Tomas Lundälv - Profile on Academia.edu (original) (raw)

Papers by Tomas Lundälv

In-situ photographs of common Antarctic glass sponges (Porifera: Hexactinellida: Rossellidae) along 7 ROV profiles during POLARSTERN cruise PS77 (ANT-XXVII/3, CAMBIO) in the Weddell Sea

Rapport om misstänkt förekomst av trålning i det trålskyddade området på kallvattenkorallrevet vid Tisler

R script and data for the analysis of sponges and asteroids abundances and sponges biomass

A guide to the fish associated with deep-water coral

2nd International Symposium on Deep Sea Corals, Erlangen, Germany, 2003

Search: onr:"swepub:oai:services.scigloo.org:85957" > A guide to the fish... ... McC... more Search: onr:"swepub:oai:services.scigloo.org:85957" > A guide to the fish... ... McCrea, M (author) Costello, MJ (author) Freiwald, A (author) show more... Lundälv, Tomas, 1944- (author) Göteborgs universitet, Tjärnö marinbiologiska laboratorium Jonsson, Lisbeth G., 1955- (author) Göteborgs universitet, Institutionen för marin ekologi show less... University of Gothenburg Faculty of Sciences. Department of Marine Ecology. University of Gothenburg Faculty of Sciences. Tjärnö Marine Biological Laboratory. 2003 English. In: 2nd International ...

Table 3) Average mound aggradation rates

Bioerosion along a bathymetric gradient in a cold-temperate setting (Kosterfjord, SW Sweden): an experimental study

Facies, 2005

... Max Wisshak · Marcos Gektidis · André Freiwald · Tomas Lundälv ... the determination of bioer... more ... Max Wisshak · Marcos Gektidis · André Freiwald · Tomas Lundälv ... the determination of bioerosion and bioaccretion rates with respect to cal-cium carbonate, and their interpretation in a bathymetric and latitudinal context as an integral part of the global car-bon cycle is the ...

Cold-Water Corals and Ecosystems, 2005

The rate of discovery of reefs of the cold-water coral Lophelia pertusa (Linnaeus, 1758) has been... more The rate of discovery of reefs of the cold-water coral Lophelia pertusa (Linnaeus, 1758) has been remarkable, and attributable to the increased use of underwater video. These reefs form a major three-dimensional habitat in deeper waters where little other ʻcoverʼ for fish is available. They are common in the eastern North Atlantic, and occur at least in the western North Atlantic and off central Africa. There are also other non-reef records of Lophelia in the Atlantic, and in Indian and Pacific oceans. Thus, not only are these reefs a significant habitat on a local scale, but they may also provide an important habitat over a very wide geographic scale. The present study examined the association of fish species with Lophelia in the Northeast Atlantic, including the Trondheimsfjord and Sula Ridge in Norway, Kosterfjord in Sweden, Darwin Mounds west of Scotland, and Rockall Bank, Rockall Trough and Porcupine Seabight off Ireland. The fish fauna associated with a shipwreck west of Shetland was also studied. Data were collected from 11 study sites at 8 locations, using 52 hours of video and 15 reels of still photographs. Video and still photographs were collected from (1) manned submersible, (2) surface controlled remotely operated vehicle (ROV), (3) a towed "hopper" camera, (4) wide Costello, McCrea, Freiwald, Lundälv, Jonsson, Bett, van Weering et al. angle survey photography (WASP), (5) seabed high resolution imaging platform (SHRIMP), and (6) an in situ time-lapse camera "Bathysnap". It was possible to identify 90 % of fish observed to species level and 6.5 % to genus or family level. Only 3.5 % of the fish were not identifiable. A guide to the fishes is given at . Twenty-five species of fishes from 17 families were recorded over all the sites, of which 17 were of commercial importance and comprised 82 % of fish individuals observed. These commercial fish species contribute 90 % of commercial fish tonnage in the North Atlantic. The habitats sampled were comprised of 19 % reef, 20 % transitional zone (i.e. between living coral and debris zone), 25 % coral debris and 36 % off-reef seabed. Depth was the most significant parameter in influencing the fish associated with the reefs, both at the species and family level. There was a complete separation of sites above and below 400-600 m depth by multi-dimensional scaling (MDS) analysis. Less distinct assemblages of fish species were associated with each habitat. Fish species richness and abundance was greater on the reef than surrounding seabed. In fact, 92 % of species, and 80 % of individual fish were associated with the reef. The present data indicates that these reefs have a very important functional role in deep-water ecosystems as fish habitat.

