Benthic resources and processes

Contact person: Erik Berg (erik.berg@hi.no) 

Intertidal colonization and mortality of early life stages of Mytilus edulis over a salinity gradient

The blue mussel (M. edulis) has external fertilization where eggs and sperms are shed directly from the genital ducts into the water column. The fertilized egg undergoes several different larval stages before metamorphosis ends the pelagic life. The larvae growth is affected by temperature, salinity and food ration, and the duration of the pelagic phase is normally between 3 to 5 weeks. Mortality during the larval phase is high, primarily due to predation, but extremes in temperature and salinity and food shortage also contribute. 

Most bivalve larvae are able to settle when they reach 250 to 300 µm in shell length, yet final settlement may not occur until the post larva reach 2 mm. The larvae show different behavior to different substrates and are understood to be able to discriminate between habitats. Settlement is difficult to measure in the field and is normally inferred from recruitment data post settlement (days to weeks). Little is known on the mortality and growth of post settled mussel in natural habitat. 

The IMR has started to monitor the abundance of mussels over a fjord to coast salinity gradient. These observations indicate recruitment of mussels to the full gradient, yet adult mussels are mainly observed in the less saline inner and mid-section of the gradient. This point to high mortality of the early life stages of mussels in coastal areas. In this MS thesis we aim to investigate: The colonization, growth and mortality of mussel larva (on natural and artificial substrate?) over a salinity gradient in the intertidal zone, by testing the overall hypothesis:

There are no differences in the colonization, growth and mortality of mussel larva (on natural and artificial substrate) over a salinity gradient in the intertidal zone.

The master thesis will comprise experimental design, field experiments and data analysis. The following parameters can be collected: Temperature, salinity, seston?, mussel metrics, predators and photos (abundance, size distribution and predators). 

The field work will be conducted in two periods with an overall duration of approx. 12-16 weeks:

1. Spring to summer – deployment of collectors and collecting settlement mussel larva
2. Summer – monitoring colonization, growth and mortality of mussel larva

The MS requires basic marine biological and ecological knowledge.

Contact persons at the HI/IMR: Tore Strohmeier (mob 90720754; tore.strohmeier@hi.no) / Antonio Aguera (mob 94880039)

 

Physiological responses in mussels to natural variation in salinity 

Mussels are osmoconformers and reside in salinities ranging from 4 psu to fully marine conditions. Mussel feeding rate may be similar for populations living under different salinities, but when transferred to a marked change in salinity the feeding rate drop. The time to acclimate feeding rate (and to recover respiration rate) to control values is dependent on the extent of the salinity change and may exceed several weeks. There is currently a lack of knowledge on the acclimatization of mussel feeding physiology to the natural variation in salinity encountered in estuaries and fjords. 

In this MS study we aim to investigate the mussel feeding and respiration rate in a natural environment (e.g. in situ) that inhabit short term fluctuations in salinity. As this experimentalapproach do not control other environmental factors known to impact mussel physiology (e.g temperature and food) it requires frequent measures of physiological rates and environmental stimuli over several events of stimulus. 

The master thesis will comprise experimental design, field experiments and data analysis. The following parameters can be collected: Temperature, salinity, food/seston, physiological rates and mussels. 

The field work will be conducted in the inner part of the Hardangerfjord during spring and summer (approx. 10-12 weeks) using the IMR mobile physiological laboratory and instrumentation. 

The MS requires statistical background and basic marine biological- and physiological knowledge.

Contact persons at the HI/IMR: Tore Strohmeier (mob 90720754; tore.strohmeier@hi.no) / Antonio Aguera (mob 94880039)

 

Mussel larvae physiology under natural environmental conditions

There is a raising interest in understanding the distribution of mussels along the Norwegian coast and assessing the impact of their culture in fjord ecosystems. Modelling the spatial and temporal distribution of adult mussel and their larvae is key to understand the impact of blue mussels in fjord ecosystem. To obtain realistic models we need to understand mussel larval physiology, how long the larvae stays in the water column, how are the natural low seston conditions and physicochemical temporal and spatial gradients affecting the larval development and their potential distribution and competition with other important zooplankton species. 

We have some knowledge already on mussel larval development, the role of food, and other environmental conditions. However, this information is not sufficient, it is based on laboratory experiments under controlled conditions that limit our understanding of the larvae feeding physiology and development. 

This experiment will aim to develop a system to successfully culture larvae in a flow through setup using natural seston as food and exposing larvae to natural variations of food and physicochemical seawater parameters (temperature, salinity and pH) during a full mussel reproductive season. Other factors such as maternal provisioning and how it changes during the reproductive season may be considered. 

The master thesis will comprise the formulation of specific hypothesis related to larval development of blue mussels, experimental design, take of measurements, data processing and statistical analyses. Experiments lasts from 3-6 weeks plus analyses, several experiments to focus on different hypothesis can be run during the reproductive season between May-August.

The MS requires basic marine biological- and physiological knowledge, life history of marine invertebrates and basic statistical skills. 

Contact persons at HI/IMR: Tore Strohmeier (mob 90720754; tore.strohmeier@hi.no) 
Antonio Aguera (mob 94880039)

 

Spatial distribution of blue mussels along a fjord coastal gradient.

The IMR has started to monitor the abundance of mussels over a fjord to coast gradient. These observations indicate recruitment of mussels may be happening along the whole shoreline, however stablished populations with several year classes are patchy. The monitoring effort initiated by IMR already comprises the assessment of presence/absence of mussels, cohort presence and other qualitative metrics of abundance at randomly selected stations along the fjord shoreline. An effort that will be continued during the coming year. 

Species distribution models (SDM) has proven a valuable tool to describe, predict and find drivers of species distributions. These models use of the concept of fundamental niche to assess the ranges and combinations of environmental (biotic and abiotic) that drives the observed patterns to predict the potential distribution of the species within the area of study.

In this MS, the student will analyze and develop SDMs for the blue mussels in Hardangerfjord, using the data gathered during the mussel monitoring program and diverse sources of spatial information on the Hardangerfjord environmental conditions (physical: depth, slope, temperature, salinity and biotic: primary production) 

The MS requires basic GIS skills and statistical analyses of spatial data using R.

Contact persons at HI/IMR: Tore Strohmeier (mob 90720754; tore.strohmeier@hi.no) / 
Antonio Aguera (mob 94880039)

 

Demersal fish

Contactperson: Jane Godiksen (jane.godiksen@hi.no)

Available Food Index

[Project is taken, but contact daniel.howell@hi.no if you are interested in projects involving 
computer simulations of fish populations] 
IMR supervisor: Dr. Daniel Howell (daniel.howell@hi.no). UIB supervisor: TBD

Historic trends in age reading of demersal fish

Background
IMR has been routinely reading otoliths to get individual age estimates from scientific survey and commercial fisheries since the 1930s. Those estimates are central to fish stock assessment as they represent the distribution of year classes in the population, and inform on the composition and selective mortality of the fisheries. While the mechanisms of otolith age reading are validated and well understood, there is no routine validation of each individual otolith, and those age estimates rely entirely on the subjective evaluation of its reader. There are regular national and international workshops to calibrate active readers and evaluate their estimate spread, but these do not inform on potential long-term drift due to reader turnover and individual perception of the age structure (shifting baselines). In addition, because otolith growth zones are directly related to fish individual growth rate and environmental conditions, punctual events such as marine heatwaves or trophic collapses may indirectly alter otolith readability.

All demersal fish species around Norway have experienced faster growth and maturation in the span of the last 70 years, in part due to fishing-related selective mortality on the oldest age classes and in part due to warming oceanic conditions. While the biological trends are well-known there is no formal evaluation of age reading variability during that period, nor of the potential effects of reader turnover and punctual environmental events.

Objective
Provide long-term perspectives on age reading trends of the main demersal fish species (cod, haddock and saithe), including an evaluation of the effects of key environmental events such as the Barents Sea capelin collapses. 

