susanne Baden - Academia.edu (original) (raw)

Papers by susanne Baden

This study compares the structure of eelgrass (Zostera marina L.) meadows and associated food web... more This study compares the structure of eelgrass (Zostera marina L.) meadows and associated food webs in two eelgrass habitats in Denmark, differing in exposure, connection to the open sea, nutrient enrichment and water transparency. Meadow structure strongly reflected the environmental conditions in each habitat. The eutrophicated, protected site had higher biomass of filamentous algae, lower eelgrass biomass and shoot density, longer and nar-rower leaves, and higher above to below ground biomass ratio compared to the less nutri-ent-enriched and more exposed site. The faunal community composition and food web structure also differed markedly between sites with the eutrophicated, enclosed site having higher biomass of consumers and less complex food web. These relationships resulted in a column shaped biomass distribution of the consumers at the eutrophicated site whereas the less nutrient-rich site showed a pyramidal biomass distribution of consumers coupled with a more diverse consum...

Ecological Studies, 2001

... During the last decade both naked and vegetated bottoms have temporarily been covered with ep... more ... During the last decade both naked and vegetated bottoms have temporarily been covered with ephemeral algae (Pihl et al. ... A similar fauna to the Swedish west coast localities has been described for an Amphibolis antarctica bed off Western Australia (Edgar 1990). ...

International Journal of Earth Sciences, 2008

Shells of Arctica islandica collected between 1884 and 2004 from Ö resund, Kattegat and Skagerrak... more Shells of Arctica islandica collected between 1884 and 2004 from Ö resund, Kattegat and Skagerrak (Swedish West Coast) were used to monitor local climate variations and the influence of human activities on the local environment. For this purpose, we analysed the growth, structure and chemical composition of these shells and compared them with shells collected from Kiel Bay, Norway and Iceland. The growth rate of the studied shells registers an NAO periodicity of ca 8 years. However, the observed signal is weak because of other environmental interferences that are either of natural or anthropogenic origin. For example, the oxygen isotope ratios show temperature fluctuation, but also the influx of low salinity water. Higher contents of S, N, Cu, Zn, As, Cd and P in shell portions formed during the last century are related to human activities such as mining and industrial development. Our study indicates that in order to use Arctica shells as archives of climate change it is necessary to study the full range of environmental data that is recorded in the shells by using a multi element and isotope approach in combination with different analytical techniques including investigation of growth rates and shell structure. Keywords Arctica islandica Á Shell chemistry Á Shell growth Á Oxygen isotopes Á Trace elements Á Shell structure

Marine Ecology Progress Series, 1994

Nephrops norvegicus exposed to starvation and hypoxia in the field as well as in the laboratory e... more Nephrops norvegicus exposed to starvation and hypoxia in the field as well as in the laboratory exhibited marked differences in glycogen reserves, haemolymph haemocyanin concentrations, and tissue copper and manganese contents. Muscle glycogen concentration was reduced by ca 50% in lobsters collected from hypoxic field conhtions. Glycogen concentrations were reduced to ca 3 "/o of initial values in muscle and 10% in midgut gland following 7 mo starvation in the laboratory. Haemolymph haemocyanin concentration was markedly reduced in N. nowegicusexposed to severely hypoxic conditions although haemolymph copper concentration remained virtually unchanged. Starvation resulted in a slower reduction of haemocyanin concentration than was associated with hypoxia. Starvation resulted in a net loss of copper after 7 mo. Experimental exposures to moderate or severe hypoxia were not associated with net losses of copper, although in long-term moderate hypoxia the whole body copper load was redistributed, especially to the midgut gland increasing the concentration there 4 times. Redistribution of copper to the midgut gland did not occur in N. norvegicus exposed to severe hypoxia in the field. Threeto four-fold lower copper concentrations were found in the midgut glands of hypoxic lobsters (compared to controls from normoxic areas). As well as low copper concentrations, these lobsters had 2 to 4 times higher manganese concentrations in internal tissues. In the absence of sediment, manganese concentrations and contents were not influenced by laboratory exposure to hypoxia.

