Hatchery seed production of flat oysters from the Mar Menor lagoon

The Mar Menor lagoon (SE Spain) suffers a severe eutrophication process aggravated since the collapse of the lagoon in 2016. Together with it, the populations of the flat oyster Ostrea edulis have been decimated in the lagoon, but also in the European seas, where the species and the habitats provided by it have mainly disappeared. The Mar Menor Oyster Initiative’s main objectives are gaining knowledge on the nutrient extraction capability of the Mar Menor flat oyster and developing the required tools for restoration and bioextraction actions. The project RemediOS, within the framework of the Mar Menor Oyster Initiative, aims to obtain flat oyster seed using the decimated local broodstock to provide the initiative with an oyster population to work with. The present work describes the results of the first attempt of Mar Menor local broodstock reproduction in captivity. Larvae produced in the hatchery accounted for 57.5 million, of which 11.8 million were cultured and 0.68 million survived to settlement and metamorphosis

Scope for growth and dietary needs of Mediteranean Pinnids maintained in captivity

Abstract Background: The measurement of the energy available for growth (scope of growth, SFG) can be used in bivalves to make a long-term prediction in a short-term experiment of the condition of the individual. In order to tackle the best conditions for captive maintenance of Mediterranean Pinnids, a SFG study was conducted using Pinna rudis as a model species. Three diets were examined to test the viability of live microalgae and commercial products: i) a control diet using 100% of live microalgae based on the species Isochrysis galbana (t-ISO), ii) a 100% of commercial microalgae diet based on the product Shellfish Diet 1800®, and iii) a 50/50% mix diet of I. galbana (t-ISO) and Shellfish Diet 1800®. Results: SFG results showed significant differences among diets in the physiological functions measured and suggested lower acceptability and digestibility of the commercial product. Negative SFG values were obtained for the commercial diet which indicates that it should be rejected for both Pinnid maintenance. The mixed diet showed improved physiological performance compared to the commercial diet, resulting in a higher SFG that had no significant differences with the control diet. However, in the long-term, the lower digestibility of the mixed diet compared to the control diet could lead to a deterioration of individuals’ conditions and should be considered cautiously. Conclusions: This work represents the first case study of SFG in Pinna spp. and provides fundamental data on dietary needs for the critically endangered species, P. nobilis.En prens

Vertical Configuration of a Side Scan Sonar for the Monitoring of Posidonia oceanica Meadows

[EN] Posidonia oceanica meadows are ecosystem engineers that play several roles in marine environment maintenance. In this sense, monitoring of the spatial distribution and health status of their meadows is key to make decisions about protecting them against their degradation. With the aim of checking the ability of a simple low-cost acoustic method to acquire information about the state of P. oceanica meadows as ecosystem indicators, ground-truthing and acoustic data were acquired over several of these meadows on the Levantine coast of Spain. A 200 kHz side scan sonar in a vertical configuration was used to automatically estimate shoot density, canopy height and cover of the meadows. The wide athwartship angle of the transducer together with its low cost and user friendliness entail the main advantages of this system and configuration: both improved beam path and detection invariance against boat rolling. The results show that canopy height can be measured acoustically. Furthermore, the accumulated intensity of the echoes from P. oceanica in the first 30 centimeters above the bottom is indirectly related to shoot density and cover, showing a relation that should be studied deeply.Funding for open access charge: Universitat Politècnica de ValènciaLlorens-Escrich, S.; Tamarit, E.; Hernandis, S.; Sánchez-Carnero, N.; Rodilla, M.; Pérez Arjona, I.; Moszynski, M.... (2021). Vertical Configuration of a Side Scan Sonar for the Monitoring of Posidonia oceanica Meadows. Journal of Marine Science and Engineering. 9(12):1-15. https://doi.org/10.3390/jmse912133211591

Recovery of eutrophized marine ecosystems using the European flat oyster, Ostrea edulis

