological status of the environment they live in. Tackling the case of a species in need of protection confirmed how detailed information on species distribution is mandatory to develop effective environmental management plans. Non-destructive techniques are to be preferred when studying and monitoring target species and valuable habitats. By comparing data collected from different observers, visual methods have proven reliable and effective in the characterization of habitat and evaluation of change over time. By applying standardized protocols and monitoring water temperature, mass mortality event and target species this work unveiled effects of climate change in all study areas, regardless of different latitude and level of protection. Due to the climate change marine ecosystems are increasingly exposed to the cumulative effects of different pressures. Analysis of short-term change in a benthic community showed that the cumulative effect of multiple stressors is stronger than that of any individual stressor, no matter how intense it is. As a result of local and global human pressures, marine ecosystems have undergone important changes that can only be detected by analysing long-term data series or revisiting sites already surveyed. By assessing change over time at three different level of complexity (i.e., population, community, and ecosystems), this work addresses the issue of decreasing abundance of native species in correspondence with increasing number of invasive species. The findings confirmed that in a given reef, a turnover in species composition determine a change in community structure. Biodiversity provides a buffer to maintain ecosystem functioning in the face of environmental changes, and decrease in functional redundancy, due to the community change, demonstrated reduced ecosystem resilience. Global warming, and the consequent changes in marine ecosystems, are occurring at an unprecedented rate and on a worldwide scale. In this context, a cooperative effort between research and international environmental policy is urgently needed

Abrupt change in a Subtidal Rocky Reef community coincided with a rapid acceleration of Sea Water Warming

Seawater warming is impacting marine ecosystems, but proper evaluation of change requires the availability of long-term biological data series. Mesco Reef (Ligurian Sea, Italy) offers one of the longest Mediterranean data series on sessile epibenthic communities, based on underwater photographic surveys. Photographs taken in four stations between 20 m and 40 m depth allowed calculating the percent cover of conspicuous species in 1961, 1990, 1996, 2008, and 2017. Multivariate analysis evidenced an abrupt compositional change between 1990 and 1996. A parallel change was observed in Ligurian Sea temperatures. Two invasive macroalgae (Caulerpa cylindracea and Womersleyella setacea) became dominant after 1996. Community diversity was low in 1961 to 1996, rapidly increased between 1996 and 2008, and exhibited distinctly higher values in 2008-2017. A novel community emerged from the climate shift of the 1990s, with many once characteristic species lost, reduced complexity, biotic homogenization, greater diversity and domination by aliens. Only continued monitoring will help envisage the possibility for a reversal of the present phase shift or for further transformations driven by global change

Multiple indices on different habitats and descriptors provide consistent assessments of environmental quality in a marine protected area

In the last decades, climate change and human pressures have increasingly and dramatically impacted the ocean worldwide, calling for urgent actions to safeguard coastal marine ecosystems. The European Commission, in particular, has set ambitious targets for member states with two major directives, the Water Framework Directive (WFD) and the Marine Strategy Framework Directive (MSFD), both designed to protect the marine environment in EU waters. Diverse biotic indices have accordingly been developed to assess water and habitat quality. The WFD adopts four Biological Quality Elements (BQEs), whereas the MSFD recommends a set of eleven qualitative descriptors. The borderline between water quality and habitat quality is hard to trace and so far most assessments have involved the use of a few indices and were mainly related to a single BQE or qualitative descriptor. In this study, thanks to the availability of a large dataset encompassing a wide array of descriptors, we compared the performance of 11 biotic indices relative to three habitats/biotic components (reefs, seagrass, and fish) of the Marine Protected Area (MPA) of Capo Carbonara (SE Sardinia, Italy). The aim was to assess whether the indices were consistent in defining the environmental status in the MPA investigated. We used the graphical approach RESQUE (REsilience and QUality of Ecosystem), which enabled us to obtain a single and comprehensive measure of the status of the environment by integrating several metrics. This approach was applied here to different habitats for the first time. All indices were consistent with each other in confirming the good status of Capo Carbonara MPA. The use of RESQUE provided insights to interpret the differences between water quality, defined according to the WFD, and habitat quality, defined according to the MSFD. Differences between the two EU directives, in terms of either requirements or goals, have long been discussed but the present study highlights for the first time that they are congruent in their assessment of the environmental status of marine ecosystems

Unpublished Mediterranean and Black Sea records of marine alien, cryptogenic, and neonative species

