Distribution and Persistence of Diflubenzuron and Teflubenzuron in the Marine Environment Around Salmonid Aquaculture Facilities

To achieve a sustainable salmonid aquaculture industry, the environmental impacts of chemicals used to treat sea lice (Caligidae) infestations need to be considered. Our ability to assess the risks associated with these treatments in relation to human and wildlife health is limited by the lack of information on their concentrations in marine coastal environments. Diflubenzuron and teflubenzuron are chitin synthesis inhibiting insecticides frequently used to treat sea lice infestations on Norwegian salmon farms. In the present study, the distribution, persistence and bioaccumulation of both compounds were assessed in marine sediments and benthic macrofauna collected at four Norwegian aquacultures sites. Both compounds were detected in sediments sampled at 30–1400 m from the selected farms and 8–22 months after the last treatments took place. Diflubenzuron was detected above the limit of quantification (LOQ) in 76% of sediment samples and measured levels ranged between 2.4 and 257 μg/kg dry weight (dw). Teflubenzuron was detected above the LOQ in 92% of sediment samples, at concentrations ranging between 1.3 and 3474 μg/kg dw. In all samples where diflubenzuron and teflubenzuron were detected, the measured levels exceeded the Norwegian environmental quality standards (EQSsediment; 0.2 and 0.0004 μg/kg dw, respectively), indicating that these compounds may pose a risk to benthic marine species living near fish farms. Both compounds were detected in wild fauna collected near the selected aquaculture sites with measured residue levels in the low micro-gramme per kilogramme wet weight range. The residue levels detected in economically important species caught for human consumption, such as pink shrimp (Pandalus montagui) and Norway lobster (Nephrops norvegicus), were substantially lower than biota EQS’s and maximum residue limits (MRL) set by the EU for salmon tissue. Further studies are needed to fully understand the ecological impacts of these compounds in the marine environment, with the potential for lethal and sub-lethal effects to occur in non-target organisms following chronic exposures.publishedVersio

Report of the Working Group of Biological Effects

The Working Group on Biological Effects of Contaminants (WGBEC) investigates the biological effects of contaminants in the marine environment. The group provides research and increases the understanding of contaminant interactions and effects, including the development of inte-grated biological effects monitoring strategies, which are used to support international research and monitoring. The WGBEC has contributed significantly to the implementation and harmonization of tech-niques that can be used to evaluate the biological effects of pollutants in national monitoring programmes. An overview of national effect-based monitoring programmes of Member States is provided with the aim to support European countries and Regional Seas Conventions on their implementation. A summary of the national effects-based monitoring programmes has been pro-vided by twelve European countries represented at the WGBEC meetings. The adoption of bio-logical effects monitoring can differ widely and comparisons between approaches and the choice of biological effects methods used acts as an important tool. A summary of the main findings is presented. Furthermore, OSPAR's Hazardous Substances and Eutrophication Committee (HASEC) has en-couraged contracting parties to perform targeted biological effects monitoring to enhance the assessment of contaminants in sediment and biota towards the OSPAR QSR2023. WGBEC mem-bers contributed to the integrated biological effects approach assessment by providing data from their national monitoring activities to produce maps and figures to enable interpretations. Revision of the biological effects methods, including new techniques and developments, and the quality assurance of existing methods are core activities for the WGBEC, which require continu-ous discussion and evaluation by the group. Activities include the production of new ICES TIMES documents as well as intercalibration exercises to ensure Member States are providing comparable data for national monitoring. To this end, intercalibration exercises were performed under the BEQUALM programme for two of the more commonly used biological effects meth-ods, including micronucleus formation in mussel haemocytes and PAH metabolites in fish bile. These intercalibrations were successful despite identifying some variation in reported values be-tween laboratories. Further intercalibration exercises are planned and the WGBEC strongly sup-port the need for such quality assurance. In addition to the national monitoring activities and the different methods and approaches for determining the effects of contaminants on biological systems, the WGBEC was interested in discussing some key questions related to the potential impacts of contaminants to marine life. These questions included: the direct and indirect effects of natural and synthetic particles; how climate change and acidification parameters can interact with contaminants and influence bioa-vailability and effect; whether the structure of marine communities can be used to indicate con-taminant exposure; to provide guidance on performing risk assessments for contaminants of emerging concern; and to evaluate the effects of contaminants in marine sediments and whether current sediment toxicity tests are adequate. In addition, and as a wider concept, the linkages between contaminants in the marine environment and human health were also described.S

Rapid respiratory responses of the deep-water sponge Geodia barretti exposed to suspended sediments

