An ASPIC Based Assessment of Redfish (S. mentella and S. fasciatus) in NAFO Divisions 3LN (assuming that the highest apparently sustained historical average level of catch is a sound proxy to MSY)

There are two species of redfish in Divisions 3L and 3N, the deep-sea redfish (Sebastes mentella) and the Acadian redfish (Sebastes fasciatus) that have been commercially fished and reported collectively as redfish in fishery statistics. Redfish in Div. 3LN is regarded as a management unit composed of two Grand Bank populations from those two very similar redfish species. The present ASPIC assessment is based on the logistic form of a non-equilibrium surplus production model (Schaeffer, 1954; Prager, 1994), adjusted to a standardized catch rate series (Power, 1997) and to most of the stratified-random bottom trawl surveys conducted in various years and seasons in Div. 3L and Div. 3N from 1978 onwards. Both CPUE and surveys were used with all observations of each series. This assessment is not a follow up of the previous ones (Ávila de Melo et al., 2012 and 2010). The logistic Schaefer production model (1954) incorporated in ASPIC operating model (Prager, 1994) can not cope anymore with the most recent biomass increases observed in both spring and (mainly) autumn Canadian 3LN surveys, unless it is allowed to provide unrealistic assessment results. And continuing to strip off the highs of each one of these series, in order to get a picture in line to what is the perception of the stock history from commercial and survey data trends, is no longer a valid option, as reflected on the last STACFIS research recommendation on this matter (NAFO, 2012). Being so, input has been reframed opening room to a new combination of Canadian autumn 3L and 3N surveys. The inclusion of the Spanish spring survey on Div. 3N and the removal of the historical CPUE series have also been considered. Two selected frameworks options have finally run with MSY kept constant at an initial starting guess, instead of being estimated by the model. Before entering the latest (2013) ASPIC Suite flow, the input selected from exploratory analysis was submitted to a sensitivity test in order to evaluate the robustness of the new framework against variability on random number seed, start user guesses for key model parameters and last year survey biomass. The consistency of the new ASPIC assessment with their predecessors was checked by comparison of biomass and fishing mortality fit trajectories against previous ones from the 2012 and 2010 assessments. A 2014-2012 retrospective analysis was also performed with good results (small retro bias on relative biomass and fishing 2 mortality in response to the general increase of the still standing survey series), and the assessment pursued successfully to bootstrap mode (again good consistency with previous results) and projections. A medium term management plan is finally proposed, based on bi-annual increases of the catch from the present TAC level of 6 500 t up to target catch/TAC of 18 100 t, the 2014 equilibrium yield from the present assessment, that should be in place by 2019-2020. This management plan allows, with a very high probability, that biomass is kept above Bmsy and fishing mortality below Fmsy

A Revised Update of the 2014 ASPIC Assessment of Redfish (S. mentella and S. fasciatus) in Divisions 3LN (how the the stock is coping with the actual Management Strategy and its likely impact on the next coming years).

There are two species of redfish in Divisions 3L and 3N, the deep-sea redfish (Sebastes mentella) and the Acadian redfish (Sebastes fasciatus) that have been commercially fished and reported collectively as redfish in fishery statistics. Both species, occurring on Div. 3LN and managed as a single stock, don’t belong to isolated local populations but, on the contrary, are part of a large Northwest Atlantic complex ranging from the Gulf of Maine to south of Baffin Island. The present ASPIC assessment of this stock is based on the logistic form of a non-equilibrium surplus production model (Schaeffer, 1954; Prager, 1994), adjusted to a standardized catch rate series (Power, 1997) and, for the first time, to all stratified-random bottom trawl surveys conducted in various years and seasons in Div. 3L and Div. 3N from 1978 onwards. Both CPUE and surveys were used with all observations within each series. In order to proceed on the threshold of the new 2014 approach, and taking into account that since then no substantial changes appear to have occurred on the state of the stock, the main features of the previous input framework were kept, with MSY fixed at 1960-1985 average catch and the rest of the approved 2014 assessment framework updated. The 3L Spanish survey, the only ongoing survey so far outside the analysis, has now been successfully included on this assessment framework (relative inter-quartile range from bootstrap analysis for the last two assessments highlight the higher consistence of most of the 2016 assessment results when compared with the ones from 2014). ASPIC assessment results confirm a stable stock from the 1960’s to the first half of the 1980’s, sustaining an average yield of 21 000t. Stock declined with a sudden rise of the catch over the late 1980’s first half of the 1990, and increased since then, after catches fell to a residual level with the stock collapse. Assessment results also confirm that the maximum observed sustainable yield (MSY) of 21 000 t can be a long term sustainable yield if fishing mortality stands at 0.11/year, exploiting a correspondent Bmsy at 190 000 t. 2 There is a very high probability that the stock was at the beginning of 2016 at or above Bmsy , after crossing 2015 under a fishing mortality most likely at or below 50% Fmsy. There is also a very high probability that catch on 2016 at 10 400 t TAC and on 2017 and 2018 at the predicted increases approved in the 2014 Risk‐Based Management Strategy for 3LN Redfish, will keep fishing mortality on 2018 below Fmsy and biomass at the beginning of 2019 above Bmsy.Postprint0,000

The status of redfish (S. mentella and S. fasciatus) in Divisions 3LN and two medium term scenarios (when recruitment is low, Risk Based Management Strategy or common sense?)

