Jane W Behrens

Jane W Behrens
Technical University of Denmark | DTU · National Institute of Aquatic Resources

PhD

About

64
Publications
12,909
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1,195
Citations
Citations since 2016
36 Research Items
838 Citations
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2016201720182019202020212022050100150
Introduction
I work with fish ecophysiology, involving experimental and field investigations of physiological and behavioural responses and adaptations to biotic and abiotic factors in the environment. Optimal behavioural strategies and habitat requirements, including bioenergetics

Publications

Publications (64)
Technical Report
Full-text available
The aim of the Workshop on Stickleback and Round Goby in the Baltic Sea (WKSTARGATE) was to update, summarize and synthesize the current knowledge of both species with respect to their ecology and potential use in fisheries. Ongoing projects were presented in the mornings of the first two days to inform participants about current research in the re...
Technical Report
Full-text available
The goal of the ICES Working Group on the Introduction and Transfers of Marine Organisms (WGITMO) is to contribute to the ICES vision and mission by addressing specific science objectives related to the introduction, spread and impacts of non-indigenous marine species (NIS). The expert working group provides information and advice on the impacts of...
Article
Full-text available
Native to the Ponto-Caspian region, the benthic round goby (Neogobius melanostomus) has invaded several European inland waterbodies as well as the North American Great Lakes and the Baltic Sea. The species is capable of reaching very high densities in the invaded ecosystems, with not only evidence for significant food-web effects on the native biot...
Article
During the 2010s, Atlantic cod Gadus morhua L. in the eastern Baltic Sea experienced increasing infection loads of the parasitic nematode Contracaecum osculatum (Rudolphi) in their livers. Starting in 2021, a mandatory part of the routine sampling protocol on Baltic monitoring surveys is to assign a liver category to individual cod livers, based on...
Article
Full-text available
The round goby ( Neogobius melanostomus ) was first observed in the Baltic Sea in 1990 and has since displayed substantial secondary dispersal, establishing numerous dense populations where they may outcompete native fish and negatively impact prey species. There have been multiple round goby diet studies from both the Baltic Sea and the North Amer...
Article
Full-text available
For externally fertilising organisms in the aquatic environment, the abiotic fertilisation medium can be a strong selecting force. Among bony fishes, sperm are adapted to function in a narrow salinity range. A notable exception is the family Gobiidae, where several species reproduce across a wide salinity range. The family also contains several wid...
Preprint
Full-text available
Non-indigenous animals can impact native fauna via predation and competition for food and habitat. The round goby (Neogobius melanostomus) was first observed in the Baltic Sea in 1990 and has since displayed substantial secondary dispersal, establishing numerous dense populations where they may outcompete native fish and negatively impact prey spec...
Article
Full-text available
Aim The few fish species able to reproduce across wide osmotic ranges either plastically acclimate sperm performance to, or are locally adapted to, different salinities. The invasive round goby (Neogobius melanostomus) is spreading in Eurasia and the Americas, into both fresh and brackish water. We aim to understand if reproduction in different sal...
Article
Full-text available
Invasive species exert negative impacts on biodiversity and ecosystems on a global scale, which may be enhanced in the future by climate change. Knowledge of how invasive species respond physiologically and behaviorally to novel and changing environments can improve our understanding of which traits enable the ecological success of these species, a...
Article
Full-text available
Species invasions often occur on coasts and estuaries where abiotic conditions vary, e.g. salinity, temperature, runoff etc. Successful establishment and dispersal of non-indigenous species in many such systems are poorly understood, partially since the species tend to show genetic and ecological plasticity at population level towards many abiotic...
Article
This study examines the impact of boldness on foraging competition of the highly invasive round goby Neogobius melanostomus Pallas 1815. Individual risk tolerance, or boldness, was measured as the time to resume movement after a simulated predation strike. Fish that resumed movement faster were categorized as “bold”, fish that took more time to res...
Article
Full-text available
Species invasions often occur on coasts and estuaries where abiotic conditions vary, e.g. salinity, temperature, runoff etc. Successful establishment and dispersal of non-indigenous species in many such systems are poorly understood, partially since the species tend to show genetic and ecological plasticity at population level towards many abiotic...