Marine Biology, 1998

The Norway lobster Nephrops norvegicus (L.) inhabits burrows in muddy clay sediments (e.g. on the... more The Norway lobster Nephrops norvegicus (L.) inhabits burrows in muddy clay sediments (e.g. on the Swedish west coast), where an autumnal oxygen de®ciency in the bottom water can occur. Our experiments investigated whether the irrigation of the burrows would re¯ect a behavioural adaptation to hypoxia, and whether any gender dierences of such behaviour exist. Irrigation is performed by the pleopods which may compensate for a decreasing oxygen tension. Pleopod activity (total number of strokes per sampling time), associated with oxygen concentration and gender, was studied in N. norvegicus kept in arti®cial burrows resembling their natural habitat. Male and female lobsters were separately exposed to either normoxia (70% oxygen saturation) or hypoxia (30% oxygen saturation). A sexual dierence in behaviour was found, where females irrigated the burrow less than males during normoxia. Females showed a signi®cant increase of pleopod activity in hypoxia compared with normoxic conditions, which was not displayed by the males probably due to the degree of individual variation found. However, when only males were studied during progressive hypoxia (from 60 to 5% oxygen saturation), following any changes of irrigational behaviour, a signi®cant increase of accumulated pleopod activity occurred. A major increase of pleopod activity appeared between 60 and 50% oxygen saturation, below which the activity remained high until a critical point (<10% saturation, 11°C, 33 psu) where irrigation dropped to a level close to that of normoxic values. Activity sessions during hypoxia were longer and had a higher stroke rate than during normoxia.

Ophelia, 1984

Abstract Mobile epifauna was sampled quantitatively with a drop-trap in three Zostera marina (L.)... more Abstract Mobile epifauna was sampled quantitatively with a drop-trap in three Zostera marina (L.) meadows on the west coast of Sweden, 1980–82. Of 20 species recorded, 10 were crustaceans (mostly shrimps) and 10 fishes (gobies, pipe-fishes and sticklebacks). Crustaceans dominated in abundance and biomass throughout the season and in all areas. Total abundance and biomass varied between 20 and 160 ind. · m−2 and 1 and 12 g (ash-free dry weight, AFDW) · m−2. The shrimp Palaemon adspersus (Rathke) and the shore crab Carcinus maenas (L.) contributed 65 to 90% of the mean seasonal biomass in the three areas, and the dynamics of these two species are described in this paper. Production of the 6–8 dominant species during eight months (May–December) of investigation varied between 2.5 and 6.0 g AFDW · m−2. No relation was found between the biomass of fauna and standing stock of Zostera, but patches of Fucus vesiculosus in the Zostera were shown to play an important role for some species.

Ophelia, 1997

Abstract The rate of filtration of the burrowing shrimp Upogebia deltaura (Leach) (Thalassinidea,... more Abstract The rate of filtration of the burrowing shrimp Upogebia deltaura (Leach) (Thalassinidea, Decapoda) was studied in different concentrations of suspended Artemia nauplii. U. deltaura showed a slow rate of filtration (clearance) at low food particle concentrations, which can be seen as a way of avoiding unprofitable effort. The rate of clearance peaked (3.5 l*h-1) in food concentrations comparable (when converted to carbon) with levels normally encountered in algal blooms on the Swedish west coast. The maximum capture rate of 700–750 nauplii*h-1 was high compared with literature data on metabolic rates, and indicated an ability of U. deltaura to utilise temporary fluxes of suspended food in high concentrations.

