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Recommendations for the inclusion of targeted testing to improve the regulatory environmental risk assessment of veterinary medicines used in aquaculture

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... While current ecotoxicity test requirements as outlined in VICH GL 38 [56] are an obligation in the frame of an MA application, they might not be entirely fit for purpose for identifying specific ecotoxicological effects of some substances. Indeed, some studies [22,83,84] have pointed out that the standard data set requirement set out in VICH GL 38 [56] may not be adequate in some cases, for instance "[…] for substances that specifically affect certain organisms or where hazards may not be predicted based on standard environmental hazard assessments alone" [84]. This shows that the choice of standardized tests performed during the authorisation of a VMP might currently not provide an accurate account of the toxicity of a given substance, particularly when it comes to the assessment of long-term effects [22,[83][84][85]. ...
... While current ecotoxicity test requirements as outlined in VICH GL 38 [56] are an obligation in the frame of an MA application, they might not be entirely fit for purpose for identifying specific ecotoxicological effects of some substances. Indeed, some studies [22,83,84] have pointed out that the standard data set requirement set out in VICH GL 38 [56] may not be adequate in some cases, for instance "[…] for substances that specifically affect certain organisms or where hazards may not be predicted based on standard environmental hazard assessments alone" [84]. This shows that the choice of standardized tests performed during the authorisation of a VMP might currently not provide an accurate account of the toxicity of a given substance, particularly when it comes to the assessment of long-term effects [22,[83][84][85]. ...
... Indeed, some studies [22,83,84] have pointed out that the standard data set requirement set out in VICH GL 38 [56] may not be adequate in some cases, for instance "[…] for substances that specifically affect certain organisms or where hazards may not be predicted based on standard environmental hazard assessments alone" [84]. This shows that the choice of standardized tests performed during the authorisation of a VMP might currently not provide an accurate account of the toxicity of a given substance, particularly when it comes to the assessment of long-term effects [22,[83][84][85]. In the last years, several concerns have also been raised regarding the potential development of antimicrobial resistance in target and non-target bacteria as well as in human consumers [43,71,86,87]. ...
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The current and future expansion of aquaculture production appears to be only manageable by using veterinary medicinal products (VMPs) to prevent and reduce disease outbreaks. However, only a very low number of VMPs are available for use in aquaculture systems. In addition, the environmental risk potentially emanating from the use of these products has gained increased attention in the last years. In this context, the present review represents an in-depth analysis of the current two-tiered (phase I and phase II) approach for the environmental risk assessment (ERA) of VMPs mandatory in the European Union and the European Economic Area (EU/EEA), and its applicability to medicinal products intended for use in aquaculture. The following conclusions are drawn: (i) the current regulatory guidance documents detailing the phase I and II ERA procedure should be updated and harmonised across Member States and simple approach(es) applicable to the assessment of the environmental exposure of VMPs intended for use in aquaculture facilities should be devised; (ii) current and future regulatory guidance documents detailing the phase II ERA procedure for VMPs intended for use in aquaculture should comprise advanced mathematical models suitable for addressing different exposure scenarios relevant across the whole EU/EEA (including scenarios addressing the exposure of VMPs to agricultural soils from fish sludge); and (iii) it is recommended that any updates of relevant ERA guidelines clearly detail the types of studies needed to determine potential adverse effects of VMPs used in aquaculture on non-target organisms. Furthermore, the application of risk mitigation measures tailored to the reduction of the environmental exposure of VMPs on an individual aquaculture farm level should be considered in any future or updated guideline. Finally, it is anticipated that the present analysis of the main drawbacks surrounding the current ERA regulatory framework will help competent authorities to harmonise and facilitate the approval process for VMPs intended for use in aquaculture.
... However, despite this reduction, the sum of VMPs (as A.I.) used still amounted to approximately two tonnes annually. VMPs are a major environmental concern, particularly since some VMPs, such as chitin synthesis inhibitors, have a very high acute to chronic toxicity ratio in aquatic crustaceans, indicating that they are highly biologically active molecules that can have adverse effects on non-target organisms at very low concentrations Lillicrap et al., 2015;Samuelsen et al., 2014). ...
... There is concern that VMPs may pose a threat to the health of nontarget species (Burridge et al., 2010;Haya et al., 2005;Macken et al., 2015;Lillicrap et al., 2015;Lillicrap, 2018). For example, chitin inhibitors such as teflubenzuron and diflubenzuron are expected to be particularly toxic to crustaceans that undergo moulting. ...
... Avermectins (emamectin benzoate) and benzoylurea insecticides (teflubenzuron, diflubenzuron) are sold with commercial feeds (similarly to antibiotics) and administered for several days to kill several parasitic pests, including sea lice (Table 1). Environmental concerns related to antiparasitics include the possible effects to non-target invertebrate species in and around the fish farms, including principally microcrustaceans and decapods (Tucca et al. 2014;Lillicrap et al. 2015;Macken et al. 2015;Olsvik et al. 2015). Furthermore, some of the antiparasitics used in aquaculture are known to bind to particulate organic material and may be of concern to filter feeders such as mussels (Norambuena-Subiabre et al. 2016) or sediment dwelling organisms (McBriarty et al. 2018). ...
