Åsa Enefalk

Karlstads Universitet · Department of Environmental and Life Sciences

1. Predator-prey interactions are one of the main ecological factors influencing the structure of fish communities. The impact of wading and diving semi-aquatic predators on riverine fish populations is poorly known. We studied the effect of feral American mink predation on brown trout juveniles during winter in two experiments conducted in semi-na...

In this study, the growth rate, gut fullness, diet composition and spatial distribution of brown trout was compared between artificial channels with and without fine wood (FW). Access to FW resulted in significantly lower brown trout growth rates over the study period from late summer to early winter as water temperatures declined from 17 °C to 1 °...

In boreal streams, juvenile salmonids spend substantial amounts of time sheltering in the streambed and in stream wood, presumably as a means of protection against the physical environment and from terrestrial endothermic predators. Relatively little is known about sheltering by salmonids in response to instream ectothermic predators. We tested the...

Most studies of stream wood have focused on pieces ≥0.1 m diameter. However, this approach may overlook an important feature of small streams, where wood <0.1 m can constitute the majority of wood pieces. We examined the effect of fine wood (FW) on local drift of stream macroinvertebrates. The study was carried out at seven sites in four boreal for...

In-stream wood can increase shelter availability and prey abundance for stream-living fish such as brown trout, Salmo trutta, but the input of wood to streams has decreased in recent years due to harvesting of riparian vegetation. During the last decades, fine wood (FW) has been increasingly used for biofuel, and the input of FW to streams may ther...

Surface ice in rivers and lakes buffers the thermal environment and provides overhead cover, protecting aquatic animals from terrestrial predators. We tested if surface ice influenced the behavior (swimming activity, aggressive encounters, and number of food items eaten) and stress level (coloration of eyes and body) of stream-living brown trout Sa...

In order to develop a sustainable society, tools are needed to analyze the relationships between human activities and ecosystems and to estimate the carrying capacity of the natural resource base. In this paper, energy analysis is applied in a study of the small island society Nämdö in the Stockholm archipelago, Sweden. Nämdö has a permanent popula...