Modeled Buoyancy of eggs and larvae of the deep-sea shrimp Aristeus antennatus (Crustacea: Decapoda) in the northwestern Mediterranean Sea

Information on the buoyancy of eggs and larvae from deep-sea species is rare but necessary for 30 explaining the position of non-swimming larvae in the water column. Due to embryonic 31 morphology and ecology diversities, egg buoyancy has important variations within one species and 32 among other ones. Nevertheless, it has hardly been explored if this buoyancy variability can be a 33 strategy for deep-sea larvae to optimize their transport beyond their spawning areas. In the 34 northwestern Mediterranean Sea, protozoea and mysis larvae of the commercial deep-sea shrimp 35 Aristeus antennatus were recently found in upper layers, but to present, earlier stages like eggs and 36 nauplii have not been collected. Using a Lagrangian transport model and larval characteristics, we 37 evaluate the buoyancy and hydrodynamic effects on the transport of A. antennatus larvae in the 38 northwestern Mediterranean Sea. The transport models suggested that 75% of buoyant eggs 39 released between 500 and 800 m depth (i.e., known spawning area), reached the upper water layers 40 (0-75 m depth). Then, according to the modeled larval drifts, three spawning regions were defined 41 in the studied area: 1) the northern part, along a continental margin crossed by large submarine 42 canyons; 2) the central part, with two circular circulation structures (i.e., eddies); and 3) the 43 southern part, with currents flowing through a channel. The number of larvae in the most upper 44 layer (0-5 m depth) was higher if the larval transport model accounted for the ascent of eggs and 45 nauplii (81%) instead of eggs reaching the surface before hatching (50%). The larvae reaching the 46 most water upper layer (0-5 m depth) had higher rates of dispersal than the ones transported below 47 the surface layer (deeper than 5 m depth). The results of larval dispersal simulations have 48 implications for the understanding of A. antennatus larval ecology and for management decisions 49 related to the shrimp fisheries in the northwestern Mediterranean S

PHEMTO: the polarimetric high energy modular telescope observatory

Based upon dual focusing techniques, the Polarimetric High-Energy Modular Telescope Observatory (PHEMTO) is designed to have performance several orders of magnitude better than the present hard X-ray instruments, in the 1–600 keV energy range. This, together with its angular resolution of around one arcsecond, and its sensitive polarimetry measurement capability, will give PHEMTO the improvements in scientific performance needed for a mission in the 2050 era in order to study AGN, galactic black holes, neutrons stars, and supernovae. In addition, its high performance will enable the study of the non-thermal processes in galaxy clusters with an unprecedented accuracy.Open access funding provided by Istituto Nazionale di Astrofisica within the CRUI-CARE Agreement

Estimating spawning locations of the deep-sea red and blue shrimp Aristeus antennatus (Crustacea: Decapoda) in the northwestern Mediterranean Sea with a backward trajectory model

Ocean Sciences Meeting (OSM), 16-21 February 2020, San Diego, CA, USAThe deep-sea red and blue shrimp Aristeus antennatus is a commercially valuable species for Spanish fishing harbors of the northwestern Mediterranean Sea. Since 2012, some fishermen of the deep-sea shrimp follow a local management plan which restricts fishing in certain areas to sustain the resource. However, little is known about the dispersal of larvae; specifically, it is not known how far larvae can be transported from spawning areas and if there could be mixing of larvae from different fishing grounds. The objective of this study was to estimate the spawning sites of larvae that were collected on a field campaign in 2016, evaluate uncertainty related to model parameterizations, and determine if collected larvae could have come from the restricted fishing areas. Using a 3-dimensional coupled hydrodynamic and Lagrangian transport model, the spawning sites of the larvae were estimated by backwards simulation of larval trajectories from the sampling stations. The backtracked larvae were assigned temperature-dependent stage durations based on a literature review of similar species. Simulated larvae were released from the sampling locations and then were backtracked to spawning sites, with median distances from starting to ending locations of 11 and 38 km when minimum and maximum Pelagic Larval Durations were implemented, respectively. Uncertainty analysis of backward trajectories showed that distance estimates could vary by as much as 27 and 3 km due to differences in how simulated Pelagic Larval Durations and turbulent mixing were parameterized. Of the 35 sampling stations from which larvae were backtracked to fishing grounds, 13 were tracked back to multiple fishing grounds, suggesting that mixing of larvae from different fishing grounds does occur. These results support the idea of multiple connectivities between subpopulations of the A. antennatus and may help inform regional management plansPre-doctoral grants: Spanish Ministry of Economy and Competitiveness (FPI2015: BES-2015-074126) - CONECTA’s project (CTM2014-54648-C2-1-R)Peer reviewe