The development of tourism and intensification of agriculture has released large amounts of nitrogen and phosphorus into the Mar Menor coastal lagoon in South-east Spain, resulting in a phytoplankton bloom in 2016. This bloom turned the clear and transparent waters turbid and greenish, and killed approximately 85% of benthic macrophytes. Nutrient bioextraction by flat oysters, Ostrea edulis, has been proposed for remediation of these eutrophication events and water quality recovery. This research aims to quantify the clearance rate and investigate the genetic origin of Mar Menor oysters under eutrophized conditions for potential applications to bioremediation projects. Oligotrophic and eutrophic conditions were replicated in the laboratory, and oyster feeding behaviour (i.e. clearance rates, ingestion rates, absorption efficiency and absorption rates) were studied using a flow-through system. The genetic characterization of oysters showed no significant difference between individuals from the Mar Menor and individuals collected from a nearby Mediterranean bed (Tabarca Island). Based on the physiological results observed, oysters were grouped into high-feeder (HF) and low-feeder (LF) categories according to their clearance rate, that was 3-fold higher in the HF group. Different responses in feeding behaviour were observed under eutrophic conditions in both oyster groups. Constraints in the absorption capacity of LF oysters seemed to be related to their reduced filtering activity. Lower body condition of LF oysters was evidenced by their negative scope for growth value. From this work, several conclusions can be drawn for future restoration/bioextraction actions: (i) the recovery of half of the oyster population that existed in the past would act as an effective top-down control on the phytoplankton community; (ii) using clearance rate measurements is recommended to select oysters as broodstock; and (iii) Mediterranean oysters could be used as broodstock in the event that Mar Menor oysters fail to reproduce.We appreciate the work done by Francisco Gomez in the maintenance and feeding of the oyster and support on the physiological measurements. We also appreciate the technical assistance of Susana Sánchez with the genetic analyses. English has been reviewed by Selby Clarke (PhD student, Dalhousie University, Canada). This research has been performed in the scope of the RemediOS Project, developed with the collaboration of the Biodiversity Foundation (Spanish Ministry for Ecological Transition and the Demographic Challenge), through the Pleamar Program, co-financed by the European Maritime and Fisheries Fund (EMFF). Genetic analyses have been financed by the General Direction of the Mar Menor from the Murcia Regional Government (Reference 2021/009284).Peer reviewe

Stable isotope analyses reveal major nutritional deficiencies in captive vs. field juvenile individuals of Pinna nobilis

The pen shell, Pinna nobilis L. is critically endangered by the spread of a haplosporidan parasite. Stable isotopes have been shown an association with dietary assimilation, trophic level, and body condition, and can provide valuable information for ex situ conservation and breeding. In this context, the aim of this study was to investigate the nutritional status of individuals using δ13C and δ15N patterns across pen shell body tissues as tracers of elemental incorporation from treatment diets based on commercial gels and living phytoplankton and/or sediment. Further comparisons were also conducted with field animals and diets to better understand nutritional needs. Captive individuals, were enriched in δ13C and δ15N (~18.9 and 1.3‰, respectively), suggesting severe nutritional stress and utilization of own N and C pools, especially muscle. The mixing model for field individuals evidenced a large contribution from the zooplankton fraction (34.9%), which was further confirmed by experimental feeding with Artemia nauplii.info:eu-repo/semantics/acceptedVersio

Pharmacokinetics of Tildipirosin in Plasma, Milk, and Somatic Cells Following Intravenous, Intramuscular, and Subcutaneous Administration in Dairy Goats

Tildipirosin is a macrolide currently authorized for treating respiratory diseases in cattle and swine. The disposition kinetics of tildipirosin in plasma, milk, and somatic cells were investigated in dairy goats. Tildipirosin was administered at a single dose of 2 mg/kg by intravenous (IV) and 4 mg/kg by intramuscular (IM) and subcutaneous (SC) routes. Concentrations of tildipirosin were determined by an HPLC method with UV detection. Pharmacokinetic parameters were estimated by non-compartmental analysis. Muscle damage, cardiotoxicity, and inflammation were evaluated. After IV administration, the apparent volume of distribution in the steady state was 7.2 L/kg and clearance 0.64 L/h/kg. Plasma and milk half-lives were 6.2 and 58.3 h, respectively, indicating nine times longer persistence of tildipirosin in milk than in plasma. Moreover, if somatic cells are considered, persistence and exposure measured by the area under concentration–time curve (AUC) significantly exceeded those obtained in plasma. Similarly, longer half-lives in whole milk and somatic cells compared to plasma were observed after IM and SC administration. No adverse effects were observed. In brief, tildipirosin should be reserved for cases where other suitable antibiotics have been unsuccessful, discarding milk production of treated animals for at least 45 days or treating goats at the dry-off period

