Gigantic breeding colonies of a marine fish in the Mediterranean.

While breeding colonies are well known in seabirds, they remain exceptional for marine fishes. Here, we report on fifteen massive breeding colonies of picarels (Spicara smaris), a small benthic zooplanktivorous fish, observed by chance during video transects in spring 2021 along the East coast of Corsica (French Mediterranean). In total, these colonies cover more than 134.6 hectares (ha) within a surveyed area of 712.1 ha, a single colony covering from 2.2 to 28 ha between 37 and 50 meters deep. The seabed, including the lower limit of Posidonia oceanica seagrass meadows, soft bottoms, and the predominant rhodolith beds, has been completely rebuilt in circular jointed nests measuring 55 cm in diameter on average. With a density of 2.6 nests per m2, the estimated number of nests in the colony exceeds 18 million. Each nest is guarded by a male. Females swim in groups above the nests and sometimes lay eggs. A rich macrofauna including threatened species can be observed around the nests, eating eggs or adults. This finding highlights the exceptional ecological role of this small fish as an ecosystem engineer creating oases of marine life. This warrants further studies and better protection of the area, at least during the breeding season.

Analysis of Posidonia oceanica's Stress Factors in the Marine Environment of Tremiti Islands, Italy.

Posidonia oceanica significantly contributes to the health of oceans and coastal areas; however, its progressive decline is becoming an increasing source of concern. The present preliminary study aims to assess the chemical parameters that describe the state of preservation of the aforementioned plant meadows located in the Tremiti Islands archipelago. To better understand the plants' response to external factors, the emission of biogenic volatile organic compounds (BVOCs) was investigated using Posidonia oceanica as a biological indicator. Subsequently, the heavy metal concentrations (Ag, Al, As, Ba, Be, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Sb, Se, Sn, Ti, Tl, V, Zn) in sediments, leaves, and seawater were determined and pollution indicators were calculated to assess the deviation from the natural background levels of sediments. The dimethyl sulfoniopropionate (DMSP) to dimethyl sulfoxide (DMSO) ratio was calculated to evaluate the oxidative stress levels in the meadows because the DMSP naturally present in Posidonia oceanica is oxidized to DMSO and decreases the ratio of DMSP/DMSO. BVOC analysis revealed dimethyl sulphide (DMS) as the most abundant molecule. Morphological features led to variations in metal concentrations across sampling sites, with sheltered bays displaying a higher metal content. Degradation is indicated by a greater DMSO content in the outer leaves. In accordance with the metal content, the bioindicator ratio confirms greater degradation on the south side, which aligns with increased oxidative stress.

AI-based seagrass morphology measurement.

Seagrass meadows are an essential part of the Great Barrier Reef ecosystem, providing various benefits such as filtering nutrients and sediment, serving as a nursery for fish and shellfish, and capturing atmospheric carbon as blue carbon. Understanding the phenotypic plasticity of seagrasses and their ability to acclimate their morphology in response to environ-mental stressors is crucial. Investigating these morphological changes can provide valuable insights into ecosystem health and inform conservation strategies aimed at mitigating seagrass decline. Measuring seagrass growth by measuring morphological parameters such as the length and width of leaves, rhizomes, and roots is essential. The manual process of measuring morphological parameters of seagrass can be time-consuming, inaccurate and costly, so researchers are exploring machine-learning techniques to automate the process. To automate this process, researchers have developed a machine learning model that utilizes image processing and artificial intelligence to measure morphological parameters from digital imagery. The study uses a deep learning model called YOLO-v6 to classify three distinct seagrass object types and determine their dimensions. The results suggest that the proposed model is highly effective, with an average recall of 97.5%, an average precision of 83.7%, and an average f1 score of 90.1%. The model code has been made publicly available on GitHub (https://github.com/sajalhalder/AI-ASMM).

Soundscape analysis can be an effective tool in assessing seagrass restoration early success.