Article
Full-text available
Establishing relationships between parasite infection and physiological condition of the host can be difficult and therefore are often neglected when describing factors causing population declines. Using the parasite-host system between the parasitic nematode Contracaecum osculatum and the Eastern Baltic cod Gadus morhua, we here shed new light on...
Article
Reefs are structurally complex habitats that are degraded in numerous coastal areas. Structural complexity is often associated with elevated fish abundance, and recent studies have indicated that such structural complexity (e.g. reefs) not only acts as a fish aggregator, but also increases fish production. The objective of this study was to advance...
Article
Vertical migration is the most widespread migration in the aquatic world, yet the mechanisms limiting the extent of this behavior are largely unknown. In the Baltic Sea, some Atlantic cod Gadus morhua perform vertical foraging migrations into severely hypoxic demersal zones where aerobic metabolism is insufficient to cover energy requirements. Afte...
Article
Differences between individuals in behavioral type (i.e. animal personality) are ecologically and evolutionarily important because they can have significant effects on fitness components such as growth and predation risk. In the present study we ere used the invasive round goby (Neogobius melanostomus) from an established population in controlled e...
Article
The round goby (Neogobius melanostomus; Pallas, 1814) is one of the most widespread invasive fish species. It originates from the Black Sea and the Sea of Azov but has unintentionally been introduced to fresh and brackish water bodies on both sides of the Atlantic. Small-scale fishermen catch large amounts of the invasive round goby as the species...
Article
Full-text available
In just two decades, round goby Neogobius melanostomus (Pallas) has dispersed throughout most of the Baltic and the North American Great Lakes. It thrives in shallow sheltered areas, where it is impacting native fauna. In Denmark, researchers, governmental institutions and fishers have joined in an effort to establish a sustainable round goby fishe...
Article
Reefs are structurally complex habitats that are degraded in numerous coastal areas. Structural complexity is often associated with elevated fish abundance, and recent studies have indicated that such structural complexity (e.g. reefs) not only acts as a fish aggregator, but also increases fish production. The objective of this study was to advance...
Article
Full-text available
Fish serve as transport hosts to a range of parasites, with potential negative effects on fish health. In the Baltic Sea, the grey seal Halichoerus grypus (Fabricius) population has increased markedly since the early 2000s. H. grypus is the main final host to the liver worm Contracaecum osculatum (Rudolphi, 1802), a parasitic nematode to which cod...
Article
Full-text available
Fish serve as transport hosts to a range of parasites, with potential negative effects on fish health. In the Baltic Sea, the grey seal Halichoerus grypus (Fabricius) population has in - creased markedly since the early 2000s. H. grypus is the main final host to the liver worm Contracaecum osculatum (Rudolphi, 1802), a parasitic nematode to which c...
Technical Report
Full-text available
HELCOM facts sheet (also available here http://www.helcom.fi/baltic-sea-trends/environment-fact-sheets/biodiversity/abundance-and-distribution-of-round-goby/) on the abundance, distribution and impacts of the invasive round goby (Neogobius melanostomus) in the Baltic region.
Article
Full-text available
Vertical migration is the most widespread migration in the aquatic world, yet the mechanisms limiting the extent of this behavior are largely unknown. In the Baltic Sea, some Atlantic cod Gadus morhua perform vertical foraging migrations into severely hypoxic demersal zones where aerobic metabolism is insufficient to cover energy requirements. Afte...
Article
Full-text available
Individual-based models (IBMs) incorporating realistic representations of key range-front processes such as dispersal can be used as tools to investigate the dynamics of invasive species. Managers can apply insights from these models to take effective action to prevent further spread and prioritize measures preventing establishment of invasive spec...
Article
Passive integrated transponder (PIT) tags are commonly used to assess fish movement for use in fisheries management. Here, we investigated physiological and behavioral effects of tagging on sandeels (Ammodytes tobianus) using PIT tags constituting 2.1 ± 0.9% of their body weight. Swimming stamina (RSS), calculated as time spent swimming against the...
Article
Full-text available
Larvae of the eye fluke, Diplostomum, emerge from snails and infect fish by penetrating skin or gills, then move to the lens where they may impair the vision of the fish. For the fluke to reproduce, a bird must eat the infected fish, and it has been suggested that they therefore actively manipulate the fish’s behaviour to increase the risk of preda...