... diflubenzuron and teflubenzuron) have raised concerns regarding their potential adverse effects to non-target crustaceans, including commercially important species such as crabs, shrimps and lobsters, due to development effects and impaired moulting (Langford et al. 2014;Samuelsen et al. 2014;Macken et al. 2015;Olsvik et al. 2015;Gebauer et al. 2017;Bechmann et al. 2018). In response to that, Lillicrap et al. (2015) provided general recommendations for the inclusion of non-target crustacean tests in the ERA of benzoylurea insecticides. Altogether, these scientific developments suggest the need for an improved regulatory framework for the ERA of aquaculture medicines, which may incorporate new exposure assessment and testing requirements depending on the chemical properties and the toxicological mode of action of the evaluated substance Lillicrap 2018). ...
Article
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Veterinary Medicinal Products (VMPs) are used in intensive aquaculture production to treat a wide range of bacterial and parasitic infestations. Their release into the environment poses concerns regarding their potential ecotoxicological risks to aquatic ecosystems, which need to be evaluated making use of appropriate Environmental Risk Assessment (ERA) schemes and models. This study presents an overview of the major aquaculture production systems in Europe, the VMPs most commonly used, and the environmental quality standards and regulatory procedures available for their ERA. Furthermore, it describes the state‐of‐the‐art on the development of environmental models capable of assessing the fate, exposure, ecotoxicological effects and risks of VMPs in aquaculture production systems, and discusses their level of development and implementation within European aquaculture. This study shows that the use of environmental models in regulatory ERA is somewhat limited in many European countries. Major efforts have been dedicated to assess the fate and exposure of antiparasitic compounds in salmonid cage systems, particularly in Scotland, while models and scenarios for assessing dispersal of antimicrobials, in general, and antiparasitic compounds in the Mediterranean as well as in Scandinavian regions are less available. On the other hand, the use of ecological models for assessing the effects and risks of VMPs is almost absent. Recommendations are provided to improve the chemical exposure and effect assessments and the ecological realism of the modelling outcomes, paying special attention to the protection goals set for the regulatory ERA of VMPs in Europe.
... The current study focuses on a delousing pharmaceutical agent (deltamethrin) that is applied as a bath treatment to control sea lice within farm cages. 2 Bath treatment pharmaceuticals are added directly to the pens that are covered with a tarpaulin or to treatment water in well boats. After the treatment of salmon, the water is released directly to the surrounding marine environment, 3−5 and large volumes containing the delousing agents are discharged to the marine environment in Norway each year. ...
Article
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Pharmaceutical deltamethrin (Alpha Max), used as delousing treatments in aquaculture, has raised concerns due to possible negative impacts on the marine environment. A novel approach combining different scientific disciplines has addressed this topic. Acute (mortality) and sublethal effects (i.e., fitness, neurological, immunological, and oxidative responses) of exposure of northern shrimp (Pandalus borealis) were studied in laboratory experiments. Passive water sampling combined with sediment analyses revealed environmental concentrations. Finally, dispersal modeling was performed to predict environmental concentrations. Ecotoxicological analyses showed mortality in shrimp after 1 h of exposure to 2 ng L-1 (1000-fold dilution of treatment dose), revealing a high sensitivity to deltamethrin. Sublethal effects included induction of acetylcholinesterase and acyl CoA oxidase activities and oxidative impairment, which may be linked to neurotoxic responses. Field concentrations of 10-200 ng L-1 in water (100 m from the pens) and <LOD-0.19 ng g-1 dw in sediment (0-400 m from pens) were measured. Ecotoxicological values were compared with measured and modeled concentrations. They showed that concentrations higher than those causing mortality could be expected up to 4-5 km from point of release, in an area of 6.4 km2, with lethal concentrations remaining up to 35 h in some areas. Hence, the study demonstrates that there is a considerable risk for negative effects on the ecologically and commercially important shrimp.
... The continued growth of the aquaculture industry in Norway has led to environmental and production 45 challenges, and one of the major challenges is related to the ectoparasitic salmon louse (Lepeophtheirus 46 salmonis) (Torrisen et al., 2013). A method to control sea lice within farm cages is treatment by various 47 pharmaceutical delousing agents (Lillicrap et al., 2015). In Norway, the delousing agents are used either 48 as bath treatments or in-feed drugs. ...
Article
This study investigated effects of sea lice pharmaceuticals on egg-bearing deep-water shrimp (Pandalus borealis). Both mortality and sub-lethal effects (behavior, embryo development, and reproductive output) were studied for each of three pharmaceuticals alone and in different sequential combinations. The most severe effect was observed for deltamethrin where 2 h exposure to 330 times diluted treatment dose (alone and in sequential application with hydrogen peroxide and azamethiphos) induced almost 100% mortality within a few days after exposure. Similar effects were not observed for hydrogen peroxide or azamethiphos. However, sequential treatment of hydrogen peroxide and azamethiphos (2 h exposure to each pharmaceutical; 500 times dilution) resulted in >40% mortality during the first week following treatment. No sub-lethal effects or loss of eggs in female shrimp could be related to exposure to the bath treatments. Future studies should investigate potential sub-lethal effects at exposure concentrations close to the no-effect concentration.
