| Overview | Details | Data Sources | Links | References |
| Coastal Biodiversity | • | Marine Biodiversity | • | Changes in Biodiversity | • | Lough Hyne | • | Irish Publications |
Ireland's coastal areas incorporate a number of habitats, with each one supporting various plant and animal species. These coastal habitats include; sea cliffs and islets, brackish waters, saltmarshes, shingle and gravel banks, sand dunes systems and coastal constructions.
Click here to view further MIDA information on Coastal Habitats.
Coastal Fauna
Representatives of almost all the animal groups can be found along the
coast. Ireland holds significant numbers of many bird species including
light-bellied Brent geese(Branta bernicla). Birds occupy all
of the coastal habitats listed above and are perhaps the most conspicuous
animals on the coast. Many fish species also live along the shore. The
Tompot blenny (Parablennius gattorugine) and Cuckoo wrasse (Labrus
mixtus) in particular, favour shallower inshore waters. The Natterjack
toad( Bufo calamita), which is an endangered species in Ireland,
can be found on sand dunes in some parts of Kerry. Mammals seen on the
coast include seals (grey and harbour) and, despite their popular association
with lakes and rivers, otters Lutra lutra) are just as common
on the coast. In fact, Ireland has long been considered to hold one of
the most important otter populations remaining in Western Europe. Coastal
invertebrates species are hugely varied and numerous with large numbers
of anemones, starfish, crabs and molluscs. |
Click here to view a map of Seal Distribution |
Coastal Flora
The instability of the coastline makes life difficult for plants, many of
which are endangered species.Few flowering plants can survive in this extreme
environment but thrift (also known as sea pink) and sea plantain can sometimes
gain a foothold in cracks and crevices. Shingle beaches in particular hold
unique plant assemblages that are scarce in a European context and have
been listed for special protection under the EU Habitat's Directive. The
plant group most associated with the seashore is undoubtedly the seaweeds
(algae). In fact, the species biodiversity of seaweeds in Ireland is regarded
as considerable compared with that of the total flora of the whole North
Atlantic. There are large numbers of all three main seaweed groups - red
(274 species), brown (147 species) and green (80 species). Seaweeds common
around our coasts include Serrated Wrack, Fucus serratus, Spiral
Wrack, Fucus spiralis and Bladder Wrack, Fucus vesiculosus.
|
Click here to view a map of Seaweed Distribution |
Marine Biodiversity
It has been estimated that 90% of the Irish territory is actually under the sea. While this may be true, our knowledge of the biodiversity of the marine zone is quite under-developed. The marine zone can be divided very simply into the continental shelf and the open sea. To the west of Ireland lies a vast sea floor which stretches out to the edge of the continental shelf. At the edge itself, the continental slope drops steeply to a depth of 4,000m, above which lies the open sea.
|
Click here to view a map of the extent and depth of the Irish seabed |
Marine Fauna
As with the coasts, almost all animal groups are represented in the Irish
marine fauna with a wide range of habitats and species present. Though most
associated with coastal cliffs, many seabirds remain far out at sea for
much of the year. Guillemots and Razorbills for example, spend the winter
in the Irish Sea. The fish fauna is composed of a rich mixture of species.
315 species are known from offshore waters, while an additional 235 species
occur in inshore shallower waters. These include commercially important
species such as cod, plaice, mackerel and herring. Another common visitor
to our shores is the basking shark - the second largest fish on the planet,
often weighing more than an elephant. While the number of terrestrial mammal
species in Ireland is poor when compared with Britain and mainland Europe,
the marine environment contains 24 cetacean (whales, dolphins and porpoises)
and 3 pinniped (seals and walruses) species. The high biodiversity of cetacean
species in Ireland is thought to reflect the high diversity of marine habitats.Irish waters also contain a wealth of invertebrate life. Deep water rocky areas are typically occupied by soft corals and sponges and areas exposed to waves are characterized by the jewel anemone, cup coral and feather star. In recent times, the North East Atlantic, and the Porcupine Seabight in particular, has proven to be of significance due to the presence of unique deepwater coral ecosystems. The more sheltered areas, meanwhile, are typically occupied by brachiopods and sponges. Polychaete worms, molluscs and crustaceans such as Dublin Bay prawns are to be found on the seabed. With regard to reptiles, marine turtles move into Irish latitudes every year to feed on jellyfish. The Hawksbill, Kemp's Ridley Loggerhead and Leatherback turtle have all been recorded off the Irish coast.
