Simon Bahrndorff

• Professor (Associate) at Aalborg University

Runge E, Neuber R, Łupikasza E, Hübner C, Holmén K (eds) 2025: SESS report 2024, Svalbard Integrated Arctic Earth Observing System, Longyearbyen. https://sios-svalbard.org/SESS_Issue7

Summary for stakeholders: Invertebrate chapter in the State of Environmental Science in Svalbard report 2024: Terrestrial and freshwater invertebrate science in Svalbard in a changing world: from regional to pan-Arctic scales (STAFIEN - Svalbard Terrestrial and Freshwater Invertebrate Ecology Network)

Mealworms and black soldier fly (BSF) larvae are two of the most reared insects at an industrial scale. Both may feed on by-products from agricultural and food industries. Feed efficiency is one of the most important aspects of such processes and varies between species and feed substrates and depends on the metabolic performance of the larvae. Comp...

Some insect species have been proposed as a sustainable alternative to traditional animal‐based food and feed sources. Optimisation of insect production can generally be achieved using two main approaches: optimising environmental conditions and improving traits of interest through selective breeding. These avenues are not inseparable as performanc...

Insect production for food and feed presents a promising supplement to ensure food safety and address the adverse impacts of agriculture on climate and environment in the future. However, optimisation is required for insect production to realise its full potential. This can be by targeted improvement of traits of interest through selective breeding...

Uniting life’s seen and unseen realms guides a conceptual advance in research

Increasing human population size and income growth are causing an increasing demand for food and feed. Insects are a more sustainable alternative to conventional animal source proteins, as they can convert waste and by-products from the agricultural industry into biomass for commercial feed for livestock and, potentially, serve as a food source for...

Increasing population size and income growth are causing and increasing demand for food and protein of animal origin. Insects are an interesting alternative to conventional animal source proteins as they can convert by-products from the agricultural industry to biomass for commercial feed for livestock and potentially as a food source for human con...

Insect production for food and feed presents a promising supplement to ensure food safety and address the adverse impacts of agriculture on climate and environment in the future. However, optimisation is required for insect production to realise its full potential. This can be by targeted improvement of traits of interest through selective breeding...

The Arctic is a highly variable environment in which extreme daily and seasonal temperature fluctuations can occur. With climate change, an increase in the occurrence of extreme high temperatures and drought events is expected. While the effects of cold and dehydration stress on polar arthropods are well studied in combination, little is known abou...

On a global scale, species biodiversity is declining rapidly, including that of terrestrial invertebrates. Environmental heterogeneity is viewed as a key factor promoting biodiversity, and previous studies have shown how beavers can have a profound effect on both habitat heterogeneity and abundance and diversity of a plethora of water-related and t...

The Arctic is impacted by some of the fastest temperature changes observed on Earth, but the impact on the terrestrial arthropod fauna is unclear. Acute physiological thermal limits of terrestrial ectotherms from high latitudes often exceed the local air temperatures, suggesting that they may be able to cope with increasing temperatures. However, k...

Background There is a burgeoning interest in using insects as a sustainable source of food and feed, particularly by capitalising on various waste materials and by-products that are typically considered of low value. Enhancing the commercial production of insects can be achieved through two main approaches: optimising environmental conditions and i...

In nature organisms are exposed to variable and occasionally stressful environmental conditions. Responses to diurnal and seasonal fluctuations, such as temperature and food accessibility, involve adaptive behavioral and physiological changes. While much work has been done on understanding the genetic architecture and evolutionary potential of stre...

Reed beds can be managed for commercial or conservation purposes, with effects on its inhabitants. In this paper, we assess the effect of management on the reed bed Coleoptera community by investigating reed beds subject to winter cutting, winter harvest, short-term unmanaged (3 years), and long-term unmanaged (25 years). Using pit fall traps, we c...

Terrestrial arthropods in the Arctic are exposed to highly variable temperatures that frequently reach cold and warm extremes. Yet, ecophysiological studies on arctic insects typically focus on the ability of species to tolerate low temperatures, whereas studies investigating species' physiological adaptations to periodically warm and variable temp...

