Survey work at Sherkin Island Marine Station has concluded and we are now archiving the data. See Datasets for information on published data.
Rocky Seashore Survey
The Rocky Shore Monitoring programme was running from Sherkin Island Marine Station from 1975 until 2015, with 69 sites surveyed annually on Sherkin Island and the islands of Roaringwater Bay and in Dunmanus Bay. In 1995 the programme was extended along the coastline from Bantry Bay to Cork Harbour, increasing the number of sites to 144.
Sites were accurately relocated from year to year using maps, photographs and detailed site directions. A transect line was set out from the top of the shore down to low water, with quadrats (0.25m2) placed at vertical distances of 30cm. The mean tidal range in this area is c.3m, so the 30cm vertical distance measurement ensured that there were at least 10 stations at most sites. In practice, this number was variable and dependent on site conditions. For example, the transect at Cobh Slipway, Cork Harbour was only 6 stations while that of Lord Bandon’s Tower in Dunmanus Bay was 22. Stations along the transect were set with permanent markings, which ensured that the quadrats were placed in exactly the same position each year. At each station the abundance of every species encountered within the quadrat was recorded and the data entered onto computer. More than 230 species of flora and fauna were recorded over the 144 sites.
There were seven sites on Sherkin Island, which were visited monthly from April through to October. At these sites two quadrats were laid down side by side at each station along the transect line, increasing the survey area.
2003 saw the publication of “The Ecology of the Rocky Shores of Sherkin Island – A Twenty-Year Perspective”. It is the first major analysis of rocky shore data from the programme begun in 1975.
The book gives well-illustrated background information on the common species of the rocky shore together with how the rocky shore food web functions. The main focus of the book are the seven monthly shores on Sherkin Island. The book was written specifically to include people and to appeal to a wider audience than the academic community. For this we are indebted to the author, Dr. Gillian Bishop, the Station’s first marine biologist in 1975 and now an environmental consultant in Aberdeen, Scotland.
Phytoplankton Survey
Phytoplankton monitoring was the other major programme being carried out at Sherkin Island Marine Station. Phytoplankton refers to the microscopic plants found in the sea which form the basis of the food chain on which most animals depend. From 1978 a team of marine biologists surveyed phytoplankton populations in the area. Permanent stations were visited every 10 to 12 days from approximately April to November, in Roaringwater Bay and South of Sherkin, into the open Atlantic up to 12 miles. Water samples were taken at different depths at each station, down to a depth of 50m. The temperature and salinity readings were also measured. The water samples were then preserved and analysed to determine the population densities of each species. In 1996 we set up a sample station off the Marine Station landing stage and we did profile sampling every 4 days. Annually we looked at approximately 2,000 water samples from the 12 sites. Preserved samples are stored in the Station’s archives since 1978.
The most well known aspects of phytoplankton studies are those relating to the “Red Tides” that have occurred. Red Tide is the name given to the phenomenon in which a population explosion or “bloom” takes place in a phytoplankton population, usually resulting in the discoloration of the water, which may be tinged with red (although other colours can be produced, depending on the pigmentation of the microscopic plants). The environmental and economic implications of certain species of phytoplankton have stimulated extensive research over the years. Some species contain toxins, which can become concentrated in filter-feeding animals such as mussels. The serious consequences arise when humans eat contaminated shellfish. Many species are also responsible for fish kills around the world. Species of special interest are Karenia mikimotoi (Gyrodinium aureolum), Dinophysis acuminata and D. acuta, as they have been responsible for some of the outbreaks around south-west Ireland.
Ireland’s Marine Institute has its own monitoring and toxicity programmes. Details of these programmes can be viewed at the www.marine.ie
Sherkin Island Marine Station is currently compiling datasets of the flora and fauna for publication online. The first dataset to be uploaded is the Station’s major phytoplankton survey for Roaringwater Bay and South of Sherkin: “SERIES 1: Long-term data series from Roaringwater Bay / Long Island Bay and South of Sherkin Island, Co. Cork, 1980-2014”
Zooplankton Survey
Zooplankton is the name given to the small animals that drift with water currents in the sea. In 1979, a monitoring project began to study zooplankton in a manner similar to that of the phytoplankton monitoring project. A researcher was assigned to the project each year, with the aim of studying annual population changes. Sampling took place from the Station’s 19′ research inflatable at the same time as the phytoplankton was sampled. The areas covered were therefore the same as those covered by the phytoplankton survey. A zooplankton net was used to collect samples as a vertical haul, representing a column of water at each sampling station. Once back at the laboratory, identification and assessment of the species’ composition took place using a binocular microscope, the samples having been preserved in formalin. A single vertical haul may contain forty or more species, amongst them some of the more important groups such as Copepods and Chaetognaths. An extensive reference collection was assembled over the years and this helped considerably with the identification of uncommon species.
