Effects of ocean acidification on boreal and Arctic Calanus spp.

Funding agencies: Institute of Marine Research and Fram Centre for High North Research Centre for Climate and the Environment
Project period: 2012 – 2017
Project Leader: Howard Browman
Co-investigators: Howard Browman, Anne Berit Skiftesvik, David Fields, Steve Shema, V. Thiyagarajan, Jeff Runge, Cameron Thompson, Haakon Hop, Peter Thor, Allison Bailey, Caroline Durif, Reidun Bjelland, Michael Arts, Andrew Mount, Vera Chan.

Project summary

This project will determine ocean acidification (OA) and temperature effects on boreal and Arctic species of copepods. We will investigate the effects of temperature and OA on natural selection in key genes and physiological traits in different copepod  populations. We will investigate changes in fitness-related traits such as growth, fecundity, and susceptibility to predation will be investigated in populations of the copepods Pseudocalanus sp. and Calanus finmarchicus (boreal species extending into the Arctic) and C. glacialis (a true arctic species).

Impact of ocean acidification on arctic zooplankton populations

Funding agency: The Research Council of Norway (HAVKYST Program)
Project period: 2013 – 2016
Project Leader: Haakon Hop
Co-investigators: Peter Thor, Howard Browman, Allison Bailey (Ph.D. student)

Project Summary

About one third of emitted CO2 is absorbed into the world´s oceans, and the elevated partial pressure of CO2 (pCO2) is now changing the pH of the oceans. This so-called “ocean acidification” (OA) may disturb affected marine populations in ways we cannot yet predict. In this respect, the Arctic constitutes one particular area of concern since the increase in sea water
pCO2 is expected to be more pronounced in Polar Regions. Almost all animal studies focus on physiological responses of individuals to elevated pCO2. However, the increase in pCO2 will be slow, and major OA effects will only occur on the time scale of several generations, which leaves room for genetic adaptation of populations to the changed environment through natural selection. We intend to investigate how the balance between natural selection and phenotypic plasticity (potential to acclimatize without genetic changes) in traits involved in pH regulation and oxidative stress influences the life history and genetic diversity of arctic copepod populations during increased pCO2. The gold standard for making predictions of evolutionary change is controlled selection experiments during several generations, and we intend to measure the balance between selection and
plasticity through at least 4 generations. Copepods will be incubated in small mesocosms and the selection/plasticity balance will be measured by means of reverse transplant tests and molecular determination of genetic diversity.

In situ swimming and orientation ability of larval cod and other plankton. Parameterizing models of prey availability to top predators

Funding agency: The Research Council of Norway (HAVKYST Program)
Project period: 2014 – 2015
Project Leader: Howard Browman
Co-investigators: Frode Vikebø, Anne Berit Skiftesvik, Steve Shema, Caroline Durif, Reidun Bjelland, Claire Paris and Alessandro Cresci

Project summary

Larval transport from spawning grounds to nursery grounds is a key processes that needs to be addressed if attempting to quantify spatiotemporal availability to top predators. However, larvae are not entirely destined to follow ocean currents. They can affect their dispersal both through vertical and horizontal movements and this will change the prey availability to their predators. While existing NFR-projects already model seabird-fish interactions under various climatic states with state-of-the-art model components, they would greatly benefit from improved model parameterizations of larval behavior. Here we propose to combine a unique field and laboratory observation platforms that, together, will add substantially to our knowledge of these critical aspects of the early life history of a keystone fish species in Norwegian waters, Atlantic cod. Specific objectives are to (1) provide and analyze in situ measurements of swimming and orientation of the early life stages and (2) elucidate the in situ behavioral responses of cod larvae, as individuals and in groups, to a combination of proximal cues. This information is complementary to observations on the sensory capabilities and behavior of cod larvae that are generated in the laboratory and/or from acoustic measurements. Furthermore, we will 3) communicate through publications how new knowledge on larval behavior gained through the experiments described above may be included in existing coupled physical-biological models involving early stages of cod. Key questions to address: Are cod larvae orienting vs. swimming at random when in open water? If larvae do orient, when during development does this begin? Where do they orient, i.e. towards what location? Are multi-modal stimuli providing useful information for detection, navigation and nursery habitat localization? What are these stimuli? How do swim speed and swim time compare in the field vs. laboratory observations?

Optimizing the use of cleanerfish on salmon farms

Funding agency: The Norwegian Seafood Research Fund (FHF) and the Institute of Marine Research
Project period: 2014 – 2016
Project Leader: Anne Berit Skiftesvik
Co-principle investigators: Howard Browman, Reidun Bjelland, Caroline Durif, Steve Shema

Project summary

To optimize the use of cleanerfish (wrasses and lumpfish on salmon farms.

Population dynamics of wild wrasse populations along the Norwegian coast

Funding agency: The Norwegian Seafood Research Fund (FHF) and the Institute of Marine Research
Project period: 2013 – 2017
Project Leader: Anne Berit Skiftesvik
Co-investigators: Howard Browman, Caroline Durif, Reidun Bjelland, Steve Shema

Project summary

To assess the population dynamics and status of wrasse populations that are now exploited for use as cleanerfish on salmon farms.

Fine-scale interactions in the plankton – empirical observations to parameterize trophodynamic models

Funding agency: Institute of Marine Research
Project period: 2011 – 2014
Project Leader: Howard Browman
Co-principle investigators: Howard Browman, Anne Berit Skiftesvik, David Fields, Caroline Durif

Project summary

This is a long-term project in which we make behavioural and physiological observations of ichthyoplankton and zooplankton with the aim of delivering empirical relationships on vital rates for parameterization of various components of ecosystem and trophic interaction models.

