Lovén Centre

Achievements for each user project

 

De Jong

The project aimed to analyze how sugar kelp status (healthy vs degraded ”forests”) affects the abundance and operational sex ratio (the sex ratio of ready-to-mate individuals) in two-spotted gobies. However, sugar kelp status proved hard to quantify in the field. This lead to two changes in our original proposal. 1. We did quantify abundance and operational sex ratio of two-spotted gobies along transects on three localities, at three different times during the season, but we did not quantify kelp forest degradation. However, combined with transect data from four previous years, this will give us an overview the changes in OSR and abundance over the season, if this differs between years and if the population in the Gullmarfjord is declining or changing over the years. 2. We put a larger focus on experimental work than proposed in our original proposal. In large tanks, we tested if the distribution of nest sites affects the number of males that can defend a nest and thus OSR and related competitive behaviour, because a change in algae structure could lead to a change in the distribution of nest sites, as well as the number of nest sites. This experiment was very successful and we expect to publish the data relatively soon.

Olivieri

The main objective of this project focuses on the comparative analysis of ophiuroids and echinoids larval skeleton gene regulatory network (GRN).

During our visit we were able to complete most of our ambitious short-term goals. Our success was obtained only with the ophiuroid species Amphiura filiformis. We were able to collect ripe animals from the Gullmarsfjord and start several cultures some of which were highly synchronized cultures from single male and single female. This allowed a thorough analysis of A. filiformis developmental stages. We were able to time precisely major embryonic events from fertilization until pluteus larval stage. We used DAPI and Calcein staining to image the cleavage stages and the formation of skeleton.  For the first time we recorded all major events in early development of A. filiformis and we made important discoveries on its development: extrusion of polar body, position of first 3 cleavage planes relative to the A-V axis, hatching, onset of gastrulation and skeleton deposition. We were also successful in preparing genetic material (genomic DNA and cDNA) and embryonic samples (fixed at different stages) for further molecular studies. We had good success in genomic DNA extraction from adult arms and dissected male gonads. The data obtained will be a substantial contribution of a near future publication.

The only problem encountered concerns animal season. Our visit didn’t coincide with O. fragilis season (too late) and A. filiformis was not at the peak of its season. This limited us in trying some injection procedures and lineage tracing experiments.

Higgs

During the ROV dives we obtained the required video to document the final stages of degradation of the whale skeleton and collected two bones for detailed diagenetic studies, as well as sediment samples for microbiological analysis. This will allow comparison with other studies from deeper sites and will provide insights into the different processes operating between them, which will be useful for interpretation of the fossil record of whales.

Difficulties with bad weather were overcome by rescheduling an ROV dive to the following day with the generous help of Tomas Lundälv.

Thamdrup

This project studies microbes and microbial processes in the extremely manganese-rich sediments of Skagerrak, focusing on two aspects: manganese reduction and nitrogen isotope fractionation. Sampling and initial investigations were carried out at the Lovén Center, mainly on board R/V Skagerak, 21 – 25 June 2010. The sampling was highly succesful and we obtained essentially all the sediment samples that were planned for, from four stations between 400 and 700 m depth, which alloed us to follow the research plan closely. Thus, we performed incubations to determine the rates of microbial manganese reduction and to identify manganese reducers using 13C labeling. We also experimentally determined the isotopic frationation during nitrate reduction in the sediments. Samples were collected for further biogeochemical and microbiological analysis. Analyses of the materials are proceding as planned and expect to have a first overview of the results by the end of 2010. The project was closely coordinated with Dr. Mark Trimmer’s project SK2010 for great mutual benefit. We thus expect to generate substantial new insights to benthic manganese and nitrogen cycling.

Kruse

The aim of our studies is twofold:

  1. The brown macroalga Fucus vesiculosus is capable of inducible chemical defence. It produces metabolites ‘on demand’ that act against herbivores. We tried to induce anti-herbivore defense in both Fucus vesiculosus and Fucus radicans trough grazing by the isopod Idotea granulosa. Samples of both Fucus species originated from sympatric sites for better comparison. This experiment is the first of its kind for recently speciated F. radicans, for which it is unknown if it is capable of inducible defence. To test if defense was successfully induced, we conducted live assays and froze samples dedicated for assays with pellets. We also froze away samples for RNA extraction from different time points after start of herbivore grazing: 30 minutes, 1h, 1 d and 3d. In case we find positive defense induction, we will hybridize the RNA to our recently developed microarrays. To optimize the protocol and yield and to train a new PhD student who joined our project, first trials of RNA extraction were also conducted.
  2. Our objective to conduct cross species hybridization of both Fucus vesiculosus and Fucus radicans onto our F. vesiculosus microarrays was developed further. We will first hybridize genomic DNA onto the arrays to estimate genomic divergence between both species at the 21.000 probes of coding sequences. In case genomic divergence is low, we will also hybridize RNA samples harvested under different environmental conditions. Ultimately, we hope to find loci potentially involved in the speciation process of F. radicans.