Tasks
•    Compile long-term time series of age readings from the archival database, including past re-readings of older material
•    Compare those time series with other biological time series (length, maturity, biomass, catch) and investigate differences in trend shifts
•    Investigate potential trend shifts in relation with reader turnover or with environmental events

Even though the project involves mainly working on datasets, the student should be partly sitting at IMR to allow for discussions and demonstrations with the age readers in place. Multiple trips to the main archive in Dokken are also planned. Participation on scientific surveys is not needed but can be organized, as the student could use it to gather and prepare a new set of data to be compared with. 

Contact (IMR):  Côme Denechaud (come.denechaud@hi.no) 

Biology of large cod/kaffetorsk

Background
In the  2010s onwards the abundance of large (> 10 kg may be a reasonable definition of large in this context) increased considerably. Data on large cod from surveys and commercial fisheries can be used to get more information about the biology of large and old cod (growth, fecundity, mortality, sex distribution, geographical distribution).  In addition, there is the time series of the number of cod > 30 kg caught annually in the Lofoten fishery available since the early 1990s, shown on the figure below  (the newspaper Lofotposten gives out 1 kg of coffee for each such cod, hence the name ‘kaffetorsk’ (coffee cod)).

Goal
Improved knowledge of biology and abundance of large and old cod. 

Tasks
Compare the time series of ‘kaffetorsk’ to existing model results of abundance of large cod. Extract survey and commercial fisheries data on large cod from IMR data bases and analyse such data together with ‘kaffetorsk’ data in more detail. 

Contact (IMR): Bjarte Bogstad (Bjarte.bogstad@hi.no) 

F Bar None

Summary
This project will example a common simplification used within ICES for computing the overall fishing pressure on fish stocks. In particular, the project will look at the current use of an unweighted average of fishing pressure over a limited range of fish ages, and test to see if the approximation in use by ICES actually tracks fishing pressure over time for the different stocks. Results will be presented at the international ICES annual science conference, and have the potential to directly affect fisheries management.

Information
Fisheries science typically quotes a single fishing pressure, F, for a given stock. This number is used to track changes in the fishing pressure over time, and compared to reference points to give information on if the fishing pressure is appropriate or not. In practice fishing pressure varies with the size and age of the fish, so the quoted F is a summary average value. The typical practice for European stocks within ICES is to produce an unweighted average of fishing pressure at age across several ages and produce a so-called “F-bar” average. For example, Northeast Arctic cod uses F ̅_(5-10), that is to say an unweighted average of fishing pressure across ages 5 to 10. This means that fishing on ages outside that range is not included in the summary measure of fishing pressure, and the relative abundance of fish at different ages is also not accounted for. The age range is chosen to cover the majority of the fishery, and avoid ages where the data is unreliable due to small catch numbers. 
This use of an average over a limited range of ages can be problematic. One issue is that if the age structure of the stock or the selectivity pattern of the fishery changes then the F-bar may not provide a good measure of changing fishing pressure over time. A large yearclass can also give problems as it first enters and then leaves the age range. A different problem is that this method makes comparing fishing pressure across different stocks of a given species difficult given that the chosen age range may be different.
This project will summarize the F-bar information across all data-rich ICES assessments. The fraction of the catch through time that falls within the age range will be analysed. In addition, several alternative methods will be used to compute overall fishing pressure without relying on unweighted averages, and the trends in the existing F-bar data compared to these unbiased estimates. Any deviations would indicate that the current measures are failing to adequately capture trends in fishing pressure, which has obvious implications for monitoring and management.

Expected outcomes
It is likely that the results will be publishable as a paper and presented at the annual ICES science conference. In addition, any identified discrepancies from unbiased estimates could be expected to feed directly into ICES stock assessments and management – this is a project with a high potential to be directly useful in fisheries management.

Required skills
Basic R and statistics, interest in fisheries management. Background in fisheries is an advantage but not a requirement.

Supervisor (IMR): Daniel Howell (daniel.howell@hi.no) 

Fuzzy quotas: How to manage fish stocks in the face of increasing knowledge of a complex reality

Summary:
This project will use computer simulations to evaluate new methods to give advice on sustainable management which will be needed as knowledge on the complex realities of fish stock structure increases. As genetic investigation becomes cheaper and faster, we are gaining more knowledge of the complex structure of overlapping sub-populations that comprises most fish stocks. However, our current assessments and management procedures often do not take account of this complexity. We therefore require a relatively simple method of adapting our existing fishing practices to protect the different components. This project will use “Management Strategy Evaluation” (MSE) techniques to simulate the ability of different ways of distributing fisheries quota across a fish stock to protect all of these components. The project will involve using an existing MSE tool creating a simulation of an artificial stock consisting of sub populations, and use this to investigate different possible Harvest Control Rules. This is ground-breaking work, which can be expected to result in a scientific publication and be directly relevant to future management practices. 

Task descriptions:
Construct a MSE simulation with multiple substock structure; design possible Harvest Control Rules; evaluate performance of different Harvest Control Rules against different substock structures

Goal:
Identify possible Harvest Control Rules which protect substock structure 

Skills: 
Suit someone with numeric skills; marine biology an advantage but not required
Required: R, desire to model fish populations
Advantageous: numeric modelling experience (not necessarily in fisheries)

Contact (IMR): Daniel Howell (daniel.howell@hi.no) 

Less is more: should we fish less hard to improve the outcomes of our fisheries?

Summary:
Most European fisheries are managed on a Maximum Sustainable Yield (MSY) basis. However, the actual level of fishing pressure that leads to MSY (the Fmsy) is difficult to estimate, and fishing harder than this can lead to reduced catches or even stock collapse. In other jurisdictions (for example the USA) a slightly lower target fishing mortality is used to guard against this. There is an ongoing debate as to if European fisheries (through the ICES organisation) should reduce their target fishing mortalities, and if so which target fishing mortality should be used. There are two tools available to analyse this, the tool “EQSIM” used by ICES to estimate what the fishing pressure should be for a given stock, and a simulation tool covering over 80 data rich ICES stock assessments. This project will look at how stable (or unstable) the estimate of Fmsy is to tiny model changes. Outcomes in terms of long-term yield, long term stock size and risk of stock collapse from the different range of possible fishing pressures will then be analysed. 

It can be expected that this work will play a part in the overall discussions leading to a change in the ICES advice giving procedures for European stocks, as well as potentially forming a scientific publication.

Task descriptions:
Gain familiarity with the simulation tools, adapt the tools to allow for different fisheries pressures. Investigate stability of Fmsy estimates. Compile a list of Fmsy proxies, and estimate these for the range of stocks. Run simulations to evaluate the performance of the different proxies. Repeat the analysis accounting for potential mis-specification of Fmsy. 

Goal:
Identify advantages and disadvantages of the different alternate target fishing pressures, both with and without errors in the estimation of Fmsy.

Skills: 
Suits someone with numeric skills, marine biology an advantage but not required
Required: R, desire to interact with fisheries management

Note: some programming required, but the modelling is relatively simple. A desire to understand the model performance, and use that understanding to influence real fisheries management is more important.

Contact (IMR): Daniel Howell (daniel.howell@hi.no),  collaboration with Henning Winkler, General Fisheries Commission for the Mediterranean (GFCM)
 

Adding video data to traditional net surveys for monitoring coastal cod

Background: 
We (IMR) have two complementary surveys that provide data to the stock assessment of coastal cod from 62N (Stadt) to 67N (nær Bodø), one using trawl (kysttokt) and one using nets (garn-ruse tokt). The garn-ruse survey targets younger (age 1-3) cod in shallow (2-30m) water. In 2024, we collected two sets of videos that could each form an MSc thesis topic. Both tasks could possibly join the survey in July-Aug 2025.

Oppgave #1: BRUVs (baited remote underwater video)
Baited remote underwater videos (BRUVs) are a standardized tool for quantifying fish communities, providing numbers and lengths of fish by species. We collected videos at ca. 100 stations in 2024 with the hope that these data will increase sampling of larger cod (50+ cm) and improve the abundance index in the assessment. 
 

