Jellyfish Stings Trigger Gill Disorders and Increased Mortality in Farmed Sparus aurata (Linnaeus, 1758) in the Mediterranean Sea

none8siJellyfish are of particular concern for marine finfish aquaculture. In recent years repeated mass mortality episodes of farmed fish were caused by blooms of gelatinous cnidarian stingers, as a consequence of a wide range of hemolytic, cytotoxic, and neurotoxic properties of associated cnidocytes venoms. The mauve stinger jellyfish Pelagia noctiluca (Scyphozoa) has been identified as direct causative agent for several documented fish mortality events both in Northern Europe and the Mediterranean Sea aquaculture farms. We investigated the effects of P. noctiluca envenomations on the gilthead sea bream Sparus aurata by in vivo laboratory assays. Fish were incubated for 8 hours with jellyfish at 3 different densities in 300 l experimental tanks. Gill disorders were assessed by histological analyses and histopathological scoring of samples collected at time intervals from 3 hours to 4 weeks after initial exposure. Fish gills showed different extent and severity of gill lesions according to jellyfish density and incubation time, and long after the removal of jellyfish from tanks. Jellyfish envenomation elicits local and systemic inflammation reactions, histopathology and gill cell toxicity, with severe impacts on fish health. Altogether, these results shows P. noctiluca swarms may represent a high risk for Mediterranean finfish aquaculture farms, generating significant gill damage after only a few hours of contact with farmed S. aurata. Due to the growth of the aquaculture sector and the increased frequency of jellyfish blooms in the coastal waters, negative interactions between stinging jellyfish and farmed fish are likely to increase with the potential for significant economic losses.Bosch-Belmar, Mar; M'Rabet, Charaf; Dhaouadi, Raouf; Chalghaf, Mohamed; Daly Yahia, Mohamed Néjib; Fuentes, Verónica; Piraino, Stefano; Kéfi-Daly Yahia, OnsBosch Belmar, Mar; M'Rabet, Charaf; Dhaouadi, Raouf; Chalghaf, Mohamed; Daly Yahia, Mohamed Néjib; Fuentes, Verónica; Piraino, Stefano; Kéfi Daly Yahia, On

Factors driving the seasonal dynamics of Pseudo-nitzschia species and domoic acid at mussel farming in the SW Mediterranean Sea

The seasonal variations in Pseudo-nitzschia species and domoic acid (DA) concentration were investigated, at three shellfish farms in SW coastal Mediterranean. In parallel, the toxicity of mussels was tested. Two distinct groups of species were enumerated according to morphology and size (Pseudo-nizschia delicatissima and P. seriata groups). DA was detected over a nine-week period from July to October 2012 in the Lagoon, with a maximum concentration recorded in July (12.71 ng DA L−1). DA was positively correlated with the presence of P. seriata-group and P. delicatissima-group and was mostly occurred during P limitation period in seawater. No DA was found in mussels that were collected during the period of DA absence in seawater. Our results suggest that temperature, salinity, inorganic and organic nutrients were significant for the seasonal dynamics of P. seriata and P. delicatissima groups, but that the P limitation was the most driving factor for DA production in these areas. The relative influence of environmental factors should be further studied to better understand the recent surfacing of massive blooms of toxigenic Pseudo-nitzschia in SW Mediterranean coast.info:eu-repo/semantics/acceptedVersio

Cross-cultural comparison of mental illness stigma and help-seeking attitudes: a multinational population-based study from 16 Arab countries and 10,036 individuals

BackgroundThere is evidence that culture deeply affects beliefs about mental illnesses\u27 causes, treatment, and help-seeking. We aimed to explore and compare knowledge, attitudes toward mental illness and help-seeking, causal attributions, and help-seeking recommendations for mental illnesses across various Arab countries and investigate factors related to attitudes toward help-seeking.MethodsWe carried out a multinational cross-sectional study using online self-administered surveys in the Arabic language from June to November 2021 across 16 Arab countries among participants from the general public.ResultsMore than one in four individuals exhibited stigmatizing attitudes towards mental illness (26.5%), had poor knowledge (31.7%), and hold negative attitudes toward help-seeking (28.0%). ANOVA tests revealed a significant difference between countries regarding attitudes (F = 194.8, p \u3c .001), knowledge (F = 88.7, p \u3c .001), and help-seeking attitudes (F = 32.4, p \u3c .001). Three multivariate regression analysis models were performed for overall sample, as well as Palestinian and Sudanese samples that displayed the lowest and highest ATSPPH-SF scores, respectively. In the overall sample, being female, older, having higher knowledge and more positive attitudes toward mental illness, and endorsing biomedical and psychosocial causations were associated with more favorable help-seeking attitudes; whereas having a family psychiatric history and endorsing religious/supernatural causations were associated with more negative help-seeking attitudes. The same results have been found in the Palestinian sample, while only stigma dimensions helped predict help-seeking attitudes in Sudanese participants.ConclusionInterventions aiming at improving help-seeking attitudes and behaviors and promoting early access to care need to be culturally tailored, and congruent with public beliefs about mental illnesses and their causations

