Search Results (11)

Seagrass meadows, including those formed by Zostera noltei, play a crucial role in marine ecosystem health by providing habitat stability and coastal protection. In the Romanian Black Sea, Z. noltei meadows are critically endangered due to pressures from eutrophication, habitat loss, and climate change. This study presents a comprehensive baseline assessment of Z. noltei meadows near Mangalia, Romania, utilizing in situ field methods and UAV mapping conducted in the spring and summer of 2023. Seven meadow sites (Z1–Z7) were identified, with notable variability in density, shoot counts, and coverage across sites. Site Z1 exhibited the highest density (1223 shoots/m⁻²) and Z5 and Z7 the longest leaves (an average of 60 cm), reflecting possible environmental influences. Statistical analyses revealed significant inter-site differences in shoot density and leaf length, with density emerging as a primary differentiator. Ex situ analyses of epiphyte load indicated a median, balanced epiphyte load. This baseline dataset supported the selection of Z1 as a reference donor site for seagrass relocation activities along the Romanian coast in 2023. By providing critical insights into Z. noltei structure and health, this study supports future conservation efforts and evidence-based management of these vulnerable coastal habitats. Full article

Endemic Mediterranean seagrass Posidonia oceanica is highly endangered today as it lives in a narrow infralittoral zone intensely exposed to human impact. P. oceanica beds are especially endangered in the Adriatic Sea as the central and northern Adriatic could be considered as a naturally suboptimal area for P. oceanica growth. In this research, we used some standard descriptors of Posidonia meadows at different locations and depths and determined the biochemical parameters (phenolic compounds, photosynthetic pigments, and enzyme activities) in its leaves in order to find possible correlations among the measured parameters and environmental conditions. Photosynthetic pigments were shown to be sensitive biomarkers in the assessment of P. oceanica response to different light conditions, but more research is needed to elucidate the impact of other environmental factors. Overall, the results of this research show that the studied parameters are good bioindicators of a meadow’s environmental state, but it is necessary to analyze a number of diverse indicators together to properly characterize the state of a particular P. oceanica meadow. This approach would be very useful in the determination of P. oceanica conservation status, which is the first step towards improving monitoring protocols and implementing appropriate conservation measures. Full article

The climate crisis poses a grave threat to numerous small island developing states (SIDS), intensifying risks from extreme weather events and sea level rise (SLR). This vulnerability heightens the dangers of coastal erosion, chronic water quality degradation, and dwindling coastal resources, demanding global attention. The resultant loss of ecological persistence, functional services, and ecosystem resilience jeopardizes protection against wave action and SLR, endangering coastal habitats’ economic value, food security, infrastructure, and livelihoods. Implementing integrated strategies is imperative. A thorough discussion of available strategies and best management practices for coastal ecosystem restoration is presented in the context of SIDS needs, threats, and major constraints. Solutions must encompass enhanced green infrastructure restoration (coral reefs, seagrass meadows, mangroves/wetlands, urban shorelines), sustainable development practices, circular economy principles, and the adoption of ecological restoration policies. This requires securing creative and sustainable funding, promoting green job creation, and fostering local stakeholder engagement. Tailored to each island’s reality, solutions must overcome numerous socio-economic, logistical, and political obstacles. Despite challenges, timely opportunities exist for coastal habitat restoration and climate change adaptation policies. Integrated strategies spanning disciplines and stakeholders necessitate significant political will. Full article

Sea turtles are keystone species in marine environments due to their essential role as seagrass grazers and population regulation of jellyfish and sponges in coral reefs. However, due to their predominant presence in coastal areas, sea turtle populations face significant threats due to the impact of human activities. In this systematic review, 655 peer-reviewed publications were analyzed to assess the extent of population monitoring for all seven sea turtle species. The analyses revealed that, although population monitoring studies have increased for sea turtles in the past four decades, these have been biased towards certain species and oceanic regions. Furthermore, sea turtle population monitoring has been undertaken primarily using field-based methods, with satellite tracking and nest surveys being the most commonly used methods; however, the implementation of genetic methods for population monitoring has increased since the 2000s. Direct conservation recommendations from this study include the urgent need to establish population monitoring studies in the Critically Endangered Kemp’s ridley and hawksbill and the Data Deficient flatback. Furthermore, population monitoring programs should be implemented in Southeast Asia and Northern and Central Africa, where knowledge on sea turtle populations is still limited. Finally, due to the long-distance movements of sea turtles, we also advocate for international cooperation and collaboration of local communities to protect these ecologically important and iconic marine species. Full article

