Development of a multi-scale monitoring programme: approaches for the Arctic and lessons learned from the Circumpolar Biodiversity Monitoring Programme 2002-2022

The Arctic Council working group, the Conservation of Arctic Flora and Fauna (CAFF) established the Circumpolar Biodiversity Monitoring Programme (CBMP), an international network of scientists, governments, Indigenous organizations, and conservation groups working to harmonize and integrate efforts to extend and develop monitoring and assessment of the Arctic’s biodiversity. Its relevance stretches beyond the Arctic to a broad range of regional and global initiatives and agreements. This paper describes the process and approach taken in the last two decades to develop and implement the CBMP. It documents challenges encountered, lessons learnt, and solutions, and considers how it has been a model for national, regional, and global monitoring programmes; explores how it has impacted Arctic biodiversity monitoring, assessment, and policy and concludes with observations on key issues and next steps. The following are overarching prerequisites identified in the implementation of the CBMP: effective coordination, sufficient and sustained funding, improved standards and protocols, co-production of knowledge and equitable involvement of IK approaches, data management to facilitating regional analysis and comparisons, communication and outreach to raising awareness and engagement in the programme, ensuring resources to engage in international fora to ensuring programme implementation

Functional diversity of chironomid communities in subarctic lakes across gradients in temperature and catchment characteristics

Northern ecosystems are experiencing rapid and large-scale changes driven by accelerated warming, which have profound effects on the terrestrial and freshwater biodiversity. A comprehensive understanding of the distribution of aquatic biodiversity of subarctic ecosystems is therefore needed to better predict future trajectories of their unique biodiversity. In this study, we examined the functional diversity of chironomid communities in subarctic lakes across a 1000 m-elevation gradient, reflecting gradual changes in temperature and landscape characteristics. Using fuzzy correspondence analyses, we investigated spatial variability in trait composition of chironomid communities from 100 lakes in northern Sweden, and tested the hypotheses that (1) climate directly and indirectly shapes chironomid trait composition across the studied gradient, and (2) that generalist taxa with smaller body size and broader food preferences are more able to persist in cold environments. Our results showed that complex interplays between direct (e.g. temperature) and indirect climate processes (e.g. elevation-driven changes in vegetation/habitats) affect the functional diversity of chironomid communities. Specifically, traits such as larval size, food preference and feeding habits were well separated along the gradient, and this pattern revealed that low elevation lakes with forested catchments tended to have more sediment-feeding taxa and larger larvae than those above the tree line. As expected, food resource availability in lakes is strongly linked to vegetation composition/cover, and traits related to resource exploitation in chironomid communities are therefore well constrained by landscape characteristics. Furthermore, our findings suggested that short life cycles could facilitate the development of viable population in northern and high-elevation lakes where the short ice-free period is a limiting factor, thus contradicting patterns showing smaller organisms in warmer environments reported for other invertebrates. As a consequence of climate warming, the highest elevation lakes in subarctic landscapes will likely lose their typical cold-adapted chironomid taxa along with their functional attributes leading to potential impacts on the food web structure and the overall functioning of northern lake ecosystems

Interactions with freshwater biofilms cause rapid removal of common herbicides through degradation - evidence from microcosm studies

We investigated the role of periphyton biofilms for the fate of three common herbicides, i.e. bentazone, metazachlor and metribuzin, at low, environmental levels and 100 times higher, during a 16 days laboratory experiment. We found that herbicide water concentrations were stable during the first 8 days, whereas substantial declines (>78%) occurred between days 8-16 for all three herbicides. These rapid declines were explained only to a small extent (<8% of the total herbicide loss) by biofilm sorption. As herbicide concentrations in light and dark treatments without biofilms were similar, and the applied light regimen did not cover the UV-spectrum, herbicide photolysis was ruled out as a possible explanation for the observed declines. Furthermore, based on the compounds' characteristics, also volatilization was judged negligible. Therefore, we conjecture that the observed declines in herbicides were due to biodegradation and subsequent evasion of (CO2)-C-14 that was driven by enzymatic action from heterotrophic microbes. We reason that heterotrophic microbes used herbicide molecules as labile organic C-sources during C-limitation. Future studies should identify the microbial communities and genes involved in biodegradation in order to understand better the role of biofilms for the self-purification of surface waters

Fatty-acid based assessment of benthic food-web responses to multiple stressors in a large river system

Rivers are often exposed to multiple stressors, such as nutrients and contaminants, whose impacts on the river food webs may not be distinguished by sole assessment of biological community structures. We examined the benthic algal assemblages and the fatty acids (FA) of benthic macroinvertebrates in the lower Athabasca River in Canada, aiming to assess the changes in algal support and nutritional quality of the benthic food web in response to cumulative exposure to natural bitumen, municipal sewage discharge (hereafter, "sewage"), and oil sands mining ("mining"). Data show that the decline in water quality (increases in nutrient concentrations and total suspended solids) was associated with decreases in benthic diatom abundance, and was driven mainly by sewageinduced nutrient enrichment. Responses in nutritional quality of benthic macroinvertebrates, indicated by their polyunsaturated FA (PUFA) concentrations, were taxon- and stressor-specific. Nutritional quality of the larval dragonfly predator, Ophiogomphus, decreased nonlinearly with decreasing benthic diatom abundance and was lowest at the sewage-affected sites, although exposure to natural bitumen also resulted in reduced Ophiogomphus PUFA concentrations. In contrast, the PUFA concentrations of mayfly grazers/collector-gatherers were not affected by natural bitumen exposure, and were higher at the sewage and sewage+mining sites. The PUFA concentrations of the shredder Pteronarcys larvae did not change with cumulative exposure to the stressors. Sediment metal and polycyclic aromatic compound concentrations were not associated with the macroinvertebrate FA changes. Overall, we provide evidence that sewage induced reduction in trophic support by PUFA-rich diatoms, and was the predominant driver of the observed changes in FA composition and nutritional quality of the benthic macroinvertebrates. Fatty-acid metrics are useful to untangle effects of concurrent stressors, but the assessment outcomes depend on the functional feeding guilds used. A food-web perspective using multiple trophic levels and feeding guilds supports a more holistic assessment of the stressor impacts