Larval transport of Aristeus antennatus shrimp (Crustacea: Decapoda: Dendrobranchiata: Aristeidae) near the Palamós submarine canyon (NW Mediterranean Sea) linked to the North Balearic Front

Este artículo contiene 10 páginas, 7 figuras.Marine fronts are oceanographic drivers for marine species dispersal, especially for their pelagic organisms like the larvae. Larvae can aggregate at the front and consequently have a limited dispersal, which in turn reduces the connectivity between marine populations. Due to the high variations in the ocean, the fronts also have annual changes (i.e., its formation period, gradient, and position), which have poorly-documented effects on larval retention. In the northwestern Mediterranean Sea, a surface density front is localized across a continental margin which is also indented by submarine canyons. There, an abundant population of the commercial deep-sea blue and red shrimp Aristeus antennatus (Crustacea: Decapoda: Dendrobranchiata: Aristeidae) inhabits the seafloor. Each summer, the shrimp offspring are released in pelagic deep-sea and access the superficial waters divided by the density front. In this study, we focused on the interannual variability of the density front influence on the larval transport of shrimps and its repercussions on the potential connectivity between shrimp populations at each front side. A particle-tracking model simulated the larval transport of A. antennatus in hydrodynamics of the northwestern Mediterranean Sea between the years 2006 and 2016. Larval drift distance and seawater density were correlated by 98%. Over the years 2006–2016, the front region retained 86% of larvae, but this rate yearly varied due to changes in density gradient and position of the front. For example, in 2010, 48% of larvae connected to zones south of the front when the density gradient was relatively low. In 2015, 99.2% of larvae were retained in the front region when the latitudinal front position and density gradient were relatively high. Interannual variability of the front position was potentially related to the strength and position of mesoscale circulation patterns. Our findings suggest that the larval retention on habitats favored by canyon productivity because of the front could explain the persistent abundance of A. antennatus population. This information is important to set or improve the fisheries management in zones with strong interannual hydrodynamic variability.Fundings were provided through the CONECTA’s project supported by the Ministerio de Economia, Industria y Competividad from Spain Government. M. C-H is funded under the FPI PhD program of the Spanish government.With the funding support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S), of the Spanish Research Agency (AEI).Peer reviewe

Abundance and distribution of the deep-sea shrimp Aristeus antennatus larvae along the eastern Spanish Mediterranean coast (GSA 6)