Questions:
1.    How do fish counts, length distributions, and community diversity compare from BRUVs and nets?
2.    Does adding BRUV data improve the abundance index model?
3.    Should BRUVs be added to this survey in the future?

Work: 
•    Analyze video from BRUVs (identify fish by species, measure lengths)
•    Basic statistical modelling in R to answer the questions above

Location: 
To discuss. Ideally Flødevigen/Arendal because Brian Stock (supervisor) and BRUV analysts are based at IMR’s Flødevigen station. Other MS students at UiA will be working on other BRUV data, and it would be very useful to sit at Flødevigen to work together. There is a UiB PhD student working from Flødevigen also. Or could live in Bergen with visits to Flødevigen.

Further reading: 
 MS thesis Elise Eidset (garn ruse survey) 
 MS thesis Astrid Skoge (BRUVs Hitra/Frøya)
 MS thesis Marit Bull (BRUVs Hitra/Frøya)
 IMR report Kleiven et al. 2021
 IMR report Espeland et al. 2022  

 Supervisor (IMR):  Brian Stock

Oppgave #2: Habitat 
The garn-ruse survey has not previously collected habitat data. It is expected that the target fish species (e.g. cod and pollack (lyr)) are not randomly distributed, but instead prefer certain habitats. In 2024 we collected drop camera videos at fyke net (ruse) stations that should allow us to classify habitat and investigate relationships between habitat and fish of different species and ages.

Questions:
1.    How variable is habitat between stations?
2.    Are catch rates of cod and other fish species higher in certain habitats?
3.    Do cod of different age/size prefer different habitats?
4.    Does fish community diversity vary by habitat?
5.    If cod has a strong preference for certain habitats, does including habitat as a covariate in the abundance index model help explain variability in catch rates across sites?

Work: 
•    Classify physical (sand, gravel, rock…) and biological (bare, eelgrass, kelp, …) habitat at ruse stations using drop camera videos
•    Basic statistical modelling in R to answer the questions above

Further reading:
Dunlop et al. 2022  
MS thesis Elise Eidset (garn ruse survey) 

Supervisor (IMR):  Brian Stock

Sammenheng mellom gonadestørrelse og rekruttering hos Nordøstarktisk torsk og hyse

Bakgrunn:
Hovedformålet til bestandsvurderinger er å beregne størrelsen til en bestand, for så å kunne regulere fisket sånn at det er bærekraftig over tid.  Gytebiomasse, det vil si den biomassen som er kjønnsmoden og dermed kan bidra til rekruttering i bestanden, brukes ofte som indikator for bærekraftig fiskeri, der fisketrykket reguleres for at gytebiomassen ikke skal falle under et kritisk nivå. Når gytebiomassen beregnes er det vanlig å anta at mange små kjønnsmodne fisk bidrar like mye til rekrutteringen sammenlignet med tilsvarende biomasse av større fisk. Dette er ikke nødvendigvis tilfelle, da eldre og store hunner ofte produsere flere egg i forhold til sin kroppsstørrelse og/eller større egg sammenlignet med mindre hunner. 

Mål med oppgaven:
Havforskningsinstituttet samler inn årlige data på gonadevekt hos Nordøstarktisk torsk og hyse under gyteperioden. Data er tilgjengelige fra 1990 til 2023(2024) og skal i denne oppgaven analyseres for å svare på (noen av) følgende spørsmål:
• Hvor mye varierer GSI (gonadevekt i forhold til kroppsvekt) mellom individer av samme størrelse?
• Hvor mye varierer GSI i tid og rom (f.eks. innside/utside av Lofoten)?  
• Er det en sammenheng mellom endringer i gjennomsnittlig gonadevekt og endringer i rekruttering?
Spesifikke forskningsspørsmål og hypoteser utarbeides av studenten i samråd med veileder.

Metodikk:
Dataanalyse i R – tilrettelegging av data og statistisk analyse.
Det er mulighet for å delta på forskningstokt som samler inn tilsvarende data («Skreitoktet» som går i mars-april eller «Vintertoktet» som går i januar-mars hvert år). Studenten må selv (ev. via UiB) sørge for reisefinansiering. HI dekker kost og losji om bord.

Kompetanse:
Studenten bør ha grunnleggende kunnskaper i programmeringsspråket R og et ønske om å arbeide med store datasett. Vi anbefaler at studenten tar kurset Biostatistikk II (https://www.uib.no/emne/BIO302) før oppstart av masteroppgaven.

Kontaktperson/veiledere Havforskningsinstituttet: Johanna Fall (johanna.fall@hi.no),  Edda Johannesen (edda.johannesen@hi.no),  og Jon-Egil Skjæraasen (jones@hi.no). 
 

Bunnsamfunn

Contact person: Sigurd Heiberg Espeland (sigurd.heiberg.espeland@hi.no) 

Heat wave and eutrophication impacts on eelgrass communities 

Seagrass meadows provide numerous ecosystem services, including sustaining biodiverse communities of fish and invertebrates. Invertebrate fauna are essential and important in ensuring proper functioning of seagrass meadows. Seagrass meadows and their associated fauna are threatened by climate change, eutrophication, and other human activities. In Norway the most common seagrass is eelgrass (Zostera marina) which is found in shallow areas along the entire coastline but is relatively understudied compared to other ecosystems. At IMR, we have launched a new project titled “NORSE: Biodiversity in Nordic seagrass meadows – drivers, responses, and resilience”, which runs 2024-2027. 

The NORSE project includes joint mesocosm experiments across northern EUrope to experimentally test the joint effects of climate change and eutrophication on eelgrass and associatedd eelgrass communities. In 2024, we ran a pilot experiment at the new IMR Flødevigen mesocosm facility, and experiments continue in 2025-2027. The experiments will be run from May-September each summer. The exact setup of the different experiments is not yet decided, but there are opportunities for multiple MSc students to work within this project. 

The MSc student(s) will: 
•    have the opportunity to participate in planning the experimental design 
•    join in field collection of eelgrass and associated invertebrates 
•    assist in setting up and maintaining the mesocosm tanks 
•    sample eegrass and biodiversity metrics in the mesocosms 
•    analyse the data (statistical analysis in R) 
•    have the opportunity to be co-authors on peer-reviewed publications results from this project 

The project is based at IMR Flødevigen research station in Arendal. Accomodation and office space are available for students at the station. 

If interested contact: Karine Gagnon (karine.gagnon@hi.no)  

Ecosystem services of Ruppia meadows

Seagrass meadows provide numerous ecosystem services, including sustaining biodiverse communities of fish and invertebrates. Invertebrate fauna are essential and important in ensuring proper functioning of seagrass meadows. At IMR, we are currently filling in gaps in our understandin of Norwegian seagrass meadows. Most of our past and current research is focused on eelgrass (Zostera marina) which occurs along the entire Norwegian coast, but widgeongrass (Ruppia spp.; i.e. havgras) meadows are also common in shallow coastal areas. Ruppia meadows are acually widespread across Europe, especially in estuarine and low-salinity areas but highly understudied compared to marine seagrasses.

In this project, we will estimate, for the first time, some of the ecosystem services of Ruppia meadows in Norway.  The project will involve measuring (a) the carbon and nutrient storage capacity of these ecosystems, and (b) their habitat provisioning capacity for invertebrate and fish biodivesity, and (c) comparing these values to eelgrass and other coastal habitats.

The student will:
•    have the opportunity to participate in planning sampling and site selection 
•    join in field collection of sediment cores and biodiversity 
•    process and analyse sediment samples
•    sort and identify invertebrate and fish samples 
•    analyse the data (statistical analysis in R) 
•    have the opportunity to be co-authors on peer-reviewed publications results from this project 

The project is based at IMR Flødevigen research station in Arendal. Accomodation and office space are available for students at the station. 

