ESTABLISHING AN ATLANTIC BLUEFIN TUNA (Thunnus thynnus) BROODSTOCK

The Spanish Institute of Oceanography owns a facility to reproduce Atlantic bluefin tuna (ABFT). This facility was built in 2015 and in August 2017, some fingerlings born in captivity were moved to this installation, and some wild tunas were added two months later. In November 2019, this batch consists in 69 2+ ABFT weighting 28 kg. Hopefully they can reach 40 kg at the beginning of June and spawn by the first time. Fertilized ABFT eggs were collected from cages owned by PisciAlba and obtained larvae were cultured in IEO facilities. At the end of July 2017, some fingerlings (Cultured batch –CB-, 2 gr mean weight) were move to ICRA facilities and placed in a 1000 m3 tank. At the end of September 2017 a total of 68 0+ ABFT fingerlings (Wild batch –WB-, 414 g mean weight), were captured from the Mazarron Bay and placed in another tank in ICRA. 4 months later, 81 tunas coming from both batches were weighted (2.5 kg mean weight), tagged and place together in a 3500 m3 tank. During all the time, temperature ranged between 17 and 27ºC, and food consisted in bait, mainly, Scomber scombrus (47% of the total food) and Clupea harengus (25%) but also Sardinella aurita, Engraulis encrasicolus and Scomber japonicus (11, 10 and 7% respectively). From February 2018 to November 2019, mortality has been 16.9% (10.9% in WB and 28.6% in CB) and tunas have grown to reach an average of 28 kg. Biomass in this moment is 1930 kg, which means a density of 0.55 kg/m3 . Feeding intake was high during the first six months (when tunas were smaller than 2.5 kg), but after this moment it has ranged between 2.5 and 7%, decreasing with the size of tunas and increasing slightly with higher temperatures (circles). Feeding conversion rate was quite stable during the period, averaging 13.8. According to forecast, at the end of next spring, average weight will be about 40 kg, with about 15 tunas greater than 50 kg. This means that they will be able to reproduce next summer if gonadal maturation develops properly

Uso del diámetro ocular en la estimación del crecimiento de larvas de atún rojo (Thunnus thynnus)

The present study aims to solve the problem related to the difficulty in measuring the bluefin tuna (Thunnus thynnus L.) larval length when the larvae curl for several reasons (freezing, fixing, handling or in notochord flexion phase). To do that, the relationship between the horizontal eye diameter and the notochord length has been studied in 1143 bluefin tuna larvae from the eye pigmentation up to the full notochord flexion (between 2 and 15 days post hatching) reared in the facilities of the Marine Aquaculture Plant in Mazarrón (Murcia, SE Spain) belonging to the Spanish Institute of Oceanography (IEO). Our results shown that the horizontal eye diameter (ED) could be used to estimate the notochord length (NL) of bluefin tuna larvae up to complete notochord flexion (around 15 days old), using the equation: NL= 1.81953 + 6.5031 ED (r2 = 89.79%, p<0.001).El presente estudio intenta resolver la problemática asociada a la dificultad de medir la longitud de larvas de atún rojo (Thunnus thynnus L.) cuando éstas se curvan debido a varios factores (al congelarlas, fijarlas, debido a la manipulación o en la fase de flexión de la notocorda). Para ello, se ha estudiado la relación existente entre el diámetro ocular (que usualmente no se ve afectada por los citados factores) y la longitud estándar en 1143 larvas de atún rojo desde la pigmentación del ojo hasta la completa flexión de la notocorda (entre dos y quince días después de la eclosión) cultivadas en las instalaciones de la Planta de Cultivos Marinos de Mazarrón (Murcia), del Instituto Español de Oceanografía (IEO). Nuestros resultados muestran que la medida horizontal del diámetro ocular (LO) puede ser utilizada para la estimación de la longitud de la notocorda (LN) de larvas de atún rojo que han completado la flexión de la notocorda (alrededor de 15 días de vida) usando la ecuación LN= 1,81953 + 6,5031 LO (r2 = 89,79%, p<0.001)

Manipulación, transporte y adaptación de juveniles de atún rojo (Thunnus thynnus) a instalaciones en tierra