To enrich spatio-temporal information on the distribution of alien, cryptogenic, and neonative species in the Mediterranean and the Black Sea, a collective effort by 173 marine scientists was made to provide unpublished records and make them open access to the scientific community. Through this effort, we collected and harmonized a dataset of 12,649 records. It includes 247 taxa, of which 217 are Animalia, 25 Plantae and 5 Chromista, from 23 countries surrounding the Mediterranean and the Black Sea. Chordata was the most abundant taxonomic group, followed by Arthropoda, Mollusca, and Annelida. In terms of species records, Siganus luridus, Siganus rivulatus, Saurida lessepsianus, Pterois miles, Upeneus moluccensis, Charybdis (Archias) longicollis, and Caulerpa cylindracea were the most numerous. The temporal distribution of the records ranges from 1973 to 2022, with 44% of the records in 2020–2021. Lethrinus borbonicus is reported for the first time in the Mediterranean Sea, while Pomatoschistus quagga, Caulerpa cylindracea, Grateloupia turuturu, and Misophria pallida are first records for the Black Sea; Kapraunia schneideri is recorded for the second time in the Mediterranean and for the first time in Israel; Prionospio depauperata and Pseudonereis anomala are reported for the first time from the Sea of Marmara. Many first country records are also included, namely: Amathia verticillata (Montenegro), Ampithoe valida (Italy), Antithamnion amphigeneum (Greece), Clavelina oblonga (Tunisia and Slovenia), Dendostrea cf. folium (Syria), Epinephelus fasciatus (Tunisia), Ganonema farinosum (Montenegro), Macrorhynchia philippina (Tunisia), Marenzelleria neglecta (Romania), Paratapes textilis (Tunisia), and Botrylloides diegensis (Tunisia).Stelios Katsanevakis, Michail Ragkousis, Maria Sini, Markos Digenis and Vasilis Gerovasileiou were supported by the Hellenic Foundation for Research and Innovation (HFRI) under the “First Call for HFRI Research Projects to support Faculty members and Researchers and the procurement of high-cost research equipment grant” (Project ALAS – “ALiens in the Aegean – a Sea under siege” (Katsanevakis et al. 2020b); Project Number: HFRI-FM17-1597). Konstantinos Tsirintanis was co-financed by Greece and the European Union (European Social Fund-ESF) through the Operational Programme “Human Resources Development, Education and Lifelong Learning”, 2014-2020, in the context of the Act “Enhancing Human Resources Research Potential by undertaking a Doctoral Research” Sub-action 2: IKY Scholarship Programme for PhD candidates in the Greek Universities. Maria Zotou was supported by the project “Coastal Environment Observatory and Risk Management in Island Regions AEGIS+” (MIS 5047038), implemented within the Operational Programme “Competitiveness, Entrepreneurship and Innovation” (NSRF 2014-2020), co financed by the Hellenic Government (Ministry of Development and Investments) and the European Union (European Regional Development Fund, Cohesion Fund). Razy Hoffman was supported by Yad-Hanadiv Foundation, through the Israel Society of Ecology and Environmental Sciences and Israel Nature and Parks Authority, an integrated program for establishing biological baselines and monitoring protocols for marine reserves in the Israeli Mediterranean Sea (Grant #10669). Tatiana Begun, Adrian Teaca and Mihaela Muresan were supported by the European Union’s Horizon 2020 BRIDGE-BS project under grant agreement no. 101000240. Fiona Tomas was supported by the project “Invasion of the tropical alga Halimeda incrassata in the Balearic Islands: ecology and invasion dynamics (AAEE119/2017)”, funded by the Vicepresidencia y Consejería de Innovación, Investigación y Turismo del Govern de les Illes Balears, with support from the European Union and FEDER funds, and the project “Una nueva alga invasora en el Mediterráneo: invasibilidad, detección y erradicación del alga tropical Halimeda incrassata (INVHALI)”, funded by the Fundación Biodiversidad, del Ministerio para la Transición Ecológica y el Reto Demográfico. Simonetta Fraschetti, Laura Tamburello, Antonia Chiarore were supported by the project PO FEAMP 2014-2020 - DRD n. 35/2019, “Innovazione, sviluppo e sostenibilità nel settore della pesca e dell'acquacoltura per la Regione Campania” (ISSPA 2.51) and the EU EASME - EMFF (Sustainable Blue Econ-omy) Project AFRIMED (http://afrimed-project.eu/, grant agreement N. 789059). Carlos Jimenez, Louis Hadjioannou, Vasilis Resaikos, Valentina Fossati, Magdalene Papatheodoulou, and Antonis Petrou were supported by MedPan Small Projects, Mava, and LIFE-IP. Louis Hadjioannou, Manos L. Moraitis and Neophytos Agrotis received funding from the European Union’s Horizon 2020 research and innovation program within the framework of the CMMI/MaRITeC-X project under grant agreement No. 857586. Ernesto Azzurro was supported by the project USEIt - Utilizzo di Sinergie operative per la gestione integrata specie aliene Invasive in Italia, funded by the research programme @CNR. Antonietta Rosso and Francesco Sciuto were supported by the University of Catania through “PiaCeRi-Piano Incentivi per la Ricerca di Ateneo 2020–22 linea di intervento 2.” This is the Catania Paleoecological Research Group contribution n. 484. Diego K. Kersting was supported by the Beatriu de Pinós programme funded by the Secretary of Universities and Research (Government of Catalonia) and the Horizon 2020 programme of research