Ecosystem engineering species, such as beavers, may help the restoration of biodiversity. Through the building of dams and lodges and altering the natural hydrology, beavers change the habitat structure and create multiple habitats that facilitate a wide variety of other organisms including terrestrial invertebrate communities. Here we study the ef...

Drying of fish to improve storage capabilities, often under hyperosmotic conditions, is a widespread and longstanding practice in many cultures throughout the world. Several drying practices are applied, and they often reflect a cultural influence. The purpose of drying is to preserve fish by lowering the availability of water to microorganisms. Ho...

Laboratory investigations on terrestrial model-species, typically of temperate origin, have demonstrated that terrestrial ectotherms can cope with daily temperature variations through rapid hardening responses. However, few studies have investigated this ability and its physiological basis in the field. Especially in polar regions, where the tempor...

Understanding how environmental factors affect the thermal tolerance of species is crucial for predicting the impact of thermal stress on species abundance and distribution. To date, species' responses to thermal stress are typically assessed on laboratory-reared individuals and using coarse, low-resolution, climate data that may not reflect microh...

The succession-driven reed bed habitat hosts a unique flora and fauna including several endangered invertebrate species. Reed beds can be managed through commercial winter harvest, with implications for reed bed conservation. However, the effects of winter harvest on the invertebrate community are not well understood and vary across studies and tax...

The marsh fritillary (Euphydryas aurinia) is a critically endangered butterfly species in Denmark known to be particularly vulnerable to habitat fragmentation due to its poor dispersal capacity. We identified and genotyped 318 novel SNP loci across 273 individuals obtained from 10 small and fragmented populations in Denmark using a genotyping-by-se...

It has long been recognized that microbial symbionts can affect hosts in many ways (e.g. [1–4]), and in recent years much emphasis has thus been put into understanding the importance of microbiomes of animals. This has happened together with the advancement in high-throughput sequencing, which has made it feasible and economically viable to identif...

Data abstract: the data files described below contains information on larval body size traits and stress tolerance traits obtained using contrasting methods (manual and automated). The species investigated are black soldier flies (Hermetia illucens) and houseflies (Musca domestica). Larval body size is estimated using manual weighing and imaging an...

Substrate moisture content is an important but not well-understood variable in production and waste reduction processes that involves black soldier fly (BSF) larvae. The purpose of this paper is to characterise growth and metabolic performance of BSF larvae on substrate moisture contents from 45 to 85%. Larvae developed into prepupae only at 45–75%...

Within ecophysiological and genetic studies on insects, morphological and physiological traits are commonly assessed and phenotypes are typically obtained from manual measurements on numerous individuals. Manual observations are, however, time consuming, can introduce observer bias and are prone to human error. Here, we contrast results obtained fr...

Terrestrial arthropods in the Arctic and Antarctic are exposed to extreme and variable temperatures, and climate change is predicted to be especially pronounced in these regions. Available ecophysiological studies on terrestrial ectotherms from the Arctic and Antarctic typically focus on the ability of species to tolerate the extreme low temperatur...

It is still common practice in Europe to dike salt marshes for agricultural use. This impacts both the vegetation and physical environment of the marsh. We studied the plant community, environmental conditions, and determined correlations between vegetation cover and diversity with environmental factors on an enclosed marsh, which has been behind a...

Temperatures in Arctic and sub-Arctic regions are highly variable, with long, and cold winters, and short summers. Studies on thermal biology of ectotherms from these latitudes have mostly focused on how organisms cope with cold temperatures. However, temperatures in microhabitats such as south-facing slopes can occasionally reach high and potentia...

We have measured growth and respiration in black soldier fly (BSF) larvae fed with mixtures of a low-quality substrate (degassed sludge, DS), and a high-quality substrate (chicken feed, CF) in order to elucidate how substrate quality affect larval metabolism and feed conversion into new biomass. The BSF larvae grew faster and became larger the high...

Temperature varies on a daily and seasonal scale and thermal fluctuations are predicted to become even more pronounced under future climate changes. Studies suggest that plastic responses are crucial for species’ ability to cope with thermal stress including variability in temperature, but most often laboratory studies on thermal adaptation in plan...

