Rivers and estuaries provide a vast and varied array of habitats, not just the water itself but also on the surrounding land. These habitats support a huge number of flora and fauna species, creating complex and hugely important ecosystems. These habitats and what they offer are outlined below.
Many rivers in the South West have a somewhat surprising resident – otters. The River Camel in Cornwall is a stronghold and was a hub for recolonisation of not only the South West but other parts of England following the otter decline of the 1950s-1980s. Otters are also making a comeback in the rivers Teign and Fal.
In terms of fish life, salmon and trout can be found in large numbers in most South West rivers, notably the Dart and Teign.
Estuaries, where the river meets the ocean, are home to a highly varied range of animal and plant species, some of microscopic size, while others are some of the biggest animals on the planet!
Marine mammals are very common in South West estuaries, with the Dart estuary being home to a colony of grey seals. Porpoises are often seen there, plus the occasional dolphin, and in June 2015 a migrating humpback whale was even spotted! Porpoises, dolphins and grey seals can also be found regularly in the Tamar estuary.
The Tamar is also home to a wide range of seaweeds, algae, and polychaete worms, and a shrimp species (Palaemon longirostris) that has only ever been recorded in two other estuaries in Britain. The Exe Estuary has large populations of cockles, mussles and crabs which have contributed to its designation as a Site of Special Scientific Interest.
In the Hayle estuary large quantities of bass, flounder, and mullet can be found, and the Tamar estuary is one of only two sites in the UK where the fish, allis shad (a herring-type fish), spawn. The Camel estuary is a sea bass conservation area.
Mudflats, Saltmarshes, and Dunes
The mudflats and saltmarshes that surround estuaries in the South West are bird watcher paradises.
Osprey, peregrine falcons, mute swans, buzzards, egrets, gannets, herons, kingfishers, lapwing, and avocet are notable species that flourish in these biologically and ecologically vital habitats.
The sand dunes at Dawlish Warren (on the Exe), are considered so ecologically diverse and important that the area has been designated a Special Area of Conservation (SAC) and both a local and national nature reserve. The designation of SAC is due to the population of Petalwort that the dunes support, and the nature reserves because of the diverse and ecologically important plant and animal species that are found there. On the Hayle estuary, the RSPB manages a nature reserve, and it is part of a Site of Special Scientific Interest (SSSI), due to its biologically important habitats such as saltmarshes, estuarine muds, and sand dunes.
Woodland, farmland and meadows.
Although often not initially thought of as part of the ecosystem of a river, the surrounding countryside is just as ecologically and biologically important and the health of the river and nearby habitats such as woodland, farmland and meadows are intrinsically linked.
The ancient woodland along the Fal is home to oak, willow, and alder and the woodlands along the Dart and Camel play host to bats and tawny owls, respectively.
Along the Teign, nightjars are notable residents of the heathland up-river, cirl buntings and skylarks can be found at farmland along the river, and the meadows are home to large numbers of butterflies and orchids.
Tiger moths and Hairy dragonflies can be found along the Exe.
So next time you are visiting a river, for whatever purpose, it is worth remembering the great diversity of animals and plants that are supported by the river and the habitats that can be found along the river – without them the river would not survive, and vice versa!