Restoration of vulnerable marine habitats is becoming increasingly popular to cope with widespread habitat loss and the resulting decline in biodiversity and ecosystem services. Lately, restoration strategies have been employed to enhance the recovery of degraded meadows of the Mediterranean endemic seagrass Posidonia oceanica. Typically, habitat restoration success is evaluated by the persistence of foundation species after transplantation (e.g., plant survival and growth) on the short and long-term, although successful plant responses do not necessarily reflect the recovery of ecosystem biodiversity and functions. Recently, soundscape (the spatial, temporal and frequency attribute of ambient sound and types of sound sources characterizing it) has been related to different habitat conditions and community structures. Thus, a successful restoration action should lead to acoustic restoration and soundscape ecology could represent an important component of restoration monitoring, leading to assess successful habitat and community restoration. Here, we evaluated acoustic community and metrics in a P. oceanica restored meadow and tested whether the plant transplant effectiveness after one year was accompanied by a restored soundscape. With this goal, acoustic recordings from degraded, transplanted and reference meadows were collected in Sardinia (Italy) using passive acoustic monitoring devices. Soundscape at each meadow type was examined using both spectral analysis and classification of fish calls based on a catalogue of fish sounds from the Mediterranean Sea. Seven different fish sounds were recorded: most of them were present in the reference and transplanted meadows and were associated to Sciaena umbra and Scorpaena spp. Sound Pressure Level (SPL, in dB re: 1 µPa-rms) and Acoustic Complexity Index (ACI) were influenced by the meadow type. Particularly higher values were associated to the transplanted meadow. SPL and ACI calculated in the 200-2000 Hz frequency band were also related to high abundance of fish sounds (chorus). These results showed that meadow restoration may lead to the recovery of soundscape and the associated community, suggesting that short term acoustic monitoring can provide complementary information to evaluate seagrass restoration success.

Salinity stress on three representative species from Mediterranean semifixed dunes: Assessment of salinity exposure and substrate conductivity data reveal variable response strategies and tolerance between species.

Coastal ecotones can disrupt natural conditions, yielding intricate ecological contexts where salinity plays a variable role. The aim of this study was to assess the salinity effect on three species representatives of semifixed dune (Crucianella maritima, Helianthemum caput-felis and Teucrium dunense). Field data were collected to assess plant cover in semifixed dunes, ecotone with other coastal habitats, and artificial Posidonia oceanica wracks. Soil samples were collected, and conductivity measured. Then, experimental exposure to salinity was conducted with 6 seawater (SW) treatments (Control, 6.25 % SW, 12.5 % SW, 25 % SW, 50 % SW, 100 % SW). Flowering, gas exchange, chlorophyll fluorescence and enzymatic antioxidant measurements were conducted after two months of exposure. In the field trial, species presence varied depending on the habitat and was null on P. oceanica. The relation between conductivity and species abundance showed moderate tolerance for the three species. For C. maritima this relation was variable depending on the habitat. Experimental data suggest moderate tolerance with stress occurring at 25 % SW onwards. Gas exchange response to salinity was similar among species, but more drastic reduction in assimilation rate and larger decrease in water use efficiency was observed for C. maritima. Instead, photoinhibition occurred in H. caput-felis and T. dunense but was absent in C. maritima likely related to the fact that H. caput-felis and T. dunense activated catalase and superoxide dismutase enzymes, while C. maritima showed activation of glutathione-related enzymes. Malondialdehyde (MDA) increased in C. maritma and decreased for the other species indicating a more complex involvement of MDA under stress conditions. Flowering response to salinity was overall more resilient in T. dunense. Our results, based on field conductivity data and measurements of physiological, antioxidant, and reproductive traits, delineate specific tolerance differences and strategies towards salinity for Mediterranean semifixed dune species.

Toxicity of inorganic nanoparticles and commercial sunscreens on marine bacteria.