If interested contact: Karine Gagnon (karine.gagnon@hi.no) 
 

Various opportunities linked to the vast MAREANO benthic fauna visual and physical sampling dataset

The MAREANO program now has over 3000 videos of the seafloor around offshore Norway, and over 300 full sampling stations on soft bottoms with video, beam trawl, rothilsberg-percy sled, and grab data. All are spread across space but there are no repeat visits at present. This gives many opportunities for Masters projects, with the risk of the data collection stage removed. Options include various ecological studies focussing on specific taxa or habitats, mapping studies defining biotopes or biogeography, research relating to vulnerable habitats of management interest, and taxonomic studies working with physical samples or imagery or linking the two. We can give support in aspects including traditional ecology, modelling (including some training), video analysis, artificial intelligence applications, and taxonomy. 

Please contact us to hear our latest ideas or discuss your own.

Contact person: Rebecca Ross (rebecca.ross@hi.no)

Deep-sea species and elasmobranchs

Contact person: Ole Thomas Albert (ole.thomas.albert@hi.no) 

Golden redfish (vanlig uer; Sebastes norvegicus) aggregation and demography in Northern Norway during spawning season

Background:
The golden redfish is listed as Endangered (Sterkt truet) on the Norwegian red list, with an estimated spawning stock biomass of ca. 25 000 tonnes. Although targeted fisheries on the species is virtually banned, ca. 5-10 000 tonnes are caught as by-catch annually. Given the current exploitation rate and stock development, a stock collapse cannot be ruled out in near future. One important reason for this serious situation is failing recruitment, yet our knowledge of the species' behaviour and area utilization during spawning is limited. 

The project:
In this master project, the candidate will analyse gillnet-based golden redfish catch data collected in near-shore areas in Nordland during the spawning period, to study the spatial and habitat distribution and degree of aggregation of golden redfish, as well as the fish size, weight, sex and maturation composition. Results can be discussed in the light of multiple contexts, including age composition, commercial fisheries (by-catch), fishery regulations, sustainability and spatial ecology. 

Contact persons (IMR): Dr. Magnus Aune (IMR-Tromsø; magnus.aune@hi.no) and Dr. Mikko Vihtakari (IMR-Tromsø)
Supervisor UiT: Prof. Raul Primicerio
 

Fish capture

Contact person: Svein Løkkeborg (svein.loekkeborg@hi.no) 

Quantifying the behaviour of Atlantic bluefin tuna (Thunnus thynnus) during rod and line capture

Ensuring animal welfare during food production is a humane and legal obligation. Despite this, understanding of how animals are impacted by wild-capture fishing is limited. This represents a missed opportunity, because promoting welfare during capture can improve the sustainability, product quality, profitability, and ethical reputation of the fishing industry. 

Together with changing societal perspectives, this suggests an important role for animal welfare in the future of fisheries management. 

In recent years, coastal power boats have used rod and line to capture Atlantic bluefin tuna (Thunnus thynnus) in Norwegian waters. The nature of the gear (i.e. catching fish one-by-one) and the target species (i.e. whose market price is highly dependent on quality) means the fishery is well placed to transition towards welfare-responsible capture methods. To do so, however, requires a thorough understanding of how tuna respond to the stress of capture. 

The aim of this MSc project is to quantitatively describe the behavioural response of bluefin tuna to rod and line capture. Cameras and accelerometers will be fitted to the gear to record fish behaviour during capture in the field. Of particular importance will be correlating behavioural states observed on camera to acceleration data. Data from this MSc project is expected to provide the basis for future development of new capture methods that promote welfare. Opportunities for the student to participate in research cruises in Autumn 2024 is likely. 

Location: Fish capture research group, Institute of Marine Research - Bergen

Contact: Applicants should send a CV and a letter of application to: Neil Anders 
(neil.anders@hi.no) and Mike Breen (michael.breen@hi.no). 

 

Can better control of trawl position relative to target fish improve catch success in acoustic trawl surveys?

Knowledge of fish stock sizes is a key element in sustainable fisheries management. The knowledge is needed to assess the state of the stock, investigate the effects of fisheries and to set future harvest levels. A common way of estimating fish stock size is by acoustic trawl surveys where acoustic energy is converted to fish abundance, with the help of samples of species composition and size distributions from trawl hauls. When schools or aggregations of fish are registered on the vessel mounted echosounder a sample of the fish is usually obtained by trawling. However, it can be difficult to catch the fish with the trawl several hundred meters behind the vessel, especially when fast swimming fish are targeted. Missed catches result in wasted effort and uncertainty in the trawl samples. In this project the aim is to investigate whether catch success can be improved by better control of the trawl position relative to the targeted fish. Fish abundance estimated from acoustic data will be compared with catch size and related to trawl position. For better temporal and spatial resolution catch data will be obtained from a stereo-camera system mounted inside the trawl. The aim is also to investigate whether catch success is affected by species or school specific behaviour. The project is part of a research-based innovation center, CRIMAC (www.crimac.no) financed by the Norwegian Research council.

The student will collaborate with other MSc and PhD students in the center. Data for the project were collected in the Norwegian sea ecosystem survey in May 2022 and there will be an opportunity to participate in a future survey for further data collection and for better understanding of the fishing operation and the monitoring methods.

Are you interested - contact: 
Maria Tenningen (maria.tenningen@hi.no) og/eller Nils Olav Handegard (nilsolav@hi.no).

 

Fisheries dynamics

Contact person: Jon Helge Vølstad (jon.helge.voelstad@hi.no)

 

Robustness-analysis of fishery dependent estimates

The IMR run several sampling programs to collect data from commercial fisheries, and provide estimates using a Bayesian modelling framework dependent on several use choices, such as categorization of fishing gears and post-stratification of spatial and temporal covariates. We wish to analyse the roboustness of estimates to user choices and sampling variation. The candidate will analyse results from different model configurations and assess the robustness of estimates and implications for interpretation. Some familiarity with Bayesian statistics and R will be required.

IMR-supervisor: Edvin Fuglebakk (edvin.fuglebakk@hi.no). 

 

Comparative study of estimators for non-probabilistic samples 

Practical constraints commonly lead to deviation from probabilistic approaches in sampling. This can be addressed with explicit modelling approaches, or with post-stratification and assumptive applications of traditional design-based estimators. These approaches come with different formulations of assumptions and different technical implications for estimation support systems. We would be interested in do a comparative study of such estimators for evaluating their practical utility and interpretability for non-probabilistic sampling of biological parameters from commercial fisheries.

IMR-supervisor: Edvin Fuglebakk (edvin.fuglebakk@hi.no).

 

Time series analysis of survey estimates 

The survey estimates are traditionally used as input to assessment models, but there could be simpler models serving as alternatives to the assessment models, which are worth pursuing. 

Suggested contact: Jon Helge Vølstad (jon.helge.voelstad@hi.no)

 

Deriving projections of fish stock state vectors from observations - A minimalistic 
assumptions approach. 

Assessing the status of fish populations involves utilizing data from two primary empirical sources: scientific surveys and commercial catches. Typically, these observations are interconnected through distinct sub-models to define a set of state variables representing the number or biomass of fish across various age groups. The objective of this project is to develop a novel modeling approach for generating anticipated population trends, even when confronted with uncertain observations. The ingenuity of this approach lies in its reliance on a minimal set of assumptions, enabling:

• A clear and straightforward modeling framework that seamlessly incorporates diverse data sources and their associated uncertainties.
• A transparent correlation between the uncertainty inherent in the data and the uncertainty reflected in the forecasts of fish stocks parameters, as well as the subsequent management decisions informed by these projections.
• An estimation process that remains independent of assumptions that cannot be verified.

Relevant background of student: Quantitative (math/statistics or quantitative ecology) and 
good programming skills (Python/R/Matlab). 

Supervisor: Sam Subbey (samuel.subbey@hi.no) 

 

Simulating fish migration: Integrating environmental data, artificial neural networks, and individual-based modeling

We have developed a modeling framework for simulating capelin spawning migration in the Barents Sea, which is based on integrating artificial neural networks (ANNs) models, individual-based model (IBM), and environmental variables. The ANNs determine the direction of the fish's movement based on environmental variables such as temperature and ocean currents. The ANNs are trained by an evolutionary algorithm, whose fitness function is dynamically adapted based on the temperature and distance to the spawning route.

