title: Effects of alkylphenols on the reproductive system of Atlantic cod (Gadus morhua).
abstract: Produced water, a by-product of offshore oil production, contains significant amounts of alkylphenols (APs). Many studies have shown that APs cause endocrine disruption in marine organisms, but relatively little is currently known about their long-term effects on the biology of pelagic fish. Here, we describe in detail the effects of APs on the reproductive potential of first-time spawning Atlantic cod (Gadus morhua). Cod were fed with feed paste containing four APs (4-tert-butylphenol, 4-n-pentylphenol, 4-n-hexylphenol and 4-n-heptylphenol), at a range of concentrations, for either 1 or 5 weeks. AP-exposed fish were compared to unexposed fish and to fish fed paste containing natural estrogen (17beta-estradiol). Our results showed that in female fish AP exposure impaired oocyte development, reduced estrogen levels, and delayed the estimated time of spawning by 17-28 days. Similarly, in male fish, we observed that AP-exposure reduced 11-keto-testosterone concentrations, and caused a small induction of VTG levels. We also observed impaired testicular development, with an increase in the amount of spermatogonia and a reduction in the amount of spermatozoa present. Taken together these results suggest that APs released into the sea via produced water may have a negative influence on the overall reproductive fitness of cod populations.
authors.affiliation: Institute of Marine Research, P.O. Box 1870, Nordnes N-5817, Bergen, Norway. sonnich.meier@imr.no
authors.forename: Sonnich
authors.initials: S
authors.lastname: Meier
authors.forename: Tom Einar
authors.initials: TE
authors.lastname: Andersen
authors.forename: Birgitta
authors.initials: B
authors.lastname: Norberg
authors.forename: Anders
authors.initials: A
authors.lastname: Thorsen
authors.forename: Geir Lasse
authors.initials: GL
authors.lastname: Taranger
authors.forename: Olav Sigurd
authors.initials: OS
authors.lastname: Kjesbu
authors.forename: Roy
authors.initials: R
authors.lastname: Dale
authors.forename: H Craig
authors.initials: HC
authors.lastname: Morton
authors.forename: Jarle
authors.initials: J
authors.lastname: Klungsøyr
authors.forename: Asbjørn
authors.initials: A
authors.lastname: Svardal
mesh_terms: D000818:Animals; D004958:Estradiol / Q000097:blood / Q000633:toxicity; D005260:Female; D048389:Gadus morhua / Q000502:physiology*; D008297:Male; D009865:Oocytes / Q000187:drug effects / Q000254:growth & development; D010636:Phenols / Q000633:toxicity*; D012098:Reproduction / Q000187:drug effects*; D013737:Testis / Q000187:drug effects; D013739:Testosterone / Q000031:analogs & derivatives / Q000097:blood; D013997:Time Factors; D014819:Vitellogenins / Q000097:blood / Q000187:drug effects; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D010636:Phenols; D014819:Vitellogenins; D014874:Water Pollutants, Chemical; D013739:Testosterone; D004958:Estradiol; C003600:11-ketotestosterone