The Balearic Islands, a top tourist destination for sunny beaches, face physical and chemical pressures from human activities, impacting keystone species like the endemic seagrass Posidonia oceanica and its associated microbiome. This study evaluated the effects of ZnO and TiO2 nanoparticles and three commercial sunscreens with varying protection factors (50 or 90) and chemical complexities (1- SPF50_E "eco-friendly"; 2- SPF50 not "eco-friendly"; 3- SPF90 not "eco-friendly") on five heterotrophic bacteria (Pseudomonas azotifigens, Marinobacterium litorale, Thiothrix nivea, Sedimenticola thiotaurini and Cobetia sp) and two autotrophic cyanobacteria (Halothece sp. and Fischerella muscicola) associated to P. oceanica, as well as a natural leaf epiphytic community. Results indicated that TiO2 affected all heterotrophic bacteria, while ZnO was toxic to only two species, while autotrophs were unaffected. Commercial sunscreens impacted three heterotrophs and the natural epiphytic community, while autotrophs were only affected by SPF50. SPF50_E reduced phosphorus uptake, and both SPF50 and SPF90 decreased alkaline phosphatase activity. Reactive oxygen species production was mainly induced by SPF90, followed by SPF50_E and SPF50. Generally, the smallest bacteria were most sensitive to UV-filters (UVFs). This study indicates that UVFs exposure may alter the epiphytic community structure of P. oceanica.

Impact assessment of multiple pressures on ecosystem services with a state and transition model: Application to Posidonia oceanica seagrass meadows.

A significant challenge in the integration of ecosystem services into decision-making processes lies in effectively capturing the dynamics of marine socio-ecological systems, including their evolutionary pathways, equilibrium states, and tipping points. This paper explores the evolutionary trajectories of a vital marine ecosystem endemic to the Mediterranean Sea: the Posidonia oceanica seagrass meadows, in response to various drivers of change. A state-and-transition model is employed to assess the ecosystem services provided by P. oceanica across different states defined by selected transitions, such as overfishing, fragmentation, pollution, and invasion by non-native species. To apply this model, scientific expertise is combined with field data generated using the Ecosystem-Based Quality Index to evaluate the conservation status of P. oceanica. This integrated approach allows for the representation of the ecosystem services offered by the meadows across different states, leveraging ecological data. The findings highlight the disproportionate impact on provisioning services, particularly sea urchins and commercial fish production, which suffer the most under various stressors. Notably, when these services decline to critical levels, the meadows cease to provide significant benefits. Finally, a synthesized representation is presented, merging ecological insights with monitoring data, offering a framework that is more accessible to stakeholders and decision-makers.

Mapping fine-scale seagrass disturbance using bi-temporal UAV-acquired images and multivariate alteration detection.

Seagrasses provide critical ecosystem services but cumulative human pressure on coastal environments has seen a global decline in their health and extent. Key processes of anthropogenic disturbance can operate at local spatio-temporal scales that are not captured by conventional satellite imaging. Seagrass management strategies to prevent longer-term loss and ensure successful restoration require effective methods for monitoring these fine-scale changes. Current seagrass monitoring methods involve resource-intensive fieldwork or recurrent image classification. This study presents an alternative method using iteratively reweighted multivariate alteration detection (IR-MAD), an unsupervised change detection technique originally developed for satellite images. We investigate the application of IR-MAD to image data acquired using an unoccupied aerial vehicle (UAV). UAV images were captured at a 14-week interval over two seagrass beds in Brisbane Water, NSW, Australia using a 10-band Micasense RedEdge-MX Dual camera system. To guide sensor selection, a further three band subsets representing simpler sensor configurations (6, 5 and 3 bands) were also analysed using eight categories of seagrass change. The ability of the IR-MAD method, and for the four different sensor configurations, to distinguish the categories of change were compared using the Jeffreys-Matusita (JM) distance measure of spectral separability. IR-MAD based on the full 10-band sensor images produced the highest separability values indicating that human disturbances (propeller scars and other seagrass damage) were distinguishable from all other change categories. IR-MAD results for the 6-band and 5-band sensors also distinguished key seagrass change features. The IR-MAD results for the simplest 3-band sensor (an RGB camera) detected change features, but change categories were not strongly separable from each other. Analysis of IR-MAD weights indicated that additional visible bands, including a coastal blue band and a second red band, improve change detection. IR-MAD is an effective method for seagrass monitoring, and this study demonstrates the potential for multispectral sensors with additional visible bands to improve seagrass change detection.

Spatial variability in blue carbon storage and sequestration of seagrass meadows in southern China.