... Chemicals are used to treat farmed salmon against the crustacean ectoparasitic salmon louse (Lepeophtheirus salmonis). These chemicals Folkehelseinsituttet, 2019;Lillicrap et al., 2015). Farmed salmon are treated several times with the same or different types of chemicals or with combinations of chemicals (Grefsrud et al., 2018;Johannessen, 2017). ...
Article
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Anti-parasitic drugs used in the aquaculture industry are discharged to the sea after treatment of salmon. In this study, the effects of azamethiphos (AZA) in the Salmosan® formulation and deltamethrin (DEL) in the Alpha Max® formulation, have been assessed in Northern shrimp larvae (Pandalus borealis) when administered both separately and in combination. The exposure concentrations were 100 ng/L for AZA and 2 ng/L for DEL, each representing a 1000-fold dilution of the prescribed concentrations for salmon. These two chemicals were combined at these concentrations to give a third treatment (AZA + DEL). When larvae were exposed for two hours on the first, second and third days post hatch (dph), significantly increased mortality and reduced swimming activity were observed for larvae from the DEL and combined AZA + DEL treatments 4 dph, though not in larvae from the AZA treatment. A single pulse exposure, delivered on the first day post hatch, caused similar effects on mortality and swimming activity 4 dph as the three-pulse exposure. Mortality was driven by the presence of DEL in both experiments, with no amplification or reduction of effects observed when DEL and AZA were combined. Larvae were observed for 13 days following the single pulse exposure, with food limitation introduced as an additional stressor on day 4. In the DEL and AZA + DEL treatments mortality continued to increase regardless of food level, with no larvae completing development to stage II. The overriding toxicity of DEL masked any potential effects the reduced food ration may have exerted. Swimming activity was lower for AZA treated larvae than Control larvae 13 dph, when both groups were fed daily, though no other significant changes to mortality, development to stage II, feeding rate or gene expression were observed. Food limited Control and AZA larvae had lower swimming activity and feeding rate than daily fed Control larvae, with expression of pyruvate kinase and myosin genes also downregulated. However, there was no negative effect on survival or successful development to stage II in these treatments. In addition, mesencephalic astrocyte-derived neurotropic factor was downregulated in food limited Control larvae when compared with the daily fed Controls. Results from this study together with reported estimates of dispersion plume concentrations of discharged pesticides indicate that toxic concentrations of deltamethrin could reach shrimp larvae several kilometers from a treated salmon farm.
... However, over the years severe problems of ectoparasite resistance to pyrethroid treatments in Southern Chile have been reported [25,26], even during synchronized sea lice treatments (i.e., bath treatments coordinated among neighboring farms), with lower adult lice levels, but juvenile stages less affected [27,28]. There have been similar reports in Norway, where increased sea lice resistance has triggered pyrethroid use by the salmon farming industry [8,29,30]. ...
Chapter
Synthetic pyrethroids such as cypermethrin and deltamethrin have been widely used in Chile to treat sea lice on salmon since 2007. The environmental risks of aquaculture practices are evaluated through the use of several tools such as fugacity-based models for predicting environmental dynamics and the fate of pyrethroids after their release into the marine environment and the determination of pyrethroid occurrence in environmental samples (i.e., water and sediment). For seawater, passive sampling devices (PSDs) are proposed as a good alternative for field monitoring. Finally, by means of ecotoxicological bioassays, the effects of pyrethroids on native biota were assessed. The results show that the application of pyrethroids may trigger some unintended risks to nontarget organisms, particularly copepods, since modeled and observed concentrations in water (dissolved phase) are in the range of fractions of ng L⁻¹, but higher cypermethrin and deltamethrin concentrations in sediment in the range of 1,323 and 1,020 ng g⁻¹, respectively, have been observed. These measured concentrations were in the range of concentrations toxic to native invertebrate species in Chile. We conclude that a stricter process should be followed when pyrethroids, particularly cypermethrin, are recommended for use in combating sea lice in the Chilean salmon farming industry. Risk assessment procedures and the establishment of stricter regulations on matters such as the maximum allowable concentrations around the cages when these pesticides are applied and recommended.
... Continued growth of salmon aquaculture may lead to increased discharge of anti-salmon lice chemicals. Despite the increasing use of non-chemical methods to remove sea lice from farmed salmon, several chemicals (bath treatment and medicated feed) are still used extensively Burridge et al., 2014;Lillicrap et al., 2015). ...