Ostras para mejorar la calidad del agua del Mar Menor

Los ecosistemas costeros están expuestos a una amplia gama de amenazas ambientales que incluyen, entre otras, la degradación de la calidad del agua por exceso de nutrientes, un proceso llamado eutrofización. Este es el caso del Mar Menor (Murcia, España), la laguna salada más grande de Europa. El Mar Menor sufre de eutrofización desde hace décadas debido a la acumulación de muchos nutrientes en el agua, lo que se ve agravado por la falta de organismos filtradores en el ecosistema. Estos animales, como los mejillones y las ostras, pueden ser, de hecho, parte de su salvaciónPeer reviewe

PHARMACOKINETICS OF CEFONICID IN GOATS

The single-dose disposition kinetics of cefonicid were determined in clinically normal lactating goats (n=6) after intravenous (IV), intramuscular (IM) and subcutaneous (SC) administration of a conventional formulation, and after subcutaneous administration of a long-acting formulation (SC-LA). Cefonicid concentrations were determined by high performance liquid chromatography with ultraviolet detection. The concentration-time data were analyzed by non-compartmental pharmacokinetic methods. Steady-state volume of distribution (Vss) and clearance (Cl) of cefonicid after IV administration were 0.14 0.03 L/kg and 0.51 0.07 L/h·kg, respectively. Following IM, SC and SC-LA administration, cefonicid achieved maximum plasma concentrations of 14.46 0.82, 11.98 1.92 and 17.17 2.45 mg/L at 0.26 0.13, 0.42 0.13 and 0.83 0.20 hours, respectively. The absolute bioavailabilities after IM, SC and SC-LA routes were 75.34 11.28 %, 71.03 19.14 % and 102.84 15.155 %, respectively. After cefonicid analysis from milk samples, no concentrations were found above LOQ at any sampling time. From these data, cefonicid administered at 20 mg/kg each 12 hours after SC-LA could be effective to treat bacterial infections in lactating animals not affected by mastitis problems

Reproduction of the endangered fan mussel Pinna nobilis under natural and captivity conditions

1. A mass mortality event that started in 2016 has put the fan mussel Pinna nobilis close to the brink of extinction, leading to the species being classified as Critically Endangered in the Red List of the International Union for Conservation of Nature. Under current circumstances, with the persistence of the disease caused by Haplosporidium pinnae in the open sea, isolated populations in coastal lagoons and estuarine bays appear to be the main chance for the survival of the species. 2. The low resilience of those populations highlights the importance of implementing additional measures to avoid the extinction of the fan mussel. One of these measures relies on completing its reproductive cycle in captivity. The reproductive window of the remaining fan mussel population in Alfacs Bay was explored to obtain gametes and to understand possible limitations in the reproductive activity in wild populations. For this purpose, during the reproductive season, several groups of individuals were relocated for short periods (~2 weeks) into the vivarium to obtain gametes under controlled conditions. Simultaneously, controlled temperature treatments and adapted food dosage for conditioning adult fan mussels out of their reproductive season in the wild were conducted in a recirculating aquaculture system. 3. The reproduction of natural populations was mostly restricted to May, featuring temperatures around 20°C. A low success of spawning was obtained in the vivarium, with a 0% success in 11 out of 20 of the trials (six to nine individuals each) and an overall success of 16% (25 out of 156 individuals). A 100% success (14 out of 14) was obtained with individuals conditioned for ~2 months in the recirculating aquaculture system. A second conditioning of six of those individuals was attempted after a ~3-month period, with a 33.3% success of spawning.We would like to thank the local government ‘Generalitat de Catalunya’ for all the permissions for the manipulation of individuals granted through the ‘Servei de Fauna i Flora’ and the Natural Park of the Ebro Delta. We would also like to thank the support of the Ministry for the Ecological Transition and the Demographic Challenge, through ‘Fundación Biodiversidad’ for supporting the work with PinnaSpat project, 2019 call for proposals. Some additional field campaigns in the Ebro Delta were also supported by the RecuperaPinna project, also funded through the ‘Fundación Biodiversidad’ in the 2020 call for proposals and EsMarEs (Ministerio para la Transición Ecológica, Spanish Government).info:eu-repo/semantics/acceptedVersio