Stelios Katsanevakis

University of the Aegean · Department of Marine Sciences

Conventional sectoral management and piecemeal governance are considered less and less appropriate in pursuit of sustainable development. Ecosystem based marine spatial management (EB-MSM) is an approach that recognizes the full array of interactions within an ecosystem, including human uses, rather than considering single issues, species, or ecosy...

Aim: To develop a standardized, quantitative method for mapping cumulative impacts of invasive alien species on marine ecosystems. Location: The methodology is applied in the Mediterranean Sea but is widely applicable. Methods: A conservative additive model was developed to account for the Cumulative IMPacts of invasive ALien species (CIMPAL) on ma...

Like most ocean regions today, the European and contiguous seas experience cumulative impacts from local human activities and global pressures. They are largely in poor environmental condition with deteriorating trends. Despite several success stories, European policies for marine conservation fall short of being effective. Acknowledging the challe...

Biological invasions have become a defining feature of marine Mediterranean ecosystems with significant impacts on biodiversity, ecosystem services, and human health. We systematically reviewed the current knowledge on the impacts of marine biological invasions in the Mediterranean Sea. We screened relevant literature and applied a standardised fra...

A literature review was conducted to investigate marine global and local extinctions and their drivers; the review followed the PRISMA-EcoEvo guidelines. The data extracted was enhanced with status assessments from the IUCN Red List. We recorded local extinctions for 717 species, of which 18 were global extinctions. Most of these extinctions were r...

Background: Systematic Conservation Planning (SCP) involves a series of steps to identify conservation areas and develop management strategies, incorporating feedbacks, revisions, and iterations at any stage. It is a valuable tool in facilitating the effective implementation of Ecosystem-Based Marine Spatial Planning (EB-MSP). However, few efforts...

In the Mediterranean Sea, the genus Pinna encompasses two large fan-shaped bivalve species, Pinna nobilis and Pinna rudis. Historically, both species coexisted in the western Mediterranean until a Mass Mortality Event brought P. nobilis to the brink of extinction. Notably, P. rudis remained unaffected by the MME, and its recent successful recruitme...

Managing marine nonindigenous species (mNIS) is challenging, because marine environments are highly connected, allowing the dispersal of species across large spatial scales, including geopolitical borders. Cross-border inconsistencies in biosecurity management can promote the spread of mNIS across geopolitical borders, and incursions often go unnot...

This scoping review (ScR) protocol aims to establish the methodological approach for identifying and mapping the evidence regarding the actual contribution of Other Effective area-based Conservation Measures (OECMs) to spatial conservation targets. Emphasis will be placed on examining the research conducted, including the methodologies applied, and...

Biological invasions are a human-induced environmental disturbance that can cause major changes in ecosystem structure and functioning. Located in the northeastern Mediterranean basin, the Aegean Sea is a hotspot of biological invasions. Although the presence of alien species in the Aegean has been studied and monitored, no assessment has been cond...

Marine heatwaves (MHWs) are periods of abnormally warm ocean temperatures that severely impact marine ecosystems. Although they can propagate beneath the ocean’s surface, MHWs are typically assessed using sea surface temperatures. Here, we investigated the future evolution and depth penetration of MHWs across the Mediterranean basin. Our analysis r...

The degradation of marine ecosystems is a growing concern worldwide, emphasizing the need for efficient tools to assess their ecological status. Herein, a novel ecosystem-based ecological evaluation index of shallow rocky reefs is introduced and tested in the Aegean and Ionian Seas (NE Mediterranean). The index focuses on a specific set of pre-sele...

Mediterranean rocky reefs are undergoing regime shifts, from a structurally complex and diverse state dominated by canopy forming macroalgae to a degraded one characterised by low-lying turf or encrusting macroalgal species, due to increased anthropogenic pressure and climate change. Using data gathered from 89 sites across the entire Aegean Sea, t...

Canopy-forming macroalgae, such as Cystoseira sensu lato, increase the three-dimensional complexity and spatial heterogeneity of rocky reefs, enhancing biodiversity and productivity in coastal areas. Extensive loss of canopy algae has been recorded in recent decades throughout the Mediterranean Sea due to various anthropogenic pressures. In this st...

Area-based fisheries management measures (ABFMs) are commonly related to the sustainable use of resources but are increasingly considered broader conservation measures. This Scoping Review (ScR) identified and mapped the evidence base regarding the contribution of ABFMs to fisheries sustainability and marine conservation. The ScR was conducted foll...

Biological invasions are a human-induced environmental disturbance that can cause major changes in ecosystem structure and functioning. Located in the northeastern Mediterranean basin, the Aegean Sea is a hotspot of biological invasions. Although the presence of alien species in the Aegean has been studied and monitored, no assessment has been cond...

