John Arthur Berge

Persistence of antibacterial agents in marine sediments

Abstract The persistence of the antibacterial agents oxytetracycline chloride (OTC), oxolinic acid (OA), flumequine (FLU), sarafloxacin (SAR), florfenicol (FLO), sulfadiazine (SDZ) and trimethoprim (TRM) were compared in marine sediments. Polyethylene boxes were filled with sediment, the antibacterial compounds added and placed on the sea bed at approximately 15 m depth for a period of 180–230 days. Sediment cores were collected by a diver and analyzed for residues of the antibacterials in four depth intervals from 1 to 7 cm. OTC and the quinolones OA, F and SAR were found to be very persistent in the sediment. In the deeper layer of the sediment the initial concentrations of these compounds were present after 180 days, whereas the residues in the top layer of the sediment depurated more rapidly. The depuration of these substances from the sediment is most probably due to leaching and redistribution rather than degradation. The quinolones were found to adsorb to sediment. SDZ and TRM were less persistent than the quinolones; however, the estimated half-life in the deepest layer (6–7 cm) was approximately 90 days for both substances. The concentration of FLO decreased rapidly in the sediment with a calculated half-life of 4.5 days, and a metabolite, florfenicol amine, was identified in the sediment.

Resistance to oxytetracycline, oxolinic acid and furazolidone in bacteria from marine sediments

Abstract Sediments experimentally treated with oxytetracycline (OTC) or oxolinic acid (OXA) were placed on the seabottom for a period of 1 year. At the end of the test period the fraction of bacteria resistant to OTC in sediments to which OTC had been added (SOT) was more than three times higher (16%) than the background level (5%). The same tendency was found for the sediments to which OXA was added (SOX). Cross-resistance towards OTC and OXA was found both in SOT and SOX. A high level of cross-resistance (34%) towards furazolidone was found for SOX, but was not observed for SOT.

Spatial diastereomer patterns of hexabromocyclododecane (HBCD) in a Norwegian fjord

Hexabromocyclododecane (HBCD) is the third most used brominated flame retardant globally, and has been found widely distributed in the environment. The present study reports concentrations and spatial patterns of alpha, beta and gamma-HBCD in a contaminated Norwegian fjord. Intertidal surface sediment and selected species from the marine food web were sampled at five locations in increasing distance from a known point source of HBCD. All sediment and biota samples were analyzed for the three HBCD diastereomers by liquid chromatography and mass spectrometry (LC/MS). The results demonstrated a HBCD gradient with decreasing concentrations at increasing distance from the point source in sediment and sedentary species, but less so in the species with large feeding ranges. Mean concentrations of Sigma HBCD at the closest/most remote locations relative to the point source were 9000/300 ng g(-1) TOC in sediment and 150/90 ng g(-1) lw in the species with largest feeding range (great black-backed gull). The HBCD diastereomer patterns were similar for each of the matrices (sediment, organisms) independent of distance from the source, indicating no difference in environmental partitioning between the diastereomers. However, the concentration ratio of diastereomers in each matrix ranged from 3:1:10 (alpha:beta:gamma) in the sediments to 55:1 (alpha:gamma) in the highest trophic level species, suggesting diastereomer-specific bioaccumulation in the organisms.

A soft-bottom sublittoral mesocosm by the Oslofjord: Description, performance and examples of application

Abstract Controlled experiments and detailed studies of behaviour in the subtidal require diving, submersible vessels or instruments placed in situ. These methods often limit experimental design. Furthermore, experiments with toxic chemicals in the field may not be possible due to lack of dosage control, environmental consequences, and public welfare. Such problems can be overcome by the use of mesocosms. In this paper a soft-bottom mesocosm in the Oslofjord, Norway is described. The mesocosm consists of two indoor basins each with a surface area of 100 m2 and a maximum water depth of 1.7 m. Each basin is divided into three compartments. Soft-bottom sediment sections were collected in the field by a modified USNEL box-corer (0.25 m2). The sediment was transferred to boxes and brought into the mesocosm. The water level in the mesocosm can be lowered so that the sediment surfaces are easily accessible for sampling, manipulation, inspection, or measurements requiring equipment or techniques not compatible wi...

Quantification of organotin compounds and determination of imposex in populations of dogwhelks (Nucella lapillus) from Norway

Unintentional effects of the antifouling agent tributyltin (TBT) have been discovered in marine gastropods as the induction of male sex characters in females, known as imposex. The occurrence of imposex in dogwhelks (Nucella lapillus) was investigated in 41 populations sampled in 1993-1995 along the Norwegian coast. A method for quantification of organotin species using gas chromatography and atomic emission detection (GC-AED) was developed. Some degree of imposex occurred in almost all populations of dogwhelks studied, except in four from Northern Norway. The concentration of organotin compounds in the gastropods from the unaffected populations was below the detection limit (7 ng Sn/g d.w.). The concentration of TBT in dogwhelks from affected populations was in the range 48-1096 ng Sn/g d.w. A positive relation between the concentration of TBT in dogwhelks and the degree of imposex was found.

Organotins in marine mammals and seabirds from Norwegian territory.