Although seagrass meadows are intense carbon sinks, information on the regional variability in seagrass blue carbon stocks and carbon sequestration remains limited. We estimated the organic carbon (Corg) stocks and carbon accumulation rates (CAR) of seven seagrass meadows along the subtropical coast of China's Zhanjiang City and analyzed the driving factors of variability in sediment Corg stocks in three seagrass meadows. Results showed that most Corg (99.83 %) was stored in the sediments, and the contribution of living biomass was minor. The average Corg stocks of living biomass and sediments across all sites were 0.04 ± 0.01 and 42.03 ± 25.07 Mg C ha-1, respectively, which were significantly lower than the world average (2.52 ± 0.48 and 194.2 Mg C ha-1). The sediment Corg stocks of the upper 1 m ranged from 24.26 to 157.12 Mg C ha-1 with substantial variability among sites: Liusha Bay (64.93 ± 22.31 Mg C ha-1) > Donghai Island (33.8 ± 10.65 Mg C ha-1) > Dongshen Ferry (27.35 ± 4.15 Mg C ha-1). The average sediment CAR was 53.47 g C m-2 yr-1, and the total CAR of 864.18 ha seagrass meadows was 260.76 ± 4.86 Mg C yr-1 in these studied sites. Physicochemical factors, such as high moisture content, salinity, CaCO3 content, and low dry bulk density, jointly inhibited the mineralization rate of Corg in sediments. Our study provides data from understudied regions to a growing dataset on seagrass carbon stocks and sequestration rates and highlights the significance of local and regional differences in seagrass blue carbon storage to accurately assess the climate change mitigation potential of seagrass ecosystems.

Diverse RNA viruses discovered in multiple seagrass species.

Seagrasses are marine angiosperms that form highly productive and diverse ecosystems. These ecosystems, however, are declining worldwide. Plant-associated microbes affect critical functions like nutrient uptake and pathogen resistance, which has led to an interest in the seagrass microbiome. However, despite their significant role in plant ecology, viruses have only recently garnered attention in seagrass species. In this study, we produced original data and mined publicly available transcriptomes to advance our understanding of RNA viral diversity in Zostera marina, Zostera muelleri, Zostera japonica, and Cymodocea nodosa. In Z. marina, we present evidence for additional Zostera marina amalgavirus 1 and 2 genotypes, and a complete genome for an alphaendornavirus previously evidenced by an RNA-dependent RNA polymerase gene fragment. In Z. muelleri, we present evidence for a second complete alphaendornavirus and near complete furovirus. Both are novel, and, to the best of our knowledge, this marks the first report of a furovirus infection naturally occurring outside of cereal grasses. In Z. japonica, we discovered genome fragments that belong to a novel strain of cucumber mosaic virus, a prolific pathogen that depends largely on aphid vectoring for host-to-host transmission. Lastly, in C. nodosa, we discovered two contigs that belong to a novel virus in the family Betaflexiviridae. These findings expand our knowledge of viral diversity in seagrasses and provide insight into seagrass viral ecology.

Posidonia oceanica (L.) Delile Is a Promising Marine Source Able to Alleviate Imiquimod-Induced Psoriatic Skin Inflammation.

Psoriasis is a chronic immune-mediated inflammatory cutaneous disease characterized by elevated levels of inflammatory cytokines and adipokine Lipocalin-2 (LCN-2). Recently, natural plant-based products have been studied as new antipsoriatic compounds. We investigate the ability of a leaf extract of the marine plant Posidonia oceanica (POE) to inhibit psoriatic dermatitis in C57BL/6 mice treated with Imiquimod (IMQ). One group of mice was topically treated with IMQ (IMQ mice) for 5 days, and a second group received POE orally before each topical IMQ treatment (IMQ-POE mice). Psoriasis Area Severity Index (PASI) score, thickness, and temperature of the skin area treated with IMQ were measured in both groups. Upon sacrifice, the organs were weighed, and skin biopsies and blood samples were collected. Plasma and lesional skin protein expression of IL-17, IL-23, IFN-γ, IL-2, and TNF-α and plasma LCN-2 concentration were evaluated by ELISA. PASI score, thickness, and temperature of lesional skin were reduced in IMQ-POE mice, as were histological features of psoriatic dermatitis and expression of inflammatory cytokines and LCN-2 levels. This preliminary study aims to propose P. oceanica as a promising naturopathic anti-inflammatory treatment that could be introduced in Complementary Medicine for psoriasis.

