The data set comprises measurements of contaminant concentrations in the blubber of harbour seals. Samples were collected from five populations around the UK coast: the Wash, southeast England; the Tay estuary, southeast Scotland; the Moray Firth, northeast Scotland; Orkney, north Scotland; and Islay and Jura, southwest Scotland. The data were collected between 24 January and 26 October 2003. Seals were captured on land, hauled out with the use of hand-held hoop nets, or caught at sea in tangle nets deployed from boats. After capture, the seals were weighed and sedated, and classified as adult or subadult on the basis of mass and body length measurements. Animals greater than 110 cm standard body length (nose–tail) were considered to be adult and those between 100 and 110 cm as subadult. Animals less than 100 cm were excluded from the study. One dead seal was also included in the analysis. Blubber biopsy samples were collected and stored at -20 °C, then extracted using the Soxhlet method. Lipid content was determined gravimetrically while Gas Chromatography-Mass Spectrometry (GC-MS) was used to determine wet weight concentrations of contaminants per lipid proportion of the sample. The work focused on polybrominated diphenyl ether (PDBE) and polychlorinated biphenyl (PCB) concentrations in seal blubber. PBDEs are the main components of brominated flame retardant chemicals, and both these and PCBs are thought to increase seal mortality. The five seal populations were chosen following differential mortality during the 2002 phocine distemper epidemic in order to determine whether contaminant concentrations had influenced mortality rates associated with that disease. The data were collected by researchers from the Sea Mammal Research Unit (SMRU) at the University of St Andrews and the University of Lancaster Department of Environmental Science. The data are held at the British Oceanographic Data Centre (BODC).

The data set comprises measurements of contaminant concentrations in the blubber of grey seal pups. Samples were collected on the Isle of May, Firth of Forth, East Scotland between 13 November and 02 December 2002. Sixty suckling pups were selected at random from the island's population, weighed, measured and tagged. Pups were recaptured repeatedly before and after weaning, with weight, length and axillary girth being re-measured each time. These measurements were used to estimate blubber reserves based on mass/length, as detailed in Hall et al. (2009). Linear regression was used to derive estimates of pup mass at weaning. Blubber biopsy samples were collected from 57 of the pups when they were first recaptured after weaning. Samples were stored at -20 °C, then extracted using the Soxhlet method. Lipid content was determined gravimetrically while Gas Chromatography-Mass Spectrometry (GC-MS) was used to determine wet weight concentrations of contaminants per lipid proportion of the sample. A linear back calculation based on the known rate of contaminant concentration in blubber post-weaning was used to correct values to the concentration at weaning. The data were collected by researchers from the Sea Mammal Research Unit (SMRU) at the University of St Andrews and the University of Lancaster Department of Environmental Science. The data are held at the British Oceanographic Data Centre (BODC).

The impacts of Persistent Organic Pollutants (POPs) are assessed in fat tissue (blubber) using live explant samples from young grey seals (Halichoerus grypus) on the east coast of Scotland. The data show POP levels in blubber and responses to intrinsic pollutants and experimental exposure to polychlorinated biphenyls (PCBs), relevant due to its applicability to other species, including humans. The study sites are located on the Isle of May (56° 10’ 57” N, 02° 33’ 17” W) between October and December 2015, 2016, and 2017, where the grey seal population had been monitored annually and from where previous POP data from blubber tissue was investigated in 2002. A second sample set was collected from yearling grey seals hauled out on the Isle of May, Moray Firth, and Culbin Sands (57° 39’10” N, 03° 43’ 15” W) and maintained in temporary captivity at the Sea Mammal Research Unit between February and August 2018. The capture and explant data includes animal identifier, moulting state (where relevant for yearlings), whether the animal was fed or fasted (where relevant for pups), body and sample tissue mass. Characteristics of the animals like sex, birth, and weaning date (where known), rate of mass change, life history stage and blubber fat content, including intrinsic blubber POP levels, were measured at the Centre for Analytical Research and Technology at the University of Liège, Belgium to be used as covariates in a Generalised Additive Mixed Model (GAMM). This analysis was undertaken after accelerated solvent extraction of the samples in hexane dichloromethane (Dionex 200 by Thermo Fisher Scientific) and the extracts were analysed using a gas chromatograph (Agilent 6890 GC) coupled to Autospec Ultima High-Res Mass Spectrometer. The response of explants was tested through measurement of gene expression (using the Stratagene Mx3000P qPCR System or StepOne Plus Real-Time PCR System), insulin signaling and glucose uptake, lactate production, oxygen consumption and lipolytic rate using Randox Monza assays. Thyroid hormones triiodothyronine (TT3) and thyroxine (TT4) were measured using Enzyme Linked Immunosorbent Assays (ELISA Fortress Diagnostics Ltd). The live explants were treated overnight with a mix of PCBs and organochlorine pesticide derivatives (DDT, DDE), which were associated with altered metabolic function symptoms such as glucose uptake and lactate production in 2015-2017. The data will facilitate an understanding of the molecular mechanisms of contaminant-induced disruption of energy balance by legacy pollutants in seals during their most vulnerable life stages. The data collection was led by Dr Kimberley Bennett from Abertay University and funded by the NERC Discovery Science project “Obesogens in a naturally obese animal: An experimental approach to assess the impact of marine pollutants on fat tissue function in seals”, parent grant reference NE/M013723/1 with child grant NE/M01357X/1.

The Marine Environment Monitoring and Assessment National database (MERMAN) is a national database which holds and provides access to data collected under the Clean Safe Seas Environmental Monitoring Programme (CSEMP) formerly the National Marine Monitoring Programme (NMMP). The data collected are the responsibility of the Competent Monitoring Authorities (CMAs) who collect the samples from stations in UK waters using water sampling techniques, trawls, nets or grabs. The CMAs then send the collected samples to accredited laboratories where they are analysed. A weighting is calculated, based on the quality of the analysis. The weighting score incorporates the laboratory accreditation, reference material, inter-laboratory comparisons, detection limits, uncertainties and standard deviations. Where data do not meet a threshold score they are given a status of ‘FAIL’ and although they are stored they are not made available to external users. The MERMAN dataset starts in 1987 with greater use of the database occurring from 1997 onwards. Data are submitted by the CMAs annually and an annual submission may include updates to legacy data to provide additional data or improve data/metadata. The data held in MERMAN fulfils the UK's mandatory monitoring requirements under the Oslo and Paris Convention (OSPAR) Joint Assessments and Monitoring Programme (JAMP). These data are used in support of European Commission (EC) directives and national assessments, such as Charting Progress 2 and are also supplied to the European Marine Observation and Data Network (EMODNET).