Article
Full-text available
Non-indigenous species (NIS) can impact marine biodiversity and ecosystem structure and function. Once introduced into a new region, secondary dispersal is limited by the physiology of the organism in relation to the ambient environment and by complex interactions between a suite of ecological factors such as presence of predators, competitors, and...
Data
Data on oxygen uptake and blood plasma osmolality. All individual values of standard metabolic rate (SMR), maximum metabolic rate (MMR) and aerobic scope (AS), in addition to blood plasma osmolality and osmotic gradient, are shown in relation to ambient (treatment) salinity. (PDF)
Technical Report
Full-text available
This report presents a brief overview of ecologically or economically important species of different habitats and trophic levels in the Baltic. It supplies the modeling groups within BIO C3 with species specific information on environmental tolerances and preferences and identifies some gaps in knowledge. Where possible, information was provided...
Article
Full-text available
The round goby, Neogobius melanostomus (Pallas, 1814), is one of the most invasive non-indigenous species in the Baltic Sea. It dominates coastal fisheries in some localities and is frequently found in offshore pelagic catches. This paper identifies management issues and suggests actions to be considered for post-invasion management. Priority shoul...
Article
Full-text available
Round goby Neogobius melanostomus is currently one of the most wide-ranging invasive fish species in Europe and North America. The present study demonstrates how the distribution of round goby has expanded from 2008 to 2013 at a rate of about 30 km yr−1 along the Danish coastline in the western Baltic Sea. Further analyses showed that fish from an...
Article
Full-text available
Jakobshavn Glacier, west Greenland, has responded to temperature changes in Ilulissat Icefjord, into which it terminates. This study collected hydrographic observations inside Ilulissat Icefjord and from adjacent Disko Bay between 2001 and 2014. The warmest deep Disko Bay waters were blocked by the entrance sill and did not reach Jakobshavn Glacier...
Article
The eastern Baltic (EB) cod (Gadus morhua) stock was depleted and overexploited for decades until the mid-2000s, when fishing mortality rapidly declined and biomass started to increase, as shown by stock assessments. These positive developments were partly assigned to effective management measures, and the EB cod was considered one of the most succ...
Article
Full-text available
We report an unexpected observation of lesser sandeel Ammodytes marinus foraging on juveniles and late larval stages of the same species. This recording sheds new light on the cannibalistic and piscivorous capacity of forage fish and raises a number of questions about the role of forage fish in marine food webs. In 2012 and 2013, the stomachs of 74...
Article
Full-text available
Changes in ambient temperature affect the physiology and metabolism and thus the distribution of fish. In this study we used intermittent flow respirometry to determine the effect of temperature (2, 5, 10, 15 and 20 °C) and wet body mass (BM) (~ 30 - 460 g) on standard metabolic rate (SMR, mg O2 h- 1), maximum metabolic rate (MMR, mg O2 h- 1) and m...
Article
Full-text available
The deep-water flatfish Greenland halibut Reinhardtius hippoglossoides (Walbaum) is common along the West Greenland coast. In the northwestern fjords, Greenland halibut is an important socio-economic resource for the Greenland community, but due to the deep and partly ice-covered environment, very little is known about its behavior and habitat char...
Article
The parasitic copepod Lernaeocera branchialis had a negative effect on cardiorespiratory function in Atlantic cod Gadus morhua such that it caused pronounced cardiac dysfunction with irregular rhythm and reduced stroke amplitude compared with uninfected fish. In addition, parasite infection depressed the postprandial cardiac output and oxygen consu...
Article
Full-text available
Atlantic cod Gadus morhua experienced oxygen deficit ( D O 2 ) when exposed to oxygen levels below their critical level (c. 73% of pcrit ) and subsequent excess post-hypoxic oxygen consumption (CEPHO ) upon return to normoxic conditions, indicative of an oxygen debt. The mean ± s.e. CEPHO : D O 2 was 6·9 ± 1·5, suggesting that resorting to anaerobi...
Article
Information from data storage tags (DSTs) is conventionally used to infer movement patterns or reveal characteristics (e.g. temperature or salinity) of the environment surrounding tagged fish. Here we link data derived from DSTs with the reproductive state of tagged fish. Individual vertical activity of adult male and female Atlantic cod Gadus morh...