 

Forsgren

We carried out novel experiments testing effects of ocean acidification on fish reproduction and larvae performance. We had two treatments, normal and low CO2. As a model species, we used the two-spotted goby, Gobiusculus flavescens. We recorded a number of variables associated with spawning, egg development, early larval performance (respiration, phototaxis, mortality) and morphology. The experiment worked out successfully, and we now have very interesting results for publication. Also, Isabel Mück carried out experiments looking at aspects of male competition in the same fish for her MSc thesis. She changed the planned set up from field to lab, but after that the project was successful.

Ellis

The main achievement of the ASSEMBLE supported project. The impact of ocean acidification on the immune response of larval Mytilus edulis is to have undertaken a comprehensive investigation of the impact of seawater pH and temperature on the timing of developmental staging and morphology of an early larval bivalve species. Additionally in investigating the impact of these environmental stressors on feeding rate and calcification, this study has demonstrated the impact on larval bivalve condition and performance. From this experiment a manuscript is expected to be produced and submitted to a peer-reviewed journal which will further the understanding in the fields of bivalve larval development and the impact of anthropogenically induced climate change. Whilst the original project was designed to measure the impact of ocean acidification and temperature on larval immune response and disease resistance, due to a number of contributing factors it was not possible to measure these parameters during the project. However, whilst theses measures would have undoubtedly increased the value of this project, the data that has been successfully obtained from this experiment is both novel and of significant value to a number of scientific fields enabling its submission for publication. Furthermore from the execution of this user-project, future collaboration has been proposed between both the host institution and the user that will enable further significant advancement of larval biology and climate change understanding.

Tait

The aim of the project was to assess the role of bacterial-derived signal molecules (N-acyl homoserine lactones – AHLs) in the settlement choices of larvae of the barnacle Balanus improvisus and the ascidian Ciona intestinalis.

Using a range of signal-producing and signal-deficient bacterial strains, it was successfully shown that signal-producing biofilms significantly enhance settlement of barnacle cyprids, and that there was no statistical difference between non-signalling biofilms and no biofilm controls. This experiment was repeated with several batches of cyprids with similar results each time. Settlement was also enhanced in the presence of synthetic AHL signal molecules, and we were also able to show higher numbers of cyprids exploring biofilms of E. coli expressing recombinant AHL synthases, compared to control biofilms. Lastly, an increase in swimming speed in the presence of synthetic AHL and signal-producing biofilms was seen.

Together, these results demonstrate a role for AHL signal molecules in barnacle cyprid surface selection. Unfortunately, the above experiments could not be repeated with C. intestinalis due to a lack of available material. But, we expect to publish the results from the B. improvisus experiments soon and a manuscript is in preparation for Biofouling.

The above result strengthens the hypothesis that AHLs are a universal cue for all fouling organisms and has major implications for the development of new anti-foulants. Further research examining the effect of signal inhibitors and blockers is planned.

Delroisse

Adult specimens of Amphiura filiformis were collected. Few specimens of Amphiura chiajei were also obtained. Unfortunaltely, larvae cultur problems during the period of the project didn’t permit to realize the study of the bioluminescence acquisition. Experiments of spectral characterization of Amphiura filiformis adults were realized. The results analysis are still in progress and will constitute part of my phD thesis. Before this study, only one proceeding shown results on spectral sensitivity of brittle-stars.  Except this example, no study deal with the spectral sensitivity of an organism with extraocular photoreception.  Next step, will be to continue the study in the specie Amphiura chiajei to compare to luminous brittle-star and the non-luminous one.

No critical problems were encountered during the stay in the Loven Center of Kristineberg.

