The Bristol Channel
The Bristol Channel is home to the second highest rise and fall of the tide in the world, over 42 feet (13m) at Avonmouth. The waters are mainly shallow with the deepest parts only about 150 feet . The physical shape of the Bristol Channel resembles a crooked funnel. The gradual reduction of the width of the channel results in a tidal surge on each making tide called the ‘Severn-Bore’. This can be seen in the higher reaches of the channel from around Sharpness upwards, most spectacularly on spring tides. The equinoxal springs in March and September regularly attract surfers, canoeists and other rafters who try to ride the massive tidal-wave up the River Severn.
The upper reaches of the channel/River Severn estuary, feature huge shifting sand banks. There is a large commercial sand dredging operation, supplying the construction industry with various sands and aggregates. Many rivers spill into the Bristol Channel, bringing with them millions of tonnes of suspended particles of earth, mud and sand. It is this that gives the waters their characteristic chocolate colour. The fast moving waters scour the seabed keeping the sediments in suspension. It is not until you get to the lower reaches of the channel where it meets The Irish Sea, and The Atlantic Ocean, do you see the waters clearing to their more usual blue/green. Here the less turbulent water allows the suspended particles to drop to the bottom.
The coloured water of the higher reaches mean that fish find their food by scent. Whereas some fish are only caught at night on many venues around the country, those species can be caught almost any time in the Bristol Channel, Sole being a prime example.
The clearer waters to the west allow the sight feeders, Pollack, Wrasse and Mackerel for instance to thrive. More exotic species have migrated during the summer/warmer months. Red Mullet and Trigger fish to name two
In summer, the reduction of flood waters from the rivers also reduces the colouration. Whereas in winter the clear waters don’t really start until well west of Combe Martin, in summer clearer water commences at about Hurlestone Point between Minehead and Porlock. This in turn allows shoals of Mackerel to venture well up the channel. Following the Mackerel come the larger predators like Tope. In recent years the Tope fishing has been phenomenal during the spring and summer.
For the greatest numbers of species, the late summer ( late August/September/early October), is best. The waters are warm, having brought the sub-tropical species such as Black-Bream and Trigger-Fish, with them, and the winter Whiting and Cod start to migrate back up the Channel from the Irish Sea. It is a regular occurrence to capture 15 or more species in a day, of course, if you fish for them!
The Bristol Channel fishery is also incredibly fickle. The catch in one place on one day can be the total opposite the next day. The Charter Boat skippers favourite saying “You should have been here yesterday”, probably originated in the Bristol Channel!