The goal of this project is to extend the framework to address key ecological questions, such as, the possible effects of climate change on migration patterns of species, and how this may affect fish recruitment and management. Applications to stocksin the Barents, and Norwegian Seas. 

Relevant background of student: Machine learning, quantitative (math/statistics or 
quantitative ecology) and good programming skills (Python/R/Matlab)

Supervisor: Sam Subbey (samuel.subbey@hi.no)

 

Assessing consistency in estimates of population state vectors from multiple data sources

Data from scientific surveys and commercial catch statistics are the main input to most models used in assessing the state (number or biomass) of fish stocks. Combining these data sourcescan be problematic due to potential biases arising from different sampling methods. For instance, fisheries surveys may focus on specific areas or time periods, while catch statistics might not accurately reflect overall fishing efforts. This amalgamation of biased data can lead to skewed or inaccurate assessments of stock state and size.

An alternative strategy involves obtaining assessments of stock state and size separately from each data source, and using e.g., management parameters, as the basis for determining the most likely solution. The problem (determining stock size independently from each data source) is computationally non-linear and underdetermined. 

The goal of the thesis is to investigate a few computational approaches to solving the underdetermined problem, which potentially lead to empirically plausible solutions. The derived computational framework will be applied to stocks on the Barents Sea.

Relevant background of student: Quantitative (math/statistics or quantitative ecology), good programming skills (Python/R/Matlab); basic course in mathematical/statistical optimization.

Supervisor: Sam Subbey (samuel.subbey@hi.no)

 

Exploring the Application of a Distribution Model for Planning Scientific Surveys in the Barents Sea

We have developed a method for predicting where and when a certain marine species will be found, using data that counts how many of the species are observed in various places over time. The method involves a mathematical model that combines two parts: the first part deals with cases where no species are observed (the "zero-inflated" part), and the other part deals with cases where the species is observed (using a Poisson distribution). Both parts of the model are influenced by additional information about the environment. The existing computer program efficiently calculates the predictions based on this model, and we have demonstrated that this method works even with missing data or when the observationlocations and times are non-uniform. 

The goal of the thesis is to investigate the use of this model in planning scientific surveys for e.g., stocks on the Barents Sea. We shall examine the performance of such an approach using projections of environmental data and compare the model performance to historical survey observations.

Relevant background of student: Quantitative (math/statistics or quantitative ecology), good 
programming skills (Python, R or Matlab).

Supervisor: Sam Subbey (samuel.subbey@hi.no)

 

Research group Feed and Nutrition

Contact person: Nina Liland (nina.liland@hi.no) 

We study the uptake and utilization of nutrients and effects of diets on health and performance in aquaculture fish. In principle, all our running research projects in the research program can be available for master student studies.

 

Investigating the requirements for micronutrients in Lump sucker (Cyclopterus lumpus).

IMR-supervisor: Øystein Sæle (oystein.saele@hi.no) 

 

Investigating the requirements for micronutrients in Ballan wrasse (Labrus berggylta).

IMR-supervisor: Øystein Sæle (oystein.saele@hi.no) 

 

Applying a gut sac model (from salmon) to investigate the impact of undesirables in feed, such as pesticides, on intestinal integrity.

IMR-supervisor: Øystein Sæle (oystein.saele@hi.no)

 

Requirement of vitamin and trace mineral for Atlantic salmon health

The new salmon health project REVITALISE offers opportunities for a master's thesis. Nutrition in freshwater and during the smoltification phase of Atlantic salmon is important. The need for micronutrients may be even higher than existing recommendations and maximum limits set by the EU. However, the health effects of micronutrients related to disease and other challenges are too poorly documented for salmon, which will be the main aim of this project. Using several feeding trials, the project aims to find the optimal levels of selected micronutrients for farmed salmon in different life phases, both under normal and challenging conditions. This will improve the salmon's ability to withstand stress and resist diseases.

Link: https://www.hi.no/hi/nyheter/2023/januar/24-millioner-til-nytt-laksehelseprosjekt 

As part of the master thesis, you will have the chance to work practical and follow up experimental trials (e.g. at our research stations in Matre) and/or learn and perform analyses in the lab (e.g. nutrient analyses).

Interested in nutrition and salmon health? 
Contact researcher and project manager Antony Philip (antony.philip@hi.no) or researcher 
Anne-Catrin Adam (aad@hi.no).

Developing an extraction protocol of prostaglandins and leukotrienes from fish plasma and quantification by liquid chromatography mass spectrometry

Prostaglandins and leukotrienes, such as PGE2 and LTB4, respectively, are members of the lipid class of biochemicals derived from arachidonic acid by means of the cyclooxygenase enzyme. These substances are known for their varying physiological properties, pathological effects and association with inflammation and pain in human and animal models. Immunological assays (e.g., ELISA) are the most widely used methods for the estimation of prostaglandins due to their inherent sensitivity, inexpensiveness, and simplicity. The main drawbacks of these assays are their lack of specificity for complex biological fluids, such as plasma, trend to overestimate the levels of metabolites due to cross-reactivity and limitation to the detection of a single product at the time. 

The present research project aims at developing a rapid, simple, and efficient method for the extraction of PGE2 and LTB4 from fish plasma and subsequent quantification using liquid chromatography mass spectrometry (LCMS). In this context, the determination relevant performance parameters such as selectivity, specificity, accuracy, precision, linearity, range, limit of detection, limit of quantitation, ruggedness, and robustness will be an essential part of the project. The developed extraction and quantification protocols will be included in the existing battery of analytical methods of the Institute of Marine Research (IMR) at Bergen. The student will gain theoretical and practical experience in experimental design, sample treatment, LCMS, analytical validation, and data analysis.

Contact researcher: Pedro Araujo (Pedro.Araujo@hi.no)

 

Contaminants and biohazards

Kontaktperson: FG-leder Monica Sanden (Monica.Sanden@hi.no)

 

Want to do your master’s thesis on antibiotic resistance? In collaboration between Institute of Marine Research (IMR) and University of Bergen (UiB). 

We have a master’s project in microbiology connected to the Res-Marine project funded by the Norwegian Research Council (NRC) funded (https://www.tv2.no/a/11567134/;https://prosjektbanken.forskningsradet.no/project/FORISS/315266?Kilde=FORISS&distributi
on=Ar&chart=bar&calcType=funding&Sprak=no&sortBy=date&sortOrder=desc&resultCount
=30&offset=0&Fritekst=Res-Marine) , that aims at understanding the role of the marine environment in dissemination and emergence of antimicrobial resistance (AMR). The student will carry out isolation of bacterial pathogens from waste water, marine sediments and water samples, and carry out antibiotic susceptibility testing. The tasks would also include learning DNA sequencing and analysis of whole genome sequences (bioinformatic analysis). 

If interested contact Nachiket Marathe (nachiket.marathe@hi.no)

 

Master’s opportunity on Microplastic and antibiotic resistance.

Plastic pollution is a global environmental problem that is projected to increase in upcoming decades because of the upward trend in global production and consumption. MPs provide surficial substrates for the microorganisms to attach and form biofilms. Fish pathogens such as Aeromonas spp., Vibrio spp. and opportunistic human pathogens like E. coli are present in biofilms from marine plastics. Recently, previous master student on the project has characterized multidrug resistant pathogens and environmental bacteria present on marine plastics from western Norway, using whole genome sequencing. This work has led to 2 publications (Radisic et al., 2020; Radisic et al., 2021). The master’s project will focus on the role of microplastics in dissemination of antibiotic resistance genes and resistant pathogens in the marine environment. The student will carry out isolation of pathogens, DNA extraction and Whole genome sequence analysis. 