Article
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Hydrogen peroxide (H 2 O 2 ) is used as anti-parasitic veterinary medicine in salmon farms worldwide. In the period from 2009 to 2018 a total of 135 million kg of H 2 O 2 was used in Norway, the world's largest producer of Atlantic salmon. Since the treatment water is discharged to the sea, concerns have been raised about effects of H 2 O 2 on the coastal ecosystem. In the present study, Northern shrimp (Pandalus borealis) have been exposed to short pulses of H 2 O 2 in the PARAMOVE ® formulation, followed by a recovery period in clean seawater. The exposure concentrations represented 100, 1000 and 10 000 times dilutions of the prescribed treatment concentration for salmon; 15 mg/L, 1.5 mg/L and 0.15 mg/L H 2 O 2 . Significantly increased mortality was observed after 2 h exposure to 15 mg/L H 2 O 2 (50%) and after 2 h exposure to 1.5 mg/L H 2 O 2 on 3 consecutive days (33%), but no mortality was observed after 2 h exposure to 0.15 mg/L. The mortality occurred 2–4 days after the first pulse of exposure. The patterns of acute effects (immobility and death) could be captured with a toxicokinetic-toxicodynamic model (GUTS), which allows extrapolations to LC50s for constant exposure, or thresholds for effects given untested exposure profiles. Effects of H 2 O 2 were also detected in shrimp that survived until the end of the recovery period. The feeding rate was 66% lower than in the control after 12 days of recovery for the three-pulse 1.5 mg/L exposure. Furthermore, dose dependent tissue damage was detected in the gills and evidence of lipid peroxidation in the hepatopancreas in shrimp exposed for 1 h to 1.5 mg/L and 15 mg/L and kept in recovery for 8 days. Fluorescence intensity in the hepatopancreas of treated shrimp increased 47% and 157% at 1.5 mg/L and 15 mg/L, respectively, compared to the control. Local hydrodynamic conditions will determine how fast the concentration of H 2 O 2 will be diluted and how far it will be transported horizontally and vertically. Results from dispersion modelling (literature data) together with the current experiments indicate that treatment water with toxic concentrations of H 2 O 2 (1.5 mg/L) could reach P. borealis living more than 1 km from a treated salmon farm.
... The continued growth of marine aquaculture production has pre- sented the industry with environmental and production challenges, one of which is the ectoparasitic salmon louse (Lepeophtheirus salmonis) (Torrissen et al., 2013). A common method to control populations of lice within farm cages is treatment by various pharmaceuticals ( Lillicrap et al., 2015). The use of benzoylurea-type insecticides, which act as chitin synthesis inhibitors (CSIs) has increased due to develop- ment of resistance in salmon lice to other types of medicine such as emamectin benzoate (Folkehelseinstituttet, 2015;Jones et al., 2013). ...
Article
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Increasing use of fish feed containing the chitin synthesis inhibiting anti-parasitic drug diflubenzuron (DFB) in salmon aquaculture has raised concerns over its impact on coastal ecosystems. Larvae of Northern shrimp (Pandalus borealis) were exposed to DFB medicated feed under Control conditions (7.0 °C, pH 8.0) and under Ocean Acidification and Warming conditions (OAW, 9.5 °C and pH 7.6). Two weeks' exposure to DFB medicated feed caused significantly increased mortality. The effect of OAW and DFB on mortality of shrimp larvae was additive; 10% mortality in Control, 35% in OAW, 66% in DFB and 92% in OAW + DFB. In OAW + DFB feeding and swimming activity were reduced for stage II larvae and none of the surviving larvae developed to stage IV. Two genes involved in feeding (GAPDH and PRLP) and one gene involved in moulting (DD9B) were significantly downregulated in larvae exposed to OAW + DFB relative to the Control. Due to a shorter intermoult period under OAW conditions, the OAW + DFB larvae were exposed throughout two instead of one critical pre-moult period. This may explain the more serious sub-lethal effects for OAW + DFB than DFB larvae. A single day exposure at 4 days after hatching did not affect DFB larvae, but high mortality was observed for OAW + DFB larvae, possibly because they were exposed closer to moulting. High mortality of shrimp larvae exposed to DFB medicated feed, indicates that the use of DFB in salmon aquaculture is a threat to crustacean zooplankton.
... Similar considerations apply to nanomaterials as they are known to behave differently in ecotoxicity tests compared to conventional chemicals, for which most test guidelines were developed (Hartmann, Ågerstrand, Lützhøft, & Baun, 2017), as well as veterinary and human medicines as they may have specific effects on non-target organisms through interactions with drug targets (Lillicrap, Macken, & Thomas, 2015;Ågerstrand et al., 2015). In spite of this, studies conducted in accordance with standardized test guidelines, such as the Organisation for Economic Co-operation and Development test guidelines, and Good Laboratory Practices are sometimes by default attributed higher reliability than (academic) research studies and preferred for regulatory hazard and risk assessments . ...
Article
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This is a call for action to scientific journals to introduce reporting requirements for toxicity and ecotoxicity studies. Such reporting requirements will support the use of peer-reviewed research studies in regulatory decision-making. Moreover, this could improve the reliability and reproducibility of published studies in general and make better use of the resources spent in research.
... The current major producers of aquaculture are in Asia, with China accounting for approximately 60% of the aquaculture market, and other Asian countries accounting for just under 30% ( Lillicrap et al. 2015). Within Asia, aquaculture production consists primarily of freshwater fish such as carp and, to a lesser degree, shellfish. ...
... The current major producers of aquaculture are in Asia, with China accounting for approximately 60% of the aquaculture market, and other Asian countries accounting for just under 30% ( Lillicrap et al. 2015). Within Asia, aquaculture production consists primarily of freshwater fish such as carp and, to a lesser degree, shellfish. ...
... Examples of chemical groups where this particularly applies are endocrine disrupting chemicals, pharmaceuticals, and nanomaterials. [1][2][3][4][5] Consequently, major sources of EU law require the use of all available data (see Table 1). This includes industry study reports and grey literature, as well as studies published in the peerreviewed literature. ...