Seagrass as a potential nutraceutical to decrease pro-inflammatory markers.

BACKGROUND: The Pro-inflammatory mediators such as prostaglandin E2, nitric oxide and TNF-α are the key players in the stimulation of the inflammatory responses. Thus, the pro-inflammatory mediators are considered to be potential targets for screening nutraceutical with anti-inflammatory activity. METHODS: In this context, we explored the anti-inflammatory potency of seagrass extract with western blot (Bio-Rad) analysis by using LPS induced RAW macrophages as in-vitro models, western blot analysis, In-silico methods using Mastero 13.0 software. RESULTS: The anti-inflammatory activity of Seagrass was demonstrated through down regulation of Pro-inflammatory markers such as Cyclooxygenase-2, induced Nitric oxide synthase and prostaglandin E synthase-1. The results were validated by docking the phytochemical constituents of seagrass namely Isocoumarin, Hexadecanoic acid, and Cis-9 Octadecenoic acid, 1,2 Benzene dicarboxylic acid and beta-sitosterol with TNF-alpha, COX-2, iNOS and PGES-1. CONCLUSION: The methanolic extract of seagrass Halophila beccarii is a potential nutraceutical agent for combating against inflammation with a significant anti-inflammatory activity.

Biochar production from various low-cost marine wastes using different production methods: Characterization of biochar and marine feedstock for agricultural purposes.

Studies on the conversion of organic materials into biochar have been preferred due to the effectiveness of biochar. Aquatic ecosystems harbor a significant amount of organic biomass, much of which is transferred to terrestrial systems, but often remains as waste. In this study, Posidonia oceanica (PO), Halidrys siliquosa (HS), Ulva lactuca (UL), and Codium fragile (CF), commonly found as marine waste along coastlines globally, were used as feedstocks for biochar production under four different pyrolysis conditions. Several analyses were conducted to characterize both marine waste and biochar forms in order to evaluate their potential for agricultural applications. The results showed that marine wastes and biochars contain almost all the necessary nutrients required for plant nutrition in varying proportions. The CF feedstock has a higher nitrogen (N) content than other feedstocks, while the UL contains greater phosphorus (P), potassium (K), and magnesium (Mg). Additionally, the PO exhibits high calcium (Ca), boron (B), and manganese (Mn) contents. Carbon (C) content also varied significantly depending on the biochar production technique. Temperature had a greater influence than holding time on the disparities in the elemental composition of biochars. The pH values of all types of biochar increased with rising temperature. However, the electrical conductivity (EC) values of HS and PO biochars decreased with increasing temperature. The highest mean BET surface area was observed in PO biochars. However, UL biochar has the most significant proportional increase compared to the UL feedstock by 218 times. All characteristics determined for all materials (feedstock, biochar) were within acceptable limits for application to soil. In conclusion, both marine waste and biochar forms may be confidently used for agricultural purposes, particularly in soil applications, when considering the characterization parameters within the scope of this research. Additionally, supporting and developing these results with more comprehensive analysis and research would be more suitable to reveal the potential of these marine wastes for agricultural systems.

Distribution and accumulation of UV filters (UVFs) and conservation status of Posidonia oceanica seagrass meadows in a prominent Mediterranean coastal tourist hub.