and innovation of the European Union under the Marie Sklodowska-Curie grant agreement No 801370. Francesco Tiralongo was supported by the AlienFish project of Ente Fauna Marina Mediterranea (Scientific Organization for Research and Conservation of Marine Biodiversity, 96012 Avola, Italy), a citizen science project for monitoring and studying rare and non-indigenous fish in Italian waters. Adriana Vella, was supported by funds through the BioCon_Innovate Research Excellence Grant from the University of Malta awarded to her. Noel Vella was supported by REACH HIGH Scholars Programme-Post Doctoral Grant for the FINS project. Some of the records provided by Victor Surugiu were obtained during surveys carried out within the framework of the project “Adequate management of invasive species in Romania, in accordance with EU Regulation 1143/2014 on the prevention and management of the introduction and spread of invasive alien species”, SMIS 2014+ 120008, coordinated by the Romanian Ministry of Environment, Water and Forests in partnership with the University of Bucharest (2018–2022). Alan Deidun and Alessio Marrone were supported by the “Spot The Alien” citizen science campaign for the monitoring of the Alien species in the Maltese archipelago and by the Interreg Italia-Malta Harmony project. The authors from the National Institute of Biology (Slovenia) acknowledge the financial support of the Slovenian Research Agency (Research Core Funding No. P1-0237) and of the Ministry of Agriculture, Forestry and Food (project “Survey of the species richness and abundance of alien species in the Slovenian Sea”). Emanuele Mancini and Fabio Collepardo Coccia were supported by the project PO-FEAMP 2014-2020 “BIOBLITZ: research, knowledge and participation for the sustainable management of marine resources (BioBlitz Blu 2020)” coordinated by CURSA for MIPAAF, the Italian Ministry of Agricultural, Food and Forestry Policies, Measure 1.40 - Protection and restoration of biodiversity and marine ecosystems and compensation schemes in the context of sustainable fishing activities. Daniele Grech was supported by the PO-FEAMP 2014-2020 project ECOGESTOCK “Approccio ECOsistemico per la tutela e la GEStione delle risorse biologiche e STOCK ittici nelle acque interne”, the citizen science project Progetto Fucales: chi le ha viste? and the Paralenz Every dive counts sponsor. Jamila Rizgalla was supported by the project Snowball for the monitoring of alien species in Libyan waters له اهتفش له اهتدطصا ؟) have you seen it have you fished it?). Gerasimos Kondylatos and Dimitrios Mavrouleas were supported by the project “EXPLIAS” (MIS (ΟΠΣ): 5049912), design and piloting methods of commercial exploitation of invasive alien species with a view to contributing to their population control, coordinated by the National Technical University of Athens with the collaboration of the Hellenic Centre for Marine Research and the University of the Aegean and co-founded by Greece and the European Union. G. Kondylatos and Savvas Nikolidakis were supported by the project “SAMOS” (ID CODE: 32.2072004/001), a study for a submarine productive park in Marathokampos of Samos. Paraskevi K. Karachle, Aikaterini Dogrammatzi, Giorgos A. Apostolopoulos, Kassiani Konida and Melina Nalmpanti were supported by the project “4ALIEN: Biology and the potential economic exploitation of four alien species in the Hellenic Seas”, funded by NRSF 2017-2020 (MIS (ΟΠΣ): 5049511). Fabio Crocetta and Riccardo Virgili were partially funded by the project PO FEAMP Campania 2014–2020, DRD n. 35 of 15th March 2018, Innovazione, sviluppo e sostenibilità nel settore della pesca e dell’acquacoltura per la regione Campania, Misura 2.51, WP5, Task 5.5 Presenza e distribuzione di specie non indigene del macrozoobenthos e del necton in Campania. Michel Bariche was partially funded by the University Research Board of the American University of Beirut (DDF 103951/2592). Constantinos G. Georgiadis, Dimitra Lida Rammou, Paschalis Papadamakis and Sotiris Orfanidis were supported by the MSFD monitoring program. Sonia Smeraldo was supported by the MPA-Engage project, led by the Institute of Marine Sciences of the Spanish National Research Council and funded by the Interreg MED program. Evgeniia Karpova acknowledge that the publication of this article was in part carried out within the framework of the state assignment of the FRC IBSS “Patterns of Formation and Anthropogenic Transformation of Biodiversity and Bioresources of the Azov– Black Sea Basin and Other Regions of the World Ocean” (No. 121030100028-0). Elena Slynko’s work was carried out within the framework of a State Assignment no. 121051100109-1 of IBIW RAS. Manuela Falautano and Luca Castriota were supported by ISPRA citizen science campaigns for the monitoring of alien species through the dedicated institutional project ([email protected]). María Altamirano was supported by the project RUGULOPTERYX funded by Fundación Biodiversidad-Ministerio para la Transición Ecológica y el reto Demográfico (Spain) and the project UMA20-FEDERJA-006 with support from the European Union and FEDER funds and Junta de Andalucía. Records provided by L. Mangialajo were collected in the framework of projects funded by the Pew Charitable Trust, by the European Commission (AFRIMED, http://afrimed-project.eu/, grant agreement N. 789059) and by the Académie 3 de l’Université Côte d’Azur (projet CONVOST).Peer reviewe

