French Research Institute for Exploitation of the Sea
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Use and Health Effects of Herbal Medicine Ocotea Guianensis During Pregnancy in French Guiana
No full textEthnopharmacological relevance - Ocotea guianensis Aubl. leaves, in Creole fey darjan (“silver leaves”) are frequently cited by women in French Guiana for childbirth related practices. Although this use has been described in several ethnographic studies, the frequency of use of this plant has not been quantified yet. Moreover, beyond alarming anecdotes, the profile of users, the ways in which leaves are used during pregnancy, and its influence on childbirth and the immediate post-partum period remained to be determined. Our main objective was thus to estimate the prevalence of O. guianensis use among women giving birth. Materials and methods - A descriptive cross-sectional study was conducted in the maternity wards of Cayenne and Kourou in the immediate postpartum period. Data were collected from 332 women between March 21 and July 10, 2023. Women willing to participate were invited by multilingual health workers to answer a 10-minute structured quantitative questionnaire. Qualitative individual interviews were also conducted with some caregivers and patients. Results - The prevalence of use in the sample was 10%. The leaves were generally used in the form of a sitz bath. Users were generally women born in French Guiana, with a relatively high level of education and social status. The study found no evidence of an increase of fetal distress or obstetrical complications in women who used O.guianensis compared with those who did not. Conclusion - The study did not reveal any significant influence of O. guianensis use on pregnancy outcomes. Due to the small sample size of users and potential under-reporting, this study may not have highlighted all user profiles in French Guiana. Even so, the study showed that the use of this herbal medicine concerned at least one in 10 women giving birth in Cayenne and Kourou, thus almost 484 deliveries per year. A complementary study conducted on a larger sample beyond maternity wards would refine usage prevalence estimates and O. guianensis user profiles
Proficiency testing and cross-laboratory method comparison to support standardisation of diatom DNA metabarcoding for freshwater biomonitoring
No full textDNA metabarcoding of benthic diatoms has been successfully applied for biomonitoring at the national scale and can now be considered technically ready for routine application. However, protocols and methods still vary between and within countries, limiting their transferability and the comparability of results. In order to overcome this, routine use of DNA metabarcoding for diatom biomonitoring requires knowledge of the sources of variability introduced by the different steps of the procedure. Here, we examine how elements of routine procedures contribute to variability between European laboratories. A set of four experiments were performed focusing on DNA extraction and PCR amplification steps to evaluate their reproducibility between different laboratories and the variability introduced by different protocols currently applied by the scientific community. Under the guidance of a reference laboratory, 17 participants from 14 countries performed DNA extraction and PCR amplification in parallel, using the same fixed protocol and their own choice of protocol. Experiments were performed by each participant on a set of standardised DNA and biofilm samples (river, lake and mock community) to investigate potential systematic and random errors. Our results revealed the successful transferability of a protocol amongst labs and a highly similar and consistent ecological assessment outcome obtained regardless of the protocols used by each participant. We propose an “all for one but prove them all” strategy, suggesting that distinct protocols can be used within the scientific community, as long as their consistency is be proven by following minimum standard requirements
Growth of hydrogenotrophic methanogen Methanoculleus bourgensis MAB1 in the presence of dunite
No full textThis study investigated the long-term potential of low-temperature serpentinization of dunite to support the growth of the hydrogenotrophic methanogen Methanoculleus bourgensis strain MAB1. Incubation experiments were conducted for over 800 days, using dunite powder as the sole energy source, with and without the addition of nickel, an essential cofactor for methanogenesis. The results indicated that hydrogen released from dunite was sufficient to sustain methanogen growth, but the process was slow, with methane production beginning only after approximately 300 days. The release of toxic metals from dunite, particularly zinc, appeared to inhibit methanogen growth over time, leading to the cessation of methane production after 528 days and likely the lysing of the methanogenic cells. The study suggests that hydrogen availability, rather than nickel, is the limiting factor for methanogen growth in these conditions
Do European Seabass Larvae Grow Better in Their Natural Temperature Regime?