Article
Full-text available
Some Atlantic cod in the Bornholm Basin undertake vertical foraging migrations into severely hypoxic bottom water. Hypoxic conditions can reduce the postprandial increase in gastrointestinal blood flow (GBF). This could subsequently postpone or reduce the postprandial increase in oxygen consumption (MO(2)), i.e. the SDA, leading to a disturbed dige...
Article
Atlantic cod (Gadus morhua L.) exhibits polymorphic hemoglobin variants with the HbI locus showing a strong North-South geographic cline in frequency distribution of three main types (1/1, 1/2 and 2/2). This may indicate selective advantages of the different HbI types under various temperature regimes. Despite this only one study has directly exami...
Article
Full-text available
The current study investigated how the gastric evacuation rate (GER) was affected after surgically introducing dummies of a blood flow biotelemetry system into the abdominal cavity of Atlantic cod, Gadus morhua. Gastric evacuation experiments were performed two and 10 days postsurgery on surgically implanted and control G. morhua force-fed sandeel,...
Article
Full-text available
The commercially and ecologically valuable sandeel (Ammodytes ssp.) make distinct vertical shifts between an inactive stage, during which they seek refuge in the sand, and a pelagic schooling stage, during which they forage. This characteristic discontinuous foraging pattern constitutes a challenge to fishery biologists and has consequences for a w...
Article
The influence of prolonged moderate (c. 60% oxygen saturation) and severe hypoxia (c. 35% oxygen saturation) on the diurnal activity pattern of sandeel Ammodytes tobianus was examined. In moderate hypoxia, the emerging and burying rates were significantly higher compared to that in normoxia, whereas fewer fish (c. 10%) were present in the water col...
Article
Full-text available
Starting in 1980s, the inner Danish waters have yearly been exposed to seasonal oxygen deficiency (hypoxia). Through spatial-temporal interpolation of monitoring data (1998-2005), we investigated oxygen deficiency impacts on suitable burying habitats for lesser sandeel (Ammodytes tobianus). Furthermore, the consequences of a predicted 4 degrees C t...
Article
Full-text available
With the aim of understanding the molecular underpinnings of the enormous variation in the temperature sensitivity of hemocyanin-O2 affinity encountered in crustaceans, we measured O2 binding to Carcinus maenas hemocyanin at two temperatures, varying pH values and in the absence and presence of lactate ions in order to assess the contributions of o...
Article
Full-text available
Lesser sandeel (Ammodytes tobianus) is abundant in near-shore areas where it is a key prey. It exhibits the behaviour of alternating between swimming in schools and lying buried in the sediment. We first determined the species’ standard metabolic rate (SMR), critical partial pressure of oxygen \((P_{{\rm O}_{2{\rm crit}}})\) and maximal oxygen upta...
Article
Full-text available
The oxygen environment around buried sandeels (Ammodytes tobianus) was monitored by planar optodes. The oxygen penetration depth at the sediment interface was only a few mm. Thus fish, typically buried at 1-4 cm depth, were generally in anoxic sediment. However, they induced an advective transport through the permeable interstice and formed an inve...
Article
The Barents Sea capelin, a schooling species, undertakes extensive migrations against the predominating current north of Norway to its spawning grounds along the Norwegian and Russian coasts. Low swimming costs (i.e. high efficiency) at cruising speeds would be advantageous for capelin, enabling allocation of more energy to reproduction. A high oxy...
Article
Full-text available
The completed fruit fly genome was found to contain up to 15 putative UDP-N-acetyl-alpha-d-galactosamine:polypeptide N-acetylgalactosaminyltransferase (GalNAc-transferase) genes. Phylogenetic analysis of the putative catalytic domains of the large GalNAc-transferase enzyme families of Drosophila melanogaster (13 available), Caenorhabditis elegans (...
Article
The completed fruit fly genome was found to contain up to 15 putative UDP-N-acetyl-α-d-galactosamine:polypeptideN-acetylgalactosaminyltransferase (GalNAc-transferase) genes. Phylogenetic analysis of the putative catalytic domains of the large GalNAc-transferase enzyme families of Drosophila melanogaster (13 available), Caenorhabditis elegans(9 gene...