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The recent increase in temperature and freshwater runoff in the Arctic will influence the functioning of the plankton ecosystem and hence the life of the fish larvae residing in these areas. Here, we studied the strength of physical–biological linkages and the adaptability of individual larval fish species to changing hydrographical and feeding environments in a sub-Arctic area in Greenland. The study was carried out along a transect covering a wide range of physical conditions from the deep ocean to the icecap in the Godthåbsfjord on the south-western Greenland coast. Along the transect, we identified a series of distinct zooplankton and larval fish assemblages which showed linkage to water mass characteristics, to the presence of frontal structures and to availability of preferred prey. Spawning site location and water circulation was also likely to influence distributional patterns of the individual larval fish species. Larvae were feeding on a variety of prey taxa and sizes; some larval species were generalists, while others were more specialized or fed on alternative prey taxa. Differences in feeding strategies might have the consequence that the species will be differently affected by changes in the plankton community. Accordingly, fish larvae that have a greater feeding flexibility and that are more adaptable to environmental variability may cope better with climate related changes. [ABSTRACT FROM PUBLISHER]

Along the west coast of Greenland several fish species spawn across a wide latitudinal range encompassing significantly different environments. In an evaluation of the constraints to fish early life in high latitude ecosystems, we compared larval feeding and growth rates of an important species from the areas, the capelin (Mallotus villosus), at two latitudinal distant localities: the subarctic Kapisigdlit Fjord (64°25′N) and the arctic Disko Bay (69°15′N). In these areas, we describe oceanography by series of CTD casts and zooplankton and capelin larvae by fine-meshed nets. Zooplankton abundance and diversity were subsequently described and related to feeding and growth rates of the capelin larvae, assessed from analyses of larval gut contents and otolith ring-patterns. Early life characteristics of larvae differed markedly between the two areas. The onset of zooplankton production and the emergence of larvae took place earlier in Kapisigdlit than in the more northern Disko Bay. In Kapisiglit Fjord the dominant prey items for larvae were small calanoid and cyclopoid copepodites while large-sized calanoid nauplii dominated in the diet of Disko Bay larvae. Larval growth rates were lower in Kapisigdlit Fjord than in Disko Bay. We suggest that the later emergence of capelin larvae in Disko Bay could be compensated by enhanced feeding and thus growth rates, so that larvae from both populations would reach comparable sizes when entering the overwintering phase. However, while larval emergence and onset of plankton production are linked to different environmental cues (temperature increase vs light increase), a former match between emergence of larvae and preferred prey might be disrupted by the present temperature changes in the Arctic. • First comparison of early life of capelin (Mallotus villosus) in two latitudinal distant localities in west Greenland. • Spawning was earliere in the southern locality. • Different zooplankton community in the two localities. • Faster larval growth rate at the northern locality. • Same sizes when entering the overwintering phase. [ABSTRACT FROM AUTHOR]