Name: Thiago Barros de Amorim
Type: MSc dissertation
Publication date: 04/04/2022
Advisor:
Name |
Role |
|---|---|
| Agnaldo Silva Martins | Advisor * |
Examining board:
| Name |
Role |
|---|---|
| Agnaldo Silva Martins | Advisor * |
| Fabian Sá | External Examiner * |
| Sarah Maria Vargas | Internal Alternate * |
| Sara Joana Pereira Pedro | External Examiner * |
Summary: PCBs ± Polychlorinated Biphenyls or ascarel are chlorinated organic compounds that were initially synthesized in the early 19th century, but their industrial production began in the 1920s and there are no natural sources of PCBs. PCBs are also persistent organic pollutants (POPs), which are characterized by being highly toxic, remaining in the environment for a long time, and being bioaccumulative and biomagnified. The quantification of PCBs has been carried out in animals all over the world, mainly in orca - Orcinus orca (Linnaeus, 1758). O. orca exists in all oceans and is a long-lived species. Your diet is an important factor that directly influences PCB concentrations. O. orca was used as a bioindicator for inference about the influence of local or global factors on PCB concentration, as well as to verify whether dietary patterns interfere
with the amount of PCBs accumulated in subcutaneous fat. The study described here is a meta-analysis based on the results of previous studies and the search methodology was in internet article databases and was based on 8 studies. We collected 75 specimens of Orcinus orca from the USA, Canada, England, Scotland, Ireland, Denmark, Greenland and Spain, Japan and Antarctica. 18 mammal-eating individuals from the Northern Hemisphere, 35 piscivorous data from the Northern Hemisphere and 22 piscivorous from Antarctica were used in the comparative analyses. The mammal-eating individuals had the highest averages of PCBs 187.42 mg/kg, followed by Piscivorous individuals from the northern hemisphere with 39.62 mg/kg and the lowest averages in Piscivorous individuals from Antarctica with 31.35
mg/kg. Individuals showed significant distribution when compared by nMDS for the diet parameter. There was a significant difference between the levels of mammal-eating orcas from the northern hemisphere, piscivorous from the northern hemisphere and piscivorous from Antarctica. PCB values in Northern Hemisphere mammal-eating and Northern Hemisphere piscivorous orcas tended to decline after mid-2000, showing that there was a response after the Stockholm Convention came into force in 2004. PCBs in organisms showed a regional distribution, with diet being a relevant factor in this distribution.
KEY WORDS Orcinus orca, PCB, bioindicator, diet, ecotypes.
