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Introduction: Even though only a few species are considered to be dangerous, pests or vectors, the majority of invertebrates produce a feeling of aversion in humans. This has contributed to the delay in the development of ethical considerations as regards this group in contrast with vertebrates, with the exception of cephalopods. Objective: In the present study, we provide an overview of the current situation on animal ethics and welfare in order to contribute to the development of a framework for ensuring invertebrate welfare. Methods: Today, animal welfare is multidisciplinary in nature to a very high degree as it includes ethology, physiology, pathology, biochemistry, genetics, immunology, nutrition, cognitive-neural, veterinary medicine, and ethics. Animal welfare is a complex concept, difficult to achieve successfully from one perspective. Results: As a consequence, we propose to include the five domains (nutrition, environment, health, behaviour and mental state) along with the three conceptions (basic health and functioning, affective state and natural living), as well as the 5R Principle (Replace, Reduction, Refinement, Respect and Responsibility) in seeking to achieve a comprehensive welfare state. Conclusions: We consider that in both research and animal production, the individual and collective ethical concerns coexist and, in fact, the main moral concern to account for is the collective one and that, within that collective view, the individual moral concern should be applied with responsibility and respect for the individual. Finally, we propose a practical example of invertebrate welfare production in sea urchin aquaculture with the aim of including animal production of invertebrates in this important discussion. [ABSTRACT FROM AUTHOR]

Introduction: The Three R's Principle (Refinement, Reduction, and Replacement), postulated more than 60 years ago, is the main ethical framework currently applied for conducting animal research. This principle has never been reviewed applying a philosophical reflection during all of these years, even though a variety of animal ethics studies have presented new insights. The Three R´s Principle was designed to be used as a policy tool to ameliorate the suffering of animals and to reduce the use of animals in research, but has failed in achieving these goals. This principle is only applied when using sentience vertebrates, and fails to consider invertebrates as their capacity to sentience is still disputed. In this way, invertebrates are reified, which has been determined to be detrimental as their suffering has been consistently denied. As a consequence, new insights are necessary to improve scientific practices. Epistemology and ethics have always been viewed as opposing approaches. ´Epistemology-based Ethics' subordinate ethical concern to scientific facts and 'Ethics-based Epistemology' purports that ethical practice should guide epistemological practices. Objective: In this paper, we maintain that unifying both approaches under a broader conceptual framework may result in the view that these are not, actually, opposite approaches. We propose to progress beyond the Three R's Principle and extend it to a position equal to the level of the ethical and epistemological approaches. We also propose to use the Precautionary Principle as it is always better to be safe than sorry, and to include two more Rs. Methods: This paper is based on the analysis of different ethical frameworks used in biology and ecology that can be implemented in invertebrates experimentation. Results: The analysis revealed that different ethical approaches are frequently used in biological research, but not all of them are implemented in experimental research that involves invertebrates. We argue that the ethical considerations used in any research field can be implemented in invertebrate research. Conclusion: We propose a Five R´s Principle: the traditional Refinement, Reduction, and Replacement, used along with Respect and Responsibility (a respectful relationship with every living being regardless of its complexity and personal commitment to conscientiously apply ethics concepts). [ABSTRACT FROM AUTHOR]

Abstract The goal of this work was to infer the spatio-temporal patterns of bottom circulation of San José Gulf (SJG), Patagonia, Argentina. The SJG is mainly affected by tidal circulation and presents two hydrographic domains. The Western Hydrographic Domain (WHD) presents vertically mixed waters year-round contrary to the seasonal stratified Eastern Hydrographic Domain (EHD), resulting in the formation of a thermal front between domains. Samples of sediments were collected in spring 2016 and summer 2017 at several locations to analyze the grain-size composition by means of laser diffractometry. A conceptual model of bottom hydrodynamics was inferred based on sediment's grain-size trends. Asymmetric dominant tidal currents affect bottom sediment distribution. A general northward sediment transport is dominant at the WHD, while at the EHD there is a seasonal shift in the transport direction. There, a net northward transport with a counterclockwise gyre dominates bottom hydrodynamics at the end of the thermal front formation, conditioned by residual currents. In contrast, a net southward circulation likely driven by strong westerly winds throughout autumn and winter prevails at the beginning of the water column stratification. The inferred sediment transport suggests a net loss of material that has to be recovered by tidal currents entering through the mouth and coastal sources as runoff, mudslides, and/or aeolian dust. Graphical abstract Image 1 Highlights • Net sediment transport in the SJG was investigated based on the grain-size analysis. • Different patterns are associated with the two hydrodynamic domains (WHD and EHD). • A general northward transport prevails in the WHD driven by the tidal currents. • Seasonal changes were detected in the EHD. • Tidal currents in the EHD are likely affected by changes in prevailing wind stress. [ABSTRACT FROM AUTHOR]

