Effects of Produced Water on Reproductive Parameters in Prespawning Atlantic Cod (Gadus morhua)

Abstract

Produced water (PW) discharged from offshore oil industry activities contains substances that are known to contribute to a range of mechanisms of toxicity. In the present study selected reproductive biomarkers were studied in prespawning Atlantic cod (Gadus morhua) exposed to PW. The fish were exposed for 12 wk within a continuous flow-through system at realistic environmental near-field concentrations. Concentrations of polyaromatic hydrocarbon (PAH) and alkylphenol (AP) compounds were analyzed by gas chromatography with mass spectrometric detection measurement, as were PAH and AP metabolites in fish bile for verification of exposure conditions and presence of compounds in PW. A suite of reproductive biomarkers (vitellogenin, zona radiata protein, and plasma steroid concentrations) and histological alterations of the gonads were determined. Results showed that exposure to sufficiently high levels of PW produced an increase in vitellogenin levels in female fish compared to the control. Impaired oocyte development and reduced estrogen levels were also observed in PW-exposed female fish. In male fish testicular development was altered, showing a rise in amount of spermatogonia and primary spermatocytes and a reduction in quantity of mature sperm in the PW-exposed fish compared to control. Data indicate that sufficiently high levels of PW have the potential to adversely affect the reproductive fitness of cod.

Transgenerational effects of polycyclic aromatic hydrocarbon exposure on sheepshead minnows (Cyprinodon variegatus)

“…Our data bolster the growing body of evidence that hydrocarbon exposure can alter egg production in female fish (Brown‐Peterson et al ; Perrichon et al ; Raimondo et al ) and decrease reproductive fitness in male fish by reducing fertilization rate (Booc et al ). Hydrocarbons have also been shown to reduce sperm quantity (Sundt and Bjorkblom ) and quality (Nagler and Cyr ) and delay spermiation (Khan ), though those endpoints were not assessed in the present study. Correlation analyses revealed that tissue concentrations of parent and alkyl PAHs were negatively correlated with both egg production and fertilization rate, providing additional supportive evidence that the changes observed in egg production and fertilization rate in the present study are a result of hydrocarbon exposure and not natural variation between tanks.…”

Fish Reproduction Is Disrupted upon Lifelong Exposure to Environmental PAHs Fractions Revealing Different Modes of Action

“…If some studies have reported no gonadal disruptions [ 17 , 43 ], some experimental exposure to PAHs as well as analysis of fish collected in the field in PAH-contaminated areas revealed disruption of gonadal structure or reproduction-related biomarkers, which could help to understand the presently observed reproductive defects. For example, some studies showed that fish exposure to PAHs results in gonadal structure disruption indicative of maturation defects in females [ 39 , 40 , 44 ] and in males [ 44 , 45 ]. Our results are in agreement with these articles, revealing a decrease in ovary maturation as shown by a decrease in mature follicles (F4) proportion in female exposed to 3X concentration for all fractions and post-vitellogenic follicles (F3) for HO-3X females.…”

“…In the case of PY females, we have also identified degeneration areas in ovaries, the relative surface of which increased with PY concentration. In the case of males, the observed defects (hypoplasia in a small proportion of LO-3X and HO-1X and in a high proportion (42%) of HO-3X males) have already been mentioned in cod after exposure to produced water [ 44 ]. Further, one ovo-testis was also found in one individual morphologically identified as a male.…”

“…Exposure to PAHs usually results in a decrease in estradiol (E2) and 11-ketotestosterone (T), this has been observed after exposure to individual compounds [ 26 , 43 , 49 ] and more complex mixtures such as Produced water [ 44 ]. However, in other cases, an increase is observed [ 50 ] or E2 is reduced while T is increased [ 41 ].…”

Disruption of the rainbow trout reproductive endocrine axis by the polycyclic aromatic hydrocarbon benzo[a]pyrene

“…Less specifically, English sole (Parophrys tetulus) captured in areas contaminated with PAHs also had lower steroid concentrations (Johnson et al, 1988). Exposure of Atlantic cod (Gadus morhua) to produced water from the oil industry (containing PAH) also showed reduced E2 concentrations (Sundt and Bjorkblom, 2011). Contrary to these results, juvenile areolated grouper (Epinephelus areolatus) exposed to B[a]P in their diet showed large fluctuations in E2 and T concentrations and a significant elevation of T (Wu et al, 2003).…”