There are two species of redfish in Divisions 3L and 3N, the deep-sea redfish (Sebastes mentella) and the Acadian redfish (Sebastes fasciatus) that have been commercially fished and reported collectively as redfish in fishery statistics. Both species, occurring on Div. 3LN and managed as a single stock, don’t belong to isolated local populations but, on the contrary, are part of a large Northwest Atlantic complex ranging from the Gulf of Maine to south of Baffin Island. The ASPIC assessment of this stock is based on the logistic form of a non-equilibrium surplus production model (Schaeffer, 1954; Prager, 1994), adjusted to a standardized commercial catch rate series (Power, 1997) and to all stratified-random bottom trawl surveys conducted in various years and seasons in Div. 3L and Div. 3N from 1978 onwards. Both CPUE and surveys were used with all observations within each series. The 2020 assessment proceed on the threshold of the new 2014 approach, with MSY fixed at 1960- 1985 average catch and the rest of the approved 2014 assessment framework updated. ASPIC results present a stock stable from the 1960’s to the first half of the 1980’s while sustaining an average yield of 21 000t. Stock declined with a sudden rise of the catch over the late 1980’s first half of the 1990’s, and started to gradually recover after catches fell to a residual level in response to stock collapse. The maximum observed sustainable yield (MSY) of 21 000 t is linked to a Fmsy at 0.11/year and a Bmsy at 185 000 t. There is a high probability (>90%) that the stock was at least 38% above Bmsy at the beginning of 2020, after crossing 2019 under a fishing mortality not higher than 46% Fmsy

An Assessment of Beaked Redfish (S. mentella and S. fasciatus) in NAFO Division 3M (With a Revised Approach to Quantify the Increase on Redfish Natural Mortality Determined by the Increase on Cod Predation Observed Over Recent Years, 2006-2012)

The 3M redfish assessment is focused on the beaked redfish, regarded as a management unit composed of two populations from two very similar species: the Flemish Cap S. mentella and S. fasciatus. The reason for this approach is the historical dominance of this group in the 3M redfish commercial catch until 2005. However a new golden redfish fishery (S. marinus) started on September 2005 on shallower depths of the Flemish Cap bank above 300m, and the Flemish Cap cod fishery reopened in 2010. These new realities implied a revision of catch estimates, in order to split recent redfish commercial catch and by-catch from the major fleets on Div. 3M into golden (S. marinus) and beaked (S. mentella and S. fasciatus) redfish catches. An Extended Survivor Analysis (Shepherd, 1999) was used with the same framework of previous assessments and with the tuning of the 1989-2012 EU survey. Survey results suggest that the beaked redfish stock has not been able to hold its growth and sustain an above average level, suffering instead a severe decline on the second half of the 2000’s. The most likely hypothesis to justify this unexpected downward trend on stock size is an increase in natural mortality by cod predation. From the sensitive analysis, natural mortality at 0.4 was applied on ages 4-6 through 2006-2010, and extended to ages 7 plus on 2009 and 2010. It has been kept constant through all ages on 2011 and 2012, but with an overall decline to 0.125.This is the highest possible level of natural mortality giving assessment results in line with the recent survey trends and at the same time with key diagnostics very close to the best ones, obtained with the return on 2011-2012 to the “standard” redfish natural mortality of 0.1. A 2013-2009 retrospective XSA was also carried out, being this assessment very much in line with their immediate predecessors (2012-2011). Above average year classes coupled with low fishing mortalities allowed a rapid growth of biomass and abundance since 2003 that pushed the stock to a 2008-2009 high. Between 2009 and 2011 biomass and abundance of exploitable and 7 plus female stock went down for causes other than fishing. These declines were halted at well above average levels on the terminal year and, at least for biomass, there was some improvement on 2012. The recruitment at age 4 increased from 2002 till 2006 and was kept at a high level until 2009, with 2005 year class as the most abundant year class of the assessment interval. Recruitment to exploitable stock declined since then and is approaching the level of the weak year classes from the 1990’s. Short and medium term stochastic projections were obtained for female spawning stock biomass (SSB) under Fstatusquo , together with SSB and yield medium term probability profiles. As it was documented on the 2011 assessment F0.1 is an unacceptable management option at the current beaked redfish stock status. Keeping on 2014 and 2015 fishing mortality at its present low level will sustain on the short term a high level of female spawning biomass. But on the long term it will be natural mortality to determine the future of beaked redfish as a fishery resource

Joining Time-Resolved Thermometry and Magnetic-Induced Heating in a Single Nanoparticle Unveils Intriguing Thermal Properties

Whereas efficient and sensitive nanoheaters and nanothermometers are demanding tools, in modern bio- and nanomedicine, joining both features in a single nanoparticle still remains a real challenge, despite the recent progress achieved, Most Of it Within the last year. Here we demonstrate a successful realization of this challenge. The heating is magnetically induced, the temperature readout is optical, and the ratiometric thermometric probes are dual-emissive Eu3+/Tb3+ lanthanide complexes. The low thermometer heat capacitance (0.021 center dot K-1) and heater/thermometer resistance (1 K center dot W-1), the high temperature sensitivity (5.8%center dot K-1 at 296 K) and uncertainty (0.5 K), the physiological working temperature range (295-315 K), the readout reproducibility (>99.5%), and the fast time response (0.250 s) make the heater/thermometer nanoplatform proposed here unique. Cells were incubated with the nanoparticles, and fluorescence microscopy permits the mapping of the intracellular local temperature using the pixel-by-pixel ratio of the Eu3+/Tb3+ intensities. Time-resolved thermometry under an ac magnetic field evidences the failure of using Macroscopic thermal parameters to describe heat diffusion at the nanoscale