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We es t~mated the mortality of hatchery-raised pink Oncorhynchus gorbuscha and chum 0 keta salmon fry from seabird predation near a salmon hatchery In Lake Bay, Prince William Sound, Alaska, USA. Fleld counts of seabirds and observations of feeding rates for plunge-diving seabirds were obtained durlng salmon fry releases between Apnl and June 1995. Several hundred birds of 7 piscivorous species aggregated in front of the hatchery. Consumption rates were determined from focalanimal sampling and energetic models. For most species, per capita consumption rates based on behavioral data were lower than those calculated from energetic considerations. From energetic models and fry movement rates, w e estimated that 2.7 to 5.9 million juvenile salmon (1.1 to 2.4 "" of released fry) were consumed during the study period. Differences between the energetics models accounted for 64 % of this range; assumptions about fry movement rates accounted for the remainder. Gulls recorded during aerial surveys throughout Prince William Sound were significantly associated with s p a w n ~ n g herring and hatchery sites, but not with miles of coast with herring spawn present. The correlation of bird aggregations with the presence of these small fish indicates that concentrations of prey fish have an important influence on the distribution of birds at sea during this time of the year. Bird numbers in both boat counts and aerial surveys declined from early May to early June. Taken together, these results lndlcate that salmon fry just entering the marine environment were not especially susceptible to avlan predation Thelr vulnerability to predation was apparently buffered by the presence of other attractlve food patches within seabird foraging range early in our study period, and by declines in the numbers of seabirds foraging along the shoreline later In the study.

Mitogen-activated protein kinase (MAPK) cascades are universal and highly conserved signal transduction modules in eucaryotes, including plants. These protein phosphorylation cascades link extracellular stimuli to a wide range of cellular responses. However, the underlying mechanisms are so far unknown, as information about phosphorylation substrates of plant MAPKs is lacking. In this study we addressed the challenging task to identify potential substrates for Arabidopsis thaliana mitogen-activated protein kinases 3 (MPK3) and 6 (MPK6), which are activated by many environmental stress factors. For this purpose, we developed a novel protein microarray-based proteomics method allowing high-throughput study of protein phosphorylation. We generated protein microarrays including 1,690 Arabidopsis proteins, which were obtained from the expression of an almost nonredundant uniclone set derived from an inflorescence meristem cDNA expression library. Microarrays were incubated with MPKs in the presence of radioactive ATP. Using a threshold-based quantification method to evaluate the microarray results, we were able to identify 48 potential substrates of MPK3 and 39 of MPK6. 26 of them are common for both kinases. One of the identified MPK6 substrates, 1-Aminocyclopropane-1-carboxylic acid synthase-6 (ACS-6) was just recently shown as the first plant MAPK substrate in vivo, demonstrating the potential of our method to identify substrates with physiological relevance. Furthermore, we revealed transcription factors, transcription regulators, splicing factors, receptors, histones and others as candidate substrates indicating that regulation in response to MAPK signaling is very complex and not restricted to the transcriptional level. Nearly all of the 48 potential MPK3 substrates were confirmed by other in vitro methods. As a whole, our approach allows to shortlist candidate substrates of MAP kinases as well as those of other protein kinases for further analysis. Follow-up in vivo experiments are essential to evaluate their physiological relevance