Projects/Activities

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Deep-burrowing crustaceans – density dependent effects on sediment chemistry Some thalassinidian crustaceans burrow exceptionally deep into the anoxic part of marine sediment where molecular diffusion normally dominates chemical transport. In this study we use tracers and microsensors to monitor the impact of such deep bioturbation. By introducing oxygen as well as advective transport to the buried material a large volume of the sediment is affected by one single burrow, and as animal density increases overlapping effects on sediment chemistry are inevitable. The relationship between burrow density and chemical impact are thus studied and modeled. Combined effect of sediment-associated compounds on marine benthic macrofauna This project investigates sub-lethal effects of complex chemical mixtures in both pristine and contaminated marine sediments. Bioturbated sediment comprises a spatially and temporally dynamic mosaic of redox reactions. By using voltammetric microelectrodes that concurrently measure, in situ, a suite of compounds involved in early diagenesis it is possible to obtain the resolution needed to study such complex and dynamic systems. The combined effects of sediment-associated compounds are primarily studied on two marine mud-shrimps, Calocaris macandreae and Upogebia deltaura. The animals’ behavioral and toxicological responses to dynamic solute matrices and associated (scavenged) anthropogenic heavy metals are studied in boxcore (microcosm) experiments. Particular attention is given to quantifying concentration-response relationships and thresholds, and in identifying physiological mechanisms, with respect to ecologically relevant chemical mixtures. Effects of chemical mixtures on the embryonic development in lobster eggs Here we look at the combined effect of diagenetically generated solutes on the embryos of two decapod lobster species, Homarus gammarus and Nephrops norvegicus. Chemical dynamics in and around egg clutches are studied in detail, using microsensor-technology. Physiological and morphological parameters are monitored to estimate effects on development in embryos exposed to chemical mixtures both in vivo and in vitro. Adult female behavioral response, genetic and ecological differences are also investigated.

Shallow coastal areas on the Swedish west coast are generally considered highly productive and important nursery grounds for both invertebrates and fish. Several commercial important coastal fish species utilize the abundant food resources in the shallow bays during their juvenile life history stages. In my research, trophic relationships are characterized among a guild of epibenthic fish and crustaceans in some shallow embayments along the Swedish west coast. I focus principally on the influence of physical factors (temperature, salinity, exposure, sediment type, oxygen level and habitat structure) on predator-prey dynamics which are quantified in a multi-level approach involving laboratory experiments and field sampling. My intention is to study biotic regulation of populations within the limits set by naturally occurring abiotic factors in coastal areas. The general hypothesis is that habitat structure (sediment and vegetation) in a coastal area has a decisive importance for community structure and function. The structure of the habitat influence the carrying capacity of the area and set the limits within which population size may fluctuate. Population dynamic, production and consumption of epibenthic fauna and fish has been estimated quantitatively in some shallow soft bottom bays, and energy flow models have been constructed for both a sandy habitat and an eelgrass bed. Interactions between habitat structure (sediment and vegetation) and the structure of epibenthic fauna has been evaluated in several types on coastal environments in the Skagerrak and the Kattegat. For example, changes in macrovegetation in shallow coastal areas and its effects on recruitment and population structure of associated crustaceans and fish has been investigated. Distribution of filamentous algae has been assessed by aerial photo documentation, and interactions between vegetation and fauna has been studied in laboratory experiments and field investigations. Structure of fish assemblages has been related to vegetation type in both rocky and soft bottom communities. In shallow sandy bays recruitment mechanisms in flatfish has been studied. Further, the structuring role of hypoxia on demersal fish communities has been investigated in SE Kattegat and York River, Chesapeake Bay, including studies of species structure, biomass, growth, migrations and food selection.

