Oil and gas exploration activities are expected to increase in the Arctic, together with a decrease in the ice cover, and increased risk of oil spills and accidental fuel discharges from ships. Marine diesel is the only fuel authorized around Svalbard. However, the potential impact of this fuel source on the Arctic ecosystem has been poorly studied, even though it has a key biological function in maintaining population and biodiversity in the ecosystem. The objectives of this project are to adapt existing methods used in the project promoter and host institution, the Institute of Environmental Assessment and Water Research, in order to assess endocrine and reproductive alterations in the Icelandic scallop. The project promoter has wide experience in investigating endocrine disruption issues in bivalves and available methodologies based on the use of radiolabelled steroids that will allow this work. The donor partner, AKVAPLAN-NIVA AS (Norway), carries out a project aimed at investigating for the first time the impact of marine diesel exposure combined with thermal stress on Arctic scallop fitness. The scientific Community will benefit from the project results.
Summary of project results
The Icelandic schallop, Chlamys islandica, is an abundant species inhabiting the hard seafloor bottom of the (sub) Artic and has been selected as a sentinel species for biomonitoring studies in the Barents Sea, particularly where the common blue mussel (Mytilus edulis) is absent. Oil and gas exploration activities are expected to increase in the Artic together with a decrease in ice cover, increased risk for oil spills and accidental fuel discharges from ships. Marine diesel is the only fuel authorized around Svalvard. However, this fuel source has been poorly studied regarding its potential impact on the Artic ecosystem. Furthermore, no studies have been conducted to assess effects of oil related compounds on the reproductive system of Artic scallops, which have a key biological function in maintaining population and biodiversity in the ecosystem. The mobility project aimed at adapting existing methods at IDAEA-CSIC for different bivalve species to the Icelandic scallop in order to assess endocrine and reproductive alterations in future biomonitoring programs in the Artic, using the Icelandic scallop as sentinel species. During her stay in Spain, Dr. Perrine from Akvaplan-Niva familiarized with the following protocols and discussed potential adaptations to work with the Icelandic scallop. 1.Extraction, purification and determination of steroids in gonads of Chlamys islandica. The obtained extracts will be analysed by LC-MS/MS to select the optimum work conditions for the analysis of steroids in scallop gonads. 2.Determination of P450 aromatase activity in microsomal fractions isolated from gonads of Chlamys islandica. 3.An attempt was made to assess the metabolism of steroid precursors (progesterone and androstenedione) in microsomal fractions isolated from gonads of scallops. The method is already available for Mytilus and was directly applied to this new species. However, due to inactivation of the enzymes during transport, no results could be obtained.
Summary of bilateral results
The project promoter, IDAEA-CSIC, has wide experience in investigating endocrine disruption issues in bivalves and available methodologies based on the use of radiolabelled steroids that allowed this work. The donor partner, AKVAPLAN-NIVA AS (Norway), carries out a project aimed at investigating for the first time the impact of marine diesel exposure combined with thermal stress on Arctic scallop fitness. Akvaplan Niva benefited from the existing knowledge at IDAEA –CSIC to obtain new and complementary data to assess petroleum effects in Arctic bivalves, while IDEA -CSIC had the opportunity to work with a new species, increasing their knowledge on bivalves endocrine. As a result of the project, the method of sex steroid determination in Icelandic scallop has been validated and learned by Dr. P. Geraudie. It has also given hope that sex steroids and other reproductive signals could be characterized in this Artic species and new biomarkers of endocrine disruptions could be developed and validated in order to provide tools for the monitoring of Artic ecosystems. Future collaborations are planned in the framework of developing in vitro / ex vivo methods in Artic species to study petroleum effects on reproductive physiology and elucidate mechanisms of action of polycyclic aromatic hydrocarbons (PHAs). Based on the complementary know-how of both institutes, a collaborative project is planned to be submitted to the Governor of Svalvard to obtain funding to assess the reproductive effects of PAH exposure in Icelandic scallops. In the context of increasing oil and gas exploitation in the Artic, more data are needed to understand the basic physiology of reproductive function in this species, and its sensitivity toward petroleum compounds.