12 pages, 8 figures, 2 tables, supplementary data https://doi.org/10.1016/j.jmarsys.2021.103611The deep-sea blue and red shrimp Aristeus antennatus is a valuable fishing resource in the Northwestern Mediterranean Sea, currently under a local co-management plan in the port of Palamós (Spain). The management measures, although effective, might benefit other ports due to the dispersal patterns of the species pelagic larvae. Gathering information about A. antennatus larval distribution is a key step to describe these patterns, towards the establishment of well-dimensioned management measures. After a first detection of its larvae as the dominant species in the decapod community in Blanes submarine canyon, this broader approach tackles the entire management area along the Eastern Spanish Mediterranean coast (Geographic Subarea 6; GSA 6). Zooplankton sampling was carried out at 101 stations in surface waters (0.5–1 m) and in 8 stations in stratified vertical sampling (0–1200 m) during July–August 2016. Over 6500 A. antennatus larvae of all known stages were found, the first protozoea (PZ I) representing over 95% of the total. This is the first study taking into account the vertical migration of A. antennatus larvae, and we observed a broad distribution of PZ I throughout the water column. Plankton observations of the species larval distribution were supported by an Individual-Based Model suggesting aggregations in the northern submarine canyons, influenced by cold waters from the Northern Current and the geomorphology of the Ibiza Channel. The present study proposes a division of the GSA 6 in three zones to improve fishery management measuresThis research was carried out within project CONECTA, funded by the Spanish Ministerio de Economía y Competitividad (MINECO) [grant number CTM2014-54648-C2]. MC benefited from a FPU2015 grant from the Spanish Ministerio de Educación y Formación Profesional. MCH benefited from a FPI2014 grant from the Spanish Ministerio de Ciencia e InnovaciónWith the institutional support of the ‘Severo OchoaCentre of Excellence’ accreditation (CEX2019-000928-S)Peer reviewe

Modeled buoyancy of eggs and larvae of the deep-sea shrimp Aristeus antennatus (Crustacea: Decapoda) in the northwestern Mediterranean Sea

Este artículo contiene 24 páginas, 9 figuras, 2 tablas.Information on the buoyancy of eggs and larvae from deep-sea species is rare but necessary for explaining the position of non-swimming larvae in the water column. Due to embryonic morphology and ecology diversities, egg buoyancy has important variations within one species and among other ones. Nevertheless, it has hardly been explored if this buoyancy variability can be a strategy for deep-sea larvae to optimize their transport beyond their spawning areas. In the northwestern Mediterranean Sea, protozoea and mysis larvae of the commercial deep-sea shrimp Aristeus antennatus were recently found in upper layers, but to present, earlier stages like eggs and nauplii have not been collected. Using a Lagrangian transport model and larval characteristics, we evaluate the buoyancy and hydrodynamic effects on the transport of A. antennatus’ larvae in the northwestern Mediterranean Sea. The transport models suggested that 75% of buoyant eggs released between 500 and 800 m depth (i.e., known spawning area), reached the upper water layers (0–75 m depth). Then, according to the modeled larval drifts, three spawning regions were defined in the studied area: 1) the northern part, along a continental margin crossed by large submarine canyons; 2) the central part, with two circular circulation structures (i.e., eddies); and 3) the southern part, with currents flowing through a channel. The number of larvae in the most upper layer (0–5 m depth) was higher if the larval transport model accounted for the ascent of eggs and nauplii (81%) instead of eggs reaching the surface before hatching (50%). The larvae reaching the most water upper layer (0–5 m depth) had higher rates of dispersal than the ones transported below the surface layer (deeper than 5 m depth). The results of larval dispersal simulations have implications for the understanding of A. antennatus larval ecology and for management decisions related to the shrimp fisheries in the northwestern Mediterranean Sea.This work was supported by the Ministerio de Economı´a, Industria y Competitividad, Gobierno de España (BES-2015- 074126) to support her PhD within the CONECTA project (CTM2014-54648-C2-1-R) to MC-H.With the funding support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S), of the Spanish Research Agency (AEI)Peer reviewe

Model de deriva larvària de la gamba vermella

V Jornada tècnica sobre la Gamba de Palamós celebrada el 16 de junio de 2018 en la Casa del Mar de PalamósPeer Reviewe

Influence of the Aristeus antennatus larval ecology on simulated dispersal patterns in Nord-Western Mediterranean Sea