Stock assessment of marine Crustecea suffers from uncertainties in estimation of size and yield due to difficulties in identifying population entities. This project will use molecular methods to investigate weather Antarctic Krill (Euphausia superba) in the Southern Ocean and northern shrimp (Pandalus borealis/ P. eous) in the north Atlantic and north Pacific should be viewed as large panmictic populations or if they ought to be subdivided in sub-populations on genetic grounds. Yearly landings of northern shrimp reach ˜ 250 000 metric tonnes, and ˜ 100 000 metric tonnes of Antarctic Krill are landed per year. In January 2000 I collected krill samples from 12 stations in an area from east of S. Georgia via the S. Orkney Islands to SW of the S. Shetland Islands. Samples of P.borealis from west Greenland, the Gulf of St. Lawrence, the Gulf of Maine, Icelandic waters, the Barents Sea, the Norwegian coast and the North Sea and Skagerrak in the Atlantic have been obtained or are being obtained. For comparisons I will also get samples from the coast of Alaska and the Berings Sea. In addition to extracting amplifying and sequencing DNA from the 16 S gene and COI gene we (co-operation with Dr. P. Sundberg, Mrs S. Viker and Mrs. A Hjelmgren, Zoology Dept. Göteborg University) will attempt to design primers for more fast-evolving genes, which we assume will be better suited for our analyses. In order to design primers that covers these sections we will endeavour to sequence the entire mitochondrial genome for the model species. Results will be analysed in co-operation with Dr. Ziad Thaib, Applied Mathematics Chalmers School of Technology and Göteborg University.

Several aspects of the effects and interactions between oxygen concentration and organic enrichment, water flow velocity, and 'sublethal predation' are studied in laboratory experiments on the common infaunal brittle stars Amphiura filiformis and A. chiajei. At slightly higher oxygen saturations (about 10% oxygen saturation) than those resulting in mortality, a change was noted in the brittle star behaviour. They left their burrow systems and elevated their central disk some cm above the sediment surface standing on their arms. No such behavioural change, compared to control, was observed during exposure to moderate hypoxia (18 to 30% oxygen saturation). However, it was noted during exposure to moderate hypoxia that both arm regeneration rate and disk growth was reduced in A. filiformis. No such response in arm regeneration rate was observed for A. chiajei. Both species responded positively to increased organic enrichment. The fact that the arm regeneration rate of A. filiformis exposed to high organic enrichment and moderate hypoxia was similar to the control suggests that this response may depend on an increased ventilation demand due to increased sulphide concentration in the sediment. An increased arm regeneration rate was observed in moderate water flow velocity (0.5 cm s-1) compared to low flow velocity (0.1 cm s-1) in moderate hypoxia (18% oxygen saturation). However, no differences in arm regeneration rates were observed in normoxia between water flows, indicating that under conditions of low oxygen, growth is affected by water flow. The hypoxic response of two marine soft-bottom communities were studied in a manipulative microcosm experiment in three levels of oxygen concentration (6 to 7%, 12% and >80% oxygen saturation). In both communities significant reductions in both abundance and species richness were observed at 6-7% oxygen saturation. However, when exposed to 12% oxygen saturation the response differed between communities. In the community collected at a site with an oxidised top sediment the diversity decreased, but not the total abundance. However, the community taken at an organic loaded site, and characterised by a more reduced sediment, both abundance and diversity decreased at 12% oxygen saturation.

Growth measuring using Otoliths...

Brissopsis lyrifera is a burrowing heart urchin often dominating soft-bottom biomass at depths between 30 and 200 m along the Swedish West Coast. It is about 5 cm in diameter and burrows through the sediment at about 5 cm depth, while feeding on organic debris, foraminifers, and small organisms within the sediment. The mouth is situated on the underneath side and specialized tubefeets are used for feeding. Burrowing spatangoids constructs ciliary currents around the body for respiration. A more or less well-developed funnel connects the urchin with the sediment surface. Particles that is deposited into the funnel are carried by respiratory currents and transferred to the mouth and ingested. The feeding strategy of B. lyrifera is not fully understood, it seems to be able to feed both from the sedment surface and within the sediment. The response of Brissopsis lyrifera, to organic matter on the sediment surface was investigated in a laboratory experiment, using sediment box-cores. Organic matter was added on the sediment surface and after each addition, one randomly chosen box was video recorded with a time-laps camera. The activity of B. lyrifera on the sediment surface and its response to the added organic matter was studied by measuring emergence behavior, time spent on the surface, locomotion rate on the surface and total reworked surface area. Gonad index, gonad lipid content, gonad water content and intestine lipid content were also measured at the end of the experiment, to evaluate B. lyrifera's ability to utilize the added organic matter. B. lyrifera emerged significantly more frequent in those boxes where organic matter was added, and the total reworked surface area was larger. This indicates that B. lyrifera is able to respond to organic matter and move upward to eat from the sediment surface. Increased gonad index in the fed treatments shows that B. lyrifera is able to utilize the organic matter as food. Lipid content of the intestine remained constant, indicating that assimilated energy is allocated to gonads rather than stored in the gut. B. lyrifera is likely to have a significant impact on the sediment property, reworking of organic matter, and on other infauna down to at least 10 cm depth.