Effects of increasing temperatures on biomarker responses and accumulation of hazardous substances in rope mussels (Mytilus galloprovincialis) from Bizerte lagoon

This study examined the influence of increasing temperatures in spring and summer on biochemical biomarkers in Mytilus galloprovincialis mussels sampled from Bizerte lagoon (northern Tunisia). Spatial and seasonal variations in a battery of seven biomarkers were analyzed in relation to environmental parameters (temperature, salinity and pH), physiological status (condition and gonad indexes), stress on stress (SoS) and chemical contaminant levels (heavy metals, PAHs and PCBs) in digestive glands. Integrated Biological Response (IBR) was calculated using seven biomarkers (AChE, BPH, MXR, GST, CAT, MDA and MT). Seasonal variations in biological response were determined during a critical period between spring and summer at two sites, where chemical contamination varies by a factor of 2 for heavy metals and a factor 2.5 for PAHs. The analysis of a battery of biomarkers was combined with the measurement of physiological parameters at both sites, in order to quantify a maximum range of metabolic regulation with a temperature increase of 11°C between May and August. According to our results, the MT, MDA, CAT and AChE biomarkers showed the highest amplitude during the 11°C rise, while the BPH, GST, and MXR biomarkers showed the lowest amplitude. Metabolic amplitude measured with the IBR at Menzel Abdelrahmen - the most severely contaminated station - revealed the highest metabolic stress in Bizerte lagoon in August, when temperatures were highest 29.1°C. This high metabolic rate was quantified for each biomarker in the North African lagoon area and confirmed in August, when the highest IBR index values were obtained at the least-contaminated Site 2 (IBR= 9,6) and the most-contaminated site 1 (IBR=19,6). The combined effects of chemical contamination and increased and salinity temperatures in summer appear to induce a highest metabolic adaptation response and can therefore be used to determine thresholds of effectiveness and facilitate the interpretation of monitoring biomarkers. This approach, applied during substantial temperature increases at two sites with differing chemical contamination, is a first step toward determining an EAC (Environmental Assessment Criteria) threshold in a North African lagoon

Seasonal variations in biomarkers in the Mytilus galloprovincialis mussel: integrated monitoring approach for chemical and biological effects in the Bizerta lagoon, Tunisia

International audienc

Effects of Pelagia noctiluca jellyfish swarms on caged gilthead sea bream

International Council for the Exploration of the Sea Annual Science Conference (ICES ASC 2014), Sustainability in a changing ocean, 15-19 September 2014, La Coruña.-- 2 pagesIn recent years, interactions between caged finfish and jellyfish have been increasingly reported, with major fish mortalities and severe economic impacts to aquaculture facilities. The scyphomedusa Pelagia noctiluca has been responsible for documented mortality events in Eastern Atlantic (Irish Sea) and the Mediterranean Sea. We investigated he impact of P. noctiluca stings on the gilthead sea bream (Sparus aurata) in laboratory experiments. Fish were pulse-incubated for 8 hours with 3 different jellyfish densities in experimental tanks. Gill disorders were assessed through histological analyses at time intervals (0, 3, 9, 24, and 48 h, and 1, 2, 3 and 4 weeks) after the pulse exposure to jellyfish. Our results demonstrated that P. noctiluca may severely affect caged sea bream gill integrity as soon as 3 h after interaction with jellyfish tissuesPeer Reviewe

Average gill scores of treatment groups.

<p>Gill scores of control, low, medium and high <i>Pelagia noctiluca</i> jellyfish density groups before (0 h) and at different times after <i>Sparus aurata</i> exposure to jellyfish. Fish were not sampled from the highest jellyfish density group at 24 h, 3 and 4 weeks sampling points (vertical bars denote standard error).</p

Histopatholical gill damage of experimental groups over time.

<p>MLH: Mild lamellar hyperplasia; MLF: Mild lamellar fusion; MoLH: Moderate lamellar hyperplasia; MoLF: Moderate lamellar fusion; MCA: Mild cellular anomalies; MoCA: Moderate cellular anomalies; SLH: Severe lamellar hyperplasia; MCO: Mild cellular oedema; FM: Fish mortality; (NA): data not available; (---): Non significant gill damage. Colours indicate the severity of gill damage: cream colour = mild injuries; orange = medium level of injuries; violet and purple = medium-high and high level of gill damage respectively.</p

Gill lesions in fish exposed to <i>Pelagia noctiluca</i>.

<p>A. Healthy fish gill from the control (no jellyfish) group (0h) (100x); B-E. pathology in fish gills from the treatment groups after 8-h exposure to jellyfish: B. black arrows indicate lamellar hyperplasia on fish gill from the low jellyfish density group at 9h (400x); C. lamellar hyperplasia (1) and fusion (2) from the medium jellyfish density group after 1 week (100x); D. epitheliocystis (black arrow) and lamellar oedema (1) from the medium jellyfish density group after 3 weeks (400x); E. hyperplasia of the epithelium of the primary lamellae (1), necrosis focal of secondary lamellae (2) and circulatory disturbances (3) from the high jellyfish density group after 48h (100x).</p