Terrestrial Flora Survey
The wild plants of West Cork have received less study than they deserve. Nevertheless there are many hints in the botanical literature of great richness, notably in the intensive study by Polunin (1949, 1950) of the islands of Roaringwater bay. Research on plants by young botanists based at Sherkin Island Marine Station confirmed this richness.
As a result of the work carried out at the Marine Station, the islands of Roaringwater Bay have been recognised as a botanical “hotspots” for rare plants. Twelve of the species found in the islands are included in the Irish Red Data Book. And a further two (Fiddle Dock and Deptford Pink) ought to be included in any future edition. The Deptford Pink was only discovered in Ireland as recently as 1992 when Sherkin Island Marine Station botanists found six plants on Horse Island. It is encouraging to see that, in 1996, the number had grown to 35.
We found a total of 627 different flowering plants, conifers and ferns (including hybrids and subspecies), which is an astonishing figure for an area of some 10 km2 in Ireland. Indeed, this would be a high figure for a similar-sized area of Britain, which has a larger flora than Ireland. The flora of Roaringwater Bay is thus of immense importance both nationally and internationally. The area is as rich as anywhere in North-Western Europe.
1996 saw the publication of “The Wild Plants of Sherkin, Cape Clear and adjacent Islands of West Cork”, a flora that was the culmination of many years’ research by the Marine Station botanists. A supplement to the above flora was also published in 2011. Rather than marking the end of botanical studies at Sherkin, the publication of the Flora only served to fire our enthusiasm for further work. The Sherkin method of thorough and repeated surveying revealed some astonishing finds in an area that was hitherto oddly neglected by the majority of mainstream botanists.
In 1997, the Station began a new survey on the islands of Bere, Dursey and Whiddy in Bantry Bay. The Flora list, when the survey was completed, surpasses that of the islands of Roaringwater Bay. There is a herbarium of over 1,000 plants of the Bantry Bay islands in the Marine Station herbarium.
Complementing the earlier study of the islands of nearby Roaringwater Bay, “The Wild Plants of Bere, Dursey, Whiddy and other Islands in Bantry Bay“ puts on record the variety of wild plants found in Ireland’s most famous natural harbour. This part of West Cork is famed for its dramatic scenery, mild climate and sub-tropical gardens, and both land and sea are richly steeped in history. Plants, people and landscape have shaped one another, and this book examines the history, geography, geology, vegetation and land use of this beautiful corner of Ireland, as well as presenting an annotated catalogue or Flora of its wild plants. The islands of Bantry Bay proved to be as floristically interesting as those of Roaringwater, with a total of 578 wild plants recorded and doubtless many more to be discovered.
John Akeroyd, the noted botanist, oversaw the botanists at the Station, making annual visits for over 20 years.
Terrestrial Plant Herbarium
The Sherkin Island Marine Station Herbarium contains over 2000 specimens of flowering plants and ferns. Of the 627 species recorded for the islands of Roaringwater Bay, 531 are represented in the herbarium – including many of the Roaringwater Bay specialities such as Lotus subbiflorus (Hairy Bird’s-foot Trefoil), Rumex pulcher (Fiddle Dock), Tuberaria guttata (Spotted Rockrose), Viola lactea (Pale Dog-violet), Geranium purpureum (Little Robin) and a magnificent specimen of Babington’s Leek (Allium ampeloprasm var. babingtonii). Of those species that remain to be collected, five are considered extinct and a further 26 have not been recorded in the islands since the 1950s.
Lucy Wright, who collected 445 specimens, initiated the plant collection in 1981-1982. Over the years, the collection increased in size and, in many cases, there are now three specimens of each species.
In addition to the flowering plants and ferns, there are also collections of bryophytes, fungi and lichens.
Seaweed Survey and Herbaria
A seaweed survey was initiated in the summer of 2000 after a pilot scheme was set up with the aim to monitor and record the vast biodiversity of intertidal marine flora around the shores of Roaringwater Bay and Cork Harbour. Further seaweed surveys were conducted over the years.
The project simply involves identifying and recording seaweed species that are present within the intertidal zone by scouring lengths of shoreline in a meandering fashion and recording the species as you go, as well as microscopic identification of samples in the lab.
The seaweed surveys, rocky shore monitoring programme and diving surveys contributed to an extensive collection of over 2,500 seaweed specimens in the Seaweed Herbarium.
