Species affected by increasing coastal change
Research shows how an increasingly dynamic coastline could radically change the face of wildlife on our coast in the coming decades.
These six species could be seriously affected by our ever changing coastline due to coastal erosion and climate change:
Little terns nest in loose colonies on sand and shingle beaches such as Blakeney Point, just above the high tide line. This makes their nests very vulnerable to exceptional high tides and summer storms, which are likely to become more frequent due to climate change. Winter storms and higher rates of beach erosion can also mean that places where they nested last year are no longer suitable when they migrate back to the UK each spring.
Little terns nest on our managed land at:
* Blakeney Point, Norfolk
* Long Nanny, Northumberland
Puffins are a great indicator of how human factors and climate change have an impact on the whole coastal ecosystem. A combination of overfishing and warming seas has led to the bony and indigestible snake pipefish, scarcely found in our waters ten years ago, moving north to replace the puffins’ main food source, the sand eel. Puffin chicks have occasionally been found dead, having choked trying to swallow pipefish.
Last summer’s wash-out saw a number of puffins’ burrows flooded, whilst an exceptionally harsh winter and spring storms this year led to the worst bird wreck in 50 years, with hundreds of puffins, guillemots, and razorbills washing up dead along the north-east coast, presumed to have starved in the difficult conditions.
These recent events have, however, been followed by summer success, with the five-yearly puffin count on the Farnes revealing that, although numbers are not as high as their peak in 2003, they are up by 8 per cent on the 2008 figures, with just under 40,000 (39,926) pairs of nesting puffins.
Glanville fritillary butterfly
The Glanville fritillary is a butterfly which exemplifies the boom and bust nature of coastal wildlife. Once found as far north as Lincolnshire, it has become restricted to the coastal landslips on the south-west coast of the Isle of Wight, pushed out by intensive farming which limits its caterpillar’s main food source, ribwort plantain.
Like many species which live on our coasts, it relies on highly specialised conditions – a gradually eroding, warm, south-facing cliff, with only the first stages of colonisation by plants. The greatest threats to its habitat therefore include the overstabilisation of cliffs through invasive plant species, and habitat loss through coastal squeeze. But increased erosion could also make cliffs too unstable for the vegetation it depends on – and with unpredictable weather caused by climate change we could lose it from our shores completely.
Conversely, if climate change leads to warmer weather, the Glanville fritillary could recolonise the mainland from the Isle of Wight.
You can find this insect on National Trust land at:
* Compton Bay, Isle of Wight
Cliff tiger beetle
Although it is a hunter, the cliff tiger beetle depends on a very specific habitat. It relies on relatively large areas of bare clay being exposed through cliff slumps and slippages, living beside wet seepages along the bare cliff face.
Two of its greatest threats are coastal development and the overstabilisation of soft cliffs (whether natural or human induced). The increased mobility of cliffs this spring followed by hot weather this July has helped it, but it is vulnerable to catastrophic events in the few places that it does survive.
Like many insects, the cliff tiger beetle lacks the ability to move if conditions suddenly become unfavourable. It is only capable of short flights, so if it is lost from an area it may be difficult for it to recolonise.
These beetles live on coastal cliffs in:
* West Dorset
Please note: Due to the recent mobility of cliffs on the Dorset coast, we strongly recommend that people do not put themselves at risk looking for cliff tiger beetles. The stability of a cliff face can be deceptive, and remember that the cliff tiger beetle relies on a degree of coastal instability to survive.
Many coastal plants have adapted to survive in a range of environmental conditions. But they are now threatened by the increased mobility of cliffs and dunes, coastal squeeze, increased drought stress, increased salinity, and increased length of time underwater.
The oysterplant is one example of a plant at risk. Now nationally scarce and appearing on the current Red List in the near-threatened category, the oysterplant grows on exposed shingle beaches along the north-west coast of England and Scotland, as well as in Northern Ireland, where it is legally protected. Like other coastal plants such as the yellow-horned poppy, it requires some disturbance to maintain its open shingle habitat, but extreme storms could wash it away completely.
Most population losses have been at the southern end of its range, due to extreme storms, excessive recreational pressures, coastal squeeze and removal of shingle from beaches. However, as its seeds can be dispersed over long distances by the sea, there is the potential for it to spread and colonise new sites.
This plant can be found at:
* Giant’s Causeway, Northern Ireland
Warming seas have led to an influx of invasive non-native species on our shores, such as zebra mussels and japweed, which can proliferate on boats, jetties, and in rock pools, able to survive in increasingly moderate sea temperatures.
Perhaps most striking, however, are the occasional sightings of new natives such as the grey triggerfish off the coast of North Wales. Normally found in the warmer waters of the Atlantic and Mediterranean, the triggerfish’s appearance off the Welsh coast gives a taste of how our marine ecosystems could see profound changes in coming years.
The National Trust property nearest to where triggerfish have been found is:
* Porthdinllaen, Wales