Netherlands Journal of Sea Research, 1996

In situ biomonitoring of roundnose grenadier (Coryphaenoides rupestris) and Norway lobster (Nephr... more In situ biomonitoring of roundnose grenadier (Coryphaenoides rupestris) and Norway lobster (Nephrops norvegicus) and measurements of pollutant levels in caged common mussel (Mytilus edulis) were used to assess the environmental impact of contaminants in the Skagerrak and Kattegat and near the Faroe Islands. By comparing the responses of a suite of established and potential biomarkers, i.e. different liver detoxification enzymes and histopathology in roundnose grenadier in the Skagerrak, and at a reference site off the Faroe Islands, evidence was found that the deeper parts of the Skagerrak are affected by anthropogenic contaminants. Levels of polycyclic aromatic hydrocarbons (PAH) and organochlorines in caged mussels were compared with those in sediment. The Skagerrak/Kattegat area was found to be more polluted than the Faroe area and the caged mussels bioaccumulated the PAHs to a higher degree than the organochlorines. This seems to indicate that the PAHs in the sediments are more bioavailable than the organochlorines and that the induced ethoxyresorufln-O-deethylase activities observed in Skagerrak roundnose grenadier may be due to PAH exposure. The Norway lobster accumulated manganese to various degrees in the different parts of the organism. The excretion rate of manganese could not cope with the uptake rate at higher exposure concentrations. Enhanced manganese concentrations, especially in the gills and haemolymph, seem to be a useful indication of increased manganese levels in the water. Hypoxia makes sediment-bound manganese much more bioavailable. The elevated levels of manganese in Norway lobster from the SkagerrakJKattegat area therefore seem to reflect the increasing occurrence of hypoxic conditions in the Kattegat and coastal areas of the Skagerrak. Accumulated manganese in Norway lobster may thus serve as a biomarker of hypoxia. In conclusion, the use of a suite of different biomarkers in ecotoxicological and ecophysiological studies and analyses of contaminant levels have provided evidence of a large-scale environmental impact of pollutants and nutrients in the Skagerrak/Kattegat area. This should lead to further efforts to decrease transport into and deposition of waste compounds in the sea.

Ambio (Sweden), 1990

AGRIS record. Record number, SE9110167. Titles, Effects of eutrophication on benthic communities ... more AGRIS record. Record number, SE9110167. Titles, Effects of eutrophication on benthic communities including fish: Swedish west coast. Personal Authors, Baden, SP,Loo, LO,Pihl, L.,Rosenberg, R. (Kristinebergs Marinbiologiska Station, Fiskebaeckskil (Sweden)). ...

Marine Pollution Bulletin, 1982

... Among the three estuaries, the Buckingham canal is grossly polluted with no surface flow. The... more ... Among the three estuaries, the Buckingham canal is grossly polluted with no surface flow. The ... A preliminary study was made on three estuaries in Madras, South India: Cooum estuary, Buckingham canal and Ennore estuary. These ...

Marine Pollution Bulletin, 2022

We conducted a short-term field sampling complemented with time integrating stable isotope analys... more We conducted a short-term field sampling complemented with time integrating stable isotope analysis to holistically investigate status and ecological interactions in a remote NE AtlanticZostera marinameadow. We found high nutrient water concentrations, large biomass of fast-growing, ephemeral macroalgae, low abundance, and biodiversity of epifauna and a food web with thornback ray (Raja clavata) as intermediate and cod (Gadus morhua) as top predator. We observed no variation with increasing depth (3.5-11 m) except for decreasing shoot density and biomass of Zostera and macroalgae. Our results indicate that the Finnøya Zostera ecosystem is eutrophicated. During the past three to four decades, nutrients from aquaculture have steadily increased to reach 75% of anthropogenic input while the coastal top predator cod has decreased by 50%. We conclude that bottom-up regulation is a predominant driver of change since top-down regulation is generally weak in low density and exposed Zostera ecosystems such as Finnøya.

Stable isotope values (C & N) from vegetation and fauna in two seagrass meadows in Denmar

Abundance and biomass raw data for infaunal and epifaunal invertebrate species collected using se... more Abundance and biomass raw data for infaunal and epifaunal invertebrate species collected using sediment cores and 200 µm mesh bags for epifauna. Depth 2 meter

