We monitored yearly recruitment (1997)(1998)(1999)(2000)(2001)(2002)(2003)(2004)(2005)(2006)(2007)(2008) of brown trout (Salmo trutta) in a fourth-order Austrian Alpine river. The relative proportion of recruits to adult fish varied strongly among years (5.6-66.4%). These proportions were strongly correlated with specific flow patterns. High flows before and during the spawning period were positively correlated with recruitment, whereas high flows during incubation and emergence were negatively correlated with recruitment success. Unsteady flow modelling supported a causal hypothesis for these relationships in demonstrating that discharges > 30 m 3 AEs )1 resulted in substantial sediment motion (erosion and deposition) in suitable spawning areas within the study stretch.

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Brown trout populations of three headwater streams in the Northern Limestone Alps of Austria were supplemented by three-month-old hatchery-reared parr from a wild and locally adapted strain and a nonresident domesticated hatchery strain. Growth and survival were monitored with three surveys over a period of 16 months after stocking. Fish descending from the wild reared origin strain demonstrated higher survival rates than the hatchery strain. Differences in growth were found among the investigated streams but not among the investigated strains. The differing temperature regimes of the streams were considered as the primary factor causing those disparities. We conclude that stocking measures had little or no additive effect on successful natural reproduction, as the resident wild brown trout performed significantly better than the stocked fish. K E Y W O R D Sbrown trout, stocking experiment, genetic background, growth, survival | 147

In East Africa, wetlands are steadily converted to agriculture for food security reasons. This study analyzed high spatial resolution panchromatic and color photographs in the Anyiko wetland in Kenya to reveal wetland conversions between 1966 and 2018. In addition, socioeconomic determinants of land use/cover change are assessed in the Anyiko wetland. Socioeconomic data was collected through a questionnaire survey of 226 households. A Chi-squared Automatic Interaction Detector (CHAID) decision tree approach is utilized to assess determinants of wetlands conversion. The results showed that between 1966 and 2018, the wetland area reduced by 55%, mostly attributed to agricultural development. Households were more likely to cultivate the wetland if they did not harvest papyrus for artisanal products, were male-headed and lacked alternative sources of income. The perceptions that wetland is "wasteland" and conversion to agriculture provides higher net monetary benefit did not influence wetland cultivation. Hence, the conversion of the wetland was determined by the socioeconomic status of the households rather than perceptions on its value.