Carl Christian Kinze

Mercury, cadmium, zinc, copper and selenium in harbour porpoise (Phocoena phocoena) from West Greenland

Muscle, liver, kidney and skin samples taken from 78 harbour porpoises (Phocoena phocoena) were analysed for mercury, cadmium, zinc, copper and selenium. The highest concentrations of mercury were found in the liver (geometric mean 4.17 μg/g wet weight), whilst the highest concentrations of cadmium were in the kidney (g.m. 13.2 μg/g ww). The levels of cadmium were more than ten times higher than in harbour porpoises from the North Sea and the British NW coast, whilst the mercury levels were about the same. The importance of the cadmium content in the prey is discussed, but this attempt did not revealed the differences. Very high levels of zinc (g.m. 359 μg/g ww) and selenium (g.m. 28.6 μg/g ww) were found in skin samples, respectively seven and ten times more than in liver. A significant correlation was found between age and the level of mercury and cadmium in all organs. The concentration of mercury and selenium in liver and skin samples and of cadmium and zinc in kidney samples were highly correlated.

A combined DNA-microsatellite and isozyme analysis of the population structure of the harbour porpoise in Danish waters and West Greenland

One hundred and twenty-four specimens of the harbour porpoise, Phocoena phocoena, occurring in inner Danish waters (IDW), the North Sea and West Greenland were analysed to study subdivision into genetically differentiated subpopulations using PCR-amplified DNA-microsa-tellites and isozyme markers. Three polymorphic microsatellites, 415/416, 417/418 and Igf-I (insulin-like growth factor I) were detected with nine, eight and 15 alleles, respectively, and from a former study two polymorphic isozymes, Mpi-1 and Pgm, with three and two alleles, respectively, were used in the analysis. Overall deviations from the expected Hardy-Weinberg distribution were only observed in the total sample and at a single locus in the North Sea-summer sample and at two loci in the West Greenland sample. Whenever this occurred a surplus of homozygotes was observed, suggesting a Wahlund effect, a null allele or nonrandom mating. The analysis of the genetical population structure showed that harbour porpoises from West Greenland, the North Sea and IDW were three geographically, genetically differentiated populations even though connected through some degree of gene flow. A tendency for females to be more stationary than males was suggested. Furthermore, the population structure suggested a closer relationship between IDW and the North Sea.

Stomach contents of northern bottlenose whales Hyperoodon ampullatus stranded in the North Sea

This paper presents information on the stomach contents of four northern bottlenose whales Hyperoodon ampullatus (Odontoceti: Ziphiidae) from the north-east Atlantic, an area for which there are few recent data on the feeding ecology of this species. Two of these whales were relatively recent strandings, a female stranded in August 1993 at Hargen (the Netherlands) and a male stranded in February 1997 on the island of Tasinge (Denmark). Stomach content samples were also examined from a juvenile male stranded in November 1885 at Dunbar (Scotland) and a female stranded in August 1956 on the island of Texel (the Netherlands).  Food remains from the four samples consisted almost entirely of cephalopod beaks. Some fish remains were also found in the stomach of the Hargen and Tasinge whales, and the latter also had crustacean remains in the stomach. The cephalopod prey consisted mainly of oceanic cephalopods: Gonatus sp. (probably G. fabricii , Cephalopoda: Teuthoidea), Taonius pavo and Histioteuthis sp. for the Dunbar whale; Gonatus and Teuthowenia megalops for the Texel whale; Gonatus for the Hargen whale and Gonatus , T. megalops and Taonius pavo for the Tasinge whale. Other prey species found in the Tasinge specimen included the squid Histioteuthis reversa , H. arcturi , and the octopods Vampiroteuthis infernalis and Vitreledonella richardi . Based on the size of the lower beaks, the squid eaten included juvenile and mature individuals of the most important species ( Gonatus and Teuthowenia megalops ). The fish remains consisted of vertebrae of Gadidae and fish eye lenses (Hargen whale) and two Trisopterus otoliths (Tasinge whale).  The results from this study are in agreement with those of previous authors in that cephalopods in general, and G. fabricii in particular, are the main prey of the northern bottlenose whale and other toothed whales in northern latitudes.

