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In the collaborative study, no deciding differences were observed between the two candidate ELISAs. Further comparison under conditions simulating the intended use combined with the criterion of long-term availability enabled the selection of one Bet v 1-specific ELISA for proposal as European Pharmacopoeia standard method.

A large-scale spatial (52 sampling stations in two areas; one previously affected by numerous sources of enrichment, and one pristine area used as a standard reference for coastal monitoring) and temporal ( 1972-1 989) analysis of hydrography and benthic macrofauna in the archipelago waters of Aland, northern Baltic Sea, revealed significant changes of the ecosystem. The nutrient levels exceeded the criteria for eutrophicated waters at all stations, and the benthic macrofauna showed significant alterations in all parameters analyzed. In the area previously (1972-73) disturbed, reduced complexity in terms of diversity and evenness (i.e. functional responses) were recorded, whereas the changes in the previously undisturbed area are classified as structural. The main conclusions are that (a) no truly "natural" coastal reference areas can be found in the northem Baltic, and (b) the importance of the local effluents will add to the large-scale effects of eutrophication.

Abstract. Aquarium experiments were performed to test for critical oxygen levels in relation to the predation efficiency of C. crangon. Short‐term (60 h) experiments where done in normoxia (> 95%). 50, 40.30, and 20% oxygen saturation with the amphipod Bathyporeiapilosa as prey. A significantly reduced predation rate was detected at 30% oxygen. Sublethal effects of C. crangon on adult Macoma balthica (mainly by siphon cropping) were studied by measuring the condition of the clams (morphometric, somatic, and biochemical). To test for these effects experiments were conducted under normoxia and moderate hypoxia (40% oxygen); Condition and siphon indices revealed no change in condition after a 3‐week exposure to moderate hypoxia, while a significant reduction in the condition of adult clams was found in both normoxia and hypoxia when subjected to siphon cropping by C. crangon. No enhanced siphon cropping could be detected due to hypoxia. The results indicate that C. crangon is able to maintain its predatory role until a level of 30% oxygen in short‐term exposure. After a 20% oxygen level, however, the abiotic stress alters the functional role of C. crangon as a predator, indicating a threshold of 20–302 oxygen for the normal functioning of the predator‐prey food webs.

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