The River Blackwater is one of the largest rivers in Ireland 169 km, draining a major part of Co. Cork and five ranges of mountains, the Boggeragh, Nagle, Ballyhoura, Galtee and Knockmeldown ranges. It flows through Kerry, Cork, Limerick and Waterford and has freshwater stretches as far upstream as Ballydesmond and tidal stretches as far as Youghal Harbour. It enters County Waterford where it flows through Lismore, before abruptly turning south at Cappaquin and finally draining into the Celtic Sea at Youghal Harbour. The abrupt right turn at Cappaquin is as a result of a phenomenon called ‘river capture’ dating back 70 million years. This involved the original river which flowed through the area, the Suir, diverting its course eastwards toward Waterford. The old river bed dried up or remained as a mere trickle. It is possible that either the Glenshelane or Finnisk rivers, which enter the modern Blackwater south of Cappoquin, are remnants of the original Suir. In any event, by the time the Suir ceased to flow through the Cappoquin area, a major tributary had been coming across Kerry and Cork to meet with it at Cappoquin. As the Suir dried up, this tributary just continued to flow along the old route from Cappoquin to the sea. So, what looks to the eye like one river, the Blackwater, changing course dramatically at Cappoquin was once, in fact, two rivers.
The site of the river is designated a Special Area of Conservation (SAC) selected because of the presence of protected habitats and species listed on Annex I / II of the E.U. Habitats Directive. Habitats on the Blackwater include the estuaries, tidal mudflats and sandflats, old oak woodlands and alluvial forests.
River estuaries are coastal inlets where there is generally a substantial freshwater influence. The mixing of freshwater and sea water and the reduced current flows in the shelter of the estuary lead to deposition of fine sediments, often forming extensive intertidal sand and mud flats. Where the tidal currents are faster than the flood tides most sediments deposit to form a delta at the mouth of the estuary.
Oak woodland is well developed on sandstone around Ballinatray, with the acid oak woodland community of Holly, Bilberry, Great Wood-rush and ferns occurring in one place. Alluvial forests are dominated by alder and willow on flood plains in a range of situations from islands in river channels to low-lying wetlands alongside the channels. A small stand of Yew woodland, a rare habitat in Ireland and in Europe, occurs on a limestone ridge at Dromana, near Villierstown. While there are some patches of the wood with a canopy of Yew and some very old trees, non-native and invasive species such as Sycamore, Beech and Douglas Fir dominate.
Species present include the freshwater pearl mussel, white clawed crayfish, lamprey, Atlantic salmon and otter.
The freshwater pearl mussel is somewhat ironically one of the longest-living invertebrates in existence but also a species that is in serious decline. The typical life-span is 100 years, but can live for over 200 years. It has been revealed to exhibit negligible senescence, meaning they do not have measurable reductions in reproductive capability or functional decline with age. Various factors have led to this decline, one interesting examples being the unique composite material of its inner shell known as Nacre or ‘mother of pearl’ which was popular up to the 19th century for use in fashion, the decorative arts and in the production of musical instruments.
Atlantic salmon are the largest of the salmon. After two years at sea they average 71 to 76 cm in length and 3.6 to 5.4 kg in weight. But specimens can be much larger. An Atlantic salmon netted in 1960 in a Scottish estuary was recorded as weighing 49.44 kg, while another netted in 1925 in Norway was recorded at 160.65 cm in length.
The colouration of young Atlantic salmon does not resemble their adult stage. While they live in freshwater, they have blue and red spots. While they mature, they take on a silver-blue sheen. When adult, the easiest way of identifying them is by the black spots predominantly above the lateral line. When they reproduce, males take on a slight green or red colouration.
Otters are active hunters, chasing prey in the water or searching the beds of rivers, lakes or the seas. Most species live beside water, but river otters usually enter it only to hunt or travel, otherwise spending much of their time on land to avoid their fur becoming waterlogged. Sea otters are considerably more aquatic and live in the ocean for most of their lives. Otters are playful animals and appear to engage in various behaviors for sheer enjoyment, such as making waterslides and then sliding on them into the water. They may also find and play with small stones. Different species vary in their social structure, with some being largely solitary, while others live in groups – in a few species these groups may be fairly large.
Birds on The Blackwater
The Blackwater is thought to support at least 30 pairs of the European Kingfisher, which has a short tail, a large head and a long bill. The one I saw had a brilliant azure-blue back. Kingfishers get their name from the ancient Greek word ‘Halcyon’ derived from ‘Alcyone’ who married ‘Ceyx’ son of ‘Phosphorous’, the Morning Star also known as Venus in its morning appearance. The story goes that they were happy together and often sacrilegiously referred to each other as ‘Zeus’ and ‘Hera’. Having angered Zeus, they were punished but out of compassion both Alcyone and Ceyx were transformed into halcyon birds. From this naming comes the origin of the phrase ‘halcyon days’ which referred to the 14 days before and after the winter solstice, during which time Alcyone laid her eggs and made her best in the beach and during which time her father Aeolus, god of winds, calmed the waves sonhis daughter would be safe. Today, the phrase refers to a peaceful time, or a bright interval in the midst of adversity.
Three breeding territories for Peregrine Falcon are known along the Blackwater Valley.The peregrine falcon is a widespread bird of prey. A large, crow-sized falcon, it has a blue-grey back, barred white underparts, and a black head and “moustache”. As is typical of bird-eating raptors, peregrine falcons are sexually dimorphic, females being considerably larger than males. The peregrine is renowned for its speed, reaching over 320 km/h during its characteristic hunting stoop (high speed dive), making it the fastest member of the animal kingdom. The peregrine falcon is a well-respected falconry bird due to its strong hunting ability, high trainability, versatility, and in recent years’ availability via captive breeding. It is effective on most game bird species from small to large.