No full textUnderstanding how warming surface waters impact the larval growth of highly prized marine fishes such as the European seabass, Dicentrarchus labrax, is important for sustainable fisheries and aquaculture. We studied the growth of larvae from three genetically differentiated seabass populations, Atlantic (AT), Western Mediterranean (WM), and Eastern Mediterranean (EM), reared in a common garden under three thermal regimes, representative of seasonal changes in a relatively cold Atlantic (rAT), intermediate Western Mediterranean (rWM), and warm Eastern Mediterranean (rEM). Survival was higher in warmer regimes until larvae reached a length of 23 mm, after which there was no major difference. Growth was monitored from 20 days posthatch to 1.5 g, with individuals sampled at regular intervals and their population of origin identified by parentage assignment using their genotypes for 96 SNPs. Significant length differences emerged among populations, the AT population being longer than WM and EM in all thermal regimes. In conclusion, the AT population had higher growth than the WM and EM populations in all thermal regimes, not just in its own, and the AT population can be considered the most robust to temperature variations at the larval stage. Further research is required to understand whether the high growth rate of the AT population reflects a process of local adaptation to a relatively cold thermal regime
Expertise de l'Ifremer sur le dossier de demande d'autorisation environnementale relatif au projet de raccordement du parc éolien AO5 (Bretagne Sud)
No full textJellyfish journey live tracking using floating electronic tag
No full textGelatinous organisms are key players of marine ecosystems, however underlying processes of their dynamics and behaviour are still to be cleared up. Understanding the areas of production, where the blooms go and what they become are therefore of major interest in marine ecosystem management. We used floating electronic tags developed in our laboratory for jellyfish live tracking. A special attention was put on the welfare of the organisms as the tag was floating and simply attached with a fishing line around the manubrium. In situ experiments were carried out in Bages Sigean lagoon (France) where a perennial population of the Mediterranean jellyfish Rhizostoma pulmo is established. Up to 47 deployments, from 20 min to 28h, took place in 2022 and 2023 summers. Live tracking indicated that the floating device did not influence the jellyfish trajectory nor its speed. A 28-hour trajectory showed that jellyfish movement can be influenced by the wind but also by other environmental factors. The relatively small area covered by the jellyfish compared to the control float one, suggests that movements significantly influence its trajectory as a response to the environment. Jellyfish were successfully recovered suggesting in a near future repeated individual measurements processes over longer deployments
Decrypting the breeding biology of the elusive and declining Tahiti Petrel Pseudobulweria rostrata
No full textAmong procellariids, the Tahiti Petrel Pseudobulweria rostrata is one of the most endangered and least known species. Its global populations are declining, yet demographic and ecological studies remain scarce. Understanding the breeding cycle and behavior of Tahiti Petrel adults and chicks is essential to develop effective protection measures. To address this knowledge gap, Tahiti Petrel colonies of various sizes were studied at three sites in New Caledonia, with extensive sampling at two main sites and limited sampling at a third. A total of 157 burrows were monitored for up to two years using endoscopic cameras and camera traps. This allowed the depiction of the breeding phenology, reproductive success, frequency of adult nest visits, chick behavior, first emergence, and fledging dates. During the study, 75% of the identified burrows were visited by Tahiti Petrels. Egg-laying peaked in December but occurred year-round, indicating aseasonal breeding by Tahiti Petrels in New Caledonia. The average breeding cycle was 329 ± 11.6 days, including an average incubation period of 55.7 ± 0.9 days and an average chick-rearing period of 110.7 ± 5.6 days. Parents visited nests every 1.3 days on average during chick-rearing. After the chick's first emergence, which typically occurred 31 days before fledging, adult visitation decreased. Chicks did not show defensive behavior against predators, and most chicks fledged after nine days without feeding. Breeding success was 50% at a predator-free site and 32% at a site with invasive predators. These findings suggest high sensitivity to disturbance and depredation, contributing to the species' decline in New Caledonia and elsewhere in the world. Together with previous studies conducted in New Caledonia, these results provide crucial information for the implementation of adapted conservation measures for this declining species
