Introduction to Natural Heritage

Area of Special Scientific Interest

The importance of the natural environment around Portrush was officially recognised by the government when it identified Ramore Head, the Lansdowne foreshore and the Skerries as an Area of Special Scientific Interest (or ASSI) in 1996. This designation protects a clearly defined area with the intention of avoiding any future damage such as, for example, mineral extraction or mining, dumping, construction or the introduction of any new species.

The geological features of the Portrush Rocks are the most important aspect of the ASSI These are described by scientists as:

“…igneous dolerite, about 60 million years old, which has intruded as a sill into shales which are 190 million years old. This has produced a fine grained, dark brown rock called a hornfels…”

To the lay person, with no interest or understanding of geology, it is the amazing trace fossils which are the main attraction, in particular the abundance of beautifully preserved ammonites.

Skerries and Causeway Special Area of Conservation

Approximately half of Northern Ireland’s wildlife and habitats lie below the sea. Our marine environment is especially rich due to the region’s geographic position at a junction of cold northern Arctic and warm southern Lusitanian waters. Our underwater habitats range from the species-rich reefs and sandbanks in the seas around Portrush to the diverse sponge reef communities of Rathlin Island to the fantastic large underwater sand formations just off the Giant’s Causeway. The local marine area is internationally important and was designated a marine Special Area of Conservation (SAC) in 2017. Known as the Skerries and Causeway SAC, it was the first marine protected area in the UK for harbour porpoise. This designation ensures that the coast and inshore waters form a strictly protected site, as designated under the EC Habitats Directive. The area’s sandbanks, reefs and sea caves, along with key species, notably the Hhrbour porpoise, are considered to be of international importance.

Portrush National Nature Reserve

The Portrush National Nature Reserve is located between Portandoo Harbour and the Blue Pool. The designation centres primarily on the area’s geological significance and gives the Department of Agriculture,  Environment and Rural Affairs (DAERA) the ability to manage the area, for example, in prohibiting the illegal removal of fossils.

The rocks along this shore were the focus of a famous argument between scientists across the world in the late eighteenth century. The debate hinged on the presence of fossils in some rocks which were believed to be volcanic – Neptunists argued that a fossil could not have survived if it was originally laid down in molten magma. A famous example of this, which was often used by Neptunists, was the rock beds here in Portrush, where ammonites could be found in hard, heavy rocks which appeared to be igneous.

Eventually, at the start of the 19th century, the Vulcanists started to win the argument when John Playfair published his Illustrations of the Huttonian Theory in 1802. They successfully proved that the fossils in Portrush were originally laid down in sedimentary mudstone rock. The mudstone was later ‘baked’ when it came into contact with an adjacent flow of volcanic rock, known as dolerite. The intense temperature hardened the mudstone but it was not hot enough to destroy the fossils. So it was that the east coast of Portrush was the last battleground of the Neptunists and Vulcanists from which the latter emerged triumphant. In an important sense it can be claimed that geology as a science was born from that moment of victory.

Our Coastal Waters

Between Ramore Head and the Skerries Islands, turbulent deep Atlantic waters converge and diverge, spilling over jagged submarine reefs and enriching the sea to create the diverse coast. The Joint Irish Bathymetric Survey (JIBS) project used multibeam sonar to produce high resolution maps of the seabed around the north coast, including Portrush, providing information on seabed type to a one metre accuracy.

Ramore Head is an exceptional year round vantage point to look for whales, dolphins and porpoises, known collectively as cetaceans (derived from the Latin word cetus, used to refer to a large sea creature and the Greek word ketos meaning sea monster). Bottlenose dolphins can also be regularly observed, feeding close to shore.

The beautifully streamlined Minke whale is Northern Ireland’s most commonly encountered baleen whale and can be seen surfacing to breathe when feeding on herring and mackerel. Early mornings and evenings provide the best sea conditions to watch for cetaceans around Portrush. Killer whales, Risso’s dolphins and common dolphin are also occasionally seen travelling through the area.

During the summer months, huge basking sharks can be seen feeding and even breaching clear of the waters all around Portrush. You may even see tropical ocean sunfish, the world’s heaviest bony fish, as they float on their sides flicking their short pectoral fins up and down. Occasionally, sailors and fishermen encounter rare leatherback turtles off the north coast; these are the deepest diving and widest ranging reptiles on earth and grow to an impressive 3 metres in length.

Cetaceans, seals, seabirds, basking sharks and marine turtles are all protected by law, making it an offence to disturb, injure or kill them. Marine conservation officers from DAERA Marine & Fisheries Division regularly patrol the area by boat and land in order to monitor and safeguard the protection of these charismatic species. The outdoor viewing platform at Portrush Coastal Zone provides an excellent vantage point to watch our diverse marine environment and visitors are welcome to view the aquaria, whale bones and seabird exhibits when the centre is open to the public during the summer months.

Our Beaches

Walking from the East Strand along the shoreline you will come to Curran point. Here amongst the sand dunes there are reports of many archaeological finds. The Ordnance Survey Memoirs refer to small mounds of stone and shells being exposed following winter storms. Large quantities of human bones were discovered and they were described as being of exceptional size.  Items of metal were also uncovered and described as weapons of defence adding to the local legend that many battles had been fought in the area.

Heading towards White Rocks several other archaeological sites have been noted. White Rocks would have provided an accessible flint source and an excavation in 1971 produced flint implements that indicated that much of the flint had been extracted as flint nodules from the local chalk cliffs. A stone lined pit called a cist was discovered containing a burial and a fragment of a burnt saddle quern stone used for grinding cereals. Dating from the Middle Bronze Age it adds to our knowledge of the importance of the area during this time.

To the West of the Portrush Peninsula the removal of sand from the beach by the winter storms south of the Castle Erin have exposed a layer of thick peat on the beach. Close examination of the peat shows it to be very hard and dense (rather like the peat briquettes that you can buy) with numerous large fragments of tree trunks, branches and roots visible. Samples of peat were taken for radiocarbon dating from the peat top and from as deep as the excavation allowed (it did not go deep enough to reach the bottom of the peat).  The age obtained from the ‘deep’ sample was 7,960-8,340 years, but because this was not from the very bottom of the peat it only tells us that the peat began forming at some stage before this time; but just how long before is not yet known.  The age from the top of the peat was 6,540-6,950 years and informs us that the peat was buried by sand at that time.

Marine Litter

Whilst the coastline around Portrush is relatively remote and unspoilt, marine litter is a growing threat to every marine environment, with impacts on the area’s appearance, wildlife and habitats. DAERA, the Causeway Coast and Glens Borough Council and local conservation charities and residents are all working together to tackle the problem with regular beach cleans and recycling initiatives.