In most animals, males play the active role in courtship and compete for mates, whereas females are discriminatory in their mate choice. As a result of this, males in many animals have evolved costly ornamental traits such as gaudy coloration and long tails. In some species, females are also ornamented, but the reasons for this are poorly known. So far, the focus of most studies have been on sexual selection acting on males, although, under some circumstances males are expected to be choosy and females competitive. Despite the large interest the field of sexual selection has received over the last decades there are still challenging areas which are not fully understood, for example, the function and evolution of secondary sexual ornaments, the evolution of mate preferences and the existence of sex-roles. The aim of this project is to test questions related to these areas. The project will not only focus on selection acting on males, but will also investigate sexual selection acting on females, i.e. male mate choice and female-female competition. The project combines field studies with laboratory experiments. The animals under study are some gobiid fishes with paternal care and conventional sex roles: the sand goby, Pomatoschistus minutus, the common goby, P. microps and the two-spotted goby, Gobiusculus flavescens. The project will, for example, investigate costs and benefits of mate choice, the function of both male and female sexual ornaments, and the plasticity of reproductive behaviour and sex-roles.

Comparative physiology on brown, red and green macroalgae, especially regulation of photosynthesis...

1. Meganyctiphanes norvegica is the most abundant krill species in the fjord, although small numbers of Thysanoessa raschii and T. inermis also occur there. The work is now concentrated on the daytime tolerance levels of light from above and hypoxic water below, in the deep part of the fjord. Nighttime vertical migration and reaction to pycnoclines and possible advection out of or into the fjord is also under investigation. (See also Bo Bergström and Maria Thomasson) 2. Samples of deep-sea epicarid isopods indicate that this taxon is much better represented in the deep sea than previously anticipated. Taxonomy and zoogeography has been partly worked up, but the project is presently resting. My interest also covers deep sea asellot isopods. 3. Most often it is difficult to distinguish between fluctuations in biomass, abundance or changes in species composition in marine ecosystems caused by natural events and those caused by human activities. Indications are clear that the macrobenthos on the Swedish west coast is affected by both large-scale climatic factors and direct anthropogenic impact. This project will soon start in co-operation with Björn Tunberg, Andrea Belgrano, Odd Lindahl and Jacob Hagberg. My involvement in the IGBP/SCOR/IOC project on the Global Ecosystem Dynamics (GLOBEC) relates now in particular to the Southern Ocean where krill is a very important component in the trophic system. My present involvement is in the planning of international research activities through the GLOBEC Working Group on the Southern Ocean.

