Plastic debris as nesting material in a Kittiwake-(Rissa tridactyla)-colony at the Jammerbugt, Northwest Denmark.

This paper continues the investigations of Clemens and Hartwig from 1992 on the proportion of garbage used as nesting material in the Kittiwake colony at Bulbjerg in the Jammerbugt in Northwest Denmark. Whereas in the year 1992 plastic garbage items were included in 39.3% of 466 Kittiwake nests in the Bulbjerg colony, in 2005 57.2% of 311 nests contained plastic debris. Although it has been forbidden to dispose of plastic garbage into the marine environment since the implementation of the MARPOL 73/78-Agreement/Annex V (Regulation for the Prevention of Pollution by Ship Waste) of 1989 and especially since the declaration of the North Sea as a MARPOL-Special Area for garbage in 1991, the pollution of the oceans and the North Sea is still an ubiquitous problem, particularly with regard to plastic waste. Plastic waste is presumably not used preferentially for nest-building, but in the context of available nesting material in the waters surrounding the breeding colony. Therefore the share of garbage parts in nests of certain species of birds is an indicator of the amount of waste in the natural environment in the vicinity of their breeding site.

Statistical analyses of the results of 25 years of beach litter surveys on the south-eastern North Sea coast.

In the North Sea, the amount of litter present in the marine environment represents a severe environmental problem. In order to assess the magnitude of the problem and measure changes in abundance, the results of two beach litter monitoring programmes were compared and analysed for long-term trends applying multivariate techniques. Total beach litter pollution was persistently high. Spatial differences in litter abundance made it difficult to identify long-term trends: Partly more than 8000 litter items year(-1) were recorded on a 100 m long survey site on the island of Scharhörn, while the survey site on the beach on the island of Amrum revealed abundances lower by two orders of magnitude. Beach litter was dominated by plastic with mean proportions of 52%-91% of total beach litter. Non-parametric time series analyses detected many significant trends, which, however, did not show any systematic spatial patterns. Cluster analyses partly led to groupings of beaches according to their expositions to sources of litter, wind and currents. Surveys in short intervals of one to two weeks were found to give higher annual sums of beach litter than the quarterly surveys of the OSPAR method. Surveys at regular intervals of four weeks to five months would make monitoring results more reliable.

Investigations on the ecophysiology of Geleia nigriceps Kahl (Ciliophora, Gymnostomata) inhabiting a sandy beach in Bermuda.

The dominant ciliate species Geleia nigriceps inhabiting a sheltered beach in Bermuda was characterized by its horizontal and vertical distribution on the beach in correlation with sediment composition and grain size, temperature, pH, oxygen, redox potential, and water coverage, its tolerance of high and low temperature under normoxic and oligoxic conditions, and its tolerance of extreme pH-values.From tolerance experiments it can be concluded that G. nigriceps is able to tolerate relatively high temperatures (up to 37.3°C) for only short time (e.g., when low tide occurs around noon on hot days).This species, inhabiting both the oxidized and the reduced milieu below the redox potential discontinuity layer of the beach, is only to a small degree dependent upon oxygen availability and can be regarded as a more or less habitual dweller of anoxic or oligoxic sediments. The functions relating LT50 and exposure time were almost identical for normoxic and oligoxic conditions.Tolerance experiments revealed that pH values from 8.2 to 9.6 present no obstacle to G. nigriceps in its occupation of the upper millimeters of the sediment. In addition, it could be demonstrated that pO2 has no effect on the tolerance of alkaline conditions.The vertical pattern of distribution of G. nigriceps correlated with water coverage during one period of outgoing tide suggests vertical migration. The upper sediment layer is more densely colonized than the lower ones at stations where water coverage exceeds 45%. A highly significant correlation exists between the population density of the upper centimeter and water coverage.