The Crustacean Society (TCS) Mid-Year Meeting, 9-22 June 2017, BarcelonaConnectivity patterns among commercial deep-sea shrimp Aristeus antennatus fishing grounds impact the survival of local populations and shape the efficiency set of management strategies. The ecology of early life stages contributes to connectivity among fishery grounds, with spatial displacements driven by both hydrodynamical features and biological adjustment of the extent and the direction of the drift dispersal. Larval drift simulations were conducted with a biophysical model based on predicted eggs abundance map on the Northwest Mediterranean Sea and a predicted pelagic larval duration. To run the simulations, the lack of knowledge on larval behaviour was substituted by simulated drifts using different buoyancies for eggs and nauplius stages and for different patterns of vertical migration at protozoea and mysis stages. As expected, larval dispersion was higher when located near the surface layers, though it decreased with increasing depth up to 100 m depth. Eggs and nauplius with a buoyancy lower than 1.016 gr.m-3, reached the surface within 3 days from 630 m depth, drifting about 135 km in 20 days. The positive buoyancy and the movement of late larval stages at shallow waters explained the larval connectivity among fishing grounds located at relatively large distances, whereas neutral buoyancies together with migration of larvae toward shallow waters explained the connectivity among nearby fishing groundsPeer Reviewe

Modeled buoyancy of eggs and larvae of the deep-sea shrimp Aristeus antennatus (Crustacea: Decapoda) in the northwestern Mediterranean Sea

Information on the buoyancy of eggs and larvae from deep-sea species is rare but necessary for explaining the position of non-swimming larvae in the water column. Due to embryonic morphology and ecology diversities, egg buoyancy has important variations within one species and among other ones. Nevertheless, it has hardly been explored if this buoyancy variability can be a strategy for deep-sea larvae to optimize their transport beyond their spawning areas. In the northwestern Mediterranean Sea, protozoea and mysis larvae of the commercial deep-sea shrimp Aristeus antennatus were recently found in upper layers, but to present, earlier stages like eggs and nauplii have not been collected. Using a Lagrangian transport model and larval characteristics, we evaluate the buoyancy and hydrodynamic effects on the transport of A. antennatus’ larvae in the northwestern Mediterranean Sea. The transport models suggested that 75% of buoyant eggs released between 500 and 800 m depth (i.e., known spawning area), reached the upper water layers (0–75 m depth). Then, according to the modeled larval drifts, three spawning regions were defined in the studied area: 1) the northern part, along a continental margin crossed by large submarine canyons; 2) the central part, with two circular circulation structures (i.e., eddies); and 3) the southern part, with currents flowing through a channel. The number of larvae in the most upper layer (0–5 m depth) was higher if the larval transport model accounted for the ascent of eggs and nauplii (81%) instead of eggs reaching the surface before hatching (50%). The larvae reaching the most water upper layer (0–5 m depth) had higher rates of dispersal than the ones transported below the surface layer (deeper than 5 m depth). The results of larval dispersal simulations have implications for the understanding of A. antennatus larval ecology and for management decisions related to the shrimp fisheries in the northwestern Mediterranean Sea

Contribution of hydrodinamics on passive drifts of Aristeus antennatus particles-like in the North-western Mediterranean Sea

The Crustacean Society (TCS) Mid-Year Meeting, 9-22 June 2017, BarcelonaThe effectiveness of an integrated fishery management plan for the deep sea red shrimp Aristeus antennatus strongly depends on the knowledge about the displacement of individuals during their larval stage among subpopulations from different fishing grounds. To contribute to this purpose, biophysical models were used to study the potential hydrodynamic connectivity among shrimp-fishing grounds along submarine canyons in the North-western Mediterranean Sea using the spawning characteristics of the species. Modelled as passive particles, the larvae followed a main southwest drift along the continental slope and drifted up to 200 km within 31 days. The Cap Creus and Palamòs canyons were inter-connected when particles were released above 600 m depth. Only four percent of the drifters reached the estimated recruitment depth for A. antennatus at about 1,000 m depth when releases of particles took place around 800 m depth. The strength of connectivity between canyons differed with velocity fields from two different hydrodynamic models though the overall connectivity patterns prevailedPeer Reviewe