uu.seUppsala University Publications
Change search
ReferencesLink to record
Permanent link

Direct link
Improved reproductive success in otters (Lutra lutra), grey seals (Halichoerus grypus) and sea eagles (Haliaeetus albicilla) from Sweden in relation to concentrations of organochlorine contaminants
Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Organismal Biology, Environmental Toxicology.
Show others and affiliations
2012 (English)In: Environmental Pollution, ISSN 0269-7491, E-ISSN 1873-6424, Vol. 170, 268-275 p.Article in journal (Refereed) Published
Abstract [en]

We studied indices of reproductive outcome in three aquatic species in relation to organochlorine concentrations during four decades. In female otters, the frequency of signs of reproduction increased after 1990. In grey seals, pregnancy rate increased 1990-2010 and uterine obstructions ceased after 1993. The frequency of uterine tumours was highest 1980-2000. The number of sea eagle nestlings per checked nest increased 1985-2000, while the frequency of desiccated eggs decreased. Organochlorine concentrations decreased at annual rates between 3.5 and 10.2%. The estimated mean concentration (mg/kg lw) for total-PCB decreased from 70 to 8 (otters), from 110 to 15 (seals) and from 955 to 275 (eagles). The corresponding concentrations for Sigma DDT decreased from 3.4 to 0.2 (otters), from 192 to 2.8 (seals) and from 865 to 65 (eagles). This study adds evidence to support the hypothesis that PCBs and DDTs have had strong negative effects on the reproduction and population levels of these species.

Place, publisher, year, edition, pages
2012. Vol. 170, 268-275 p.
Keyword [en]
Reproductive outcome, Otter, Grey seal, White-tailed sea eagle, Organochlorine contamination, Packed vs capillary column GC, Sweden
National Category
Natural Sciences
URN: urn:nbn:se:uu:diva-183538DOI: 10.1016/j.envpol.2012.07.017ISI: 000308450100033OAI: oai:DiVA.org:uu-183538DiVA: diva2:575135
Available from: 2012-12-07 Created: 2012-10-29 Last updated: 2013-05-13Bibliographically approved
In thesis
1. The Otter (Lutra lutra) in Sweden: Contaminants and Health
Open this publication in new window or tab >>The Otter (Lutra lutra) in Sweden: Contaminants and Health
2013 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

In the 1950s the otter started to decline in numbers and distribution in Sweden and other parts of Europe. In 1972 a game law came into force, listing otter as a species that if found dead should be reported and sent to the authorities. The numbers of dead otters reported from different areas indicate population status and distribution. Between 1970 and 2012, 832 otters were sent to the authorities, the majority (66%) during the last ten years. Most were killed in traffic accidents or drowned in fishing gear. However, the main cause of the decline is believed to be environmental contaminants. Experimental data show that a PCB residue level in muscle tissue of 12 mg/kg lw causes reproductive impairment in mink (Neovison vison), suggesting reproductive problems also in the highly PCB-exposed otters in Sweden. Since the bans of PCB and DDT in the mid-1970s, concentrations of these substances in otter and fish have decreased and the otter population is increasing.

Few pathological changes in otters have been found that can be related to high contaminant concentrations. However, we found a correlation between elevated PCB concentrations and alterations in bone mineral density. No relationship was seen between DDE and bone parameters.

The decline of the otter coincided with the decline of grey seals (Halichoerus grypus) and white-tailed sea eagles (Haliaeetus albicilla) in Sweden, all showing decreased reproductive outcome. Reproductive success started to increase for all of them around 1990 and during the same period concentrations of PCB and DDE have decreased in these species.

The body condition among female otters has increased over the study period, indicating an improved health status. However, we found a high prevalence (71%) of cysts on the spermatic duct in otters collected between 1999 and 2012, possibly caused by endocrine disrupting chemicals.

Although the organochlorine concentrations in otters have decreased, otters still face many problems. New threats to the otter population in Scandinavia are the perfluorinated chemicals, including PFOS and PFOA. Results in this thesis show an increasing trend for these compounds in otters up to 2011, including some extremely high concentrations of PFOS in otters from southern Sweden.

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2013. 47 p.
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1651-6214 ; 1051
Otter (Lutra lutra), PCB, DDT, PFAAs, reproduction, bone, time trends
National Category
Developmental Biology
Research subject
Biology with specialization in Environmental Toxicology
urn:nbn:se:uu:diva-199068 (URN)978-91-554-8688-4 (ISBN)
Public defence
2013-06-11, Lindahlsalen, Norbyvägen 18A, Uppsala, 13:00 (English)
Available from: 2013-05-21 Created: 2013-05-03 Last updated: 2013-08-30Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Roos, Anna M.
By organisation
Environmental Toxicology
In the same journal
Environmental Pollution
Natural Sciences

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 298 hits
ReferencesLink to record
Permanent link

Direct link