Evening folks, thank you all for your help so far, only need these few now:
11. Monks and Royalty fed on these (7,4) 20. Main character in Graham Green's famous novel (4) 29. Small freshwater fish (6) 39. Has distinctive camouflage stripes (8) 43. Gave its name to a village near Grange over Sands (8) 44. Marine cricket (10) 45. Can be seen on a ebb tide (5,5)