Distribution and persistence of the anti sea-lice drug teflubenzuron in wild fauna and sediments around a salmon farm, following a standard treatment

Aquaculture-derived trophic subsidy boosts populations of an ecosystem engineer

“…As wild marine fauna typically have diets high in n-3 LC PUFA (Twining et al 2016), high consumption of aquaculture waste represents a substantial quantitative and qualitative biochemical shift in dietary intake. A shift in nutritional quality of diet, combined with other challenges associated with near farm environments, such as heavy metals, synthetic chemicals and persistent organic pollutants (Burridge et al 2010, Samuelsen et al 2015, may supersede fitness benefits associated with the bulk organic subsidy. In this manner, aquaculture outputs could function as an ecological trap, whereby individuals are attracted to the trophic subsidy, with detrimental fitness and reproductive consequences (Robertson & Hutto 2006, Hale & Swearer 2016.…”

Transcriptional responses to teflubenzuron exposure in European lobster (Homarus gammarus)

“…To control the level of infestation, the salmon farming industry uses considerable amounts of antiparasitic drugs either dissolved in water and used for bath treatment or administered orally via the feed. The increasing use of pharmaceutical drugs to control salmon lice has led to concerns about their environmental impacts (Olsvik et al, 2013;Langford et al, 2014;Samuelsen et al, 2014;Samuelsen et al, 2015;Macken et al, 2015).…”

“…Released into the environment, the pharmaceutical drugs may negatively affect invertebrates, either by directfeeding onuneaten pellets inthe vicinity of open net pens or by exposure to the drugs spread to the surrounding water and sediments.Drugs that are developed to target chitin synthesis and prevent exoskeleton change in arthropods, such as benzoylurea pesticides,are of special concern (Langford et al, 2014;Samuelsen et al, 2015). Two of these, diflubenzuron [1-(4-chloro-phenyl)-3-(2,6-difluorobenzoyl)urea]) and teflubenzuron [1-(3,5-dichloro-2,4-difluorophenyl)-3-(2,6-difluorobenzoyl)urea], in frequent use from late 1990s and until 2001 against salmon lice, were reintroduced in Norway in 2009.…”

“…Environmental input comes from uneaten food, estimated to be 5-15% of medicated feed (Chen et al, 1999), and feces.Approximately 90% of the dose of the benzoylurea agents administered in feed and absorbed by the fish is excreted in active form in feces and spread to the environment (Chen et al, 1999). A recent study showed that particles containing pharmaceutical drugscould be found 1000 meters from a salmon farm following a standardmedicationwith teflubenzuron (Samuelsen et al, 2015). The study showed that, although low concentrations were found in the water column, organic waste beneath the farm contained higher concentrations of the drug than the medicated feed.…”

“…Other studies have estimated a half-life of this compound of 115 days in marine sediments (Langford, 2011). Teflubenzuron residues were found in most of the examined wild fauna species, with highest concentrations in polychaetes and fish (Pollachiusvirens) (Samuelsen et al, 2015). Elevated levels of teflubenzuron in the vicinity of fish farms treated with the drug have been found in species such as brown crab (Cancer pagurus), shrimp (Pandalus borealis), amphipod (Gammaruslocusta) and blue mussel (Mytilusedulis) (Langford et al, 2014).…”