In summarizing the main results on recruitment that emerged from the series of Flatfish Symposia, two aspects were distinguished: mean level and interannual variability. Recruitment to a stock appears to be related to the quantity of juvenile nursery habitats, suggesting that either larval supply or the carrying capacity of the nurseries is the limiting factor. However, available information on growth of 0-group flatfish suggests that the carrying capacity of nursery areas is never reached. Variability in year-class strength is generated during the pelagic egg and larval stage, probably by variations in the hydrodynamic circulation and in the mortality rates of eggs and larvae. Density-dependent processes seem to occur only during the juvenile stages, particularly in respect of growth. However, no impact on recruitment variability has been found. Density-dependent mortality during the phase shortly after settlement dampens the interannual recruitment variability. There is no evidence of densitydependent effects in the adult phase at present, but these may have been important at lower levels of exploitation. The importance of the factors determining recruitment vary not only among species, but also over the species' range. It is suggested that damping processes can only occur in the demersal stage, implying that variability in year-class strength can only decrease in fish species with a demersal stage. If true, ultimate variability in recruitment in fish species will be related to the relative duration of the pelagic and demersal stages. 2000 International Council for the Exploration of the Sea

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The results from 3 different rogrammes concerning by-catch mortality in shrimp fisheries are reported. Mortalities increased consigrably after the catch passed the sorting sieve. 100 mortality was detected for whiting (Merlangius merlungus). Mortalities were about 10 % for sculpin (Myxocephalus scorpius), hooknose (Agonus catupbractus), and eelpout (Zoarces viviparus) in the discard fraction. Survival of flatfish depended strongly on the species, the size of the s ecimens as well as the catch and catch processing conditions, and ranged from 17 to 100%. No difirences could be detected in the survival after sorting on different machines. However, due to better sorting efficiency, the rotary sieve may reduce mortality of fish in the by-catch. Zusammenfassung Sterblichkeit von Fischen aus dem Beifang von Garnelenkuttern in tier NordseeEs werden die Ergebnisse von 3 verschiedenen Untersuchungsprogramrnen zur Beifan sterblichkeit in der Garnelenfischerei mitgeteilt. Die Sterblichkeit nahm betrachtlich zu, wenn der Beikng das Sortiersieb passiert hatte. 100 % Sterblichkeit wurde fur Wittlinge (Merlangius rnerlangus) ermittelt. Fur Seeskorpione (Myoxocephalus sco ius), Steinpicker (A onus cataphranus) und Aalmuttern (Zoarces viviparus) lag die Sterblichkeit in $r Discard-Fraktion i e i 10 %. Die Uberlebensraten bei Plattfischen waren stark von der jeweili en Art, der GroRe derTiere, wie auch vom Fang und der Fangbearbeitung abhangig und bewegten sici zwischen 17 und 100%. Es konnten keine Unterschiede in den Uberlebensraten nach der Sortierung mit verschiedenen Maschinen festgestellt werden. Allerdin s kann der Trommelsonierer aufgrund seiner besseren Sortiereigenschaften die Sterblichkeit im Beifang herabsetzen.