Sentence:  It is well known, for instance, that the superiority of the herrings caught in the inland sea-<WSD>lochs</WSD> of Scotland is owing to the fish finding there a better feeding-ground than in the large and exposed open bays. Look, for instance, at Lochfyne: the land runs down to the water's edge, and the surface water or drainage carries with it rich food to fatten the <WSD>loch</WSD>, and put flesh on the herring; and what fish is finer, I would ask, than a Lochfyne herring? 
Meaning of the word marked with <WSD> tags:  A bay or arm of the sea.