Article
Full-text available
Regulatory hazard and risk assessments of chemical substances have to include all reliable and relevant data to be credible and complete. However, screening the literature for appropriate studies and extracting data is burdensome. Therefore, reducing impediments by making data easily and readily accessible to risk assessors could result in more comprehensive hazard and risk assessments. In this paper, we study WikiPharma, a database that aggregates ecotoxicity data for pharmaceuticals, extracted from peer-reviewed studies. The use of the WikiPharma database is explored to develop strategies on how similar tools can bridge between science and policy by providing risk assessors with easily accessible summary data. Specifically, adapting the concept of WikiPharma to industrial chemicals regulated under the REACH regulation is discussed. Experiences with WikiPharma show that there is interest in using peer-reviewed studies in regulatory decision-making. However, tools like WikiPharma require constant updates. Hence, as for "WikiREACH", effective incentives are needed to motivate researchers to feed in relevant data for regulatory assessments. Besides, support by automated processes can aid in the labour-intensive activity of gathering data. To ensure that such a tool is continuously maintained and compatible with the regulatory system, and thereby useful for hazard and risk assessments of chemicals, it would benefit from being developed in collaboration with the major stakeholders in the field, i.e. regulatory agencies, academia, industry, scientific journals, and providers of research network platforms.
... H 2 O 2 is a pro-oxidant and functions as a pest control by being a topic disinfectant, indicating that this compound is administered directly through water to remove attached lice from fish skin. Because H 2 O 2 exerts an acute effect and is readily broken down to oxygen and water through abiotic processes, it is considered less environmentally harmful than many of the other pesticides which exhibit larger acute-to-chronic ratios (ACRs > 300,000) due to their specific (and delayed) modes of toxic action (Lillicrap et al. 2015). However, high H 2 O 2 concentrations are necessary for lice removal has created a cause for concern for acute effects on treated fish as well as for organisms in the environment surrounding the fish farms. ...
Article
Use of hydrogen peroxide (H2O2) for removal of salmon lice in the aquaculture industry has created concern that non-target organisms might be affected during treatment scenarios. The aim of the present study was to examine the potential for H2O2 to produce oxidative stress and reduce survival in one of the most abundant zooplankton species in Norwegian coastal areas, the copepod Calanus finmarchicus. Copepods were subjected to two 96-hr tests: (1) acute toxicity test where mortality was determined and (2) treated copepods were exposed to concentrations below the No Observed Effect Concentration (0.75 mg/L) H2O2 and analyzed for antioxidant enzyme activities, as well as levels of glutathione (GSH) and malondialdehyde (MDA). Compared to available and comparable LC50 values from the literature, our results suggest that C. finmarchicus is highly sensitive to H2O2. However, 96-hr exposure of C. finmarchicus to 0.75 mg H2O2/L did not significantly affect the antioxidant systems even though the concentration is just below the level where mortality is expected. Data suggest that aqueous H2O2 exposure did not cause cellular accumulation with associated oxidative stress, but rather produced acute effects on copepod surface (carapace). Further investigation is required to ensure that aqueous exposure during H2O2 treatment in salmon fish farms does not exert adverse effects on local non-target crustacean species and populations. In particular, studies on copepod developmental stages with a more permeable carapace are warranted.
... The Asian pharmaceutical market is growing at a rate of 10-15% annually, compared to a 5-7% growth in G7 countries (Rehman et al. 2013). The Food and Agriculture Organization of the United Nations (FAO) indicates that the value of global aquaculture production increased from approximately $50 billion to nearly $140 billion in the years between 2003 and 2012 (Lillicrap et al. 2015). In 2013, 1452 tons of VPs were supplied with TC S and penicillins (PEN S ) being the most distributed active compounds (454 tons and 473 tons, respectively), followed by SA S (152 tons) (Spielmeyer et al. 2015). ...
Chapter
The use of veterinary pharmaceuticals (VPs) is a result of growing animal production. Manure, a great crop fertilizer, contains a significant amount of VPs. The investigation of VPs in manure is prevalent, because of the potential risk for environmental organisms, as well as human health. A re-evaluation of the impact of veterinary pharmaceuticals on the agricultural environment is needed, even though several publications appear every year. The aim of this review was to collate the data from fields investigated for the presence of VPs as an inevitable component of manure. Data on VP concentrations in manure, soils, groundwater and plants were collected from the literature. All of this was connected with biotic and abiotic degradation, leaching and plant uptake. The data showed that the sorption of VPs into soil particles is a process which decreases the negative impact of VPs on the microbial community, the pollution of groundwater, and plant uptake. What was evident was that most of the data came from experiments conducted under conditions different from those in the environment, resulting in an overestimation of data (especially in the case of leaching). The general conclusion is that the application of manure on crop fields leads to a negligible risk for plants, bacteria, and finally humans, but in future every group of compounds needs to be investigated separately, because of the high divergence of properties.