Dinophysis spp and the Koljö fjord. It has been known since some years that blue mussels in the fjord system north of Orust very seldom or never contains the diarrhetic shellfish toxin (DST) at the same time as toxic mussels can be found at the mouth areas of the fjord system. Our research has shown that the causative organism, the dinoflagellate Dinophysis spp, generally do not occur in the fjords while high abundance’s were found outside the mouth, although there is a tidal exchange and a net current flowing through the fjord system. Field and laboratory experiments have so far demonstrated that growth and survival of Dinophysis is less in the Koljö fjord compared to controls. We are for the moment looking at what factors may control these processes. This is part of the Ph.D. work by Fredrik Norén within the MISTRA project "Recycling of nutrients from sea to land using mussel culture".(http://www.mistra-research.se) Molecular identification of Dinophysis spp. Dr Ann-Sofi Rehnstam-Holm, after a postdoctoral position at the Woods Hole Oceanographic Institution (USA) will start working at Göteborg University and at Kristineberg on a MISTRA-project concerning new detection methods for Dinophysis. These methods consists in species specific identification by molecular probes and by a sophisticated signal amplification system, they are ready to be tested in the field at Kristineberg in co-operation with the MISTRA(http://www.mistra-research.se) project "Recycling of nutrients from sea to land using mussel culture". Production of DST by Dinophysis spp. Our experience since several years is that the Dinophysis species do not always contain DST. Recently a database containing all observations on phytoplankton from 1989 and onwards from the Gullmar fjord area was completed. This database will now be run against other databases containing environmental data, since it is known that the toxin production of many dinoflagellates may depend on nutrient stress. Together with professor Edna Granéli (http://www.hik.se) we are also planning laboratory experiments which hopefully will increase the knowledge about toxin production of Dinophysis. Uptake and fate of pathogenic microbes in the blue mussel, Mytilus edulis Linneaeus. The aim of this research project, which also is part of the M.D. work of Bodil Hernroth (BSc.), will contribute to increase the knowledge of how mussels process pathogenic bacteria and viruses, to try to predict which microbes may reach humans when consuming mussels. Comparative and quantitative studies of endocytos, anti-microbial activity, exocytos and elimination of pathogenic microbes by the mussels will be carried out. This project is a part of the MISTRA (http://www.mistra-research.se) project "Recycling of nutrients from sea to land using mussel culture" in close co-operation with Prof. Lars Edebo (M.D. supervisor) at the Institute of Laboratory Medicine at Gothenburg University (http://www.medfak.gu.se). Time-series analysis of pelagic data in the Gullmar fjord. Dr Andrea Belgrano (ecosystems ecologist), has a two-year individual postdoctoral fellowship position at Kristineberg funded by the European Commission (EC) within the Marine Science and Technology Programme (MAST III), is now working with advanced time-serie analysis on the project : " Plankton Community Dynamics in Relation to Water Exchange: The Gullmar Fjord Time Series Data Set- EC-MAST III - individual postdoctoral fellowship Research Project (MAS3-CT96-5028). (http://www.ecology.su.se/databases/biomad/lajos/pm32.htm). For the analysis of the time series data set co-operation have been established with Prof. Björn Malmgren, Göteborg University ( http://www.gmf.gu.se/Departments/MarineGeology.html), Dr. Andrew R. Solow , Woods Hole Oceanographic Institution (http://www.whoi.edu/mpcweb/), Dr. Mercedes Pascual, University of Maryland (http://www.umbi.umd.edu/~comb/index.html) and Dr. Peter Turchin, University of Connecticut (http://www.eeb.uconn.edu/) The exchange of deep-water of the Gullmar fjord. The hydrography and oxygen situation of the deep water of the Gullmar fjord has been monitored monthly for 20 years within different research and monitoring programmes. The ongoing analysis of this time-series will focus on the detection of trends and periodicity in the observed oxygen fluctuations, as well as on the changes in the timing and extent of the annual exchanges of the deep-water. The data analysis will benefit from the established co-operation with physical oceanographer at the Oceanographic Institution at Gothenburg University. Modelling of onshore and offshore marine populations. We are partner in a collaborative Virtual University Education Programme(http://www.umbi.umd.edu/virtue/index.html) established between Gothenburg University, and the University of Maryland (USA) in relation to the project " The temporal dynamics of vibrios in aquatic environments ". The objective of this project will focus on a better understanding of the dynamics of the bacterium Vibrio cholerae in aquatic ecosystems in relation to climatic and environmental forcing, as well as the role played by plankton as a potential reservoir for Vibrio cholerae outbreaks. This project will run for three years (1998-2000) and will involve a co-operation on new methods for the analysis of time series data and plankton dynamics between Dr. Mercedes Pascual and Dr.Anwar Huq at the Center of Marine Biotechnology, University of Maryland, Baltimore,U.S.A (http://www.umbi.umd.edu/~comb/index.html), Dr. Andrea Belgrano and Dr. Odd Lindahl at Kristineberg Marine Research Station (KMF) and Prof. Björn Malmgren at the Department of Earth Sciences - Marine Geology, Earth Sciences Center, Göteborg University (http://www.gmf.gu.se/Departments/MarineGeology.html)