Question Reed beds, dominated by common reed (Phragmites australis), have high ecological value. Several studies have examined the differences between managed and unmanaged reed beds without taking into account the time passed since the last management. In this paper, we seek to answer the question: how does the time passed since last management an...

Numerous assays are used to quantify thermal tolerance of arthropods including dynamic ramping and static knockdown assays. The dynamic assay measures a critical temperature while the animal is gradually heated, whereas the static assay measures the time to knockdown at a constant temperature. Previous studies indicate that heat tolerance measured...

Temperature varies on a daily and seasonal scale and thermal fluctuations are likely to become even more pronounced under future climate changes. Studies suggest that plastic responses are crucial for species’ ability to cope with thermal stress, but traditionally laboratory studies on ectotherms are performed at constant temperatures and often lim...

The housefly (Musca domestica L.) lives in close association with its microbiota and its symbionts are suggested to have pivotal roles in processes such as metabolism and immune response, but it is unclear how the profound physiological changes during ontogeny affect the housefly’s associated microbiota and their metabolic capabilities. The present...

Questions Temperature and precipitation variation between years may affect plant species composition directly or indirectly. We wish to investigate whether salt marsh edaphic conditions and plant species composition change as a result of climatic variation. Further, whether areas with the largest edaphic variations also experience the largest chang...

Background: Houseflies (Musca domestica L.) live in intimate association with numerous microorganisms and is a vector of human pathogens. In temperate areas, houseflies will overwinter in environments constructed by humans and recolonize surrounding areas in early summer. However, the dispersal patterns and associated bacteria across season and lo...

The ability to cope with increasing and more variable temperatures, due to predicted climate changes, through plastic and/or evolutionary responses will be crucial for the persistence of Arctic species. Here, we investigate plasticity of heat tolerance of the Greenlandic seed bug Nysius groenlandicus, which inhabits areas with widely fluctuating te...

Headwater streams in the highland regions of Ethiopia are exposed to severe human disturbances because of rapid population growth. Protection and management of headwater streams require the development of informative indices that can capture disturbance and assess streams water quality in highland regions. Therefore, we developed a multi-metric ind...

Variations in stress resistance and adaptive plastic responses during ontogeny have rarely been addressed, despite the possibility that differences between life stages can affect species' range margins and thermal tolerance. Here, we assessed the thermal sensitivity and hardening capacity of Drosophila melanogaster across developmental stages from...

The relative contributions of phenotypic plasticity and adaptive evolution to the responses of species to climate change are poorly understood. It has been suggested that some species or populations will have to rely on their ability to adjust their phenotype rather than on adaptation through evolutionary adaptation. We test the extent of intra‐ an...

Introduction: Organisms use environmental cues to match their phenotype with the future availability of resources and environmental conditions. Changes in the magnitude and frequency of environmental cues such as photoperiod and temperature along latitudes can be used by organisms to predict seasonal changes. While the role of temperature variation...

In 2009, a frozen mummy of the steppe bison (SB) (Bison priscus) was discovered between the lower Kolyma River and the Alazeya River in northeast Siberia, Russia. The specimen was dated with 14C and estimated to have lived more than 48,000 14C years before present (BP). The relationship between SB and the European Bison (EB) (Bison bonasus), also k...

The study of riparian plant communities along running streams offers information on the state of habitat and can help increase our knowledge on the use of bioindicators. We developed a riparian index of biotic integrity (RIBI) to evaluate the conditions of highland streams in response to anthropogenic disturbances in the southwest Ethiopian highlan...

Springtails are important members of the soil fauna and play a key role in plant litter decomposition, for example through stimulation of the microbial activity. However, their interaction with soil microorganisms remains poorly understood and it is unclear which microorganisms are associated to the springtail (endo) microbiota. Therefore, we asses...

Physiological responses to changes in environmental conditions such as temperature may partly arise from the resident microbial community that integrates a wide range of bio-physiological aspects of the host. In the present study, we assessed the effect of developmental temperature on the thermal tolerance and microbial community of Drosophila mela...