This study investigates the presence and impact of UV filters in Posidonia oceanica meadows in Formentera, a Mediterranean tourist hotspot. It highlights the distribution of inorganic (TiO2 and ZnO) and organic UV filters (UVFs) in different environmental matrices, their accumulation in seagrass tissues and their impact on the seagrass health. In the overlying and canopy waters of P. oceanica, Zn concentrations surpassed Ti, with three organic UVFs (benzophenone-3 [BP-3], avobenzone and homosalate [HMS]) consistently detected. Ti concentrations were generally higher than Zn in rhizosphere sediments, along with recurrent presence of octocrylene, HMS, 2-ethylhexyl methoxycinnamate (EHMC), and 4-methylbenzylidene camphor (4-MBC). Maximum Zn concentrations were found in canopy waters (3052.9 ng L-1). Both Ti and Zn were found in all P. oceanica tissues and leaf epiphytes across all study sites. Additional UVFs like octocrylene, avobenzone, and BP-8 were also detected in P. oceanica tissues and epiphytes. Elevated levels of octocrylene in leaf epiphytes (2112.1 ng g-1 dw) and avobenzone in leaves (364.2 ng g-1 dw) and leaf epiphytes (199.6 ng g-1 dw) were observed in the Port of La Savina, the island's main entry port. Octocrylene concentrations (up to 2575 ng g-1 dw) in rhizosphere sediments near sewage discharge points exceeded reported maxima, highlighting wastewater treatment plants as significant sources of organic UVFs. Correlational analyses suggested that the accumulation of octocrylene, avobenzone, and BP-3 negatively impacted P. oceanica's conservation status, affecting global density, density at 100 % cover, and leaf morphometry. Positive correlations were observed between leaf polyphenols (antioxidants) and concentrations of avobenzone, benzophenone-8 (BP-8), and BP-3, indicating potential oxidative stress induced by UVFs in P. oceanica. Our study underscores the pervasive presence of UV filters in P. oceanica habitats, with implications for seagrass health and conservation, especially in areas of high tourism and sewage discharge.

Stress responses of the seagrass Cymodocea nodosa to environmentally relevant concentrations of pharmaceutical ibuprofen: Ecological implications.

Pharmaceuticals like ibuprofen (IBU) entering marine environments are of great concern due to their increasing consumption and impact on wildlife. No information on IBU toxicity to seagrasses is yet available. Seagrasses form key habitats and are threatened worldwide by multiple stressors. Here, the responses of the seagrass Cymodocea nodosa to a short-term exposure (12 days) to environmentally realistic IBU concentrations (0.25-2.5-25 µg L-1), both at organism (plant growth) and sub-organism level (oxidative status, photosynthetic efficiency, and specialized metabolites production), were assessed in mesocosm. Chemical analyses to detect the presence of IBU and its metabolites in seawater and plants were also performed. IBU did not affect plant growth but caused physiological alterations which varied in severity depending on its concentration. Concentrations of 0.25 and 2.5 µg L-1 resulted in oxidative stress, but an increased antioxidant enzyme activity enabled plants to tolerate stress. A concentration of 25 µg L-1 caused greater oxidative stress, reduced antioxidant enzyme activity and specialized metabolites production, and impaired photosynthetic machinery functioning (particularly PSII). IBU was detected in seawater but not in plants suggesting no bioaccumulation. These findings indicate that C. nodosa could not withstand high IBU stress, and this could reduce its resilience to additional environmental stressors.

How the seagrass Posidonia oceanica flowering will benefit from climate change.

This study aimed at identifying the importance of the thermal framework preceding Posidonia oceanica flowering induction (autumn before the flowering year) and anthesis (summer of the flowering year). In 53 locations of Sardinia (Italy), 35 vertical shoots were collected in 2001, 2020 and 2023 and analyzed through lepidochronology, detecting past flowering events from 1991 to 2022. Flowering probability was positively correlated with autumn SST range and MHWs, stressing the importance of the temperature in the year preceding the flowering. Summer SST mean and Marine Cold Spell duration (the latter emerged as a novel outcome) also positively influenced flowering. A negative association was highlighted with the summer SST range. As the occurrence of MHWs will increase, and the SST range will also increase in the autumn and decrease in the summer, P. oceanica might benefit through a higher flowering frequency, leading to a greater resilience to disturbances due to higher genetic variation.

Nutrient enrichment and herbivory alter carbon balance in temperate seagrass communities.