Effects of climate change on the Calanus complex (ECCO)

Funding agency: The Research Council of Norway
Project period: 2010 – 2014
Project Leader: Webjørn Melle
Co-investigators: Espen Bagøien, Howard Browman, Geir Huse et al.

Project summary

Understanding and being able to quantify dynamics of the Calanus species complex are crucial for producing realistic forecasts of the climate change effects on the north-east Atlantic ecosystem, including fish stocks. The Calanus complex contains four species (Calanus helgolandicus, C. finmarchicus, C. glacialis, C. hyperboreus) that dominate both warm and cold water herbivore communities along the North Sea to Arctic Ocean axis. Despite their morphological similarities, these species exhibit important differences in behaviour, size, fat metabolism and deposition, reproduction, overwintering, diapause, diet, susceptibility to predation, etc. It is not known precisely why a given Calanus species succeeds in one environment and not in another – arriving at a better understanding of this will allow us to better predict how the herbivorous communities of the northeast Atlantic will change in response to global warming. We propose to examine the underlying mechanisms and potential long term impact of changes in the Calanus complex at the three predefined adult and larval fish feeding grounds, and in the north-east Atlantic in general. We will do so by using historical data, process studies, experimental studies and ecosystem modelling.

This Strategic Institute Program will enable IMR to give better advice on the ecosystem effects of climate change. In particular changes in the dynamics at lower trophic levels, being the part of the ecosystem where the most pronounced climate induced changes are expected. New knowledge on Calanus species interactions and climate effects will improve our abilities to give advice under the ecosystem approach to fisheries management. Improved model simulation capabilities will enable forecasts of Calanus distribution and production in their present and new areas under a changing climate, with particular focus on feeding areas and spawning sites of commercial fish stocks.



The importance of the marine habitat for the critically endangered European eel (MAREEL)

Funding agency: The Research Council of Norway (FRIMEDBIO Program)
Project period: 2016 – 2019
Project leader: Caroline Durif
Co-investigators: Anne Berit Skiftesvik, Howard Browman, Asbjørn Vøllestad, Eva Thorstad, Michael Arts, Cynthia Jones, Michael Power, Janet Koprivnikar

Project summary

The European eel, (Anguilla anguilla) is semi-catadromous: it spawns in the sea but spends most of its life in freshwater (FW). Some individuals either skip the FW phase or shift habitat throughout the pre-spawning migration phase of their life history. Despite habitat shifting sometimes being a dominant trait at high latitudes, little is known about eels that remain in marine habitats (saltwater (SW) residency). A. anguilla is currently red listed as critically endangered. Causes for the decline are associated mainly with FW residency: dams and power plants, parasites and elevated contaminant levels. Although the proximate and ultimate drivers of FW vs. SW residency are unknown, residing in SW, or shifting habitats, may confer considerable advantages. To test whether eels that have lived in the marine environment are fitter and have a better chance at reproduction than FW eels, we will investigate condition, growth, length and age at maturation of eels caught in different salinity environments along a latitudinal gradient in Norway. The salinity history of eels will be retraced using microchemistry analyses
on otoliths and compared with back-calculated growth rates. Their overall condition will be linked to the parasite load, their fatty acid (FA) profile and their long-term dietary patterns obtained by stable isotope analysis (SIA). Once FA and SIA profiles are established, we will use these proxies to infer the salinity histories of a larger sample of eels. Additionally, we will investigate seasonal movements of eels in SW, FW and in between, using data storage tags to link movements with environmental factors.
The proportion of eels exhibiting the different life-histories will be analyzed at different latitudes along the Norwegian coast. This project will provide unique new knowledge on the determinants of diadromy and on the SW and shifting life history strategies of eels that will contribute to worldwide efforts to conserve this ancient species.

Hybridization in the Calanus species complex (HYCAL)

Funding agency: The Research Council of Norway (MARINFORSK Program)
Project period: 2016 – 2019
Project Leader: Howard Browman
Co-investigators: Tor Knutsen, Espen Bagoien, Tone Falkenhaug, Kevin Glover, Maria Quintela, David Fields, Jeffrey Runge, Ann Bucklin.

Project Summary

This study will examine hybridization and its ecological implications among Calanus species residing in the Northeast Atlantic Ocean.  Recent evidence suggests that sympatric Calanus species mate and hybridize, producing intermediate phenotypes in regions where species overlap. The common assumption that these species are reproductively isolated has been challenged with the discovery of successful reproduction among genetic hybrids of C. finmarchicus and C. glacialis, two Calanus species that predominate in the seas adjacent to the Norwegian coast. The revelation that some species in the genus Calanus hybridize challenges our current understanding of the abundance, distribution and integrity of what are currently considered distinct Calanus species. Widespread hybridization  would fundamentally change our understanding of the dynamics controlling population abundances of Calanus species, with significant consequences  for the ecology of the region’s pelagic food web and the trophic levels (fish, seabirds, whales…) that fundamentally rely on the production of energy rich Calanus for food. Moreover, climate-driven influences on water mass distributions and physical characteristics of pelagic habitats will change phenologies and distributions of Calanus species, altering mechanisms of reproductive isolation and perhaps providing new opportunities for hybridization to occur. These findings point to a new hypothesis: that continued warming in the northeast Atlantic will lead to increased overlap of Calanus congeners and, consequently, increase the proportion of hybrids resulting in reduced recruitment and population abundance. If borne out by the research detailed in this proposal, this hypothesis is ground breaking in its implications for the productivity of northern North Atlantic ecosystems and our ability to predict climate-forced ecosystem change.