Article
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Swimming behaviour was investigated in adult egg-carrying northern shrimp (Pandalus borealis) exposed to dilute concentrations of the pesticides Alpha Max® (active ingredient deltamethrin) and Salmosan® (active ingredient azamethiphos) used to control parasitic copepods in salmon aquaculture. These treatments are applied topically within fish nets or well boats. Following a short treatment period, the pesticides are directly discharged to sea, exposing non-target organisms such as P. borealis to diluted concentrations of these chemicals. Locomotor activity was measured continuously in individual shrimp over several days within which they were exposed to treatments of diluted AlphaMax® or Salmosan®. Dilutions were based on modelling and dispersion studies from the literature and were considered environmentally realistic for greater than 1 km from point of discharge. 24 h continuous flow treatments were delivered within a 3.5-day monitoring period to observe the timeline of events following the release of treatment water, addressing questions of temporal responses in locomotor activity, recognising key time points of significant events and assessing the survival capacity of the shrimp. Exposure of shrimp to 1 ng l-1 deltamethrin triggered an immediate increase in swimming activity which reduced in intensity over the following 22 h leaving all shrimp either moribund or dead. A further exposure trial exposing shrimp to 0.2 ng l-1 deltamethrin (nominal) showed an increase in activity at the start of exposure that continued throughout the 24 h delivery, returning to previous levels by the end of the 3.5-day monitoring period. All these shrimps survived for at least four weeks after exposure, putting the threshold concentration of deltamethrin leading to immobility or death in adult P. borealis within this study at greater than 0.2 ng l-1 (nominal) and less than 1 ng l - 1 (measured). Exposure of P. borealis to azamethiphos at 30 ng l-1 induced several periods of significantly increased activity within the first 10 h of exposure and an extended period of reduced activity during post exposure, though no morbidity was observed with this treatment. No significant increase in activity or morbidity was observed in shrimp during a water vehicle control assessment. Shrimps exposed to a combination of 30 ng l-1 azamethiphos and 1 ng l-1 deltamethrin broadly followed the response pattern shown by shrimp exposed to 1 ng l-1 deltamethrin alone. Pesticide residues were not detected in post exposure tissue analyses for either chemical. The potential ecological significance of increased swimming activity at the start of pesticide exposures is discussed.
Article
China is the largest mariculture producer in the world. In recent years, pharmaceuticals and pesticides have been widely used in mariculture activities; however, most studies have only focused on the occurrence of limited types of antibiotics and organochlorine pesticides. It is critical to comprehensively investigate the occurrence of pharmaceuticals and pesticides in mariculture areas and assess their potential impacts on ocean ecosystems. In this study, the occurrence, distribution, and ecological risk of 484 compounds, including 296 pesticides, 156 pharmaceuticals, and 32 other substances, in the drainage ditches of culture ponds and raft-culture areas were investigated. A total of 51 compounds were detected in the mariculture area, with total concentrations ranging from 5.4 × 10² to 2.0 × 10⁴ ng/L at each sampling site. Eleven pesticides, three pharmaceuticals, and five other compounds were detected, with detection frequencies of 100%. The cluster analysis indicated that mariculture is a source of herbicide pollution in coastal waters. To assess the ecological risks of the detected compounds, toxicity data collected from the database and predicted from quantitative structure activity relationship (QSAR) models were used to calculate the risk quotients and probabilistic risks. According to the risk quotients, five pollutants, including diuron, ametryn, prometryne, simetryn, and terbutryn, were estimated to pose high risks to marine organisms. The results of the probabilistic risk assessment indicated that only diuron, a biocide used in antifouling paint and mariculture, would have an adverse effect on up to 8% of the aquatic species in nearshore areas. These findings could be helpful in determining the aquatic benchmarks of pesticides and pharmaceuticals in mariculture discharge to promote the sustainable development of mariculture and ecological protection in coastal areas.
Article
Low dose antibiotics have been used as growth promoters in livestock and fish. The use of antibiotics has been associated with reduced pathogen infections in livestock. In contrast, antibiotic growth promoter has been suspected of leading to disease outbreaks in aquaculture. However, this phenomenon is circumstantial and has not been confirmed in experimental conditions. In this study, we showed that antibiotic olaquindox increased the susceptibility of zebrafish to A. hydrophila infection. Olaquindox led to profound alterations in the intestinal microbiota of zebrafish, with a drastic bloom of Enterobacter and diminishing of Cetobacterium. Moreover, the innate immune responses of zebrafish were compromised by olaquindox (P<0.05). Transfer of microbiota to GF zebrafish indicated that while the immuo-suppression effect of olaquindox is a combined effect mediated by both OLA-altered microbiota and direct action of the antibiotic (P<0.05), the increased pathogen susceptibility was driven by the OLA-altered microbiota and was not dependent on direct antibiotic effect. Taken together, these data indicate that low level of OLA induced gut microbiota dysbiosis in zebrafish, which led to increased pathogen susceptibility.
Technical Report
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EFSA’s Panel on Plant Protection Products and their Residues (PPR) was tasked to revise the Guidance Document (GD) on Aquatic Ecotoxicology under Council Directive 91/414/EEC (SANCO/3268/2001 rev.4 (final), 17 October 2002). This Guidance of the PPR Panel is the first of three requested deliverables within this mandate. It has its focus on tiered acute and chronic effect assessment schemes with detailed guidance on tier 1 and higher tier effect assessments for aquatic organisms in edge-of-field surface waters and on proposals regarding how to link effects to exposure estimates. The exposure assessment methodology was not reviewed and it is assumed that the current FOCUS surface water exposure assessment methodology will continue to be used for exposure assessment at EU level. The current GD is intended to be used for authorisation of active substances at EU level as well as for plant protection products at Member State level. The effect assessment schemes in this GD allow for the derivation of regulatory acceptable concentrations (RACs) on the basis of two options: (1) the ecological threshold option (ETO), accepting negligible population effects only, and (2) the ecological recovery option (ERO), accepting some population-level effects if ecological recovery takes place within an acceptable time period. In the tiered effect assessment schemes, in principle, all tiers (1, 2 and 3) are able to address the ETO, while the model ecosystem approach (tier 3), under certain conditions, is able to also address the ERO. The GD provides the scientific background for the risk assessment to aquatic organisms in edge-of-field surface waters and is structured to give detailed guidance on all assessment steps. An executive summary joining all parts of the guidance and decision schemes in a concise way is provided and is intended to help applicants and regulatory authorities in day-to-day use.