Vannier

The main purpose of my visit to the  The Sven Lovén Centre for Marine Sciences – Kristineberg was to collect and observe priapulid worms (Priapulus) from the Gullmar Fjord, and  eventually, to use the data obtained from living organisms for the ecological interpretation of the ancestors of the group preserved as fossils in rocks from the Cambrian period (ca. 500 Ma). The sampling went successfully (2 trips of 4 hours with Oscar von Sydow using dredger and boxcore sampler). Laboratory experiments (vidéo recordings) were made in order to observe the feeding behaviour of priapulids tested with various potential prey. Feces of worms were fixed for further microscopic analysis (Univ. Lyon) of the natural diet of priapulids. The presence of undigested elements such as chetae indicates that Priapulus feeds on other worms sch as polychaetes. Similar feeding relationships are observed in Cambrian priapulids (e.g. Burgess Shale, Canada). Several specimens of Priapulus were fixed for SEM observations of the digestive system and the main features involved in feeding (e.g. pharyngeal teeth). Stefan Agrenius gave me access to his faunal data base that provides accurate information on the fauna associated with Priapulus along the west coast of Sweden. We also discussed the possibility to keep Priapulus in aquarium for long-term observations and experiments. The comparative data obtained during my stay at Kristineberg are of key-importance for interpreting the role of priapulid worms as predators in the early marine ecosystems (work in progress with The Royal Ontario Museum, Toronto - Programme supported by ANR, France).

Mayer

The study primary objective of this study was to investigate whether hormone implants containing the primary teleost androgen 11-ketotestosterone (11kT) could alter reproductive behaviour and sperm traits between in the black goby (Gobius niger) which displays two pronounced male reproductive strategies.

For the purpose of this study the Loven Centre provided excellent facilities in terms of experimental aquaria, and laboratory space to undertake sperm analysis. In addition, the staff were extremely helpful in providing the necessary equipement for catching the fish. The main problem encountered during this study was in catching sufficient fish still in active reproductive condition (both territorial males and sneaker males). For this reason, it would have been better to start one month earlier. However, this pilot study allowed us to conduct a number of novel methods, including:

-    the use of Silastic capsule implants to elevate endogenous androgen levels in a goby species.

-    measurement of plasma hormone levels from the heart (dissected from gobies)

-    measurement of sperm density using a NuclearCounter.

We were able to complete our first pilot study, which has now been written up as a manuscript. This MS is still at an early stage and describes methodology and the behavioural and sperm density results. The hormone analysis (from heart samples) has still to be completed.

Hoeg

During the stay at Sven Loven Marine Research Centre (Kristineberg) we attempted to sample:
The acrothoracican cirripede trypetesa lampas
The pedunculated cirripede Scalpellum scalpellum
Sampling of T. lampas proceed as planned. In the nearby Bökevik we sampled hermit crabs imhabiting shells of Littorina. In these the frequency populated by the symbiotic acrothoracican barnacle was in excess of 20%, provising us with sufficient material. The T. lappas specimens wree examined as follows
Numbers per host
Presence of dwarf males and general reproductive state
Videos of the live barnacles for selected specimens
In vivo still photography of selected specimens
Fixation for histology or scanning electron microscopy to proceed at my home institution
A main objective was to collect and study larvae of T. lappas. Interestingly, while we monitored many specimens, we collected only a single batch of larvae, whoch contrats with the high frequency of larvae obtained in an earlier study, also in August (1991). But the material collected will furnish important material for the main project and the T. lappas part of the project can be called a success.

S. scalpellum. We tried two times, with a very efficient and experienced ship´
s crew, to collect specimens but in vain. The frequency of this species has declined gradually during the last 20 years or so. All our efforts were therefore allocated to T. lampas.

During the stay, we gave a seminar on the “
Biology of barnacles”, speakers were both jens T Hoeg and MSc student Uwe Spremberg.

CONCLUSION: The entire stay was a success. As ALWAYS, the staff at
Kristineberg was professional and extremely helpful. The working environment is unique for marine science. We were grateful to have this opportunity and can recommend the Sven Loven Centre for Marine Science as a cutting edge facility. WE also thank the entire ASSEMBLE program for having been granted this stay.

Averof

We used plankton and sediment trawls in the Gullmarfjord, to collect pelagic and benthic species known to occur in the region. Sediment trawls yielded a number of gammarid species. The plankton trawls were extremely poor, probably due to a dinoflagellate bloom in this season; no specimens were recovered.