Marine Flora
The basis of most food chains in the sea is the floating plant life (or phytoplankton). Much of this phytoplankton consists of tiny single-celled plants, which are only visible under the microscope. It has been estimated that the amount of plant life under a given area of the sea may exceed that produced for the same area in a tropical forest. While microscopic algae may dominate many Irish marine habitats, kelp have also been shown to be crucial to the marine ecosystem as a whole. Kelp is a large seaweed with leaves often reaching up to 3m in length. Many of these plants together form a kind of underwater forest. Kelp forests have been described as one of the most biologically diverse habitats on the planet. Large numbers of animal species rely on kelp for food, protection and shelter. In fact, the removal of these kelp forests can affect animals as diverse as invertebrates, fish and birds, though this phenomenon has not been well researched in Irish waters.
Changes in Biodiversity
A number of human activities (including seabed trawling, oil and gas exploration and pollution) can have a negative effect on species and habitats, potentially leading to species extinction and habitat destruction. Although there appears to be less extinction of marine compared to land and freshwater species, this is probably because man has only significantly impacted the marine environment since the 20th Century. Examples of marine extinctions in the Atlantic Ocean include the Atlantic gray whale, the Sea mink, the Labrador duck and the Great auk. With regard to Irish waters, the lack of adequate descriptions of species and information on their distribution mean that much marine extinction may have gone unnoticed.
Non-native (introduced) species can also impact heavily on biodiversity. Twenty three non-native species are known from Irish waters and a further 18 established elsewhere (mainly Britain) have been deemed likely to spread to Irish waters. The impact of introduced species may be negative, neutral or, in some cases, it may even be positive. The zebra mussel (Dreissena polymorpha) and wireweed (Sargassum muticum) are two species which have recently been introduced to Ireland. Though the negative effects of these species have been well-documented, some positive effects of the wireweed have been noted. Strands of wireweed provide shelter for young fish and crustaceans, while fishermen have reported higher catches of eels, mullet, bass and prawns in strands of this seaweed. Although the vast majority of species become introduced unintentionally, it is thought that further species establishments can be controlled by appropriate monitoring of aquaculture and living trade species.
Link to MIDA Invasive Species page
Lough Hyne- A Biodiversity Hotspot
Lough Hyne is a small, semi-enclosed
sea lough near Skibbereen in Co. Cork. It was established as a marine nature
reserve in 1981, the first of its kind in Europe. The lough supports many
different marine habitats and has an incredibly rich biodiversity with sponges,
crustaceans and molluscs particularly abundant. The flora and fauna of Lough
Hyne are considered unusual and contrast with that of the Atlantic Coast.
It is composed of both cold water and warm water species. The uniqueness
of the lough is such that regular biological research, which first began
in the 1920's, has continued to the present day.Irish Publications on Biodiversity
Two of the most significant publications with regard to biodiversity in Ireland have been the 'National Biodiversity Plan' by the now dissolved Department of Arts, Heritage, Gaeltacht and the Islands (2002) and 'A Framework for an Action Plan on Marine Biodiversity in Ireland' (2000).
The National Biodiversity Plan highlighted many of the threats to marine and coastal biodiversity. These include loss of habitat, pollution, introduction of non-native species, aquaculture and over-fishing. The National Biodiversity Plan proposed a number of actions to deal with these issues such as the preparation of a National Integrated Coastal Zone Management Strategy, developing a National Marine Biodiversity Resources Database and appropriate monitoring and research on the effects of aquaculture, over-fishing and pollution on biodiversity. Arising from this, the National Biodiversity Data Centre was set up by the Heritage Council within Waterford Institute of Technology in 2007. The NBDC collates manages, analyses and disseminates information on Ireland's biological diversity. At the moment it primarily holds terrestrial records although it aims to expand into the area of marine biodiversity. At the end of 2010 the Centre held over one and a half million records documenting more than ten thousand species. In addition to recording biodiversity the 'Framework for an Action Plan on Marine Biodiversity in Ireland' suggests that indirect actions should also be taken, such as education, economic, social and political measures, based on current knowledge of marine ecology and ecosystem processes.