Article
Diflubenzuron and teflubenzuron are benzoylureas that are used in aquaculture to control sea lice. Flubenzurons have low toxicity to many marine species such as fish and algae, but by their nature are likely to have significant adverse effects on non-target species such as crustaceans and amphipods. Although the exact mechanism of toxicity is not known, these compounds are thought to inhibit the production of the enzyme chitin synthase during moulting of immature stages of arthropods. These chitin synthesis inhibitors are effective against the larval and pre-adult life stages of sea lice. Due to their low solubility and results of recent monitoring studies conducted in Norway, the sediment compartment is considered the most likely reservoir for these compounds and possible remobilization from the sediment to benthic crustaceans could be of importance. For this reason, the epibenthic copepod, Tisbe battagliai, was selected for use in the investigations into acute and developmental effects of these compounds. For comparative purposes, azamethiphos was investigated to identify differences in sensitivity and act as a negative control for developmental effects at environmentally relevant concentrations. Standard acute studies with adult copepods showed little or no acute toxicity at mg/L levels with the flubenzurons, while a naupliar developmental test demonstrated that environmentally relevant concentrations (e.g. ng/L) caused a complete cessation of moulting and finally death in the exposed copepods. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
Article
Aquaculture production is an important industry in many countries and there has been a growth in the use of medicines to ensure the health and cost effectiveness of the industry. This study focussed in the inputs of sea lice medication to the marine environment. Diflubenzuron, teflubenzuron, emamectin benzoate, cypermethrin and deltamethrin were measured in water, sediment and biota samples in the vicinity of 5 aquaculture locations along the Norwegian coast. Deltamethrin and cypermethrin were not detected above the limits of detection in any samples. Diflubenzuron, teflubenzuron and emamectin benzoate were detected, and the data was compared the UK Environmental Quality Standards. The concentrations of emamectin benzoate detected in sediments exceed the environmental quality standard (EQS) on 5 occasions in this study. The EQS for teflubenzuron in sediment was exceeded in 67% of the samples and exceeded for diflubenzuron in 40% of the water samples collected. A crude assessment of the levels detected in the shrimp collected from one location and the levels at which chronic effects are seen in shrimp would suggest that there is a potential risk to shrimp. It would also be reasonable to extrapolate this to any species that undergoes moulting during its life cycle.
Article
This study describes experiments carried out to examine effects of the antiparasitic drug teflubenzuron, used in delousing farmed salmon, on a non-target species, the European lobster (Homarus gammarus). Juvenile lobsters were fed two doses of teflubenzuron, 10 and 20mg/kg successively for 7 days corresponding to a standard medication of the fish (10mg/kg day) and twice the standard dose (20mg/kg day). Monitoring lasted 3 months to include at least one moulting period for all individuals. Cumulative mortality was higher in all replicates given medicated feed compared with the control group. Mean cumulative mortality for each dosing was 41±13% for 10mg/kg and 38±8% for 20mg/kg, i.e. no difference. Drug residue was analysed in all juveniles that died, in addition to 12 juveniles at day 8 and the first 12 surviving lobsters. A decline in concentration of teflubenzuron from over 8000ng/g (day 5) to 14ng/g (day 70) was observed in the juveniles that died during the experiment. Twelve individuals that died contained 82ng/g or less whereas the mean concentration in the first 12 lobsters that survived moulting was 152ng/g. Following a single oral administration, the half-life of teflubenzuron in lobster was estimated to 3.4 days and the initial concentration (C0) to 515ng/g at time t0. At the end of the study a considerable number of juvenile lobsters were observed with deformities in various organs; carapace, walking legs, cheliped, tail fan, abdomen and antenna. The occurrence of observed deformities varied from 0 to 15% in treated replicates and will most likely affect ability to locate and consume food (antenna, claw and walking legs), respiration (carapace) and ability to move/swim (walking legs, tail fan and abdomen). In total, the mortality and senescent damages were close to 50% in all replicates. Juveniles that survived medication without deformities however, moulted and increased in size at each moult equally well as the unmedicated controls.