Sponges often dominate deep-water benthic faunal communities and can comprise up to 90% of the benthic biomass. Due to the large amount of water that they filter daily, sponges are an important link between benthic and pelagic ecosystems. Across the Tromsø-flaket, Barents Sea, Norway, there are high biomasses of deep-water sponges. This area is also an important fishing ground, with fishing activity in some areas >27000 trawl hours yr–1. Bottom trawling suspends large quantities of sediment into the water column, with measured concentrations up to 500 mg l-1. This is the first study on the effects of suspended sediment exposure on deep-water sponges. In a laboratory experiment, Geodia barretti (Bowerbank 1858) (Class: Demospongiae) was exposed to 5 different sediment concentrations (0, 10, 50, 100 and 500 mg l-1). Respiration rates were measured before, during and after the exposure period. The results demonstrate that G. barretti physiologically shuts down when exposed to concentrations of 100 mg l-1 (86% reduction in respiration), with thresholds of responses occurring between 10 to 50 mg l-1. However, rapid recovery to initial respiration levels directly after the exposure indicates that G. barretti can cope with a single short exposure to elevated sediment concentrations. Given the high bottom-trawling frequency in Tromsø-flaket, sponges may be frequently exposed to suspended sediments. Therefore, it is important that further investigations on the effects of suspended sediments on filter feeding organisms focus on the effects of repeated and long-term suspended sediment exposures to evaluate the overall ecological impacts

Distribution and Persistence of Diflubenzuron and Teflubenzuron in the Marine Environment Around Salmonid Aquaculture Facilities

To achieve a sustainable salmonid aquaculture industry, the environmental impacts of chemicals used to treat sea lice (Caligidae) infestations need to be considered. Our ability to assess the risks associated with these treatments in relation to human and wildlife health is limited by the lack of information on their concentrations in marine coastal environments. Diflubenzuron and teflubenzuron are chitin synthesis inhibiting insecticides frequently used to treat sea lice infestations on Norwegian salmon farms. In the present study, the distribution, persistence and bioaccumulation of both compounds were assessed in marine sediments and benthic macrofauna collected at four Norwegian aquacultures sites. Both compounds were detected in sediments sampled at 30–1400 m from the selected farms and 8–22 months after the last treatments took place. Diflubenzuron was detected above the limit of quantification (LOQ) in 76% of sediment samples and measured levels ranged between 2.4 and 257 μg/kg dry weight (dw). Teflubenzuron was detected above the LOQ in 92% of sediment samples, at concentrations ranging between 1.3 and 3474 μg/kg dw. In all samples where diflubenzuron and teflubenzuron were detected, the measured levels exceeded the Norwegian environmental quality standards (EQSsediment; 0.2 and 0.0004 μg/kg dw, respectively), indicating that these compounds may pose a risk to benthic marine species living near fish farms. Both compounds were detected in wild fauna collected near the selected aquaculture sites with measured residue levels in the low micro-gramme per kilogramme wet weight range. The residue levels detected in economically important species caught for human consumption, such as pink shrimp (Pandalus montagui) and Norway lobster (Nephrops norvegicus), were substantially lower than biota EQS’s and maximum residue limits (MRL) set by the EU for salmon tissue. Further studies are needed to fully understand the ecological impacts of these compounds in the marine environment, with the potential for lethal and sub-lethal effects to occur in non-target organisms following chronic exposures

Report of the Working Group of Biological Effects

The Working Group on Biological Effects of Contaminants (WGBEC) investigates the biological effects of contaminants in the marine environment. The group provides research and increases the understanding of contaminant interactions and effects, including the development of inte-grated biological effects monitoring strategies, which are used to support international research and monitoring. The WGBEC has contributed significantly to the implementation and harmonization of tech-niques that can be used to evaluate the biological effects of pollutants in national monitoring programmes. An overview of national effect-based monitoring programmes of Member States is provided with the aim to support European countries and Regional Seas Conventions on their implementation. A summary of the national effects-based monitoring programmes has been pro-vided by twelve European countries represented at the WGBEC meetings. The adoption of bio-logical effects monitoring can differ widely and comparisons between approaches and the choice of biological effects methods used acts as an important tool. A summary of the main findings is presented. Furthermore, OSPAR's Hazardous Substances and Eutrophication Committee (HASEC) has en-couraged contracting parties to perform targeted biological effects monitoring to enhance the assessment of contaminants in sediment and biota towards the OSPAR QSR2023. WGBEC mem-bers contributed to the integrated biological effects approach assessment by providing data from their national monitoring activities to produce maps and figures to enable interpretations. Revision of the biological effects methods, including new techniques and developments, and the quality assurance of existing methods are core activities for the WGBEC, which require continu-ous discussion and evaluation by the group. Activities include the production of new ICES TIMES documents as well as intercalibration exercises to ensure Member States are providing comparable data for national monitoring. To this end, intercalibration exercises were performed under the BEQUALM programme for two of the more commonly used biological effects meth-ods, including micronucleus formation in mussel haemocytes and PAH metabolites in fish bile. These intercalibrations were successful despite identifying some variation in reported values be-tween laboratories. Further intercalibration exercises are planned and the WGBEC strongly sup-port the need for such quality assurance. In addition to the national monitoring activities and the different methods and approaches for determining the effects of contaminants on biological systems, the WGBEC was interested in discussing some key questions related to the potential impacts of contaminants to marine life. These questions included: the direct and indirect effects of natural and synthetic particles; how climate change and acidification parameters can interact with contaminants and influence bioa-vailability and effect; whether the structure of marine communities can be used to indicate con-taminant exposure; to provide guidance on performing risk assessments for contaminants of emerging concern; and to evaluate the effects of contaminants in marine sediments and whether current sediment toxicity tests are adequate. In addition, and as a wider concept, the linkages between contaminants in the marine environment and human health were also described.Versión del edito