Marine Pollution Bulletin, 2020

The interaction between bottom-up and top-down processes in coastal ecosystems has been scarcely ... more The interaction between bottom-up and top-down processes in coastal ecosystems has been scarcely studied so far. Temporal changes in trophic interactions of Zostera marina along the Swedish west coast are relatively well studied, with the exception of epifaunal communities. Epifauna was used as a model study to explore resource (bottom-up) or predator (top-down) regulated in a vegetated ecosystem. We conducted a 21-year comparative study (1997 and 2018) using epifauna of 19 Zostera marina meadows along the Swedish Skagerrak coast. Large changes were observed in the composition of small (0.2-1 mm) and large (> 1 mm) epifauna. In the small-sized epifauna, the nematode Southernia zosterae and harpacticoids showed an increase of 90% and a decrease of 50% of their abundances, respectively. In the large-sized epifauna, the polychaete Platynereis dumerilii and chironomid larvae were absent in 1997 but thrived in 2018 (> 2000 ind. m −2). Mesoherbivores (Idoteids and gammarids) were locally very abundant in 1997 but disappeared in 2018. An 83% decline of mytilids settling in Zostera marina leaves was observed. Our results showed that epifauna is predominantly top-down regulated. An integrative framework of the study area is outlined to shed light on the causes and consequences of the environmental shifts reported in Zostera meadows from the northern Skagerrak area throughout the last three decades.

Marine Biology, 2001

The extent to which exposure to environmental hypoxia (PO 2 =8, 6, and 4 kPa, approximately 40%, ... more The extent to which exposure to environmental hypoxia (PO 2 =8, 6, and 4 kPa, approximately 40%, 30%, and 20% saturation, respectively) resulted in an increase in the concentration of the respiratory pigment haemocyanin ([Hc]) in individuals of the Norway lobster Nephrops norvegicus depended crucially on the initial [Hc] as well as the intensity of the hypoxia itself. While mean [Hc] did increase with decreasing PO 2 (and the variation decreased), for individuals with relatively high initial [Hc] there was no change or even a decrease observed. The greatest hypoxia-related increases in [Hc] were observed in the individuals with the lowest initial [Hc]. Consequently the notion of an`optimum' [Hc] for a given level of oxygenation was postulated. The changes in [Hc] recorded took place over a considerably shorter time scale (hours rather than days) than has been observed in previous studies. It was not possible to correlate environmental PO 2 and median [Hc] in the ®eld. However, it was interesting that the [Hc] frequency distribution curve for lobsters collected from a site that had been markedly hypoxic (PO 2 =8.0 kPa, approximately 40% saturation) until a few days before sampling was almost exactly the same shape (i.e. leptokurtic) and position (i.e. similar median) to that obtained when lobsters were exposed to PO 2 =8.0 kPa in the laboratory. Although it would have been desirable to investigate the eect of hypoxia on the frequency distribution of a physiological trait, in this case [Hc], it was not possible due to insucient sample size, even though the sample sizes employed were considerably larger than those normally used in physiological investigations.

Fish & Shellfish Immunology, 2016

Here, we aimed to investigate potential effects of ocean acidification on antimicrobial peptide (... more Here, we aimed to investigate potential effects of ocean acidification on antimicrobial peptide (AMP) activity in the gills of Mytilus edulis, as gills are directly facing seawater and the changing pH (predicted to be reduced from ∼8.1 to ∼7.7 by 2100). The AMP activity of gill and haemocyte extracts was compared at pH 6.0, 7.7 and 8.1, with a radial diffusion assay against Escherichia coli. The activity of the gill extracts was not affected by pH, while it was significantly reduced with increasing pH in the haemocyte extracts. Gill extracts were also tested against different species of Vibrio (V. parahaemolyticus, V. tubiashii, V. splendidus, V. alginolyticus) at pH 7.7 and 8.1. The metabolic activity of the bacteria decreased by ∼65-90%, depending on species of bacteria, but was, as in the radial diffusion assay, not affected by pH. The results indicated that AMPs from gills are efficient in a broad pH-range. However, when mussels were pre-exposed for pH 7.7 for four month the gill extracts presented significantly lower inhibit of bacterial growth. A full in-depth proteome investigation of gill extracts, using LC-Orbitrap MS/MS technique, showed that among previously described AMPs from haemocytes of Mytilus, myticin A was found up-regulated in response to lipopolysaccharide, 3 h post injection. Sporadic occurrence of other immune related peptides/proteins also pointed to a rapid response (0.5-3 h p.i.). Altogether, our results indicate that the gills of blue mussels constitute an important first line defence adapted to act at the pH of seawater. The antimicrobial activity of the gills is however modulated when mussels are under the pressure of ocean acidification, which may give future advantages for invading pathogens.