Unpublished Mediterranean and Black Sea records of marine alien, cryptogenic, and neonative species

To enrich spatio-temporal information on the distribution of alien, cryptogenic, and neonative species in the Mediterranean and the Black Sea, a collective effort by 173 marine scientists was made to provide unpublished records and make them open access to the scientific community. Through this effort, we collected and harmonized a dataset of 12,649 records. It includes 247 taxa, of which 217 are Animalia, 25 Plantae and 5 Chromista, from 23 countries surrounding the Mediterranean and the Black Sea. Chordata was the most abundant taxonomic group, followed by Arthropoda, Mollusca, and Annelida. In terms of species records, Siganus luridus, Siganus rivulatus, Saurida lessepsianus, Pterois miles, Upeneus moluccensis, Charybdis (Archias) longicollis, and Caulerpa cylindracea were the most numerous. The temporal distribution of the records ranges from 1973 to 2022, with 44% of the records in 2020–2021. Lethrinus borbonicus is reported for the first time in the Mediterranean Sea, while Pomatoschistus quagga, Caulerpa cylindracea, Grateloupia turuturu, and Misophria pallida are first records for the Black Sea; Kapraunia schneideri is recorded for the second time in the Mediterranean and for the first time in Israel; Prionospio depauperata and Pseudonereis anomala are reported for the first time from the Sea of Marmara. Many first country records are also included, namely: Amathia verticillata (Montenegro), Ampithoe valida (Italy), Antithamnion amphigeneum (Greece), Clavelina oblonga (Tunisia and Slovenia), Dendostrea cf. folium (Syria), Epinephelus fasciatus (Tunisia), Ganonema farinosum (Montenegro), Macrorhynchia philippina (Tunisia), Marenzelleria neglecta (Romania), Paratapes textilis (Tunisia), and Botrylloides diegensis (Tunisia).peer-reviewe

Seawater warming favours the northward range expansion of Lessepsian species in the Mediterranean Sea: the cephalaspidean Lamprohaminoea ovalis

Monitoring the spread of non-indigenous species is fundamental to study global warming effects on marine biodiversity. A valuable tool is represented by the continuous updating of the geographic range expansion of non-indigenous species. Lamprohaminoea ovalis is a Lessepsian mollusc initially recorded in the Mediterranean Sea in 2001. This paper reports its range expansion over the last 20 years related to water warming. The first record of Lamprohaminoea ovalis from the Ligurian Sea (NW Mediterranean) is also reported. Two individuals (about 10 mm length) were observed on a sub-vertical rocky bottom at 26 m depth displaying potential trailing behaviour. This recent finding extends the currently known distributional range of Lamprohaminoea ovalis, representing the northernmost occurrence of this non-indigenous species in the western Mediterranean Sea

Patterns of change in coral reef communities of a remote Maldivian atoll revisited after eleven years