This study evaluates gleaning exclusion as an approach for the rehabilitation of seagrass ecosystems and as an option for important intertidal resource management that contributes to the social well-being of communities. The monitoring of seagrass plant and invertebrate recovery after the implementation of gleaning exclusion was conducted over 50 plots of 5 m × 5 m each, which were settled in the seagrass meadow of NW Maputo Bay, Mozambique. The exclusion experiment was designed to compensate for the important loss of seagrass in the area due to gleaning activity characterized mainly by digging and revolving sediments to collect mostly clams. Results showed that, in general, seagrass plant shoot density started having significant positive recovery after five months: three months for Halophila ovalis, five months for Halodule uninvervis, and much more time (>six months) for the IUCN Red List endangered Zostera capensis. For invertebrates, 194 individual invertebrates were collected belonging to 13 species. Solen cylindraceus was the most dominant edible invertebrate species in the local community, and Dosinia hepatica for non-edible species. The result of the experiment showed a positive recovery in the abundance and diversity of invertebrates. The results support previous findings, suggesting that the installation of a no-take zone can enhance the health of an ecosystem. Therefore, to limit the violation and conflicts of the no-take zones, the creation of alternative activities for harvesters and the flexibility of restrictions are vital. Further investigation should be considered to obtain an effective management of the zones, including documentation of species, gleaning practices, and an effective restoration of seagrass meadows. Full article

Habitat complexity plays a critical role in shaping biotic assemblages and ecosystem processes. While the impacts of large differences in habitat complexity are often well understood, we know less about how subtle differences in structure affect key ecosystem functions or properties such as biodiversity and biomass. The late-successional seagrass Posidonia australis creates vital habitat for diverse fauna in temperate Australia. Long-term human impacts have led to the decline of P. australis in some estuaries of eastern Australia, where it is now classified as an endangered ecological community. We examined the influence of P. australis structural complexity at small (seagrass density) and large (meadow fragmentation) spatial scales on fish and epifauna communities, predation and sediment erosion. Fine-scale spatially balanced sampling was evenly distributed across a suite of environmental covariates within six estuaries in eastern Australia using the Generalised Random Tessellation Structures approach. We found reduced erosion in areas with higher P. australis density, greater abundance of fish in more fragmented areas and higher fish richness in vegetated areas further from patch edges. The abundance of epifauna and fish, and fish species richness were higher in areas with lower seagrass density (seagrass density did not correlate with distance to patch edge). These findings can inform seagrass restoration efforts by identifying meadow characteristics that influence ecological functions and processes. Full article

The fitness of the endangered green sea turtle (Chelonia mydas) may be strongly affected by its gut microbiome, as microbes play important roles in host nutrition and health. This study aimed at establishing environmental microbial baselines that can be used to assess turtle health under altered future conditions. We characterized the microbiome associated with the gastrointestinal tract of green turtles from Guinea Bissau in different life stages and associated with their food items, using 16S rRNA metabarcoding. We found that the most abundant (% relative abundance) bacterial phyla across the gastrointestinal sections were Proteobacteria (68.1 ± 13.9% “amplicon sequence variants”, ASVs), Bacteroidetes (15.1 ± 10.1%) and Firmicutes (14.7 ± 21.7%). Additionally, we found the presence of two red algae bacterial indicator ASVs (the Alphaproteobacteria Brucella pinnipedialis with 75 ± 0% and a Gammaproteobacteria identified as methanotrophic endosymbiont of Bathymodiolus, with <1%) in cloacal compartments, along with six bacterial ASVs shared only between cloacal and local environmental red algae samples. We corroborate previous results demonstrating that green turtles fed on red algae (but, to a lower extent, also seagrass and brown algae), thus, acquiring microbial components that potentially aid them digest these food items. This study is a foundation for better understanding the microbial composition of sea turtle digestive tracts. Full article

