Justice in fishing territories: Human rights violations in artisanal fisheries analyzed by the Colombian Constitutional Court

Seas and inland waters have historically been spaces where social struggles have been overlooked and made invisible. This article offers an interdisciplinary analysis of the Colombian Constitutional Court decisions related to human rights violations in artisanal fishing territories. We used a human rights-based approach to study 79 Constitutional Injunctions (Acciones de Tutela) and built a digital database 'Justice in Fishing Territories' (Justicia en Territorios Pesqueros). We identify and discuss the most frequently claimed and protected rights. Most Court proceedings are centered on participatory processes, indicating that actors within the artisanal fisheries sector are excluded from the discussion and approval of development projects. We conclude that the Colombian State has historically privileged the interests of industrial economic sectors to the detriment of the ways of living, territories, and rights of artisanal fishing populations.</jats:p

A Synthesis of Global Coastal Ocean Greenhouse Gas Fluxes

The coastal ocean contributes to regulating atmospheric greenhouse gas concentrations by taking up carbon dioxide (CO2) and releasing nitrous oxide (N2O) and methane (CH4). In this second phase of the Regional Carbon Cycle Assessment and Processes (RECCAP2), we quantify global coastal ocean fluxes of CO2, N2O and CH4 using an ensemble of global gap-filled observation-based products and ocean biogeochemical models. The global coastal ocean is a net sink of CO2 in both observational products and models, but the magnitude of the median net global coastal uptake is ∼60% larger in models (−0.72 vs. −0.44 PgC year−1, 1998–2018, coastal ocean extending to 300 km offshore or 1,000 m isobath with area of 77 million km2). We attribute most of this model-product difference to the seasonality in sea surface CO2 partial pressure at mid- and high-latitudes, where models simulate stronger winter CO2 uptake. The coastal ocean CO2 sink has increased in the past decades but the available time-resolving observation-based products and models show large discrepancies in the magnitude of this increase. The global coastal ocean is a major source of N2O (+0.70 PgCO2-e year−1 in observational product and +0.54 PgCO2-e year−1 in model median) and CH4 (+0.21 PgCO2-e year−1 in observational product), which offsets a substantial proportion of the coastal CO2 uptake in the net radiative balance (30%–60% in CO2-equivalents), highlighting the importance of considering the three greenhouse gases when examining the influence of the coastal ocean on climate

Hotspots of Floating Plastic Particles across the North Pacific Ocean

The pollution of the marine environment with plastic debris is expected to increase, where ocean currents and winds cause their accumulation in convergence zones like the North Pacific Subtropical Gyre (NPSG). Surface-floating plastic (>330 μm) was collected in the North Pacific Ocean between Vancouver (Canada) and Singapore using a neuston catamaran and identified by Fourier-transform infrared spectroscopy (FT-IR). Baseline concentrations of 41,600–102,700 items km–2 were found, dominated by polyethylene and polypropylene. Higher concentrations (factors 4–10) of plastic items occurred not only in the NPSG (452,800 items km–2) but also in a second area, the Papaha̅naumokua̅kea Marine National Monument (PMNM, 285,200 items km–2). This second maximum was neither reported previously nor predicted by the applied ocean current model. Visual observations of floating debris (>5 cm; 8–2565 items km–2 and 34–4941 items km–2 including smaller “white bits”) yielded similar patterns of baseline pollution (34–3265 items km–2) and elevated concentrations of plastic debris in the NPSG (67–4941 items km–2) and the PMNM (295–3748 items km–2). These findings suggest that ocean currents are not the only factor provoking plastic debris accumulation in the ocean. Visual observations may be useful to increase our knowledge of large-scale (micro)plastic pollution in the global oceans

Dataset from RNAseq analysis of differential gene expression among developmental stages of two non-marine ostracodes

We contribute transcriptomic data for two species of Ostracoda, an early-diverged group of small-sized pancrustaceans. Data include new reference transcriptomes for two asexual non-marine species (Dolerocypris sinensis and Heterocypris aff. salina), as well as single-specimen transcriptomic data that served to analyse gene expression across four developmental stages in D. sinensis. Data are evaluated by computing gene expression profiles of the different developmental stages which consistently placed eggs and small larvae (at the stage of instar A-8) similar to each other, and apart from adults which were distinct from all other developmental stages but closest to large larvae (instar A-4). We further evaluated the transcriptomic data with two newly sequenced low-coverage genomes of the target species. The new data thus document the feasibility of obtaining reliable transcriptomic data from single specimens – even eggs – of these small metazoans

