Are Nordic Saltmarshes Europe’s Way to ‘Live in Harmony with Nature’? Scientists Driven Future Scenarios via a Participatory Workshop

Saltmarshes have the ability to not only promote biodiversity, but to put nations on the path towards climate recovery and net-zero emissions through saltmarshes’ capability to take up carbon. As the European Union’s (EU) Green Deal sets out to reach net-zero emissions by 2050, innovative solutions will need to be identified, possibly even through better preserving century-old habitats such as saltmarshes. Based on the upcoming needs from the EU, in the Spring of 2021, a workshop was held with leading Nordic saltmarsh and blue carbon scientists using the transdisciplinary methods of Systems Thinking and Bayesian Belief Networks to identify solutions that can include saltmarshes in future policy. These joint methods elicited multiple future scenarios in which data were collected on perceived notions of the value of saltmarshes and how to better govern them to ensure their longevity. The models developed in this study include human perceptions and comprehensive quantitative scenarios through their ability to define paths forward in the form of comprehensive policy recommendations. We found through scenario analysis that a major belief among the stakeholders was numerous events of change such as ‘outreach, getting salt marshes on the political agenda and forming new narratives would help to increase saltmarsh area via conservation and restoration prioritization’ would have a positive impact of saltmarshes in Nordic countries.publishedVersio

Capturing of organic carbon and nitrogen in eelgrass sediments of southern Scandinavia

The ability of seagrass meadows to filter nutrients and capture and store CO2 and nutrients in the form of organic carbon (OC) and nitrogen (N) in their sediments may help to mitigate local eutrophication as well as climate change via meadow restoration and protection. This study assesses OC and N sediment stocks (top 50 cm) and sequestration rates within Danish eelgrass meadows. At four locations, eelgrass-vegetated and nearby unvegetated plots were studied in protected and exposed areas. The average OC and N sediment 50 cm stocks were 2.6 ± 0.3 kg OC m − 2 and 0.23 ± 0.01 kg N m − 2, including vegetated and unvegetated plots. In general, OC and N stocks did not differ significantly between eelgrass meadows and unvegetated sediments. Lack of accumulation of excess 210Pb suggested sediment erosion or low rates of sediment accumulation at most sites. OC accumulation rates ranged from 6 to 134 g m − 2 yr − 1 and N from 0.7 to 14 g m − 2 yr − 1. Generalized additive models showed that ≥ 80 % of the variation in sediment OC and N stocks was explained by sediment grain size, organic matter source, and hydrodynamic exposure. Long cores, dated with 210Pb, showed declining OC and N densities toward present time, suggesting long-term declines in eelgrass OC and N pools. Estimates of potential nation-wide OC and N accumulation in eelgrass sediments show that they could annually capture up to 0.7 % ± 0.5 % of CO2 emissions and 6.9 % ± 5.2 % of the total terrestrial N load

Region-specific drivers cause low organic carbon stocks and sequestration rates in the saltmarsh soils of southern Scandinavia

Saltmarshes are known for their ability to act as effective sinks of organic carbon (OC) and their protection and restoration could potentially slow down the pace of global warming. However, regional estimates of saltmarsh OC storage are often missing, including for the Nordic region. To address this knowledge gap, we assessed OC storage and accumulation rates in 17 saltmarshes distributed along the Danish coasts and investigated the main drivers of soil OC storage. Danish saltmarshes store a median of 10 kg OC m−2 (interquartile range, IQR: 13.5–7.6) in the top meter and sequester 31.5 g OC m−2 yr−1 (IQR: 41.6–15.7). In a global context, these values are comparatively low. Soils with abundant clay (&gt; 20%), older and stable saltmarshes in mesohaline settings, and with low proportion of algal organic material showed higher OC densities, stocks, and accumulation rates. Grazing led to significantly higher OC stocks than neighboring ungrazed locations, likely due to trampling modifying soil abiotic conditions (higher erosion-resistance and higher clay content) that slow carbon decay. Scaling up, Danish saltmarsh soils, comprising about 1% of the country's area, have the potential to yearly capture up to 0.1% of Denmark's annual consumption-based CO2 emissions. Our research expands the baseline data needed to advance blue carbon research and management in the Nordic region while highlighting the need for a more comprehensive approach to saltmarsh management that considers the full range of services of these ecosystems and does not only focus on climate benefits.</p

Toxic effects and bioaccumulation of nano-, micron- and ionic-Ag in the polychaete, \u3ci\u3eNereis diversicolor\u3c/i\u3e

There is increasing concern about the toxicities and potential risks, both still poorly understood, of silver nanoparticles for the aquatic environment after their eventual release via wastewater discharges. In this study, the toxicities of sediment associated nano (\u3c100 \u3enm)-, micron (2–3.5 μm)- and ionic (AgNO3)-Ag on the sediment-dwelling polychaete, Nereis diversicolor, were compared after 10 days of sediment exposure, using survival, DNA damage (comet assay) and bioaccumulation as endpoints. The nominal concentrations used in all exposure scenarios were 0, 1, 5, 10, 25, and 50 μg Ag/g dry weight (dw) sediment. Our results showed that Ag was able to cause DNA damage in Nereis coelomocytes, and that this effect was both concentrationand Ag form-related. There was significantly greater genotoxicity (higher tail moment and tail DNA intensities) at 25 and 50 μg/g dw in nano- and micron-Ag treatments and at 50 μg/g dw in the ionic-Ag treatment compared to the controls (0 μg/g dw). The nano-Ag treatment had the greatest genotoxic effect of the three tested Ag forms, and the ionic-Ag treatment was the least genotoxic. N. diversicolor did accumulate sediment-associated Ag from all three forms. Ag body burdens at the highest exposure concentration were 8.56 ± 6.63, 6.92 ± 5.86 and 9.86 ± 4.94 μg/g dw for worms in nano-, micron- and ionic-Ag treatments, respectively, but there was no significant difference in Ag bioaccumulation among the three treatments