Thermal plasticity can increase thermal limits and may be of central importance to the ability of species to cope with future climatic changes. However, little is known about the costs and benefits of plastic responses of ectotherms and for soil species in particular. Here, we examine the costs and benefits [measured as critical thermal minimum and...

Ecotherms adjust their physiology to environmental temperatures. Long-term exposures to heat or cold typically induce acclimation responses that generate directional, but reversible shifts in thermal tolerance and performance. However, less is known about how short exposure in different life stages will affect the adult phenotype. In the present st...

Buffer strips are permanently vegetated areas situated immediately adjacent to streams and provide an efficient and economical way to reduce nutrient loads from agricultural areas, but no studies exist of their effectiveness from the East African highlands. We thus evaluated the sediment filtering capabilities of natural herbaceous buffer strips un...

Agricultural land use is expanding and at an accelerated rate. In Ethiopia, most of this expansion has occurred in highland areas and involve deforestation of natural riparian vegetation. However, the impacts on the water quality of streams are poorly understood, especially with regard to the influence of land use patterns on highland streams. In t...

Report on: Greenhouse Gas Emission from the Danish Broiler Production estimated via LCA Methodology

Human disturbances of waterways in Ethiopian highlands have increased throughout the last century due to population growth and increased land use. Despite this, there is a lack of knowledge on macroinvertebrate responses to human disturbances and the application of biological monitoring in tropical highland waterways in general. In this study, we h...

The housefly feeds and reproduces in animal manure and decaying organic substances and thus lives in intimate association with various microorganisms including human pathogens. In order to understand the variation and association between bacteria and the housefly, we used 16S rRNA gene amplicon sequencing to describe bacterial communities of 90 ind...

Heatmap (mean ± STD) representing the bacterial phyla found, samples are sorted by location. (EPS)

Rarefaction curves of OTUs clustered at 97% similarity for the housefly individuals collected at 10 farms. (EPS)

Heatmap (mean ± STD) representing the 25 most abundant bacterial genera, samples are sorted by location. Some OTUs were only identified to order or family (o = order and f = family). (EPS)

The concept of developmental instability (DI) is a well-known indicator of environmental and genetic stress and is often investigated using various indices such as fluctuating asymmetry, directional asymmetry, antisymmetry and phenotypic variance. Investigations dealing with DI are using morphometric traits. The aim of this investigation is to pres...

In recent years the human microbiome has become a growing area of research and it is becoming clear that the microbiome of humans plays an important role for human health. Extensive research is now going into cataloging and annotating the functional role of the human microbiome. The ability to explore and describe the microbiome of any species has...

The house fly, Musca domestica, has been implicated as a vector of Campylobacter spp., a major cause of human disease. Little is known whether house flies serve as biological amplifying hosts or mechanical vectors for Campylobacter jejuni. We investigated the period after C. jejuni had been ingested by house flies in which viable C. jejuni colonies...

Differences or similarities in the variance of fitness traits are crucial in several biological disciplines, e.g. ecological, toxicological, developmental and evolutionary studies. For example the variance of traits can be utilized as a biomarker of differences in environmental conditions. In the absence of environmental variability, the difference...

Acclimation to environmental change can impose both costs and benefits to organisms. In this study we explored to what extent locomotor behaviour of Drosophila melanogaster is influenced by developmental temperature and adult temperature in both the laboratory and the field. Following development at 15, 25, or 31 °C, adult flies were tested for loc...

Aquatic pollutants are often biologically active at low concentrations and impact on biota in combination with other abiotic stressors. Traditional toxicity tests may not detect these effects, and there is a need for sensitive high-throughput methods for detecting sublethal effects. We have evaluated an automated infra-red (IR) light-based monitor...

Social behavior is broadly defined as the interaction between members of the same species that changes their subsequent behavior. Isolation has been shown to affect behavioral traits such as courtship, mating aggression, foraging, learning and memory. This study investigated the effect of isolation (8 days) on adult Musca domestica locomotion. We f...

Organisms can respond to and cope with stressful environments in a number of ways including behavioural, morphological and physiological adjustments. To understand the role of behavioural traits in thermal adaptations we compared heat resistance, locomotor (walking and flying) activity, flight performance and morphology of three European population...

