Possible Clues:

• Empty trawler, away for fish
• Try to persuade of the merits of importing river fish
• Fish dish served after short time
• Fish left part of Thames by Waterloo?
• Jog round university to find fish
• Angler's catch
• Swimmer's brisk pace round bend
• Test not unknown for fish
• Lake denizen, and hint to this puzzle's theme
• Fish found in Thames, initially west of Waterloo