We also collected a number of algal samples in the vicinity of the Marine Station, which yielded a number of isopods (including Idothea pelagica) and gammarid species. Unfortunately no caprellids were found.

One of our primary target taxa were hyperiid amphipods, which are often associated with medusae, especially those of Aurelia in this area. Although we were not able to find any Aurelia during our visit, we were able to collect a specimen of Hyperia galba among the algal samples that we collected.

At Kristineberg, we extracted genomic DNA and total RNA from single individuals of Hyperia galba (hyperiid amphipod) and Idothea pelagica (isopod). We preserved a variety of gammarid species that we collected, for identification and DNA/RNA extraction in our home laboratories.

During our visit we received valuable advice and help with specimen identification from Dr. Matz Berggren, a crustacean expert at Kristineberg. Dr. Berggren was also able to provide us with amphipod (Rhachotropis, Themisto), cumacean (Leptostylis, Leucon), isopod (Munnopsis) and mysid (Amblyops, Pseudomma) specimens stored in ethanol.

Jaspers

The aim of my project was to follow the population dynamics of the invasive Ctenophore Mnemiopsis leidyi in the field and supplement these data with laboratory studies on egg production rates. I achieved laboratory results on size dependent egg production rates (n=60) of field caught animals for 6 days including hatching time and success of the eggs. Field sampling was conducted every second day and all data are analyzed as planned. Due to the delay of the Mnemiopsis leidyi appearance in the field, I could not follow the field cohorts to estimate life stage dependent mortality rates as originally planned. Therefore, additional experiments on food dependent egg production rates were performed using laboratory reared Mnemiopsis leidyi and laboratory reared food (Acartia tonsa). Additional results from these experiments enlighten the trade off between growth and reproduction from an energy budget point of view.

Van Duyl

We collected sponges with the ROV at Tisler reef between 90 and 115 m depth. The sponge species collected was Hymedesmia coriacea, which was used for the experiments in the lab. Some Mycale lingua was collected as well, but explants of the sponge needed more time to recover than foreseen in the planning of the field/experimental work. A pulse chase experiment in a 30L aquarium (filled with 16L seawater during labeling) and experiments in incubation chambers of 1L were conducted with sponge pieces of H. coriacea in a climate room at 8-9*C. In most experiments the sponge pieces were supplied with excess 13C-DIC to label the chemoautotrophic sponge associated nitrifying microorganisms. To enhance labeling of sponge associated microbes, ammonia sulfate was added to the pulse chase experiment and part of the chamber incubations with sponge. Pulse chase experiments (n=2) ran for more than 2 weeks. Closed incubation chamber experiments (n=3) ran for 2-3 days. Water and sponge samples have been fixed and stored according to the protocols of different types of analyses (e.g. in liquid nitrogen, with fixatives, in the -20 or -80*C freeze). Water of Tisler reef as well as water from incubation experiments, will be analyzed at the home laboratory for inorganic nutrients, dissolved inorganic carbon, total and dissolved organic carbon and nitrogen, and bacterial abundance. Sponge samples and controls will be analyzed for 13C and 15N and labeling of specific biomarkers. The translocation of labeled carbon from sponge microbes to sponge cells will be assessed in the pulse chase experiment.

Burns

Four hundred explants (autotomised arms) were prepared from the brittle star Ampbiura filiformis. After a period of time these explants were then sub sampled into proximal, middle and distal samples from which RNA was successfully extracted. These RNA samples will form the basis of a microarray experiment to investigate polarity and wound healing in explants of Amphiura filiformis using DNA microarray technology.
Each RNA sample will be compared to a control (non-regenerating arm) on a 9,000 cDNA Amphiura filiformis microarray to measure gene expression. Once analysed, several hundred candidate genes of interest will be sequenced to determine their identity to known genes. Several of these identified genes will then be chosen to have their expression profile confirmed by quantitative PCR.
It is envisaged that these results will form the basis of a manuscript to be published detailing the extent of gene expression in relation to polarity and wound healing in explants of Amphiura filiformis. Subsequently this publication will form part of a PhD thesis. It is also intended that the results gained from this work be presented at an international conference.
All work at the host institute was carried out without any problems or delays. The facilities provided were ideal for the sample collection and RNA extractions.