Ashallow-waterwhale-fall experiment in the north Atlantic

CBM - Cahiers de Biologie Marine, 2006

The study of hydrothermal vent and seep fauna is associated with great costs due to the deep and ... more The study of hydrothermal vent and seep fauna is associated with great costs due to the deep and distant locations. Whale-falls, which are thought to have habitat conditions which overlap seep ecosystems, may be used as a model system to explore questions such as the evolution of dispersal strategies and interactions between hosts and their symbiont microbes. Our discovery of whale-fall fauna at a whale carcass sunk at shelf depth in a Swedish fjord contrasts the apparent lack of specialized organisms from shallow water seep environments. Representatives of a whale-fall fauna found at the Swedish study site include bacterial mat feeding dorvilleid annelids and the whale-bone eating pogonophoran worm Osedax mucofloris Glover et al., 2005. We are maintaining whale-fall fauna alive in aquaria, and initial results from these studies suggest that O. mucofloris has a continuous reproduction life-history strategy.

Marine images and movies from Remotely Operated Vehicle (ROV) - KH60, V Koster

The Marine stations at University of Gothenburg have several underwater recording facilities. One... more The Marine stations at University of Gothenburg have several underwater recording facilities. One of them is the Remotely Operated Vehicle (ROV underwater robot) at Tjärnö marine station. This data source includes image and movie files, originating from ROV underwater surveys in the region of the Koster islands and Koster national park and date back to 1993.

Hermione Month 24 scientific progress report

Physical oceanography at ROV station PS77/253-1, Larsen A

Preliminär rapport från ROV-kartering i Rauerfjorden 06-12-18/19

This study represents the first swine transcriptome hive plots created from gene set enrichment a... more This study represents the first swine transcriptome hive plots created from gene set enrichment analysis (GSEA) data and provides a novel insight into the global transcriptome changes occurring in tracheobronchial lymph nodes (TBLN) and spanning the swine genome. RNA isolated from draining TBLN from 5-week-old pigs, either clinically infected with a feral isolate of Pseudorabies virus or uninfected, was interrogated using Illumina Digital Gene Expression Tag Profiling. More than 100 million tag sequences were observed, representing 4,064,189 unique 21-base sequences collected from TBLN at time points 1, 3, 6, and 14 days post-inoculation (dpi). Multidimensional statistical tests were applied to determine the significant changes in tag abundance, and then the tags were annotated. Hive plots were created to visualize the differential expression within the swine transcriptome defined by the Broad Institute's GSEA reference datasets between infected and uninfected animals, allowing us to directly compare different conditions.

(Table 2) Uranium-series dating obtained from cold-water corals

Zooplankton drive diurnal changes in oxygen concentration at Tisler cold-water coral reef

Coral Reefs, 2018

Tisler Reef is a Norwegian cold-water coral reef in the Northeastern Skagerrak, which lies at an ... more Tisler Reef is a Norwegian cold-water coral reef in the Northeastern Skagerrak, which lies at an average depth of 120 m, is constructed principally of the scleractinian coral Lophelia pertusa and hosts a dynamic and diverse ecosystem. The availability of oxygen within Tisler Reef, recorded between 2006 and 2008, showed a decline during the summer months, caused by both the isolation of the reef from the atmosphere under conditions of seasonal stratification, and the enhanced respiration in the water column during the seasonal zooplankton proliferations. Concentrations of dissolved oxygen were replenished from high-current flows advecting water from off the reef. Low current flow conditions (< 0.05 m s−1) coincided with a short-term reduction in oxygen, the extent of which varied seasonally and were observed to be greatest during July and August, coinciding with the summer Calanus proliferation in the Skagerrak. Normalized acoustic backscatter amplitude during the summer months showed a strong signal of zooplankton diurnal vertical migration, coinciding with the lowest oxygen concentrations at the reef observed during, and lagging slightly after, the deep phase of the zooplankton vertical migration. This effect was most obvious during low-flow conditions; highlighting the importance of zooplankton and associated activity as a consumer of oxygen at the reef.

