Rönne River is excellent for canoeing and you can rent them in town (walking along the river you will see how popular it is). Glide through the quiet river landscape shown in so many other pictures on this page and enjoy the Scanian Amazones at your own pace, maybe paddle all the way to the beach (where another company has canoes for rent) for a swim. Renting canoes early in the day is also a good way to spot rare birds.
Of course a seaside town with a good river has to have fish. You need to have a card to be allowed to fish, and this can be bought at the tourist office or by the local taxi company to name a few. It comes in a cheap day version or you can buy for a week, a month or a season. Skåne Marin can let you a boat if you call 0431-203 00 and you can fish for salmon, perch, pike and some other fish along the 5 kilometres from the river mouth and back towards town. Fly fishing, spinning or the traditional way are all fine once you have your card.
One of Scania's if not the south of Sweden's most important bird areas, the Rönne River between Ängelholm town centre and the mouth by the Skälder Bay are a few precious kilometres where you can be spoilt with kingfishers and other rare birds. Important enough to be put on the international Ramsar list. Just make sure you are early (or later) as the sightseeing boat and all other pleasure boats on a sunny day will scare the wildlife away. If you are early, you might also be rewarded by deer coming to drink. You could rent a canoe (see below) for a more independent view.
As I said in the intro, Ängelholm has one of the best beaches in the entire Scania. Not as fine and white as down south but more coarse, it is still fine enough to create a wonderful beach with water shallow enough for children but once you get further out, you can have a nice swim as an adult. There are also a couple of nice restaurants and bars near the beach for sunset and this really is where the locals want to see and be seen in summer. :) If you want to, you can go here by boat from the town centre, stay on the beach for several hours and then return by a later boat. Just make sure you know when the last one is unless you want to walk the 6 kilometres or so back to town.