The role of Patagonian wind-borne dust as a source of macronutrients to the surface waters of the Southwest Atlantic Ocean was evaluated for the first time. During spring 2016, a series of experiments with dust was conducted to evaluate the dynamics of macronutrient dissolution in seawater. The results showed a differential contribution of macronutrients to seawater depending on the dust source and the amount added. Addition of a conservative amount of Patagonian dust to the seawater contributed nitrate (NO3-) and silicic acid (Si(OH)4), but not phosphate (PO43-). Additional dust input to the system resulted in higher macronutrient concentrations. Particles collected from a nearby burned field did not contribute any macronutrients to the seawater. Thus, each dust event may affect biological productivity differently, depending on the source of the particles. Dissolution experiments suggest that macronutrients from dust are available immediately after particle deposition on the sea surface. The study includes field measurements of macronutrient concentrations before and after a dust storm at three nearshore marine stations. The data are consistent with macronutrient increase after the storms. Dust storms could become a very important source of nutrients to the ocean in future global warming scenarios. [ABSTRACT FROM AUTHOR]

Introduction: Righting behaviour has been used as a health indicator in response to stressor variables. Using this parameter in aquaculture could help to reduce mortality and improve welfare in the sea urchin Arbacia dufresnii culture. Objective: The purpose of this study was to determine the effect of sex, diameter, and three stressor factors on the righting behaviour of the sea urchin A. dufresnii. Methods: A total of 300 animals were evaluated for complete righting behaviour (CRB) time, with 100 of them also recording half righting behaviour (HRB) time. Three stressors were applied to the animals: serial repetitions (three successive turnings), temperature (24-hour shock), and spawning induction with KCl injection. A stopwatch was used to record the time, and a precision calliper was used to measure the diameter. Results: Righting time was discovered to be diameter dependent but sex independent. The upper temperature limit of 19 °C had a significant effect on righting behaviour compared to 16 °C and 13 °C with CRB times up to 150 seconds. Serial repetitions and spawning had no significant effect. However, based on the recorded times, it can be deduced that spawning had an effect on the health of the animals, with CRB times of up to 150 seconds compared to the control, with lower times. Conclusions: Complete righting behaviour appears to be an optimal indicator for evaluating the health and condition of the sea urchin A. dufresnii, but more tests would be performed to confirm the effect of the control treatment on post-spawning stress. [ABSTRACT FROM AUTHOR]

Abstract: Traditionally, it was assumed that major spawning activity of Illex argentinus occurs in discrete pulses along the outer-shelf/slope off Argentina/southern Brazil during late-fall/winter and that early life stages develop near the Brazil–Malvinas Confluence (BMC). However, a novel hypothesis of the population structuring of the species was proposed that states that coastal waters may be important as spawning and feeding grounds. Here, we analyzed the spatial distribution of Illex argentinus inside San Matias Gulf based on the position of the CPUE of jiggers in order to improve the knowledge of the population structuring in coastal regions. Squids were mainly concentrated on the northern region of the gulf where favorable oceanographic conditions (e.g. water stratification, chlorophyll-a concentration peaks) to feeding and spawning are present. These results provided empirical evidences that individuals of I. argentinus use Argentinean coastal waters, particularly San Matias Gulf, as permanent feeding and spawning grounds which supports the new hypothesis. [Copyright &y& Elsevier]