Biogeosciences Discussions, 2016

Cold-water corals form prominent reef ecosystems along ocean margins that depend on suspended res... more Cold-water corals form prominent reef ecosystems along ocean margins that depend on suspended resources produced in surface waters. In this study we investigated food processing of 13C and 15N labelled bacteria and algae by the cold-water coral Lophelia pertusa. Coral respiration, tissue incorporation of C and N and metabolic-derived C incorporation into the skeleton were traced following the additions of different food concentrations (100, 300, 1300 µg C L−1) and two ratios of suspended bacterial and algal biomass (1:1, 3:1). Respiration and tissue incorporation by L. pertusa increased markedly following exposure to higher food concentrations. The net growth efficiency of L. pertusa was low (0.08 ± 0.03), which is consistent with their slow growth rates. The contribution of algae and bacteria to total coral assimilation was proportional to the food mixture in the two lowest food concentrations, but algae were preferred over bacteria as food source ...

A first glimpse of the intricate interactions between a shallow cold-water coral reef (Tisler Reef Skagerrak) and its close environment as revealed by biomarkers and isotopes

Aim: A preliminary investigation to assess the relationship in the severity of periodontal diseas... more Aim: A preliminary investigation to assess the relationship in the severity of periodontal disease in diabetics when compared with non-diabetic subjects. Materials and Methods: A retrospective, comparative study using periodontal case notes of 40 subjects (20 Type 2 diabetics, 20 non-diabetics) who were selected based on the inclusion and exclusion criteria. Severity of periodontal disease was assessed through number of periodontal pocket ≥5mm. The results were compared between subjects whose age, gender and plaque scores are matched with the test group. Data obtained was then analyzed by SPSS Version 12. Results: When comparisons were made between test (Type 2 diabetic) and control (non-diabetic) groups, there were no significant difference (p>0.05) in the severity of periodontal disease. However, there was a clinically mean difference between the two groups. Conclusions: This preliminary investigation indicated that the severity of chronic periodontitis, as indicated in periodontal pocketing, increased in diabetic patients when compared to non-diabetics clinically, although it was not statistically significant. The finding of this investigation was thus not conclusive as it was only a retrospective study using patients' case notes. However, the results are now being further investigated with a proper clinical trial which examines periodontal parameters and diabetic status (HbA1c) of the subjects to determine the association between periodontal disease and diabetes mellitus.

Marine Biology, 2005

Ophiurid basket stars belonging to the family Gorgonocephalidae are distributed from the Arctic t... more Ophiurid basket stars belonging to the family Gorgonocephalidae are distributed from the Arctic to the Antarctic and from the shallow subtidal to the deep sea, but their biology remains poorly known. In situ observations at the mouth of the Oslofjord by a remotely operated vehicle showed that Gorgonocephalus caputmedusae had a patchy distribution at 85 to 120 m water depth and frequently occurred in association with the gorgonian Paramuricea placomus and the coral Lophelia pertusa. Morphological and histological studies show that G. caputmedusae is well adapted to capture macroplanktonic prey. Histological examination of the arms revealed the presence of a thick layer of dermal mutable connective tissue which is probably an energyefficient way to maintain its feeding posture against the current. This layer is connected to the nerve cord suggesting that the passive mechanical properties (stiffness) is controlled by the nervous system. In the distal parts of the arms, each segment has a pair of sticky tube feet and a sophisticated system of spines and hooks, which are connected to muscles and collagenous tendons. In combination, these features were shown, in an experimental flume study, to be used for capturing the locally abundant krill species Meganyctiphanes norvegica. This is the first documentation of G. caputmedusae of this kind. Communicated by M. Ku¨hl, Helsingør