Article
We have become progressively more concerned about the quality of some published ecotoxicology research. Others have also expressed concern. It is not uncommon for basic, but extremely important, factors to apparently be ignored. For example, exposure concentrations in laboratory experiments are sometimes not measured, and hence there is no evidence that the test organisms were actually exposed to the test substance, let alone at the stated concentrations. To try to improve the quality of ecotoxicology research, we suggest twelve basic principles that should be considered, not at the point of publication of the results, but during the experimental design. These principles range from carefully considering essential aspects of experimental design through to accurately defining the exposure, as well as unbiased analysis and reporting of the results. Although not all principles will apply to all studies, we offer these principles in the hope that they will improve the quality of the science that is available to regulators. Science is an evidence-based discipline and it is important that we and the regulators can trust the evidence presented to us. Significant resources often have to be devoted to refuting the results of poor research when those resources could be utilised more effectively.
Article
Abstract Chitin is the most abundant natural aminopolysaccharide and serves as a structural component of extracellular matrices. It is found in fungal septa, spores, and cell walls, and in arthropod cuticles and peritrophic matrices, squid pens, mollusk shells, nematode egg shells, and some protozoan cyst walls. As prokaryotes, plants and vertebrates including humans do not produce chitin, its synthesis is considered as an attractive target site for fungicides, insecticides, and acaricides. Although no chitin synthesis inhibitor has been developed into a therapeutic drug to treat fungal infections in humans, a larger number of compounds have been successfully launched worldwide to combat arthropod pests in agriculture and forestry. This review summarizes the latest advances on the mode of action of chitin synthesis inhibitors with a special focus on those molecules that act on a postcatalytic step of chitin synthesis.
Article
Fungal and parasitic infections of fish can significantly impact the survival of cultured fish. Formalin is currently used to control such infections; however, concern has arisen over its safety to users and to the environment. Hydrogen peroxide has been designated as a low priority fungicidal drug by the United States Food and Drug Administration (FDA), yet, little information is available on treatment concentrations or its toxicity to trout. Rainbow trout Oncorhynchus mykiss and cutthroat trout Oncorhynchus clarki fry and Angerlings were exposed to hydrogen peroxide concentrations of 0, 70, 170, 280, 420 and 540 ppm for 30, 60 or 120 rnin at 15 C to determine the chemical's toxicity. Rainbow trout fry and fingerlings experienced elevated mortalities (>20%) during treatments using 420 and 540 ppm for 30 min; 280, 420 and 540 ppm for 60 min; and >170 ppm for 120 min. Cutthroat trout fry experienced elevated mortalities (>23%) during treatments using 540 ppm for 30 min; 420 and 540 ppm for 60 min; and >170 ppm for 120 min. Cutthroat trout fingerlings experienced elevated mortalities (>60%) during treatments using 540 ppm for 60 min and >280 ppm for 120 min. No control mortalities were encountered for both life stages of either species. The lethal concentrations (LC50) of both age classes and species for each of the three durations ranged from 514–636 ppm for 30 min treatments, 322–506 ppm for 60 min treatments, and 189–280 for 120 min treatments. Mortalities for all four toxicity tests which occurred during a 96-h post-treatment period were centered around the following treatments: 30 min, 540 ppm; 60 min, 280–540 ppm; 120 min, 170 ppm. Tissue damage to gills was found only among fish that did not survive the initial chemical exposure. Test concentrations proved to be relatively stable during a 24-h period, retaining better than 85% of their original strength for all five dilutions. At a water temperature of 15 C concentrations should not exceed 280 ppm for a 30-min treatment.
Article
"Developments during the past two years confirm the trends already observed at the end of the 1990s: capture fisheries production is stagnating, aquaculture output is expanding and there are growing concerns with regard to the livelihoods of fishers and the sustainability of commercial catches and the aquatic ecosystems from which they are extracted. The State of World Fisheries and Aquaculture 2004 reports on several of these issues. "It is not only fishers and fish farmers who have these concerns; they are increasingly shared by civil society at large. Moreover, the importance of international trade in fish and fish products, combined with the trend for major fishing and trading companies to operate on a multinational basis, means that such issues are becoming global in nature affecting a growing number of countries, be they large fish producers or large consumers of fish. It is heartening to note that governments and other stakeholders have begun to collaborate with their neighbours and partners in trade in an effort to find shared solutions. "Concrete examples of positive outcomes of this globalization of concerns are the establishment of new regional fishery management organizations and the strengthening of existing ones. It is probable that ongoing discussions among intergovernmental organizations on topics such as trade in endangered aquatic species, the use of subsidies in the fishing industry, and labour standards in fisheries will also result in agreements of overall benefit to world society. "Given the nature and tone of the international discussion on fishery issues and the developments observed during recent years, I believe that fishers and fish farmers, in collaboration with governments and other stakeholders, will overcome the obstacles they face currently and will succeed in ensuring sustainable fisheries and continued supplies of food fish at least at their present levels."
Article
The evaluation of the quality of data and their use in hazard and risk assessment as a systematic approach is described. Definitions are proposed for reliability, relevance, and adequacy of data. Reliability is differentiated into four categories. Criteria relating to international testing standards for categorizing reliability are developed. A systematic documentation of evaluating reliability especially for use in the IUCLID database is proposed. This approach is intended to harmonize data evaluation processes worldwide. It may help the expert in subsequent assessments and should increase the clarity of evaluation.
Article
As scientists investigate whether low levels of human pharmaceuticals in water have environmental effects, they are turning to their usual armada of experimental tests and assessments. However, the authors say that these tools may not accurately predict chronic effects for some compounds. They describe a different approach that incorporates a water-shed model and could be the basis of future studies.
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