During the last 30 years, interpretation of the population structuring of Illex argentinus evolved from a single to a six-stock model, in which stocks are characterized by having distinct spawning seasons, areas and migration patterns. It is assumed that major spawning activity occurs in discrete pulses along the outer-shelf/slope off Argentina/southern Brazil during late-fall/winter and that early life stages develop near the Brazil-Malvinas Confluence (BMC). Nevertheless, there are inconsistencies in the delimitation of stocks and the interpretation of their life histories. Here, we developed a model based on records of seawater temperature and chlorophyll- a concentration to establish the quality of different areas of the species' geographic distribution as spawning and nursery grounds. Whereas the outer-shelf/slope domain south of 37°S presents marked seasonal restrictions for embryonic development and breeding, coastal areas within 44°-28°S are highly suitable most of the year. Squid in pre-spawning aggregations at the outer-shelf/slope south of 41°S would invest less energy to reach equally suitable spawning areas at the coast than at the BMC. Findings of paralarvae, stranded juveniles and mature squid in coastal areas off northern Patagonia support the predictions of the model. Based on these results, the population structuring and reproductive-migration patterns are reviewed and a new interpretation is proposed: Illex argentinus spawns not only in discrete seasons and areas on the slope and mid/outer shelf, but also conducts quasi-permanent spawning migrations to coastal areas, resulting in a more continuous pattern of recruitment than previously considered and in weak stock differentiation. [ABSTRACT FROM AUTHOR]

The structural patterns of the mesozooplankton community of San José Gulf (SJG), a one of a kind semi-enclosed basin located in the northern margin of the Valdés Peninsula (Argentine Patagonia), were studied by means of semi-automatic image analysis. Samples were obtained bimonthly during the warm season (October 2012–April 2013) at stations distributed on a regular grid. Cluster analyses outlined two spatially consistent groups of stations showing similar patterns when based on physical (SST, Chl-a, and bottom depth) and community structure (abundance, biomass, and slope of the size spectra) descriptors, each broadly distributed on one of two previously described hydrographic domains formed by the interaction of tidal circulation, coastal morphology, bottom topography, and seasonal vertical stratification. Examination of the slope of the mesozooplankton size spectra revealed that the stratified waters of the East Domain sustain higher proportions of small organisms and higher biomass, suggesting potentially low trophic transfer efficiency compared to its vertically-mixed West counterpart. Three-clustering analyses resulted in still spatially consistent groups of stations when based on the community descriptors, revealing the existence of a transition zone, presumably resulting from intermediate hydrodynamic conditions. Principal component analysis revealed that biomass of cladocerans modulates the size spectra and is related with distances from sampling stations to SJG's mouth. Overall, a consistent spatial correlate was found between physical conditions of water masses and the structure of the mesozooplancton community contained within. [ABSTRACT FROM AUTHOR]

In order to assess the relevance of sporadic upwelling events on primary productivity, the availability of nitrogen (N) sources and their uptake by phytoplankton were studied. Incubations of 15N-enriched samples were performed at 3 depths in 12 stations in San Jorge Gulf (SJG, Patagonia Argentina) aboard of the R/V "Puerto Deseado" during November 2016. Additional coastal stations were sampled to analyze the upwelling event. The total uptake of N sources (ρNO 3 - + ρNH 4 +) was higher on the surface than in the deep layer. The ρNO 3 - by phytoplankton doubled that of ρNH 4 + suggesting SJG acted as a CO 2 sink during the period studied. However, NH 4 + played an important role in maintaining primary productivity where NO 3 − was low. In most stations, phytoplankton showed a preference for the uptake of the less available N source, likely resulting from adaptation to low nutrient concentrations. However, in the southwestern sector of the gulf, where a wind-induced upwelling occurred, phytoplankton preferred to uptake NO 3 −, this being the most abundant N source. As a consequence, the integrated primary productivity in the water column of that sector was high. Results suggest that such high productivity was governed by the optimal relationship between the preference and availability of N, established by the presence of elevated NO 3 − and low NH 4 + ambient concentration. This would be a physiological process regardless of community composition. The new primary productivity generated by upwelling events could be key to feeding the biological resources of the gulf. Image 1 • Factors controlling primary productivity in the San Jorge Gulf, Patagonia were studied. • In the upwelling, phytoplankton preferred to take up the most available nitrogen source. • Response to upwelling appears to be a physiological adaptation of the entire community. • The SW of the gulf is a sector of CO 2 sequestration and primary production export. • Upwelling events could be key to feed the gulf fishing resources. [ABSTRACT FROM AUTHOR]