Bird Survey
From 1975, birds were regularly studied at the Station, and detailed breeding bird surveys of the islands in Roaringwater Bay were carried out. The geographical position and range of habitats provide good breeding sites for many types of birds. In addition, the area is important for migratory birds that need food and shelter, especially when there are adverse weather conditions. Sea-bird passage along the south coast of Sherkin Island was monitored and collated with sea birds recorded at sea from the Station’s research boat. See: Bird Reports of Sherkin Island
Otter Survey
At Sherkin Island Marine Station, a continuing research project was set up to monitor otter (Lutra lutra L.) activity on Sherkin itself and on the other islands of Roaringwater Bay. These included the following islands, which were accessed by the Marine Station’s boat:
Ardillaun, Badger Island, Bird Island, The Calf Islands, Carrigreagh, The Carthy’s, Castle Island, The Catalogues, Clear Island, Coolim, Goat Island, Little Goat, Goose Island, Heir Island, Horse Island, Illaunnagrogh, Illaunrahee, Jeremiah’s Island, Long Island, Mannin Island, Quarantine Island, Sandy Island, Skeam East, Skeam West, Spanish Island, Two Women’s Rock.
The first otter survey of Roaringwater Bay was conducted in 1981. A new addition to the project in the mid 1990s was an evaluation of activity along the banks of the River Ilen Estuary, which runs from the Mainland into the Bay, NE of Sherkin Island. The survey involved traversing the coastlines and mapping tracks and signs to establish the distribution of areas utilised by otters. Further survey work was undertaken in the 2000s.
See: Bulletin No 12: Otter Survey of Roaringwater Bay, South West Cork, Ireland, 1990.
Diving Survey
The waters around Sherkin Island are ideal for those people interested in underwater surveying. The first survey was undertaken in 1975 by Dr. Keith Hiscock et al, with various surveys undertaken over subsequent years. Due to costs and time, diving surveys were discontinued in 2001.
Sponge Survey
Two projects concerning sponges of Roaringwater Bay and adjacent areas were carried out from 1981 to 1983. A monitoring project was established to study the life cycle and changes of certain sponge species. This project was run with the wonderful help of Miss Shirley Stone – the noted world authority on sponges – then at the Porifera Section (sponges) of the British Museum (Natural History). A population survey of all species of sponges in the area, together with a study of their biology, was also run during 1982 and 1983. Methods used to survey the sponges included shore exploration and scuba diving. There is a major slide collection of sponge skeletons in the Marine Station archives from the Roaringwater Bay area.
See: “European Contributions to the Taxonomy of Sponges”
Rockpool Survey
Rockpools are conspicuous components of the rocky shore and have been reported to contain both a diverse flora and fauna population. In 1995, Sherkin Island Marine Station began a rockpool survey. In that year, 48 pools were surveyed on both Sherkin (42 pools) and East Skeams (6 pools). In all cases, the maximum length, width and depth of the pools were measured. Elevation was recorded (as the height below the barnacle line) to give a measure of the position of the pool along the shoreline. Pools were extensively searched for both flora and fauna species. In many cases, the pools were partially bailed to reach the deepest sections. This measure was used sparingly to prevent destructive sampling. A species list of both flora and fauna was compiled, where the former was noted via absence or presence and the latter, when applicable, via numbers counted.
Since the basis of the project was to set up a framework for a permanent study, detailed site descriptions for all pools were prepared. These included (per pool) a minimum of two photographs, a map of the pool in its surrounding area and written instructions. This ensured that the correct pools could be relocated for future studies.
Macrofauna Survey
Sandy beaches are the most widely distributed type of intertidal environments worldwide, but as they appear to be barren and inhospitable they are the least studied of all intertidal habitats. The aim of the research at the Sherkin Island Marine Station was to study a number of diverse sandy beaches for their macrofauna communities. In total twenty-eight sandy beaches, from Cork Harbour to Roaringwater Bay, were quantitatively sampled for their macrofauna populations between June and mid-September 1996 and 1997.
Macrofauna are living organisms which inhabit beaches and are retained by a 0.5mm sieve. This study was an extension of a number of surveys carried out by undergraduates from 1976-1978 on Sherkin Island.
Within Roaringwater Bay, County Cork, Ireland, sixteen beaches were sampled. Including seven on Sherkin Island, three on Heir Island, two on Horse Island and one on East Calf Island. Beaches were examined on the uninhabited Islands of East Skeams, Middle Calf, Catalogues and Carrigreagh.