Diatom-mediated food web functioning under ocean artificial upwelling

Enhancing ocean productivity by artificial upwelling is evaluated as a nature-based solution for food security and climate change mitigation. Fish production is intended through diatom-based plankton food webs as these are assumed to be short and efficient. However, our findings from mesocosm experiments on artificial upwelling in the oligotrophic ocean disagree with this classical food web model. Here, diatoms did not reduce trophic length and instead impaired the transfer of primary production to crustacean grazers and small pelagic fish. The diatom-driven decrease in trophic efficiency was likely mediated by changes in nutritional value for the copepod grazers. Whilst diatoms benefitted the availability of essential fatty acids, they also caused unfavorable elemental compositions via high carbon-to-nitrogen ratios (i.e. low protein content) to which the grazers were unable to adapt. This nutritional imbalance for grazers was most pronounced in systems optimized for CO2 uptake through carbon-to-nitrogen ratios well beyond Redfield. A simultaneous enhancement of fisheries production and carbon sequestration via artificial upwelling may thus be difficult to achieve given their opposing stoichiometric constraints. Our study suggest that food quality can be more critical than quantity to maximize food web productivity during shorter-term fertilization of the oligotrophic ocean

Seasonal variations of a coastal fish community in relation to environmental parameters - A case study of the Sylt-Rømø Bight, southeastern North Sea

The Wadden Sea is a transition area between land, rivers, and the North Sea. It is of great ecological importance for a wide range of fish species that use it in the course of their life cycle for various purposes. It is a highly dynamic environment and is subject to strong seasonal patterns and annual variations in abiotic conditions. The Sylt-Rømø Bight (SRB) is a semi-enclosed tidal basin in the northern Wadden Sea between the islands of Sylt (Germany) and Rømø (Denmark). Monthly monitoring data of juvenile fish taken in the SRB from 2007 to 2019 were analyzed to determine the changes in species composition in comparison to previous monitoring programs (1989–1995). The long-term trends, common patterns, and potential effects of environmental parameters (sea surface temperature (SST), salinity, chlorophyll a, and the North Atlantic Oscillation (NAO) winter indices) were determined. In total, 55 species were recorded and only 22 of these together accounted for more than 95% of the total abundance for the entire monitoring. Results showed a changed species composition as we did not find two boreal, one Lusitanian, and one circum-temperate species recorded in the previous programs. Instead, one boreal, six Lusitanian, and one Atlantic species were observed for the first time. The fish community was dominated by high seasonal fluctuations of abundance with either dome-shaped, increasing, or decreasing trends. Dynamic Factor Analysis (DFA) partitioned the fish community into three seasonal assemblages based on SST preferences. Redundancy Analysis (RDA) revealed that environmental parameters explained 29 % of the variations in the fish community. These variances were partly a result of the spring immigration of Lusitanian species and the emigration of boreal species and vice versa in autumn. The absence of four previously reported species and the addition of eight new species support the hypothesis that warm-adapted species are increasing in the Wadden Sea. The inclusion of these seasonal variations into conservation and management practices is critical to the sustainable management of marine and coastal ecosystems covering spawning, nursery, and feeding grounds

The Arctic summer microbiome across Fram Strait: Depth, longitude, and substrate concentrations structure microbial diversity in the euphotic zone