Jekely

During the visit to Kristineberg we tested and optimized a vertical microcosm coupled to fast video-microscopy to analyze the behaviour of microscopic zooplankton. We did pharmacological experiments using copepods freshly captured with a plankton net. These experiments suggest that Transient Receptor Potential (Trp) channels are involved in thermotactic behaviour of copepods. We could not carry out the initial research project on Aurelia larvae, since very surprisingly, we did not find any adult individual during the entire period. This is very unusual, since several years of experience has shown that Aurelia is abundant in the waters around Kristineberg in the summer. Nevertheless, we took full advantage of the facilities, and even though with a changed research project, our stay in Kristineberg was very useful. 

Penna

In this Project , we studied the effects of increasing temperature and pCO2 - as predicted consequences of global change - on sets of 8 genetically different isolates from a northern Baltic PSP toxic dinoflagellate Alexandrium ostenfeldii population, a diatom Skeletonema marinoi population from the Skagerrak (Swedish West coast) and a northern Adriatic (Mediterranean Sea) S. marinoi population. Acclimated batch cultures of each isolate were incubated in triplicates for 5 to 10 generations in a factorial set up at 20 and 25 °C and 350 and 750 ppm CO2, respectively. Growth was monitored throughout the experiment by measuring Chl a fluorescence, and maximum growth rates as response variable were calculated from individual growth curves. Comparison of growth rates revealed that increased temperature and high pCO2 had a favorable effect on overall growth of both investigated species per se, although the effect was less pronounced when both were combined. However, despite the general trends, significant differences were observed in the response of individual strains of the same population. Phenotypic variability was most pronounced in A. ostenfeldii. The diatom S. marinoi generally responded more uniformly to the changes. The implications of the results for acclimation and adaptation processes will be discussed as well as possible reasons for the observed differences at strain, population and taxon level.
No great difficulties were encountered during the experiment phases of this Project.

Rosenqvist

The aim of this project is to experimentally evaluate different metrics of mating systems and sexual selection in the sex role reversed pipefish Syngnathus typhle. And especially to investigate the effect of sex ratios, density, and spatial patterns on the genetic mating system. We used experimental breeding populations with different sex ratios and densities to investigate how these factors influenced the number of mates in both sexes. We have started to reconstruct the mating system using microsatellites to reveal the parents of all offspring. This work will provide knowledge important to the field of sexual selection, especially since density is understudied in this field. Preliminary results indicate that both the sex ratio and density influences the number of mates per individual. It is especially interesting to note that density seems to decrease the variation in the number of mating per individual, something that would indicate that dense populations may experience weaker sexual selection than more sparse populations. In the close future the complete mating system of several replicates of these experimental populations will have been reconstructed, this will provide us with unique data that can be used to evaluate different ways to measure mating systems and sexual selection

These results will be important to evaluate the impact of environmental changes.

Koski

The project focused on the effects of appendicularians and copepods for the efficiency of the biological pump. The concrete short- term goals of the proposed experimental period were to 1) quantify the vertical flux and its attenuation in Gullmasfjord, 2) investigate the role of copepods vs. appendicularians in creating the vertical flux and to quantify their rates of particle production vs. degradation, 3) investigate the behavioral processes resulting in marine snow degradation and 4) compare the importance of bacterial vs. metazoan degradation of diverse aggregates. These goals were pursued using a combination of field (day cruises on small vessels) and laboratory experiments: we set up sediment traps and measured particles profiles and particle sinking rates (#1), conducted laboratory incubations on feeding and pellet / house production of zooplankton (#2, 3) and measured zooplankton feeding and bacterial respiration on different types of aggregates using incubations and microelectrodes, respectively (#4). Although most of the results will still need to be analyzed and synthesized, it appears that most experiments / sampling were successful and that we will thus be able to construct a carbon budget for sinking / remineralisation of aggregates in Gullmarsfjord. In addition, we obtained new information of the rates and processes of particle production / consumption as well as of the vertical flux and its attenuation. Apart from the bad weather cancelling one of our sampling trips, we did not encounter any difficulties at the site.

Trimmer

We collected intact sediment from four sites along a depth transect from 700 m to 200 m in the Skaggerak. We made measurements of oxygen penetration into the sediment which was maximal at 2.1cm for sediment from 700 m and minimal at 0.4 cm for sediment from 200 m. We also made measurements of oxygen consumption by the sediment which again was maximal and minimal along the depth gradient described. We also completed all of our measurements of N2 production by denitrification and anammox but these samples are awaiting analysis on the mass spectrometer, which I hope to complete in the next 6 weeks.