A number of changes were observed subsequent to fertilisation at uswayford. There was an increase in the relative abundance of Fragilaria spp. in Usway Burn (Fig. 3b); however, this change was mirrored in the River Alwin so cannot be attributed to fertilisation. By contrast, there was a dramatic increase in the relative
abundance of Epithemia in Usway Burn. Prior to fertili-sation, only a single valve of Epithemia was recorded in Usway Burn, but both E. turgida and E. sorex became abundant from August onwards, constituting up to 40% of the total count (Fig. 3c). Throughout this period, only one valve of Epithemia was recorded in the River Alwin.
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