Status, ecology and life history of harbour porpoise (Phocoena phocoena), in Danish waters

A review of historical harbour porpoise catches in Danish waters, together with current distribution, are provided. Most information on distribution is derived from historical catch data with a total of about 100,000 animals taken in Little Belt alone and 40,000 from Isefjord area during the 19th century. Recent sightings surveys and tagging indicate extensive movements of animals within and between Inner Danish Waters and the Skagerrak / North Sea. Biological information is reviewed for the region, drawing on directed catches, bycatches and strandings from a database comprising nearly 1,900 records from 1834 through 1998. Diet, parasites, pollutants, biological parameters (age and reproduction) and body condition are reported, focusing mainly on the period 1996-98 when comprehensive data were collected. In 1980s samples, gadoids were the most important prey items (found in 62% of stomachs) followed by clupeoids (35%), gobiids (30%), and ammodytids (30%). Some dietary differences were observed between North Sea and Inner Danish waters. Pollutant analyses indicated a decline in sumDDT concentrations yet an increase in sumPCB and HCH levels in Danish porpoises, with comparatively higher levels here than in Baltic and Norwegian waters. Heavy metal concentrations appear higher than in Baltic porpoises. Biological parameters indicate a longevity of up to 23 years in both sexes but with fewer than 5% living beyond 12 years. Sexual maturity occurred at slightly over age 3 years in both females and males, with corresponding lengths of about 135 cm in males and 143 cm in females. The data indicate a size range at birth of 65 - 75 cm (weight 4.5 – 6.7 kg), with a minimum of 60 cm and 3.4 kg, and a likely gestation time of 10 months. Conception most likely occurs during August, with peak births in June. Directed catches comprised adult animals whereas bycaught and stranded porpoises comprised predominantly juveniles. In data from all sources, males outnumbered females. Directed catches occurred in winter months, strandings year-round with a peak in late summer, and bycatches year-round with most in September and the later part of the year.

Stable Isotopes Provide Insight into Population Structure and Segregation in Eastern North Atlantic Sperm Whales

In pelagic species inhabiting large oceans, genetic differentiation tends to be mild and populations devoid of structure. However, large cetaceans have provided many examples of structuring. Here we investigate whether the sperm whale, a pelagic species with large population sizes and reputedly highly mobile, shows indication of structuring in the eastern North Atlantic, an ocean basin in which a single population is believed to occur. To do so, we examined stable isotope values in sequential growth layer groups of teeth from individuals sampled in Denmark and NW Spain. In each layer we measured oxygen- isotope ratios (δ18O) in the inorganic component (hydroxyapatite), and nitrogen and carbon isotope ratios (δ15N: δ13C) in the organic component (primarily collagenous). We found significant differences between Denmark and NW Spain in δ15N and δ18O values in the layer deposited at age 3, considered to be the one best representing the baseline of the breeding ground, in δ15N, δ13C and δ18O values in the period up to age 20, and in the ontogenetic variation of δ15N and δ18O values. These differences evidence that diet composition, use of habitat and/or migratory destinations are dissimilar between whales from the two regions and suggest that the North Atlantic population of sperm whales is more structured than traditionally accepted.

Population structure of harbour porpoises in the Baltic region: evidence of separation based on geometric morphometric comparisons

The harbour porpoise is seriously depleted and threatened with extinction in the Baltic Sea. It is usually assumed that Baltic porpoises form a separate population unit, although the evidence for this has been disputed lately. Here, a 3-D geometric morphometric approach was employed to test a number of hypotheses regarding population structure of the harbour porpoise in the Baltic region. 277 porpoise skulls from Denmark, Sweden, Finland, Germany and Poland were measured with a suite of 3-D landmarks. Statistical analyses revealed highly significant shape differences between porpoises from the North Sea, Belt Sea and the inner Baltic Sea. A comparison of the directionalities of the shape vectors between these units found differences that cannot be attributed to a general, continual shape trend going from the North Sea to the inner Baltic Sea. These vectors indicate a morphological adaptation to the specific sub-areas. Such adaptation may be the result of the topographic peculiarities of the area with variable topography and shallow waters, e.g. in the Belt Sea porpoises, there may be a greater reliance on benthic and demersal prey. The present results show that isolation by distance alone is an unlikely explanation for the differences found within the Baltic region and thus support previously reported molecular indications of a separate population within the inner Baltic Sea.

