Life-stages, exploitation status and habitat use of Lutjanus goreensis (Perciformes: Lutjanidae) in coastal marine environments of Lagos, SW Nigeria

Life-stages, exploitation status and habitat use of the Gorean snapper, Lutjanus goreensis ( Perciformes : Lutjanidae)  from comparative  length  - frequency  distributions in a mangrove - poor tidal creek and coastal marine environments of Lagos, South -west Nigeria.   Kafayat.A. Fakoya1*.,  Martins, A.    Anetekhai1,  Shehu, L. Akintola1,  Abdulwakil, O. Saba1 &  M.Abass. 21Department of Fisheries,  Faculty of Science, Lagos State University, Ojo, Lagos State Nigeria. Email: [email protected]; [email protected] 1Department of Fisheries, Faculty of Science, Lagos State University, Ojo, Lagos State Nigeria. Email: [email protected] of Fisheries, Faculty of Science, Lagos State University, Ojo, Lagos State Nigeria. Email: [email protected] Institute for Oceanography and Marine Research, 3  Wilmot Point, Off  Bar Beach Road, Victoria Island, Lagos State, Nigeria.The Gorean snapper, Lutjanus goreensis is an important component of artisanal fisheries and trawl landings in the Gulf of Guinea. Despite its economic importance, there is a dearth of information on size structure and life history strategies of the species. Therefore, the objectives of this study were to provide baseline data on the life stages, exploitation status and habitat use for the species in Nigeria. Monthly samples were obtained from artisanal and trawl catches in Five Cowrie Creek and Lagos coastal waters between December 2008 and December 2010, respectively. Length-frequency distributions of the fishes caught were analysed to provide preliminary information on mean and modal lengths at capture and life - history strategies based on habitat use and estuarine-dependency for L. goreensis. A total of 822 specimens of L. goreensis were collected from Five Cowrie Creek, while 377 specimens were collected from Lagos coastal waters. Total length varied between 7.90-34.90cm for estuarine samples and from 21.90-56.10cm for marine samples. Length-frequency histograms showed polymodal size distributions in estuarine and marine samples. Length-frequency distributions of L. goreensis showed a high abundance of juveniles (<20cm) and sub-adults (20-35cm) which accounted for 84.1% and 68.4% of estuarine and marine samples examined, respectively. For the estuarine samples, fish in modal length class of 13.00-13.99cm were the most exploited while in marine samples, length classes of 29.00-30.99cm and 31.00-32.99cm constituted the most frequently exploited fishes. Increase in total lengths from the creek (mean±SD; 16.19±3.73cm) to the marine habitat (32.89±6.14cm) indicated ontogenetic shift in habitat use. Occurrence of a predominant juvenile population in Five Cowrie Creek by L. goreensis suggests estuarine-dependency and is indicative of a temporary juvenile habitat or a migratory corridor. In conclusions, data from the presently reported study and previous studies demonstrated that juvenile L. goreensis displays estuarine dependency and habitat flexibility. Hence, this underscores the importance of preserving estuarine environments as essential fish habitats to prevent overfishing. The study also concludes that the species is vulnerable to recruitment overfishing in the marine environment especially as a consequence of shrimping. Consequently, it advocates for ban on all fishing activities during peak spawning periods in breeding grounds and shrimp ground assemblage

SARS-CoV-2 vaccination modelling for safe surgery to save lives: data from an international prospective cohort study

Background: Preoperative SARS-CoV-2 vaccination could support safer elective surgery. Vaccine numbers are limited so this study aimed to inform their prioritization by modelling. Methods: The primary outcome was the number needed to vaccinate (NNV) to prevent one COVID-19-related death in 1 year. NNVs were based on postoperative SARS-CoV-2 rates and mortality in an international cohort study (surgical patients), and community SARS-CoV-2 incidence and case fatality data (general population). NNV estimates were stratified by age (18-49, 50-69, 70 or more years) and type of surgery. Best- and worst-case scenarios were used to describe uncertainty. Results: NNVs were more favourable in surgical patients than the general population. The most favourable NNVs were in patients aged 70 years or more needing cancer surgery (351; best case 196, worst case 816) or non-cancer surgery (733; best case 407, worst case 1664). Both exceeded the NNV in the general population (1840; best case 1196, worst case 3066). NNVs for surgical patients remained favourable at a range of SARS-CoV-2 incidence rates in sensitivity analysis modelling. Globally, prioritizing preoperative vaccination of patients needing elective surgery ahead of the general population could prevent an additional 58 687 (best case 115 007, worst case 20 177) COVID-19-related deaths in 1 year. Conclusion: As global roll out of SARS-CoV-2 vaccination proceeds, patients needing elective surgery should be prioritized ahead of the general population