La presente comunicación muestra las últimas técnicas desarrolladas por el equipo de cultivo de túnidos del Instituto Español de Oceanografía (IEO) para la captura, la manipulación, el transporte y la adaptación a instalaciones en tierra, de juveniles de atún rojo (Thunnus thynnus). La técnica utilizada para la captura fue usando anzuelos sin muerte. El uso de bolsas de plástico llenas de agua de mar resultó muy eficaz al eliminar prácticamente los daños por abrasión, y permitiendo medir, pesar, marcar/identificar con pit-tags, y obtener muestras para caracterización genética, de forma no traumática.The present communication shows the last techniques developed by the tunid aquaculture team belonging to Spanish Institute of Oceanography (IEO), for capturing, handling, transporting and adapting to the land based facilities of bluefin tuna juveniles (Thunnus thynnus). The technique for capturing was using barbless hooks. The use of soft plastic bags filled with sea water was very effective avoiding practically the injures due to the abrasion, allowing to obtain the size and weight, the tagging with pit-tags and the samples collection for genetic characterization, in a non traumatic way

Estimación del crecimiento de juveniles de atún rojo ( Thunnus thynnus ) en instalaciones en tierra mediante el uso de un sistema de visión estereográfica

En esta comunicación se presentan los resultados de crecimiento de alrededor de 80 juveniles de atún rojo criados entre el 15 de febrero de 2018 y el 22 de enero de 2019 (300 días) en un tanque de 22 m de diámetro y 10 m de profundidad de la Instalación del IEO para el Control de la Reproducción del Atún rojo (ICRA). Los datos de crecimiento en talla y en peso se obtuvieron de forma no invasiva mediante un sistema de estéreo-video cámaras. El peso medio inicial fue de 2,90 kg (CV=14,2%) y el final 14,1 kg (CV=23%) con una tasa específica diaria de crecimiento (SGR%) de 0,73. El índice de conversión FIFO estuvo en torno a 14 con una tasa de conversión de alrededor de 4 (considerando 70% de agua en la carnada).The growth of around 80 bluefin tuna juveniles, reared between 15th February 2018 and 22nd January 2019 (300 days) in a 22m diameter and 10m depth tank held in the IEO bluefin tuna reproduction facility (ICRA) are shown in the present study. The growth data in size and weight have been obtained in a non invasive way by means of a stereo-video camera system. The initial and final mean weight were 2.90 kg (VC=14.2%) and 14.1 kg (VC=23%) with a specific daily growth rate of 0.73, a FIFO index about 14 and a conversion rate close to 4 (considering 70% water in the bait

IMPORTANCE OF DIETARY TAURINE AND SELENIUM ON GROWTH AND SURVIVAL OF ATLANTIC BLUEFIN TUNA Thunnus thynnus LARVAE

One of the most important bottleneck in the farming of Atlantic bluefin tuna (ABT) is the growth and survival during the larval rearing phase, mainly related with the diet quality. For the last ten years the Spanish Institute of Oceanography (IEO) in Mazarrón (Murcia, SE Spain) has developed a technique for ABT larval rearing and juvenile production. Taurine and selenium are essential water soluble compounds in live preys and inert diets for ABT larvae and juveniles. To know the importance of dietary taurine and selenium on growth and survival of ABT larvae, two experiments have been carried out with different taurine (Exp1) and selenium (Selplex® ) (Exp2) doses added to rotifers enriched with ALGAMAC 3050® . Both experiments were finished at 14 days post hatching. ABT fertilized eggs were collected from captive breeders spawning spontaneously in floating cages in the area. The eggs, transported to the IEO facilities, were quantified, cleaned, selected by buoyancy and distributed randomly in 1400 L fiber cylindrical glass tanks at a density of 10 ABT eggs per liter, whereas prey density was maintained at 5 rotifers per mL. Temperature ranges were: 24.0±0.5ºC and 26.0±0.5ºC for Exp1 and Exp2, respectively. Fig 1 shows the growth results in size for both experiments at 14 dph. Survival in both cases was close to 10% with no significant differences due to the different treatments. The lowest growth in size was observed in larvae fed dose 0 in both experiments Standard length average (mm ± confidence intervals) in Exp1 and Exp2 at 14 dph. Letters indicate statistically significant differences (95%

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries