Joe Crowley is on the south Devon coast, the stunning English Riviera where disco scallops are the talk of the town. A chance discovery that they react to lights could revolutionise scallop fishing. Joe also discovers how new technology can reveal some watery wonders without having to put a toe in the sea, and we meet the farming brothers who've turned to aquaponics. Adam Henson meets the two final contenders going for glory in One Man and His Dog. For Scotland, it's veteran Sandy and his dog Sam, while Dewi and Jock run for Wales. John Craven catches up with the winner of Countryfile's 2023 Calendar in aid of Children in Need, and we meet young Riley, who doesn't let a rare lung condition stand in his way of conquering the world.