As climate-related impacts threaten marine biodiversity globally, it is important to adjust conservation efforts to mitigate the effects of climate change. Translating scientific knowledge into practical management, however, is often complicated due to resource, economic and policy constraints, generating a knowledge-action gap. To develop potentia...

We used Ecopath with Ecosim to describe the structure and functioning of the shelf ecosystem of the island of Cyprus (eastern Mediterranean) and simulate a series of scenarios related to fisheries and ecosystem management strategies. Analysis was based on a previous 2015–17 model of the same ecosystem, updated with recent data on recreational catch...

The Greek Seas are greatly exposed to the proliferation of marine alien species. At least 242 alien species have been reported within Greek territorial waters, three-quarters of which are considered established, while their rate of introduction is increasing. Some of these species exhibit high invasiveness, imposing severe impacts on native ecosyst...

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 12,64...

Rapid anthropogenic climate change is driving threatened biodiversity one step closer to extinction. Effects on native biodiversity are determined by an interplay between species' exposure to climate change and their specific ecological and life-history characteristics that render them even more susceptible. Impacts on biodiversity have already bee...

Marine caves are protected habitats with high biodiversity and low ecological resilience, vulnerable to multiple pressures including biological invasions. Therefore, comprehensive lists of alien species in sea caves and assessments of their impacts are urgently needed. This study aimed to provide an updated and validated list of introduced species...

Truly sustainable development in a human-altered, fragmented marine environment subject to unprecedented climate change, demands informed planning strategies in order to be successful. Beyond a simple understanding of the distribution of marine species, data describing how variations in spatio-temporal dynamics impact ecosystem functioning and the...

In the past years, efforts have been made to include connectivity metrics in conservation planning in order to promote and enhance well-connected systems of protected areas. Connectivity is particularly important for species that rely on more than one realm during their daily or life cycle (multi-realm species). However, conservation plans for the...

A coral bank of the scleractinian Cladocora caespitosa is documented for the first time in the Gulf of Kalloni, Lesvos Island, Greece. It is among the largest Cladocora reefs in the Mediterranean, and corals can be found up to 5.8 m depth. Overall, 1,492 colonies were visually sampled in situ by scuba divers to assess colony size, coral surface are...

In an effort to track the progress of the Pinna nobilis mass mortality event in Greece by 2022, the present study attempted to assess the status of fan mussel populations in the Aegean and Ionian Seas by means of underwater visual surveys.

Brachiopods, though common in marine caves, have been so far rarely reported from caves of the Eastern Mediterranean Sea. Herein we present new records of brachiopods collected in eleven marine caves located on eight Greek islands (Kastelorizo, Rhodes, Crete, Samos, Agios Efstathios, Polyaigos, Pantieronissi and Skyros). Four species (60 individual...

Herein we present new records of brachiopods collected in eleven marine caves located on eight Greek islands (Kastelorizo, Rhodes, Crete, Polyaigos, Agios Efstathios, Pantieronissi, Samos and Skyros), spanning from the Levantine to the North Aegean Sea. None of these caves had been studied before for its brachiopod diversity. Qualitative samples (6...

Species introduced through human-related activities beyond their native range, termed alien species, have various impacts worldwide. The IUCN Environmental Impact Classification for Alien Taxa (EICAT) is a global standard to assess negative impacts of alien species on native biodiversity. Alien species can also positively affect biodiversity (for i...

To effectively future-proof the management of the European Union fishing fleets we have explored a suite of case studies encompassing the northeast and tropical Atlantic, the Mediterranean, Baltic and Black Seas. This study shows that European Union (EU) fisheries are likely resilient to climate-driven short-term stresses, but may be negatively imp...

In spite of the ecological services provided by elasmobranchs, their diversity and populations are significantly declining even before appropriate assessments are conducted. This paper presents information on elasmobranch diversity in the Saudi waters of the Arabian Gulf based on fishery-independent and dependent surveys. A total of 369 individual...

Climate change is causing an increase in the frequency and intensity of marine heatwaves (MHWs) and mass mortality events (MMEs) of marine organisms are one of their main ecological impacts. Here, we show that during the 2015–2019 period, the Mediterranean Sea has experienced exceptional thermal conditions resulting in the onset of five consecutive...

Given the accelerating rate of biodiversity loss, the need to prioritize marine areas for protection represents a major conservation challenge. The three-dimensionality of marine life and ecosystems is an inherent element of complexity for setting spatial conservation plans. Yet, the confidence of any recommendation largely depends on shifting clim...

Given the accelerating rate of biodiversity loss, the need to prioritize marine areas for protection represents a major conservation challenge. The three‐dimensionality of marine life and ecosystems is an inherent element of complexity for setting spatial conservation plans. Yet, the confidence of any recommendation largely depends on shifting clim...

Ascidians are the largest and most diverse class of the subphylum Tunicata, and are important components of marine benthic communities. They are also renowned worldwide invaders, of growing concern due to ease of spread and impacts on native biota. We hereby combined bathymetric and habitat mapping, extensive transect and photo-quadrat sampling, an...

