Sentence:  Turning now to more <WSD>lotic</WSD> environments, Norelius (1967) and Bronmark and Malmqvist (1982) have studied populations of "Anodonta anita" and "Unio pictorum" inhabiting Swedish lake outlets. 
Meaning of the word marked with <WSD> tags:  Characterised by flowing water; swiftly flowing; concerned with flowing rivers, streams, etc.