If interested contact Nachiket Marathe (nachiket.marathe@hi.no)

 

Master opportunity on microplastics in food

Microplastics are everywhere, in the fields, rivers, ocean, air, animals, food and in us. Recently, a first publication reported a correlation between the presence of plastic in arterial plaque with stroke and death. We have already detected microplastics in fish, where we find more small microplastics than large ones. We wonder what other sources of microplastics there are to our diet. Maybe some sources can easily be dealt with. We want to investigate the production of microplastic particles by plastic spice mills, which are common in Norwegian households and compare the amount added by those on a meal with the amounts we find in seafood. This master thesis will offer the opportunity to learn methods for chemical identification, particle size characterization and quantification of microplastics and to modify/develop the wet chemistry of extracting microplastics from food. It will teach you the principles of contamination avoidance. There is also the opportunity of adding other food items if time allows. You should have a background in chemistry, environmental chemistry, biochemistry or similar.

If interested contact Tanja Kögel (tanja.kogel@hi.no)

Masterstudents for the topic above and below may work closely together.

 

Master opportunity in methods comparison for microplastic analysis

The world has recognized the importance to regulate plastics production and pollution. A global agreement on ending plastic pollution is under production and a revised version will be discussed within April 2024 in Ottawa, Canada at the INC-4 (international negotiation committee). Directives have set binding monitoring demands for EU member states and Norway usually implements such directions in the national management. All this is happening while analysis methods forsmaller microplastics are still immature, and very expensive. Cheaper reliable methods are not available, imposing financial capacity problems to the field and excluding communities with lower funding from such research opportunities. One easier method is the staining Nile Red, a lipophilic dye that also stains other fatty particulates or organelles. In this master thesis we offer the opportunity to compare the number and size profile of microplastic isolated from food and analysed by high end methods with this low-budget method, to characterize the reliability of both methods. This master thesis will offer the opportunity to learn methods for chemical identification, particle size characterization and quantification of microplastics and to modify/develop the wet chemistry of extracting microplastics from food. It will teach you the principles of contamination avoidance. You should have a background in chemistry, environmental chemistry, biochemistry or similar.

If interested contact Tanja Kögel (tanja.kogel@hi.no).

 

Quantification of microplastic polymers using artificial intelligence (AI) approach 
based on random decision forests and thermoanalytical analysis using pyrolysis associated with gas chromatography mass spectrometry (PY-GCMS) 

Studies have shown the adverse impact of microplastics (MP) in the marine environment. There is a significant challenge in MP measurements due to the lack of standardized methods, resulting in difficulties in comparing results across studies because researchers use different protocols. To comprehend the distribution of MP in the marine environment, it is essential to develop robust, reliable selective and sensitive methods for measuring MP. In this project, we will develop, examine, and compare methods for microplastic analysis. Subsequently, these methods will be utilized to study the occurrence of MP in fish and shellfish.

Kontaktperson: PhD Jennifer Gjerde (Jennifer.Gjerde@hi.no)

 

Marin toksikologi

Contact person: forsker Marc Berntssen (marc.berntssen@hi.no) 

In recent years, in the global food market fraud and adulteration is increased violating consumers' safety. The food products available in the market are highly processed; therefore, difficult to identify the species or tissue origin by visual inspection. Molecular tools, i.e., PCR, genome sequencing, barcoding, and proteomics can be used to identify species from highly processed samples. Among the established methods, DNA methods are accurate and precise but unable to identify the tissue origin of the food sample. Our present study will implement an untargeted shotgun proteomics approach for species and tissue authentication from food 
and feed samples with the spectral library method. The approach is independent of any genomic information and is easy to implement on non-model species lacking such information. To implement this method for routine analyses across various laboratories, we want to create a spectral library database with bioinformatics tools and would like to involve a student with bioinformatics or biotechnology expertise. This database will use a tool to match any given food or feed spectra to all the available libraries and help to identify the origin of the sample. All the required proteomic data is collected by us (Institute of Marine research); libraries were built for sample matching and testing food and feed samples of interest. Making these libraries available online as a database will benefit regulatory agencies to use this approach for routine analyses. Besides authentication, the spectra data from the database can be used to establish a phylogenetic relationship between species by using a direct spectracomparison tool called ‘compareMS2’. 

Are you interested - contact: Madhushri Shrikant Varunjikar (madhushri.shrikant.varunjikar@hi.no) 

 

Ecosystem acoustics

Contact person: Rolf Korneliussen (rolf.korneliussen@hi.no) 

 

Bootstrapping of acoustic-trawl surveys

Variance estimation of acoustic-trawl and sweptarea survey estimates has received increasing attention with the on-going REDUS project (Reduced Uncertainty in Stock Assessment) at the IMR. Using the StoX software, the variance of the survey estimates can be estimated by bootstrapping echosounder and trawl data. This routine has however not been intensively tested with regards to number of bootstrap replicates, number of data points available and the stochastic nature of the data. Evaluating these bootstrap routines and suggesting alternatives would be a valuable contribution to the assessment of fish stocks. 

Suggested contact: Espen Johnsen (espen.johnsen@hi.no).

 

Image analysis of echosounder and sonar data

Machine learning initiatives have been initiated at the IMR for categorizing images of fish, seals and other organisms, and similar 
approaches are intended for acoustic data. Alternatively, traditional image analysis can be applied. 

Suggested contact: Nils Olav Handegard (nilsolav@hi.no).

 

Detecting internal waves in echosounder data

Waves in the ocean does not only occur at the surface. They are also commonly observed in the ocean interior as internal waves and are considered important features for vertical mixing of water masses.

For internal waves to exist, the ocean must be stratified. As such, the density must change with depth due to changes in temperature and/or salinity. If the density changes over a small vertical distance (as in the case of the thermocline) the waves propagate horizontally like surface waves, although at slower speeds due to the density difference across the thermocline interface. If the density changes continuously, the waves can also propagate vertically as well as horizontally through the ocean.

Uniformly scattered organisms and particles in the water column can be observed using scientific echosounders. If these scatters are located where internal waves occur, the wave patterns become visible on the echograms. Conversely, if no waves are present, the scatterers will be evenly distributed. The scatterers can then be used to detect internal waves in the water column.

The objective of the project is to develop a data mining algorithm that automatically locate the presence of internal waves from acoustic data. 

The One Ocean expedition is collecting acoustic data around the world, and this data set will be used as test case. IMR has also a large database of historical acoustic data that also can be mined for these features and can be used as a complementary option. 

The project is associated with the One Ocean expedition (https://oneoceanexpedition.com/), the Center for Research-based Innovation in Marine Acoustic Abundance Estimation and Backscatter Classification (https://crimac.no/) and the Nansen Environmental and Remote Sensing Center.

Are you interested - contact: Nils Olav Handegard (nilsolav@hi.no) and/or Johnny A. 
Johannessen (johnny.johannessen@nersc.no).

 

Oceanography and climate

Contact person: Jan Erik Stiansen (jan.erik.stiansen@hi.no)

Predicting the Future of the Arctic Ocean is a Non-Linear Story: Can a stronger river inflow actually increase the salinity of the Arctic?

The Oceanography & Climate Research team at IMR has designed a new regional ocean model based on the NEMO Ocean Engine, a community Ocean Model publicly available (check links below), that represents the thermo-haline dynamics of the Arctic Ocean. This ocean model permits to conduct cool experiments, such as for example study what happens if one increases the river inflow to the Arctic basin. Figure 1 shows what happens if one increases the river inflow to the Arctic basin by 4% over a period of 50 years: the surface salinity of the Arctic Ocean becomes lower in most places, but actually becomes higher in the central region of the Arctic. Why is this possible? How can putting more freshwater lead to areas of higher salinity? What are the implications for the Arctic Ocean in a changing climate? If you like to brainstorm on non-linear problems you can help us answer these questions!! 

