Organochlorines in harbour porpoises (Phocoena phocoena) stranded along the southern North Sea between 2010 and 2013

Abstract

7 polychlorinated biphenyls (PCBs), 6 dichlorodiphenyltrichloroethanes (DDXs) and 8 polybrominated diphenyl ethers (PBDEs) were measured in the blubber of 20 harbour porpoises stranded on the coasts of the southern North Sea between 2010 and 2013. The results showed that porpoises that died from infectious diseases displayed significantly higher levels of PCBs in their blubber compared to healthy porpoises that died from physical trauma. P 7CBs and P DDXs were higher in juvenile porpoises compared to adult females. Except for three individuals, PBDE concentrations were below the limit of quantification in the blubber samples treated. In general, levels of PCBs and DDXs obtained in the blubber of porpoises from this study were in the same order of magnitude or even lower than those obtained in the blubber of porpoises stranded along the North East Atlantic Ocean and the Black Sea over the period 1987 and 2013. The results of the present study suggest that even if the status of marine pollution has been improved, a continuous long-term contamination by toxic organochlorines over many generations may be observed. Environmental impactThis paper investigated organochlorine concentrations and proles in the blubber of stranded harbour porpoises (Phocoena phocoena) along the southern North Sea between 2010 and 2013. In the last decade, porpoise stranding has increased in French, Belgian and Dutch coastal waters. Since organochlorines are known to exert immunotoxicity in harbour porpoise individuals, special interest may be accorded to the contaminant levels in their organs and tissues. Based on the results, the paper relates polychlorinated biphenyls (PCBs) and dichlorodiphenyltrichloroethane (DDT) to the maturity status and the gender of stranded porpoises, along with the cause of death of porpoises whether it was a natural mortality or a death due to infectious diseases.

Contaminants in harbour porpoises beached along the Dutch coast : A first overview of contaminants in all age classes

“…Adult males possessed highest PCB concentrations due to PCB intake via all routes combined: placenta, lactation and diet, without the potential of offloading (figures 1 and 2). (present study andWeijset al, 2009 and and southern North Sea (Mahfouz et al, 2014 (Jepson e.a., 2016). Sample…”

“…This corresponds with earlier published levels of PCBs harbour porpoises in the UK (0.4 -160 mg/kg lw; Jepson et al, 2016) and North Sea (Table 5) (Weijs et al, 2009;Weijs et al, 2020;Mahfouz et al, 2014). Not enough samples were analysed per age group, sex and year to asses time Table 5 and Annex A).…”

Estrogenic Evaluation and Organochlorine Identification in Blubber of North Sea Harbour Porpoise (Phocoena phocoena) Stranded on the North Sea Coast

“…Metabolites play a dominant role if their persistence exceeds that of the parent product. Even though DDT was banned from utilisation in North America and Western Europe in the 1970s with no new input in the southern North Sea during the last decades [ 59 ], the breakdown products of DDT were still detected in the analyzed samples (DDE showing the highest concentrations). In fact, DDT is rapidly metabolised to DDD and slowly metabolised to DDE.…”

Modelling fine-scale distribution and relative abundance of harbour porpoises in the Southern Bight of the North Sea using platform-of-opportunity data

“…Since the early 1990s, the harbour porpoise ( Phocoena phocoena ) has made a significant return along the North Sea coasts of Europe due to a shift of their distribution from the northern to southern North Sea and it is currently the most abundant species of cetacean (Hammond et al ., 2002, 2013, 2017; Evans et al ., 2003; Reid et al ., 2003; Camphuysen, 2004, 2011; Kiszka et al ., 2004, 2007; Gilles et al ., 2011). However, in this region and across European Atlantic waters, the species faces multiple threats, particularly from by-catch in fishing nets (Vinther & Larsen, 2004; Siebert et al ., 2006; ICES, 2008; Jauniaux et al ., 2008; Gilles et al ., 2011; Haelters et al ., 2011), chemical (Mahfouz et al ., 2014 a , 2014 b ; Murphy et al ., 2015; Jepson et al ., 2016) and noise pollution from commercial boat traffic and wind farm development (Gilles et al ., 2009, 2011; Scheidat et al ., 2011), as well as seismic surveys and explosions of military ordnance (Von Benda-Beckman et al ., 2015). To maintain a favourable conservation status of the species (and other small cetaceans), a regional Agreement on the Conservation of Small Cetaceans in the Baltic and North Seas (ASCOBANS) was created in 1992, which was expanded over a wider region of the North-east Atlantic in 2008 (ASCOBANS, 2009; IJsseldijk et al ., 2018).…”