Temporal and life history related trends of perfluorochemicals in harbor porpoises from the Danish North Sea

Eighty-five stranded or bycaught harbor porpoises collected from the Danish North Sea between 1980 and 2005 were analyzed for perfluorochemicals in the liver. PFOS was the predominant compound, making up on average 88.9% of the ∑PFC, followed by PFOSA (7.8%). PFUnA (1.9%) and PFDA (1.2%) were detected in most samples. PFHxS, PFNA and PFOA were only found in a minority of the samples. We found substantial differences in PFC concentrations among life history stages, the highest concentrations were found in neonates, suckling juveniles and lactating females. Such differences should be considered when PFC levels in wildlife are evaluated. The high concentrations found in young porpoises are of concern as PFCs have known toxic effects on the development of the central nervous system and reproductive organs. Despite efforts to reduce PFC emissions, a decreasing temporal trend of concentrations was not detected for any compound. PFCA concentrations were found to be increasing.

OCCURRENCE OF VERTEBRAL OSTEOPHYTOSIS IN A MUSEUM SAMPLE OF WHITE-BEAKED DOLPHINS (LAGENORHYNCHUS ALBIROSTRIS) FROM DANISH WATERS

The occurrence of pathologic new bone formation in the vertebral column was studied in 46 skeletons of the white-beaked dolphin (Lagenorhynchus albirostris) stranded in Denmark between 1903 and 2002 and held in the collections of the Zoological Museum, University of Copenhagen. New bone formation was evident in 18 (72%) of 25 physically mature specimens and in one of 21 physically immature specimens. This pattern of occurrence is consistent with spondylosis deformans, which is caused by degeneration of the intervertebral disk. In general, females seemed to be more susceptible, exhibiting a higher number of affected vertebrae and more severe cases. Lesions were predominantly detected in the lumbar and cranial caudal vertebra. Data on blubber thickness were available for part of the sample; one of the most heavily afflicted specimens had the thickest recorded blubber, indicating that secondary bone formation leading to blocks of fused vertebrae had not necessarily impaired the body condition of afflicted specimens. However, age determinations conducted on the sample revealed that none of the most severe cases occurred among the oldest animals, implying that these severe cases may cause premature fatality.

Preliminary results of a DNA-microsatellite study of the population and social structure of the harbour porpoise

Abstract A total of 106 specimens were used in the analysis of the subdivision into genetically differentiated subpopulations of the harbour porpoise, Phocoena phocoena , occurring in inner Danish waters (IDW), North Sea and West Greenland using PCR amplified DNA microsatellites. To date, two polymorphic microsatellites, 417/418 and insulin-like growth factor-I (IGF-I), were detected, consisting respectively of 8 and 15 alleles. Deviations from the expected Hardy-Weinberg distribution were observed at the IGF locus in the North Sea sample and subsamples from the North Sea, and in the West Greenland male sample. All the North Sea samples showed a surplus of homozygotes which could be explained by a Wahlund effect; the mixing of several subpopulations or non-random mating illustrated bystraying males from different breeding areas in the North Sea. The analysis of the genetical population structure performed by Monte-Carlo simulations showed that harbour porpoises from West Greenland are geographically differentiated from harbour porpoises in IDW and North Sea. It was not possible with the present sample size and number of microsatellite loci to differentiate between harbour porpoises in IDW and the North Sea.

Vertebral column deformities in white-beaked dolphins from the eastern North Atlantic.

Five white-beaked dolphins Lagenorhynchus albirostris with outwardly vertebral kyphosis, kyphoscoliosis or lordosis were identified during a photo-identification survey of over 400 individuals (2002-2013) in Faxaflói and Skjálfandi Bays, Iceland. In addition, 3 stranding reports from Denmark, The Netherlands and the UK were analysed, providing both external observation and post mortem details of axial deviations of the vertebral column in this species. Two of the free-ranging cases and 2 of the stranded specimens appeared to have an acquired disease, either as a direct result of trauma, or indirectly from trauma/wound and subsequent infection and bony proliferation, although we were unable to specifically identify the causes. Our data represent a starting point to understand vertebral column deformations and their implications in white-beaked dolphins from the eastern North Atlantic. We recommend for future necropsy cases to conduct macro- and microscopic evaluation of muscle from both sides of the deformed region, in order to assess chronic or acute conditions related to the vertebral deformations and cause of death.