Polychlorinated dioxins, furans and dl-PCBs in ringed seals (Pusa hispida botnica) from the Baltic Sea 1978-2014
Swedish Environmental Protection Agency 2015 (English)Report (Other academic)
Blubber tissue samples from in total 40 juvenile ringed seals from the Baltic Sea collected between 1978 and 2014 were analyzed for "dioxins"; polychlorinated dibenzo-p-dioxins, dibenzofurans (PCDD/PCDF) and dioxin-like PCBs (dl-PCB). Thirty-eight of the seals were bycaught in fishing gear and two were shot by mistake, taken for grey seals.
Concentrations of PCDDs, PCDFs and dl-PCBs have decreased over the study period in ringed seals with only a few exceptions. The decrease was primarily seen until year 2000 while the concentrations have been stable the last 15 years with a few exceptions. Two dioxins (1,2,3,4,6,7,8-HpCDD and OCDD) and one furan (1,2,3,7,8-PeCDF) demonstrate increased levels the last 15 year of the study period while one furan decreases (1,2,3,7,8,9-HxCDF). OCDD demonstrates the highest increase rate with 15 % yearly increase the last 15 years.
Concerning the dioxin-like PCBs, the four non-ortho, dl-PCBs demonstrate no trend the last 15 years. Four of the mono-ortho dl-PCBs continue to decrease until 2014 while the other four mono-ortho congeners show no statistically significant trends the last 15 years.
It should however be stated that a limited number of seals have been analyzed with an average of one seal/year and more analyses are demanded in order to achieve more significant time trend results.
Ringed seals show a low increase in population, approximately half of what is natural and reproductive impairment is still noted among ringed seals. If this has a connection to the concentrations of PCDD/F and dl-PCBs cannot be ruled out.
Place, publisher, year, edition, pages
Naturhistoriska riksmuseet , 2015. , 18 p.
Östersjön, Bottenhavet, Bottenviken, Dioxiner, furaner, plana PCB, vikare, späck
Research subject Miljöövervakningens programområden, Coast and sea; Environmental Objectives, A Non-Toxic Environment; Finance, National
IdentifiersURN: urn:nbn:se:naturvardsverket:diva-6792OAI: oai:DiVA.org:naturvardsverket-6792DiVA: diva2:1049322