Large nutrient levels and herbivory stress, particularly when acting together, drive a variety of responses in seagrass communities that ultimately may weaken their carbon balance. An in situ three-months experiment was carried out in two contrasting seasons to address the effects of two levels of nutrient load and three levels of artificial clipping on Cymodocea nodosa plants. Nutrient enrichment shifted the community from autotrophic to heterotrophic and reduced DOC fluxes in winter, whereas enhanced community carbon metabolism and DOC fluxes in summer. Herbivory stress decreased the net primary production in both seasons, whereas net DOC release increased in winter but decreased in summer. A reduction of seagrass food-web structure was observed under both disturbances evidencing impacts on the seagrass ecosystems services by altering the carbon transfer process and the loss of superficial OC, which may finally weaken the blue carbon storage capacity of these communities.

A risk-based approach to the analysis of potential climate change effects on fish communities associated to Posidonia oceanica in the Mediterranean.

The Mediterranean is recognized as a climate change hotspot, with ongoing warming anticipated to impact its habitats and their associated fish fauna. Among these habitats, the seagrass Posidonia oceanica stands out as a foundational species, critical for the stability of coastal fish communities. However, our understanding of climate change consequences on P. oceanica associated fish fauna to date remains limited in part due to a lack of long-term data. This study aimed to highlight potential climate change risks to fish species associated with Posidonia, integrating data on species' thermal envelopes with their habitat and depth preferences into a climate change risk index. Specifically, 9 species, including three pipefish and several wrasse species of the genus Symphodus, emerged as being at higher potential risk from climatic change. A historical time series from Palma Bay (Balearic Islands, Spain), spanning 45 years and providing clear evidence of warming, was employed to evaluate trends in species abundance and occurrence in relation to their relative climate risk score. While certain high-risk species like Symphodus cinereus and Diplodus annularis showed an increase in abundance over time, others, such as the pipefish Syngnathus acus, Syngnathus typhle and Nerophis maculatus experienced declines. The absence of observed declines in some high-risk species could be attributed to several factors, such as acclimation, adaptation, or unmet response thresholds. However, this does not rule out the potential for future changes in these species. Factors such as increased nutrient influx due to growing human populations and changes in fishing regulations may also have contributed to the observed trends. These findings underscore the intricate interplay of environmental and anthropogenic factors and accentuate the pressing need for sustained, long-term data acquisition to fathom the implications of climate change on this highly important marine ecosystem.

Peronia peronii as a bio-indicator to assess the toxicity of waterpipe tobacco leachates in aquatic and sediment media.

This study was aimed to survey toxicity of waterpipe wastes leachates on Peronia peronii in aquatic and sediment environments as two exposure media. For this, leachates of four tobacco types including burnt traditional tobacco (BTT), fresh traditional tobacco (FTT), burnt fruit-flavored tobacco (BFT) and fresh fruit-flavored tobacco (FFT)) were prepared and used to assess their toxic effects on P. peronei in two aquatic and sediment media. The in-vivo toxic effects of five different concentrations of waterpipe tobacco waste leachates on P. peronii were evaluated. The LC50 values of BTTs leachates to P. peronii were 17.50, 16.05, 11.31 and 9.38 g/L at exposure times of 24, 48, 72 and 96 h, respectively in aquatic media. These values for BFTs leachates were 14.86, 12.38, 9.53 and 7.46 g/L at exposure times of 24, 48, 72 and 96 h, respectively. In the case of sediment media, the LC50 values of BTTs leachates were 15.33, 13.70, 9.09 and 6.70 g/L at exposure times of 24, 48, 72 and 96 h, respectively while these values for BFTs leachates were 12.00, 10.32, 8.20 and 5.65 g/L. Fruit-flavored tobacco leachates had significantly higher toxicity than traditional tobacco leachates for P. peronii. The findings also showed significant differences between the LC50 values of different leachates in different media of water and sediment. The results demonstrated that even small amount of tobacco waste (~ 5 to 6 g/L) can lead to P. peronii mortality and may also pose a hazard to other aquatic and benthic organisms. The results obtained from the present study can be used as a baseline data to assess local effects causing from unsafe disposal of post-consumption tobacco waste in beach areas. In addition, these findings can lead to encouraging decision-makers to focus more on the types of tobacco waste in the municipal solid waste management system and to implement a source separation process for these wastes.