Working Group on Mixed Fisheries Advice (WGMIXFISH-ADVICE; outputs from 2024 meeting)
No full textThe ICES Working Group on Mixed Fisheries Advice (WGMIXFISH-ADVICE) produces mixed fisheries forecasts for the Bay of Biscay, Celtic Seas, Iberian Waters, Irish Sea, and North Sea. These forecasts highlight the potential implications of single-stock (total allowable catch and ef-fort) management on the catches of multiple stocks caught together in mixed fisheries. Mixed fisheries models consider past fishing patterns and catchability of the different fleets, and the catch advice produced by the single-stock advice groups, to provide quantitative forecasts of over- and underexploitation of the different stocks given mixed fishery interactions. The mixed fisheries forecasts were produced using the “FCube” (Fleet and Fishery Forecasts) methodology for the Celtic Sea and Irish Sea, and the “FLBEIA” (Bio-Economic Impact Assessment using FLR) methodology for the Bay of Biscay, Iberian Waters, and North Sea. The Bay of Biscay mixed fisheries projections consider the single-species advice of 13 stocks (ank.27.78abd, bss.27.8ab, hke.27.3a46-8abd, hom.27.2a3a4a5b6a7a-ce-k8, mac.27.nea, meg.27.7b-k8abd, mon.27.78abd, nep.fu.2324, pol.27.89a, sdv.27.nea, sol.27.8ab, whb.27.1-91214, and whg.27.89a). Given the single-stock catch advice for 2025, the most limiting stock for demer-sal fisheries in the Bay of Biscay is pollack, whose stock share is first reached for eight of 21 defined fleets. The least limiting stock is black-bellied anglerfish (seven of 21 fleets). The Celtic Sea mixed fisheries projections consider the single-species advice for 15 stocks (cod.27.7e-k, had.27.7b-k, whg.27.7b-ce-k, nep.fu.16, 17, 19, 20–21, 22, and outside FUs, sol.27.7e, sol.27.7fg, mon.27.78abd, ank.27.78abd, meg.27.7b-k8abd, and hke.27.3a46-8abd). Given the sin-gle-stock catch advice for 2025, the most limiting stocks for demersal fisheries in the Celtic Sea are cod and whiting, with 30 of 33 defined fleets choked by these two stocks due to the zero-catch advice, and the fact that almost all fisheries operating with demersal gears catch them. The least limiting stock is black-bellied anglerfish (16 fleets), followed by hake (nine fleets), Norway lob-ster in FU 20–21 (seven fleets) and white anglerfish (one fleet). The Iberian waters mixed fisheries projections consider the single-species advice for 5 stocks (ank.27.8c9a, hke.27.8c9a, lbd.27.8c9a, meg.27.8c9a and mon.27.8c9a). Given the single-stock catch advice for 2025, the most limiting stock for demersal fisheries in the Iberian Waters is hake, with all 11 defined fleets reaching their hake quota with a lower effort than for the other stocks. The least limiting stock is black-bellied anglerfish (10 of 11 fleets). The Irish Sea mixed fisheries projections consider the single-species advice for 7 stocks (cod.27.7a, had.27.7a, ple.27.7a, sol.27.7a, whg.27.7a, nep.fu.14, and 15). Given the single-stock catch advice for 2025, the most limiting stocks for demersal fisheries in the Irish Sea are whiting and cod, with all 12 defined fleets choked by these two stocks due to the zero-catch advice, and the fact that 11 of 12 fleets catch them both. The least limiting stock is haddock (nine of 12 fleets). The North Sea mixed fisheries projections consider the single-species advice for 20 stocks (bll.27.3a47de, cod.27.47d20, had.27.46a20, ple.27.420, ple.27.7d, pok.27.3a46, sol.27.7d, tur 27.4, whg.27.47d, wit.27.3a47d, nep.fu.5, 6, 7, 8, 9, 10, 32, 33, 34, and 4 outFU). Given the single-stock catch advice for 2025, the most limiting stock for demersal fisheries in the North Sea is cod, whose stock share is first reached for 23 of 37 defined fleets. The least limiting stock is whiting (35 of 37 fleets). Additional work included contributions to four technical requests