Links: The NEMO Ocean Engine, an Open Source Ocean Model anyone can download 
https://www.nemoocean.eu/. An article with detailed results on our Arctic Ocean 
simulations using the NEMO Ocean Engine 
https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2021JC017270

Contact person: Robinson Hordoir (robinson.hordoir@hi.no) 

 

Pelagic fish

Contact person: Espen Johnsen (espen.johnsen@hi.no) 

Capelin acoustics

The capelin is a key species in the Barents Sea efficiently linking low-trophic zooplankton with high trophic predators. It is also harvested commercially and each year IMR provides advice on catch quota based on acoustic estimates of capelin from research surveys. Recently a new winter monitoring of capelin has been tested out, and it has been revealed that the acoustic response from capelin is sometimes very different from what is expected, which can potentially strongly bias biomass estimates. In this proposed master, the aim is to find out whether the unexpected acoustic response is linked to a changing size of the swimbladder. The student will work with acoustic data collected in situ and frozen samples of capelin that will be scanned or X-Rayed to quantify swimbladder size and investigate whether there is a link between swimbladder size and observed acoustic response.

Contact person: Georg Skaret (georg.skaret@hi.no) 

 

Validation of 1st winter ring in otoliths of blue whiting

Calcified structures such as otoliths are usually used for age reading of fish and their size is clearly related to fish length (Smoliński and Berg, 2022). However, identifying the first annual growth zone, also called winter ring, is the most challenging part for age readers. Misidentification would lead to over-/under-estimation of age which impacts stock assessment. For blue whiting (Micromesistius poutassou), the problem has been highlighted during the latest age reading workshop. Therefore, the aim of this project is to validate the 1st winter ring in blue whiting. Otoliths of young-of-the-year (YOY) and potentially 1-year-old blue whiting should be measured monthly over a year covering the winter season. Measurements will be used to provide an estimate where the 1st winter ring should be deployed in an otolith. Furthermore, this can be combined with more complex otolith shape analysis as well as weight measurements of otoliths.

During this project, you will learn how to apply growth measurements of calcified structures used for age reading. This includes both, technical methods like photographing and measuring of growth increments as well as statistical analysis. You might have the possibility to sample your own material during a survey in the Norwegian Sea during summer.

Keywords: blue whiting, growth trajectories, Norwegian Sea, otoliths, age validation

Supervisor: Florian Berg, Institute of Marine Research (IMR), Bergen, Norway; telephone: +47 
94209887; e-mail: florian.berg@hi.no

Co-supervisor: Arild Folkvord, Department of biological science, University Bergen, Norway; 
e-mail: arild.folkvord@uib.no

 

Reproduction and developmental biology 

Contact person:  Anna Troedsson Wargelius (annaw@hi.no).

Egg quality in farmed versus wild captured European plaice

European plaice is a species with a considerable potential, and it is currently under evaluation as an alternative species for aquaculture. Preliminary studies shown farmed plaice to produce poor quality eggs and offspring with low survival. The objective of this study is to compare the quality of egg batches from wild (captured in spring 2024) and farmed F1 plaice during the 2025 reproductive season (Feb-May 2025).

Collected egg batches will be fertilized and incubated for egg quality assessment. Subsamples of batches will be collected and snap frozen for molecular analyses. Development of a specific egg quality assessment protocol based on fertilization rate, survival rate and morphometric developmental parameters will be part of this study. Validity of egg quality markers, previously identified in Atlantic halibut, will be assessed via quantification of gene expression in these egg batches. The MSc student will be responsible of sample collection, egg quality assessments and development of the protocol, collection and analysis of data, and reporting findings through scientific publications. 

Arbeidssted: Austevoll. Start: February 2025. Contact person: ozlem.yilmaz@hi.no 

Sex reversal in European plaice: production of Neomales using 17-α methyltestosterone

Preliminary studies have shown sexual dimorphic growth with females growing larger than males in European place. This study involves production of genetically female but phenotypically male fish (neomales) to be crossed with natural females at maturity with the objective of generating all female populations. To induce neomale production, fish were treated with 5mg/kg 17-α methyltestosterone (or EtOH treated diets as control) from 45dph or 60dph up until 111dph. Tissue samples for histological observations of gonadal formation and differentiation, for gene expression analyses of sex determination genes, and for sex diagnostic test were collected every 5 days during the experimental period. The MSc student is expected to process and analyze these samples for a description of gonad formation and differentiation in plaice, and for validation of neomale production, collect and analyze data, and report findings through scientific publications. 

Arbeidssted: Austevoll. Start: September 2024, duration 8-12 months. Contact person: ozlem.yilmaz@hi.no 
 

Marine mammals

Contact person: Martin Biuw (martin.biuw@hi.no)

Assimilation rates of nutrients by baleen whales in the North Atlantic
There is a growing scientific interest in understanding the role of whales in nutrient and carbon cycling within marine ecosystems. Whales are known to excrete essential nutrients, such as nitrogen (N), phosphorus (P), and iron (Fe), which can enhance primary production—a process referred to as the "whale pump." Despite this, the exact quantities of nutrients released by whale populations remain uncertain. Previous research has estimated nutrient excretion by whales based on the nutrient content of their prey, under the unlikely assumption that whales assimilate nutrients similarly to terrestrial mammals.

This study aims to quantify the assimilation rates of key nutrients (N, P, Fe, and other trace elements) by minke and fin whales in the North Atlantic. To achieve this, nutrient concentrations will be measured and compared between whale excreta (feces and urine) and their prey. This approach will, for the first time, enable the estimation of nutrient assimilation rates in whales, providing a crucial parameter for quantifying their contribution to nutrient and carbon cycling in the ocean and, consequently, their ecological role within marine ecosystems.

Arbeidssted: Flødevigen, Arendal. Kontaktperson: carla.freitas.brandt@hi.no
 

Ecosystem processes 

Contact person: Mette Mauritzen (mette.mauritzen@hi.no). 

 

Study programme: Fisheries biology and Management / Marine biology

Energy and lipids in capelin 0-group fish in the Barents Sea: Study the spatial variations and the role the zooplankton distribution has for the energy status and lipid composition in different ocean currents (Atlantic, mixed sone and Arctic waters).

Supervisor University of Bergen:
Prof. Arild Folkvord (BIO), email: arild.folkvord@uib.no, phone: 55584456

Supervisors Institute of Marine Research:
Georg Skaret (Institute of Marine Research), IMR: georg.skaret@hi.no, phone 65161038
Sonnich Meier (Institute of Marine Research, IMR): sonnich.meier@hi.no, phone 47272166
Other Collaborations at IMR (Elena Eriksen, Erling Kåre Stenevik, Geir Odd Johansen).

Objective: To compare the energy status and fatty acid composition of capelin 0-group fish caught in different areas of the Barents Sea and relate it to the zooplankton distribution.

Background: The Barents Sea is an important nursery area for many of the commercial important fish in Norwegian water. In 2022 high numbers of fish larvae and early juveniles were observed in the Barents Sea. However, there was also observed low abundances of large Calanus copepods, and it is therefore a question if there will be enough high-quality prey for the fish larvae/early juvenile to build up a good energy storage to survive the first winter. 

The aim of this study is to compare the energy status measured by energy density and lipid content of 0-group capelin. In addition will the fatty acids composition be analyzed in 0-group capelin and different zooplankton as biomarkers of prey selection.

Climate changes are affecting the recruitment of the fish in the Barents Sea (Skjoldal et al., 2022), and we wish to establish a baseline study on energy content in different 0-group fish that can be used for measure potential changes with changing in water temperature in the future.

During the ecosystem cruises in autumn 2022 have there been collected a large sample material of 0-group fish: Atlantic Cod (Gadus morhua), Haddock (Melanogrammus aeglefinus), Saithe (Pollachius virens), Caplin (Mallotus villosus) and Polar cod (Boreogadus saida). In addition, have there been collected samples of important prey organism (copepods and other zooplankton). We aim for several master theses analyzing different species.

Method: Capelin 0-group fish shall be measured (length, body weight), and after being freeze dried the lipid amount will be quantified, and the fatty acid composition will be analyzed by gas chromatography (Meier et al., 2006). Energy density will be analyzed by calorimetry.