The long-term dynamics of microbial communities across geographic, hydrographic, and biogeochemical gradients in the Arctic Ocean are largely unknown. To address this, we annually sampled polar, mixed, and Atlantic water masses of the Fram Strait (2015–2019; 5–100 m depth) to assess microbiome composition, substrate concentrations, and oceanographic parameters. Longitude and water depth were the major determinants (~30%) of microbial community variability. Bacterial alpha diversity was highest in lower-photic polar waters. Community composition shifted from west to east, with the prevalence of, for example, Dadabacteriales and Thiotrichales in Arctic- and Atlantic-influenced waters, respectively. Concentrations of dissolved organic carbon peaked in the western, compared to carbohydrates in the chlorophyll-maximum of eastern Fram Strait. Interannual differences due to the time of sampling, which varied between early (June 2016/2018) and late (September 2019) phytoplankton bloom stages, illustrated that phytoplankton composition and resulting availability of labile substrates influence bacterial dynamics. We identified 10 species clusters with stable environmental correlations, representing signature populations of distinct ecosystem states. In context with published metagenomic evidence, our microbial-biogeochemical inventory of a key Arctic region establishes a benchmark to assess ecosystem dynamics and the imprint of climate change

Heatwave responses of Arctic phytoplankton communities are driven by combined impacts of warming and cooling.

Marine heatwaves are increasing in frequency and intensity as climate change progresses, especially in the highly productive Arctic regions. Although their effects on primary producers will largely determine the impacts on ecosystem services, mechanistic understanding on phytoplankton responses to these extreme events is still very limited. We experimentally exposed Arctic phytoplankton assemblages to stable warming, as well as to repeated heatwaves, and measured temporally resolved productivity, physiology, and composition. Our results show that even extreme stable warming increases productivity, while the response to heatwaves depends on the specific scenario applied and is not predictable from stable warming responses. This appears to be largely due to the underestimated impact of the cool phase following a heatwave, which can be at least as important as the warm phase for the overall response. We show that physiological and compositional adjustments to both warm and cool phases drive overall phytoplankton productivity and need to be considered mechanistically to predict overall ecosystem impacts

Post-depositional modification on seasonal-to-interannual timescales alters the deuterium-excess signals in summer snow layers in Greenland

Abstract. We document the isotopic evolution of near-surface snow at the East Greenland Ice Core Project (EastGRIP) ice core site in northeast Greenland using a time-resolved array of 1 m deep isotope (δ18O, δD) profiles. The snow profiles were taken from May–August during the 2017–2019 summer seasons. An age–depth model was developed and applied to each profile, mitigating the impacts of stratigraphic noise on isotope signals. Significant changes in deuterium excess (d) are observed in surface snow and near-surface snow as the snow ages. Decreases in d of up to 5 ‰ occur during summer seasons after deposition during two of the three summer seasons observed. The d always experiences a 3 ‰–5 ‰ increase after aging 1 year in the snow due to a broadening of the autumn d maximum. Models of idealized scenarios coupled with prior work indicate that the summertime post-depositional changes in d (Δd) can be explained by a combination of surface sublimation, forced ventilation of the near-surface snow down to 20–30 cm, and isotope-gradient-driven diffusion throughout the column. The interannual Δd is also partly explained with isotope-gradient-driven diffusion, but other mechanisms are at work that leave a bias in the d record. Thus, d does not just carry information about source-region conditions and transport history as is commonly assumed, but also integrates local conditions into summer snow layers as the snow ages through metamorphic processes. Finally, we observe a dramatic increase in the seasonal isotope-to-temperature sensitivity, which can be explained solely by isotope-gradient-driven diffusion. Our results are dependent on the site characteristics (e.g., wind, temperature, accumulation rate, snow properties) but indicate that more process-based research is necessary to understand water isotopes as climate proxies. Recommendations for monitoring and physical modeling are given, with special attention to the d parameter. </jats:p

Spatial distribution of small microplastics in the Norwegian Coastal Current

High concentrations of microplastic (MP) particles have been reported in the Arctic Ocean. However, studies on the high-resolution lateral and vertical transport of MPs from the European waters to the Arctic are still scarce. Here, we provide information about the concentrations and compositions of MPs in surface, subsurface, and deeper waters (300 μm), and overall, SMPs 80 % of all detected MPs. However, no statistically significant geographical patterns were observed in SMP concentrations in surface/subsurface seawaters between the six sampling transects, suggesting a relatively homogeneous horizontal distribution of SMPs in the upper ocean within the NCC/Norwegian Atlantic Current (NwAC) interface. The Lagrangian particle dispersal simulation model further enabled us to assess the large-scale transport of MPs from the Northern European waters to the Arctic