An increasing number of studies indicate that marine mammals and some seabirds are exposed to organotins. However, results from northern and Arctic areas are few. Here results from analysis of tributyltin (TBT), dibutyltin (DBT), monobutyltin (MBT), triphenyltin (TPhT), diphenyltin (DPhT) and monophenyltin (MPhT) in harbour porpoise (Phocoena phocoena), common seal (Phoca vitulina), ringed seal (Phoca hispida) and glaucous gull (Larus hyperboreus) from Norwegian territory are presented. Relatively high concentrations of DBT, TBT and MBT were observed in muscle, kidney and liver from harbour porpoises caught in northern Norway in 1988, just before restrictions on the use of tributyltin (TBT)(mainly on small boats) were introduced in several European countries. The concentrations in harbour porpoise muscle tissue were reduced significantly 11 years later, possibly as a result of the introduced restrictions. Considerably lower concentrations of butyltins were observed in the seals compared to porpoises. The lowest levels of organotins were found in ringed seals from Spitsbergen, where only traces of dibutyltin (DBT) and monobutyltin (MBT) were observed. Traces of DBT and MBT were also found in some individual glaucous gulls from Bear Island. The sum of the degradation products MBT and DBT in liver samples from all analysed species were generally higher than TBT itself. Triphenyltin (TPhT) was observed in all porpoise samples and in livers of common seals. Also the sum of the degradation products MPhT and DPhT in liver samples from porpoise and common seals were higher than TPhT. No traces of phenyltins were found in ringed seals from Spitsbergen or in glaucous gulls from Bear Island. The limited data available indicate low to moderate exposure to organotins in northern areas (Spitsbergen and Bear Island). Marine mammals are however more exposed further south along the Norwegian Coast.

Uptake of metals and persistent organochlorines in crabs (Cancer pagurus) and flounder (Platichthys flesus) from contaminated sediments: Mesocosm and field experiments

In the mesocosm experiment, the crabs and flounders were exposed to sediments strongly contaminated with persistent organochlorine compounds (OCs). Uptake of OCs in fillet of flounder and crab hepatopancreas was observed. The final concentrations of PCDF/D, given as toxic equivalency factors (TEQ) in flounder and crabs were more than one order of magnitude below levels in the recipient area. In the field experiment uptake of Cr, Pb, Ni and Fe was observed in crabs. No clear uptake of Cu and As was observed, despite high concentrations in the sediment. In flounder, no evidence of increased concentration of metals could be seen after one month. The relative uptake of organochlorines (OCs) in the two experiments reflects the local degree of sediment contamination. The metal concentrations did not increase more than 6 times whereas the persistent OCs increased up to 100 times in crabs, illustrating the importance of sediments as a source especially for OCs contamination of the biota.

Diastereomer-specific bioaccumulation of hexabromocyclododecane (HBCD) in a coastal food web, Western Norway

The present study reports diastereomer-specific accumulation of HBCD from a point source in five marine species representing a typical food web in a Norwegian coastal area. Samples of mussels, polychaetes, crabs and seabird eggs were analyzed for the diastereomers α-, β- and γ-HBCD, as well as lipid content and stable isotopes of nitrogen ((15)N/(14)N) to estimate trophic level. Accumulated HBCD did not correlate well with lipid content for most of the species, thus wet-weight based concentrations were included in an assessment of biomagnification. In contrast to β- and γ-HBCD, the α-diastereomer increased significantly with trophic level, resulting in magnification factors >1 in this coastal marine ecosystem. Data for poikilotherms did not show the same positive correlation between the α-diastereomer and trophic position as homeotherms. The apparent biomagnification of the α-HBCD could be due to bioisomerization or diastereomer-specific elimination that differed between poikilotherms and homeotherms.

Interactions between eutrophication and contaminants. III. Mobilization and bioaccumulation of benzo(a)pyrene from marine sediments

Abstract A major environmental issue is to understand how eutrophication processes, such as organic enrichment and hypoxia may act on the distribution patterns and bioavailability of contaminants to benthic organisms. An experiment with sediment organic C content (control vs enriched with concentrated phytoplankton) and oxygen level (normoxia vs 2–3 mg O 2 l −1 ) as fixed factors, and 14 C-B(a)P in benthic organisms and sediment as dependent variable, was conducted for 93 days. Three species of sediment-dwelling organisms with different feeding strategies ( Amphiura filiformis, Nereis diversicolor and Abra alba ) were chosen. Blue mussels ( Mytilus edulis ), kept in separate aquaria, were exposed to the outflowing water of the microcosms. Concentration of 14 C-B(a)P in the sediment surface at the end of the experiment was significantly higher in the organically enriched sediments than in the control sediments. Accumulation of 14 C-B(a)P in A. filiformis and N. diversicolor was also higher in the presence of organic enrichment. Concentrations of 14 C-B(a)P in M. edulis placed downstream of aquaria treated with organic matter were also higher, indicating a higher leaching of bioavailable 14 C-B(a)P from the enriched sediments. Hypoxia had no significant effect on the sediment distribution and bioaccumulation of 14 C-B(a)P, and there was no significant interaction between hypoxia and organic enrichment. Our results support the concept of selective feeding on labile organic matter as a major exposure route of organic contaminants in benthic organisms.

Impact of elevated levels of CO2 on animal mediated ecosystem function: The modification of sediment nutrient fluxes by burrowing urchins

A mesocosm experiment was conducted to quantify the relationships between the presence and body size of two burrowing heart urchins (Brissopsis lyrifera and Echinocardium cordatum) and rates of sediment nutrient flux. Furthermore, the impact of seawater acidification on these relationships was determined during this 40-day exposure experiment. Using carbon dioxide (CO2) gas, seawater was acidified to pHNBS 7.6, 7.2 or 6.8. Control treatments were maintained in natural seawater (pH≈8.0). Under normocapnic conditions, burrowing urchins were seen to reduce the sediment uptake of nitrite or nitrate whilst enhancing the release of silicate and phosphate. In acidified (hypercapnic) treatments, the biological control of biogeochemical cycles by urchins was significantly affected, probably through the combined impacts of high CO2 on nitrifying bacteria, benthic algae and urchin behaviour. This study highlights the importance of considering biological interactions when predicting the consequences of seawater acidification on ecosystem function.