Prerequisites: An interest in ecology of fish at early life stages and interactions between environment, fisheries, and other human activities. The work will involve combining marine biology with analytical chemistry. The candidate will work in a team together with technician from the chemistry laboratory at IMR and will be given training in different lipid detecting methods (direct metanolysis and gas chromatography, lipid extraction and lipid classes analysis by HPLC), as well as multivariate data exploration and analysis.

References

Meier, S., S. A. Mjøs, H. Joensen and O. Grahl-Nielsen (2006). "Validation of a one-step 
extraction/methylation method for determination of fatty acids and cholesterol in marine 
tissues." Journal of Chromatography A 1104(1-2): 291-298.

Skjoldal, H. R., E. Eriksen, H. Gjosaeter, O. Skagseth, D. Prozorkevich and V. S. Lien (2022). 
"Recruitment variability of fish stocks in the Barents Sea: Spatial and temporal variation in 0-
group fish length of six commercial species during recent decades of warming (1980-2017)." 
Progress in Oceanography 206.

 

Energy and lipids in cod 0-group fish in the Barents Sea: Study the spatial variations and the role the zooplankton distribution has for the energy status and lipid composition in different ocean currents (Atlantic, mixed sone and Arctic waters).

Study programme: Fisheries biology and Management / Marine biology

Supervisor University of Bergen: Prof. Arild Folkvord (BIO), email: arild.folkvord@uib.no, 
phone: 55584456

Supervisors Institute of Marine Research:
Elena Eriksen (Institute of Marine Research), IMR: elena.eriksen@hi.no, phone 90813570
Sonnich Meier (Institute of Marine Research, IMR): sonnich.meier@hi.no, phone 47272166

Other Collaborations at IMR (Georg Skaret, Erling Kåre Stenevik, Geir Odd Johansen).

Objective: To compare the energy status and fatty acid composition of cod 0-group fish caught in different areas of the Barents Sea and relate it to the zooplankton distribution.

Background: The Barents Sea is an important nursery area for many of the commercial important fish in Norwegian water. In 2022 high numbers of fish larvae and early juveniles were observed in the Barents Sea. However, there was also observed low abundances of large Calanus copepods, and it is therefore a question if there will be enough high-quality prey for the fish larvae/early juvenile to build up a good energy storage to survive the first winter. Climate changes are affecting the recruitment of the fish in the Barents Sea (Skjoldal et al., 2022), and we wish to establish a baseline study on energy content in different 0-group fish that can be used for measure potential changes with changing in water temperature in the future.

The aim of this study is to compare the energy status measured by energy density and lipid content of 0-group cod. In addition will the fatty acids composition be analyzed in 0-group cod and different zooplankton as biomarkers of prey selection.

During the ecosystem cruises in autumn 2022 have there been collected a large sample material of 0-group fish: Atlantic Cod (Gadus morhua), Haddock (Melanogrammus aeglefinus), Saithe (Pollachius virens), Caplin (Mallotus villosus) and Polar cod (Boreogadus saida). In addition, have there been collected samples of important prey organism (copepods and other zooplankton). We aim to have several master theses analyzing different species.

Method: 0-group Cod shall be measured (length, body weight and liver weight), and the otolith shall be removed for age measurement. After being freeze dried, the lipid amount will be quantified, and the fatty acid composition will be analyzed by gas chromatography (Meier et al., 2006). Energy density will be analyzed by calorimetry.

Prerequisites: An interest in ecology of fish at early life stages and interactions between environment, fisheries, and other human activities. The work will involve combining marine biology with analytical chemistry. The candidate will work in a team together with technician from the chemistry laboratory at IMR and will be given training in different lipid detecting methods (direct metanolysis and gas chromatography, lipid extraction and lipid classes analysis by HPLC), as well as multivariate data exploration and analysis.

 

References: 

Meier, S., S. A. Mjøs, H. Joensen and O. Grahl-Nielsen (2006). "Validation of a one-step 
extraction/methylation method for determination of fatty acids and cholesterol in marine 
tissues." Journal of Chromatography A 1104(1-2): 291-298.

Skjoldal, H. R., E. Eriksen, H. Gjosaeter, O. Skagseth, D. Prozorkevich and V. S. Lien (2022). 
"Recruitment variability of fish stocks in the Barents Sea: Spatial and temporal variation in 0-
group fish length of six commercial species during recent decades of warming (1980-2017)." 
Progress in Oceanography 206.

 

Energy and lipids in Herring 0-group fish in the Barents Sea: Study the spatial variations and the role the zooplankton distribution has for the energy status and lipid composition in different ocean currents (Atlantic, mixed sone and Arctic waters).

Study programme: Fisheries biology and Management / Marine biology

Supervisor University of Bergen: Prof. Arild Folkvord (BIO), email: arild.folkvord@uib.no, 
phone: 55584456

Supervisor Institute of Marine Research:

Erling Kåre Stenevik (Institute of Marine Research), IMR: erling.stenevik@hi.no, phone 
4790813570
Sonnich Meier (Institute of Marine Research, IMR): sonnich.meier@hi.no, phone 47272166
Other Collaborations at IMR (Georg Skaret, Elena Eriksen, Geir Odd Johansen).

Objective: To compare the energy status and fatty acid composition of herring 0-group fish caught in different areas of the Barents Sea and relate it to the zooplankton distribution.

Background: The Barents Sea are an important nursery area for many of the commercial important fish in Norwegian water. In 2022 high numbers of fish larvae and early juveniles were observed in the Barents Sea. Especially were the 0-group of Atlantic herring very abundant and distributed over most of the Barents Sea. This may be promising for recruitment of new strong year classes of herring (Hi.no). However, there was also observed low abundances of large Calanus copepods, and it is therefore a question if there will be enough high-quality prey for the fish larvae/early juvenile to build up a good energy storage to survive the first winter. 

Climate changes are affecting the recruitment of the fish in the Barents Sea (Skjoldal et al., 2022), and we wish to establish a baseline study on energy content in different 0-group fish that can be used for measure potential changes with changing in water temperature in the future.

The aim of this study is to compare the energy status measured by energy density and lipid content of o-group herring collected in the Barents sea in August/Semptember2022. In addition will the fatty acids composition be analyzed in o-group herring and different zooplankton as biomarkers of prey selection.

The energy and lipid composition of o-group Herring collected in November 2022 and (1 year-old) herring collected in February will also be analysed to establish the “energy coast of overwintering".

Method: Herring o-group fish shall be measured (length, body weight), and the otolith shall be removed for age measurement. After being freeze dried, the lipid amount will be quantified, and the fatty acid composition will be analyzed by gas chromatography (Meier et al., 2006). Energy density will be analyzed by calorimetry.

Prerequisites: An interest in ecology of fish at early life stages and interactions between environment, fisheries, and other human activities. The work will involve combining marine biology with analytical chemistry. The candidate will work in a team together with technician from the chemistry laboratory at IMR and will be given training in different lipid detecting methods (direct metanolysis and gas chromatography, lipid extraction and lipid classes analysis by HPLC), as well as multivariate data exploration and analysis.

 

References

Meier, S., S. A. Mjøs, H. Joensen and O. Grahl-Nielsen (2006). "Validation of a one-step 
extraction/methylation method for determination of fatty acids and cholesterol in marine 
tissues." Journal of Chromatography A 1104(1-2): 291-298.

Skjoldal, H. R., E. Eriksen, H. Gjosaeter, O. Skagseth, D. Prozorkevich and V. S. Lien (2022). 
"Recruitment variability of fish stocks in the Barents Sea: Spatial and temporal variation in 0-
group fish length of six commercial species during recent decades of warming (1980-2017)." 
Progress in Oceanography 206.

Økotoktet: Er en ny sterk sildeårsklasse på vei? | Havforskningsinstituttet (hi.no)

 

 

See also https://www.hi.no/hi/forskning/student-som-vil-bli-havforsker