be kept behind by 〜
「〜によって後手にまわされた」的な意味?「〜の後に続いて」的な意味?
What happened in 2008?
The summer saw heavy rain which affected this year's Salmon migration. From the data, it seems there were two distinct Salmon migrations - those that pressed ahead early on and those that were kept behind by the large volume of fast-flowing water. Our first tagged Salmon, named Wylam, was sadly caught by an angler over the summer but our other two Salmon, Hadrian and Corrie made very slow progress up the Tyne, probably in a bid to conserve energy.