Local, regional and global targets have been set to halt marine biodiversity loss. Europe has set its own policy targets to achieve Good Environmental Status (GES) of marine ecosystems by implementing the Marine Strategy Framework Directive (MSFD) across member states. We combined an extensive dataset across five Mediterranean ecoregions including...

Truly sustainable development in a human-altered, fragmented marine environment subject to unprecedented climate change, demands informed planning strategies in order to be successful. Beyond a simple understanding of the distribution of marine species, data describing how variations in spatio-temporal dynamics impact ecosystem functioning and the...

Angel sharks are among the most threatened species of sharks globally. Twenty-two species have been identified globally so far, with three species being present in the Mediterranean Sea: Squatina aculeata, Squatina oculata, and Squatina squatina. The Mediterranean populations of all three species have been assessed as Critically Endangered by the I...

The European Union (EU) has committed to an ambitious biodiversity recovery plan in its Biodiversity Strategy for 2030 and the Green Deal. These policies aim to halt biodiversity loss and move towards sustainable development, focusing on restoring degraded habitats, extending the network of protected areas (PAs), and improving the effectiveness of...

Sea turtles are highly mobile species that use oceanic, neritic, and coastal habitats as nursery, foraging, wintering, breeding and migration areas at distant locations throughout their lifetime. Due to their highly migratory nature and large-scale habitat use, they are subjected to multiple threats across marine and coastal ecosystems that can im...

The nudibranch Baeolidia moebii Bergh, 1888 is a sea slug widely distributed in the Indo-Pacific, including the Red Sea, from where it presumably entered the Mediterranean Sea through Lessepsian migration. Although the first record of this species in the invaded area dates back to at least 2007, it is only known so far from the Mediterranean basin...

Sea turtles are highly mobile species that use oceanic, neritic, and coastal habitats as nursery, foraging, wintering, breeding and migration areas at distant locations throughout their lifetime. Due to their highly migratory nature and large-scale habitat use, they are subjected to multiple threats across marine and coastal ecosystems that can imp...

Although marine caves are considered as biodiversity reservoirs, little is known about their mobile inhabitants. Thus, in the framework of the research program ALAS, both the abundance and species richness of mobile fauna were recorded at 12 marine caves across the Aegean Sea. A total of 14 alien species were recorded with higher abundance at the s...

This Collective Article includes records of 29 alien and cryptogenic species in the Mediterranean Sea, belonging to eight Phyla (Rhodophyta, Ochrophyta, Cnidaria, Annelida, Mollusca, Arthropoda, Echinodermata, and Chordata) and coming from 11 countries. Notes published here can be divided into three different categories: occupancy estimation for wi...

Five years have passed after the first reported mass mortality event of the fan mussel Pinna nobilis, and the populations of this emblematic species have mostly collapsed across the Mediterranean basin. Scattered populations are surviving within the basin, in lagoons or enclosed bays with special environmental conditions. Greek fan mussel populatio...

Marine Ecosystem Models (MEMs) provide a deeper understanding of marine ecosystem dynamics. The United Nations Decade of Ocean Science for Sustainable Development has highlighted the need to deploy these complex mechanistic spatial-temporal models to engage policy makers and society into dialogues towards sustainably managed oceans. From our shared...

Objective: This scoping review (ScR) aims to identify and map the evidence base on the contribution of area-based fisheries management measures (ABFMs) to fisheries sustainability and marine conservation. Emphasis will be given to the research that has been conducted in terms of the methodologies applied and the key findings acknowledged. Introduc...

Global change is striking harder and faster in the Mediterranean Sea than elsewhere, where high levels of human pressure and proneness to climate change interact in modifying the structure and disrupting regulative mechanisms of marine ecosystems. Rocky reefs are particularly exposed to such environmental changes with ongoing trends of degradation...

Scenario analysis has emerged as a key tool to analyze complex and uncertain future socio-ecological developments. However, currently existing global scenarios (narratives of how the world may develop) have neglected biological invasions, a major threat to biodiversity and the economy. Here, we use a novel participatory process to develop a diverse...

Whereas sea urchins are considered as the most important grazers in Mediterranean shallow sublittoral rocky reef ecosystems, fish can also have an important role in overgrazing and the reduction of habitat complexity. In this study, the trophic behavior of fish was recorded when providing access on experimental surfaces with increased macroalgal bi...

http://www.marinespecies.org/introduced

The silver-cheeked toadfish (Lagocephalus sceleratus, from the pufferfish family Tetraodontidae) and the Pacific red lionfish (Pterois miles, family Scorpaenidae) have recently invaded the Mediterranean Sea. Lagocephalus sceleratus has spread throughout this entire sea with the highest concentrations in the eastern basin, while more recently, Ptero...