Coral reefs are exposed worldwide to several global and local human pressures including climate change and coastal development. Assessing the effects of such pressures on coral reef communities and the changes they undergo over time is mandatory to understand their possible future trends. Nonetheless, some coral reefs receive no or little scientific attention, as in the case of Huvadhoo Atoll that is an under-studied region in the southernmost area of the Maldives (Indian Ocean). This study analyzes the changes occurring over time in eight coral reefs (four inner reefs within the atoll lagoon and four outer reefs on the ocean side) at Huvadhoo Atoll, firstly surveyed in 2009 and revisited in 2020 using the same field methods. The cover of 23 morphological benthic descriptors (including different growth forms of Acropora) was taken into account and then grouped into three categories (i.e., hard coral, other benthic taxa and abiotic descriptors) to analyze the change in the composition of the coral reef community. Significant changes (e.g., increase in hard coral cover and decrease in abiotic descriptors) were observed in the inner reefs as compared to the outer reefs, which showed less variability. A significant decrease in tabular Acropora cover was observed in both inner and outer reefs, with possible negative effects on reef complexity and functioning. By comparing two time periods and two reef types, this study provides novel information on the change over time in the community composition of Maldivian coral reefs

Troubles Never Come Alone: Outcome of Multiple Pressures on a Temperate Rocky Reef

Climate change is affecting rocky reef ecosystems in a multitude of ways at global scale. During summer 2018, the rocky reef communities of Portofino Marine Protected Area (MPA) (NW Mediterranean) were affected by thermal anomalies, a mucilaginous event, and the seasonal expansion of Caulerpa cylindracea. Moreover, a severe storm occurred on 29 October. The effects of these pressures on the rocky reef communities were analysed at different depths (10 m, 20 m, 30 m, and 40 m) and at three times (June, October, December) to evaluate change at short temporal scale. Portofino MPA’s communities have significantly changed: thermal anomalies mostly affected the biota living above the summer thermocline (ca 20 m depth); mucilaginoius aggregates first impacted the communities in shallow waters and only later those in deep waters, where they typically fall in late summer; the greatest impact by Caulerpa cylindracea was detected at 20 m depth; the storm directly impacted communities in shallow and intermediate waters by uprooting algal species, while it had indirect effects at greater depths through sediment redistribution. Disentangling the effects of multiple pressures on coastal ecosystems is one of the most pressing goals in marine ecology and biodiversity conservation. This study represents an attempt in this direction as applied to the short-term dynamics of rocky reef communities under a climate change scenario

Biodiversity Monitoring in Mediterranean Marine Protected Areas: Scientific and Methodological Challenges

Biodiversity is a portmanteau word to indicate the variety of life at all levels from genes to ecosystems, but it is often simplistically equated to species richness; the word ecodiversity has thus been coined to address habitat variety. Biodiversity represents the core of the natural capital, and as such needs to be quantified and followed over time. Marine Protected Areas (MPAs) are a major tool for biodiversity conservation at sea. Monitoring of both species and habitat diversity in MPAs is therefore mandatory and must include both inventory and periodic surveillance activities. In the case of inventories, the ideal would be to census all species and all habitats, but while the latter goal can be within reach, the former seems unattainable. Species inventory should be commeasured to investigation effort, while habitat inventory should be based on mapping. Both inventories may profit from suitability spatial modelling. Periodic surveillance actions should privilege conspicuous species and priority habitats. Efficient descriptor taxa and ecological indices are recommended to evaluate environmental status. While it seems obvious that surveillance activities should be carried out with regular recurrence, diachronic inventories and mapping are rarely carried out. Time series are of prime importance to detect marine ecosystem change even in the absence of direct human impacts

A Tale of Two Sisters: The Southerner <i>Pinna rudis</i> Is Getting North after the Regional Extinction of the Congeneric <i>P. nobilis</i> (Mollusca: Bivalvia)

In the Mediterranean Sea, the bivalve genus Pinna is represented by two species: the endemic Pinna nobilis and the (sub)tropical Atlantic Pinna rudis. P. rudis is generally less common and mostly restricted to the warmer regions of the western Mediterranean. However, since a mass mortality event, caused by a pathogen infection, has brought P. nobilis to the brink of extinction, records of P. rudis have increased in several Mediterranean regions, where it had not been previously observed. This paper reports on the presence of several P. rudis individuals in the Ligurian Sea, the northernmost reach of this species in the western Mediterranean. P. rudis has become increasingly common between 2021 and 2023, with a total of 28 new records from seven localities along the Ligurian coast. The size of the individuals and their estimated growth rate (3.6 cm·a−1) indicated that a recruitment event most likely took place in summer 2020, when P. nobilis was no longer present in the area. Our observations suggest that the recruitment success of P. rudis increased following the decline of P. nobilis. However, considering the thermophilic nature of P. rudis, in all likelihood, the ongoing water warming is playing a crucial role in the successful establishment of this species in the Ligurian Sea. A full understanding of the recent range expansion of P. rudis in the Mediterranean is far from being achieved, and whether P. rudis will be able to fulfil the ecological role of P. nobilis is difficult to predict. Large scale monitoring remains the only effective way to know about the future of Pinnids in the Mediterranean Sea