DNA sequence baits targeting ultra-conserved elements in marine invertebrates

This dataset includes four files of DNA sequence baits targeted to ultra-conserved elements (UCEs) identified from four different taxonomic groups of marine invertebrates: Annelida, Bivalvia, Gastropoda and Crustacea. UCE loci are genomic regions of high conservation that can be found throughout the genomes that can be extracted from the genome and sequenced for use in phylogenetic, phylogeographic and population genetic analyses. The UCE loci were located by aligning a minimum of five species’ genomes to a base genome in each taxonomic group and searching for overlapping highly conserved areas. The UCE baits were designed with screening coverage of 4X using the pipeline phyluce v. 1.6.6 (https://github.com/faircloth-lab/phyluce; Faircloth 2015). The analysis generated 3316 baits for 590 conserved loci in annelids, 4110 baits for 519 loci in bivalves, 25547 baits for 4367 loci in gastropods and 27545 baits for 3755 conserved loci in crustaceans. A final set of 3000 baits per taxonomic group (12000 baits in total) was created by Arbor Biosciences (Ann Arbor, MI, USA, arborbiosci.com) using their myBaits probe design support. For more detailed documentation, see the downloadable dataset description file

Ultra-conserved elements provide insights to the biogeographic patterns of three benthic macroinvertebrate species in the Baltic Sea

The Baltic Sea, with its steep salinity gradient, high water retention time, and relatively young age, represents a marginal ecosystem between marine and freshwater extremes. Due to differing invasion history and dispersal capabilities of Baltic species, there are large differences in species distributions, species-specific genetic structure and variation, and edge populations that may represent both a subset of the original population, as well as unique genetic lineages. We used a phylogenomic approach to investigate relationships between populations of three benthic macroinvertebrate species: Pygospio elegans, Corophium volutator, and Mya arenaria, providing new insight into evolutionary dynamics among populations in the Baltic Sea and the adjacent North Sea. We found little relation among the populations of P. elegans and C. volutator, in contrast to M. arenaria, which exhibits a higher degree of resemblance between populations. We also found low relation within sites sampled at different times of the year for all species. Each species exhibited unique phylogenetic patterns, suggesting the North Sea populations of P. elegans and M. arenaria are closely related to populations within the Baltic Sea, and with only C. volutator showing trends resembling isolation by distance. These differences could be explained by both their different invasion histories and dispersal capabilities of the individual species.peerReviewe

Species and genetic diversity relationships in benthic macroinvertebrate communities along a salinity gradient

Background Species- and genetic diversity can change in parallel, resulting in a species-genetic diversity correlation (SGDC) and raising the question if the same drivers influence both biological levels of diversity. The SGDC can be either positive or negative, depending on whether the species diversity and the genetic diversity of the measured species respond in the same or opposite way to drivers. Using a traditional species diversity approach together with ultra-conserved elements and high throughput sequencing, we evaluated the SGDCs in benthic macrofauna communities in the Baltic Sea, a geologically young brackish water sea characterised by its steep salinity gradient and low species richness. Assessing SGDCs from six focal marine invertebrate species from different taxonomic groups and with differing life histories and ecological functions on both a spatial and temporal scale gives a more comprehensive insight into the community dynamics of this young ecosystem and the extrinsic factors that might drive the SGDCs. Results No significant correlations between species diversity and genetic diversity were found for any of the focal species. However, both negative and positive trends of SGDCs for the individual focal species were observed. When examining the environmental drivers, no common trends between the species were found, even when restricting the analysis to specific taxonomic classes. Additionally, there were no common environmental factors driving the diversity relationships for species sharing the same SGDC trend (positive or negative). Local population dynamics, together with the invasion history of the individual species and their unique adaptation to the distinctive environment of the Baltic Sea, are expected to be of major influence on the outcome of the SGDCs. Conclusions The present results highlight the importance of assessing SGDCs using multiple species, not just a single indicator species. This emphasises a need to pay attention to the ecology and life history of the focal species. This study also provides insight into the large differences in both patterns and drivers of genetic diversity, which is important when including genetic biodiversity in conservation plans. We conclude that the effects of environmental and biological factors and processes that affects diversity patterns at both the community and genetic levels are likely species dependent, even in an environment such as the Baltic Sea with strong environmental gradients.peerReviewe

Bias-corrected Pearson estimating functions for Taylor`s power law applied to benthic macrofauna data

Estimation of Taylor`s power law for species abundance data may be performed by linear regression of the log empirical variances on the log means, but this method suffers from a problem of bias for sparse data. We show that the bias may be reduced by using a bias-corrected Pearson estimating function. Furthermore, we investigate a more general regression model allowing for site-specific covariates. This method may be efficiently implemented using a Newton scoring algorithm, with standard errors calculated from the inverse Godambe information matrix. The method is applied to a set of biomass data for benthic macrofauna from two Danish estuaries. (C) 2011 Elsevier B.V. All rights reserved.FAPESPCNPq (Brazil)Danish Natural Science Research Counci