Santa Catalina Island, located off the southern California coast, is home to the Blue Cavern Onshore State Marine Conservation Area (SMCA), which is recognized as a marine protected area. Here, we provide an updated species inventory of nearshore macroalgae, seagrasses, bony and cartilaginous fishes and invertebrates documented inside the Blue Cavern Onshore SMCA. Species richness data were compiled using scuba-based visual surveys conducted in the field, references from the primary and gray literature, museum records, unpublished species lists and online resources. The current checklist consists of 1091 marine species from 18 different taxonomic groups, which represents an ~43% increase in species diversity compared to the value reported previously. These data are indicative of the high biodiversity known from the Southern California Bight (SCB) region. The total number of intertidal and subtidal taxa reported represent approximately 85% and 45% of the documented macroalgae and plants, 41% and 24% invertebrates, and 62% and 20% of fishes from Catalina Island and the SCB, respectively. Among the marine taxa documented, 39 species either have undergone a geographic range shift or were introduced as the result of human activities, while another 4 species are listed as threatened, endangered or critically endangered. Research findings presented here offer an important baseline of species richness in the California Channel Islands and will help improve the efforts by resource managers and policy makers to conserve and manage similar habitats in the coastal waters off southern California. Full article

The anthropogenic pressures of the twentieth century have seriously endangered the Mediterranean coastal zone; as a consequence, marine seagrass habitats have strongly retreated, mostly those of Posidonia oceanica. For this reason, over time, restoration programs have been put in place through transplantation activities, with different success. These actions have also been conducted with other Mediterranean marine seagrasses. The results of numerous transplanting operations conducted in the Northern Adriatic Sea and lagoons with Cymodocea nodosa, Zostera marina and Z. noltei and in the Central and Southern Adriatic Sea with P. oceanica (only within the project Interreg SASPAS), are herein presented and compared, taking also into account the presence of extensive meadows of C. nodosa, Z. marina and Z. noltei, along the North Adriatic coasts and lagoons. Full article

In the Mexican Caribbean, 15 marine protected areas (MPAs) have been established for managing and protecting marine ecosystems. These MPAs receive high anthropogenic pressure from coastal development, tourism, and fishing, all in synergy with climate change. To contribute to the MPAs’ effectiveness, it is necessary to provide a long-term observation system of the condition of marine ecosystems and species. Our study proposes the establishment of a new marine biodiversity monitoring program (MBMP) focusing on three MPAs of the Mexican Caribbean. Five conservation objects (COs) were defined (coral reefs, seagrass beds, mangroves, marine turtles, and sharks-rays) for their ecological relevance and the pressures they are facing. Coral reef, seagrass and mangroves have multiple biological, biogeochemical and physical interactions. Marine turtles are listed as endangered species, and the status of their populations is unknown in the marine area of the MPAs. Elasmobranchs play a key role as top and medium predators, and their populations have been poorly studied. Indicators were proposed for monitoring each CO. As a technological innovation, all information obtained from the MBMP will be uploaded to the Coastal Marine Information and Analysis System (SIMAR), a public, user-friendly and interactive web platform that allows for automatic data management and processing. Full article

Climate related changes can have significant effects on Posidonia oceanica, an endemic seagrass species of the Mediterranean Sea (MEDIT). This seagrass is very important for many aspects of functioning of the sea but there is an increasing number of reports about the ongoing loss of its biomass and area coverage. We analysed multiyear data of the sea surface temperature (SST), sea level anomalies, ocean colour MODIS-A and ERA-Interim reanalysis. The results provide a description of current environmental conditions in the MEDIT and their spatial and temporal variability, including long-term trends. We defined regions where the extent of the P. oceanica meadows may be limited by specific environmental conditions. Light limitation is more severe near the northern and western coasts of the MEDIT, where the vertical diffuse attenuation coefficient is large. In the zone extending from the Gulf of Lion towards the south, significant wave heights reach large values. Wave action may destroy the plants and as a result the shallow water depth limit of P. oceanica meadows is most likely deeper here than in other regions. The highest SST values are documented in the south-eastern part of the Mediterranean Sea. In this area P. oceanica meadows are more endangered by the climate warming than in other regions where SSTs are lower. The absence of P. oceanica meadows in the south-eastern edge of the Mediterranean Sea can be attributed to high temperatures. Our conclusions are partly confirmed by the information about P. oceanica from the literature but more monitoring efforts are needed to fully describe current extent of the meadows and their shifts. Results presented in this paper can help with designing special programs to confirm the role of environmental conditions on the spatial distribution of P. oceanica and their future trends in the Mediterranean Sea. Full article