Consumption of poultry meat is considered as one of the main sources of human campylobacteriosis, and there is clearly a need for new surveillance and control measures based on quantitative data on Campylobacter spp. colonization dynamics in broiler chickens. We conducted four experimental infection trials, using four isolators during each infectio...

The house fly (Musca domestica L.) is a well-established vector of human pathogens, including Campylobacter spp., which can cause infection of broiler chicken flocks, and through contaminated broiler meat can cause outbreaks of campylobacteriosis in humans. We investigated whether Campylobacter jejuni (Jones) could be transferred between life stage...

The behavior of ectotherm organisms is affected by both abiotic and biotic factors. However, a limited number of studies have investigated the synergistic effects on behavioral traits. This study examined the effect of temperature and density on locomotor activity of Musca domestica (L.). Locomotor activity was measured for both sexes and at four d...

Studies have suggested that flies play a linking role in the epidemiology of Campylobacter spp. in broiler chickens and that fly screens can reduce the prevalence of Campylobacter spp. We examined the year-round and long-term effects of fly screens in 10 broiler chicken houses (99 flocks) in Denmark. Prevalence of Campylobacter spp.-positive flocks...

Description of broiler chicken houses.

The development of effective vaccines against zoonotic pathogens represents a priority in public health protection programs. The design of clinical trials and appropriate data analysis of the experiments results are crucial for the assessment of vaccine effectiveness. This manuscript reviews important issues related to the assessment of the effecti...

Although locomotor activity is involved in almost all behavioral traits, there is a lack of knowledge on what factors affect it. This study examined the effects of sex–ratio and density on the circadian rhythm of locomotor activity of adult Musca domestica L. (Diptera: Muscidae) using an infra–red light system. Sex–ratio significantly affected loco...

The functional relationship between thermotolerance and heat shock protein (HSP) expression is well described. However, the intraspecific variation in HSP70 expression and heat resistance is not fully understood. Some studies have shown a correlation between thermotolerance and HSP70 expression levels at the intraspecific level, whereas others have...

1. The relationship between thermal resistance and expression of inducible heat shock proteins, especially Hsp70, depends on the species and temperature treatments. The induction of Hsp70 has been shown to be essential for heat stress survival in a number of species, yet the maximum protein expression levels do not coincide with peak survival after...

Humidity has a large impact on the distribution and abundance of terrestrial invertebrates, but the molecular mechanisms governing drought resistance are not fully understood. Some attention has been given to the role of the heat shock response as a component of desiccation tolerance, but recent focus has been on the chaperone-like LEA (late embryo...

Summary • It has been argued that species living under unpredictable thermal conditions need to have more flexible physiological capabilities to meet with thermal stress than species living in thermally stable environments. Here we investigate if the ability to rapidly cold-harden in Collembola is influenced by thermal conditions of the habitat. •...

The springtail Megaphorura arctica (Onychiuridae: Collembola) inhabits the arctic and sub-arctic parts of the northern hemisphere where it on a seasonal basis will be exposed to severe cold and desiccating conditions. In the present study we compared how traits of stress resistance differed between two populations of M. arctica that were collected...

Multiple traits of stress resistance were investigated in the epedaphic springtail Orchesella cincta. Second generation adults from five laboratory populations were compared with respect to resistance to extreme temperatures and desiccation, and traits relevant to climatic adaptation. Populations were collected along a 2000-km latitudinal gradient...

Chironomids may adapt to pollution stress but data are confined to species that can be reared in the laboratory. A microcosm approach was used to test for adaptation and species differences in heavy metal tolerance. In one experiment, microcosms containing different levels of contaminants were placed in polluted and reference locations. The respons...

Host associations of four endofaunal amphipods were investigated during three months of fieldwork at Phuket Marine Biological Center (PMBC) in Thailand. Two amphipod species, Colomastix lunalilo and Leucothoe tridens, were reported in the area around Phuket for the first time. Colomastix lunalilo was found in two sponge species, Haliclona sp. and A...