Along the Cork Coastline eleven beaches were surveyed, extending from Baltimore to Cork and including Tragumna, Rosscarbery Strand, Ownahincha Strand, Summercove, Robert’s Cove, Inch Strand, Myrtleville Bay, Inchydoney, Long Strand and Howes Strand.
The methodology employed to sample the beaches involved setting up three line transects, from high to low water. At 10cm vertical heights along the transect, 4 replicate 0.01m2 cores to a depth of 15cm were taken. The core samples were sieved on the beach and any organisms collected were taken back for identification, with the aid of a microscope and appropriate keys. All new macrofauna species were fixed and preserved. A full specimen collection is held at Sherkin Island Marine Station.
Insect Survey
During surveys of Sherkin Island and other islands in Roaringwater Bay, insects from various groups were collected and identified and stored in the Station’s archives:
- Hymenoptera (bees, ants and wasps)
- Neuroptera (lacewings, alderflies, snakeflies & antlions)
- Dermaptera (earwigs)
- Orthoptera (grasshoppers and crickets)
- Coleoptera (beetles) See: Beetles Survey
- Heteroptera (bugs)
Beetle Survey
Coleoptera (Beetles) surveys were undertaken in the 1980s, 1990s and 2000s on some islands in Roaringwater Bay. Sherkin Island was the main island surveyed. The list for all the islands now stands at 550 species. The collection of the beetles took place between May and September and involved sweep-netting, hand collection and pit-falling. All specimens are stored in the Marine Station archives.
Butterflies & Moths
Lepidoptera work was carried out at Sherkin Island Marine Station in the 1970s, 1980s, 1990s and 2000s. This work makes Sherkin Island one of the most intensively studied places in Ireland for Lepidoptera.
Miscellaneous Surveys
The Marine Station carried out many short term surveys. For example, a survey of the Grey Seal population was carried out during 1985 to monitor possible changes since a 1981 survey. There are several sites around the bay in which seals may be observed hauled out on the rocks.
Flatfish Survey
Sherkin Island contains a number of areas important to flatfish as “nurseries”. These are regions where the growth and survival of juvenile fish are enhanced due to less risk of predation, more amenable temperatures and a more readily available food source. A number of surveys were conducted by the station since 1980 and concentrated on one such nursery, Kinish Harbour. This site was fished regularly by beach seine between the months of June and September.
Reference Collection
The Sherkin Island Marine Station Reference Collection includes:
- Seaweed Herbarium – Roaringwater Bay and the island, Bantry Bay – Bere Island, Dursey Island and Whiddy Island, Mainland
- Terrestrial Plants Herbarium – Roaringwater Bay and the island, Bantry Bay – Bere Island, Dursey Island and Whiddy Island, Mainland
- Sponge Skeleton Slide Collection
- Specimens of Marine Animals: Over 3,500 preserved specimens of marine animals from mainly the Roaringwater Bay area – Sherkin Island and the Islands.
- Otter Spraints
- Insect Collection – includes beetles, flies, dragonflies, moths and butterflies, aquatic bugs
Photographic Collection
The photographic collection includes:
- Over 4,000 colour slides on the natural history of Roaringwater Bay.
- Littoral and sub-littoral in the main, taken by Paul Kay and Pete Atkinson, former Sherkin Island Marine Station biologists. Both are now international natural history photographers.
- Over 2,500 black and white photographs of ruins/buildings/sea shores of Roaringwater Bay.
- This major collection was taken on the various islands of Roaringwater Bay by Paul Kay and Ian Watts during 1981 and 1982.
- A collection of phytoplankton photographs of many of the species identified in the area.
- Aerial photographs of County Cork by Daphne Pochin Mould
Meteorological Records
Sherkin Island Marine Station manually recorded weather data from July 1972 to September 2025, beginning with daily rainfall measurements and expanding to include sunshine and temperature data from August 1974. As Ireland’s southernmost weather station, it reported its data monthly to Met Éireann in Dublin and was among a select group of stations whose records were featured in the Irish Meteorological Office’s monthly bulletin. The manual station ceased operations in September 2025.
In 2004, Met Éireann installed an Automatic Weather Station on Sherkin Island as part of their TUCSON program (The Unified Climatological and Synoptic Observational Network), which began in 2000. The island was selected due to limited weather station coverage along Ireland’s south coast. The station became operational on April 28, 2004, and transmits hourly weather data to Met Éireann via the internet.
The station measures:
- Temperature: Air, Grass, Soil – 5cm,10cm, 20cm, Earth – 30cm, 50cm, 100cm
- Rainfall: 0.1mm & 0.2mm gauges
- Solar radiation
- Wind speed & direction
- Atmospheric Pressure
- Relative Humidity