Microbial metabolism directly affects trace gases in (sub) polar snowpacks

Concentrations of trace gases trapped in ice are considered to develop uniquely from direct snow/atmosphere interactions at the time of contact. This assumption relies upon limited or no biological, chemical or physical transformations occurring during transition from snow to firn to ice; a process that can take decades to complete. Here, we present the first evidence of environmental alteration due to in situ microbial metabolism of trace gases (methyl halides and dimethyl sulfide) in polar snow. We collected evidence for ongoing microbial metabolism from an Arctic and an Antarctic location during different years. Methyl iodide production in the snowpack decreased significantly after exposure to enhanced UV radiation. Our results also show large variations in the production and consumption of other methyl halides, including methyl bromide and methyl chloride, used in climate interpretations. These results suggest that this long-neglected microbial activity could constitute a potential source of error in climate history interpretations, by introducing a so far unappreciated source of bias in the quantification of atmospheric-derived trace gases trapped within the polar ice caps

Mesoscale patterns in barnacle reproduction are mediated by upwelling-driven thermal variability

18 pages, 3 tables, 7 figuresEnvironmental variables are known to regulate the reproductive output of marine intertidal organisms, but typically these variables are studied as averages and interpreted at a macroscale level. Along 200 km of coast in NW Iberia, great variability in the reproductive activity of the stalked barnacle Pollicipes pollicipes was found among 7 different locations. We found the highest number of broods reported to date in this species and suggest a more realistic method of predicting reproductive success that takes into account sea surface temperature (SST). At these same locations, we studied 13 yr of SST, thermal upwelling index (UI), ground skin temperature and chlorophyll a (chl a) satellite data, using spectral analyses to partition their temporal variability over ecologically relevant time scales. SST played the most relevant role as an environmental driver, explaining 48% of the variability in the proportion of breeding individuals (BI), but the SST-BI goodness-of-fit decreased sharply northwards. Variance-partitioning analyses indicated that cycles between 20 and 100 d in SST and UI were more important southwards, which is consistent with a latitudinal gradient in upwelling intensity and frequency along this coast. Thus, we found better biophysical coupling towards the south, where shorter fluctuation time scales in SST match the gonadal development period (around 1 mo). This pattern may explain the spatial variability in the strength of association between key environmental variables and the reproductive cycle of coastal species along their distribution rangeThis research was funded by the BiodivERsA3 2015-2016, EU HORIZON 2020 ERA-NET COFUND and the Spanish Spanish Ministerio de Economía y Competitividad under project PERCEBES (PCIN-2016-063) and the Autonomous government Xunta de Galicia-FEDER (project ED431C-2017-46). During data processing and manuscript elaboration, S.R. was funded by a PhD fellowship from the Xunta de Galicia (ED481A-2020/199) and N.W. by NASA grant 80NSSC20K0074. C.M. was supported by a contract through project PCIN-2016-063. G.M. was supported by post-doctoral contracts from projects MARISCO (CTM2014-51935-R, Spanish Ministerio de Economía y Competitividad) and PERCEBES (PCIN-2016-063). A.A. was supported by a FPU fellowship (FPU2016-04258, Spanish Ministry of Science, Innovation and Universities). J.S., P.S., B.B. and R.O. were funded by the European Maritime and Fisheries Fund (EMFF) Operational Programme for Spain (2014-2020), and the Consellería do Mar. D.V.-R. was funded by the Marie Sklodowska-Curie grant agreement No. 793627 (BEMAR, EU Horizon 2020 research and innovation programme)Peer reviewe

Research priorities for seafood-dependent livelihoods under ocean climate change extreme events

The current magnitude of ocean extreme events already exceeds the end-of-the-decade scenario estimates, and therefore incremental adaptation measures will render insufficient for seafood-dependent livelihoods. Nevertheless, transformational change is deemed promising, but uncertainties remain as to what activates such processes and how maladaptation outcomes can be avoided. While the science on extreme events is advancing fast, little is known about livelihood adaptation and transformation processes in the context of single or compound ocean extreme events. We identify a set of research priorities: 1) the identification of hotspot areas for coastal compound extreme events, 2) the development of bottom-up case study analysis of adaptation to extreme events, 3) the identification of constrainers and enablers to livelihood adaptation and transformation under abrupt change, and 4) directing research to contribute to climate -change policy. An effort addressing these key gaps will inform seafood-dependent livelihood adaptation policies for the 2030 Agenda and beyond

Diverse pathways for climate resilience in marine fishery systems

Both the ecological and social dimensions of fisheries are being affected by climate change. As a result, policymakers, managers, scientists and fishing communities are seeking guidance on how to holistically build resilience to climate change. Numerous studies have highlighted key attributes of resilience in fisheries, yet concrete examples that explicitly link these attributes to social‐ecological outcomes are lacking. To better understand climate resilience, we assembled 18 case studies spanning ecological, socio‐economic, governance and geographic contexts. Using a novel framework for evaluating 38 resilience attributes, the case studies were systematically assessed to understand how attributes enable or inhibit resilience to a given climate stressor. We found population abundance, learning capacity, and responsive governance were the most important attributes for conferring resilience, with ecosystem connectivity, place attachment, and accountable governance scoring the strongest across the climate‐resilient fisheries. We used these responses to develop an attribute typology that describes robust sources of resilience, actionable priority attributes and attributes that are case specific or require research. We identified five fishery archetypes to guide stakeholders as they set long‐term goals and prioritize actions to improve resilience. Lastly, we found evidence for two pathways to resilience: (1) building ecological assets and strengthening communities, which we observed in rural and small‐scale fisheries, and (2) building economic assets and improving effective governance, which was demonstrated in urban and wealthy fisheries. Our synthesis presents a novel framework that can be directly applied to identify approaches, pathways and actionable levers for improving climate resilience in fishery systems

Diverse pathways for climate resilience in marine fishery systems

Includes authors from ICES.</p