Ecological effects of mosquito control with Bti: evidence for shifts in the trophic structure of soil- and ground-based food webs

The microbial control agent Bacillus thuringiensis var. israelensis (Bti) has been successfully used worldwide to reduce abundances of biting Nematocera (Diptera), often with little direct impact on non-target organisms observed. However, the potential for additional indirect effects on other ecosystem properties, including on trophic linkages within food webs, is poorly known. We investigated the effects of multiple-year mosquito control treatments using the Bti product VectoBac((R))-G on the stable isotope composition of epigeal and soil-based consumers inhabiting replicate floodplains along the River Dalalven, Sweden. We observed significant changes in the isotopic composition of detritivores feeding at the base of floodplain food webs. Enchytraeid worms were characterised by 3.5% higher delta C-13 values in treated floodplains, suggesting increased consumption of delta C-13-enriched food. The overall range of community-wide delta N-15 values was 56% greater in the treated floodplains, whilst delta N-15 values of oribatid mites were elevated by 97%. These results suggest extra fractionation in the transfer of nitrogen through floodplain food chains. We conjecture that the ecological mechanisms driving these food web shifts are (1) the mass mortality of high delta C-13 A. sticticus larvae, which leaves high concentrations of dead mosquito biomass deposited on soils at local scales, after the floodwaters have receded and (2) incorporation of the very high delta C-13-enriched corn particles comprising the bulk of the VectoBac((R))-G product into floodplain food webs. Our results suggest that repeated applications of Bti might have wider, still largely unknown implications for nutrient and energy cycles within floodplain ecosystems

Inverting nutrient fluxes across the land-water interface - Exploring the potential of zebra mussel (Dreissena polymorpha) farming

We studied the potential of zebra mussel farming for nutrient retention in a eutrophic lake. Duplicate experimental long-line cultivation units were deployed and mussel growth and nutrient retention were quantified after 28 months. Mussels grew well at shallow water depth (<3 m) and our 625 m(2) (lake area) experimental units produced 507 and 730 kg dry biomass, respectively, of which 94% were shells. These yields corresponded to an average retention of 92.7 +/- 23.1 kg C, 6.1 +/- 0.68 kg N, and 0.43 +/- 0.04 kg P retention, or 742 kg C, 49 kg N, and 3.5 kg P for a full-size (0.5 ha) mussel farm. We estimate that concentrating the long-lines to a depth of 2.5 m would probably have doubled these yields, based on the differences in mussel growth among depths. We further estimate that a full-size cultivation unit (0.5 ha) thus could compensate for the annual total-P run-off from 23 ha, or the biologically available P from approximately 49 ha of agricultural soils. As traditional measures have proven insufficient, decision-makers need to facilitate novel approaches to mitigate the negative effects of cultural eutrophication. We envision that zebra mussel farming, within their invaded range, provides a promising approach to invert nutrient losses in lakes and coastal lagoons

Riksinventering 2000

Inventeringen år 2000 omfattade ca 3400 sjöar och 700 vattendrag. I huvudsak provtogs samma objekt som vid riksinventeringen 1995. Prover för vattenkemi togs i alla objekt, medan bottenfaunaprover togs i alla vattendrag och i en tredjedel av sjöarna. Inventeringen bidrar med underlag för uppföljning av fyra av Sveriges miljömål; levande sjöar och vattendrag, bara naturlig försurning, ingen eutrofiering och giftfri miljö (spårmetaller). Vid sammanställningen av resultaten från riksinventeringen 2000 är det lockande att jämföra resultatet från riksinventeringen 1995, men man bör komma ihåg att inventeringar ger ögonblicksbild och att skillnader kan bero på en mängd andra miljöfaktorer än just föroreningsläget. Miljödata visar normalt en mellanårsvariation som beror på flera olika faktorer (t.ex. variationer i klimat) och det är därför vanligt att mätvärden skiljer mellan olika mättillfällen. Hösten 2000 kännetecknades av en ovanligt hög nederbörd som medförde höga vattenstånd och flöden. Västra Götalands län, Värmlands län, Örebro län och Västmanlands län drabbades extra hårt och som följd av de extrema väderleksförhållandena saknas till exempel från Örebro län samtliga bottenfaunaprover utom ett i riksinventeringen 2000. Utgående från Naturvårdsverkets Bedömningsgrunder för miljökvalitet beskrivs tillstånd och påverkan (avvikelse från jämförvärde. Med hjälp av en ny digitaliserad karta (GSD 1:100 000) kunde mer områdesspecifika uppgifter erhållas. Dessutom inkluderades områden som tidigare saknades, som t.ex. fjälltrakterna. Provtagningarna genomfördes väl trots höga vattenstånd och andra väderproblem. Alla bestämningar har gjorts vid Inst. för miljöanalys vid SLU, utom aluminiumfraktioner som bestämdes av ITM, Stockholms universitet