Appropriate Assessment Screening Report

MS51/9/603

Assessment of the likely effects of the construction of a slipway and concrete pad with ladder to access floating pontoon and gangway at Inishkeragh Island, Sneem, Co. Kerry.

Project Description:

InishkeraghIsland is currently uninhabited and the applicant has received planning permission for a dwelling house on the Island. The proposed development is required to provide safe access at all stages of the tide to the dwelling from the mainland. (Location map attached)

The Development will consist of

  1. A reinforced concrete slipway 15m x 2.5m to launch and retrieve boats.
  2. A 10m x 2m pontoon with 15m access gangway to board and unboard boats.
  3. The pontoon will be secured to a concrete pad placed on existing rocks on the shoreline.

KenmareRiver SAC 002158

Kenmare River, Co. Kerry, is a long and narrow, south-west facing bay. It is a deep, drowned glacial valley and the bedrock is mainly Old Red Sandstone which forms reefs along the middle of the bay throughout its length. Exposure to prevailing winds and swells at the mouth diminishes towards the head of the bay. Numerous islands and inlets along the length of the bay provide further areas of additional shelter in which a variety of habitats and unusual communities occur.

KenmareRiver has a very wide range of marine communities from exposed coast to ultra-sheltered areas. The site contains three marine habitats listed on Annex I of the EU Habitats Directive, namely reefs, large shallow bay and caves. There is also an extremely high number of rare and notable marine species present (24) and some uncommon communities. KenmareRiver is the only known site in Ireland for the northern sea-fan, Swiftia pallida and is the only known area where this species and the southern sea-fan Eunicella verrucosa co-occur.

KenmareRiver contains an exceptional complement of marine and terrestrial habitats, many of which are listed on Annex I of the EU Habitats Directive. The presence of a number of rare species, including two species listed on Annex II of the Directive and a protected plant, together with the ornithological interest of the area, adds further to the importance of the site. (NPWS 2004)

Objective 1 of the Conservation Objectives (NPWS 2010) is to maintain the favourable conservation status of the following habitats and species;

  • Vertigo angustior [1014]
  • Large shallow inlets and bays [1160]
  • Reefs [1170]
  • Perennial vegetation of stony banks [1220]
  • Vegetated sea cliffs of the Atlantic and Baltic coasts [1230]
  • Lesser horseshoe bat (Rhinolophus hipposideros) [1303]
  • Atlantic salt meadows (Glauco-Puccinellietalia maritimae) [1330]
  • Otter (Lutra lutra) [1355]
  • Common seal (Phoca vitulina) [1365]
  • Mediterranean salt meadows (Juncetalia maritimi) [1410]
  • Shifting dunes along the shoreline with Ammophila arenaria (white dunes) [2120]
  • Fixed coastal dunes with herbaceous vegetation (grey dunes) [2130]
  • European dry heaths [4030]
  • Calaminarian grasslands of the Violetalia calaminariae [6130]
  • Submerged or partly submerged sea caves [8330]

Impact of Project on Key Species and Key Habitats

Loss of Habitat

A small area of shingle and gravel habitats are likely to be lost and unavailable for feeding and spawning in the shore term during construction of the pier/pontoon. The loss of habitat is likely to be temporary in nature as a result of the floating nature of the pier. Once constructed it is expected that the habitats will return to its natural state. (OES Consulting. 2007)

Loss of Species

There will be a direct loss of sessile species through the removal of habitat during the construction phase of the pier. There may also be an indirect loss of species (invertebrates, vertebrates and plants) through the loss of feeding and spawning grounds available. Mobile species should be able to avoid the area and avoid potential adverse impacts.

However, once the pier is constructed it is expected that species will readily recolonise the area from the surrounding habitat. The loss of species as a result of the feeding and spawning grounds is likely to be negligible as only a small area would be impacted when compared with similar area available in the area.(OES Consulting. 2007)

Increased Suspended Solids

As a result of the construction works siltation may cause damage to fisheries and wildlife. It is envisaged that there will be a short term increase in the turbidity of the water column during the construction of the pier. This could result in increased siltation, which could potential suffocate sessile non mobile organisms, and reduce light for phytoplankton.

It is anticipated that the contribution from construction activities would be minimal in nature however some sheltered area could experience increased sedimentation. (OES Consulting. 2007)

Noise Vibration and Physical Disturbance

Noise vibration and physical disturbance as a result of the construction of the development may disturb the surrounding flora and fauna. Disturbance to Common Seals in particular has the most significant effects in the nursery period which occurs between June to August. During this period the seal pups must gain adequate weight and become self-sufficient. During this period the seals are nursed on islands during low water periods in particular PotatoIsland located 100m west from Inishkeragh. Any disturbance during this period may result in a reduction of the required intake of milk. This would subsequently result in less fat intake and reduced chances of survival of the pups and potentially result in displacement of the seals and otters from the area.

The disturbance from construction activity (material storage, machinery such asdiggers, rock breakers, generators, marine activity, and human presence) willcause birds resident and breeding, visiting and feeding on the island to bedisplaced, notably the Rock Pipit (Anthus petrosus) and wren (Troglodytestroglodytes). The latter birds are Green listed species. They are not underthreat with regard to their numbers. The birds are likely to relocate to othernearby islands and set up a new home during construction. In relation to theamber listed species, the Cormorant (Phalacrocroax carbo) and the CommonGull (Larvus canus) are not dependant on the island for habitat as they can befound in the larger area of Kenmare river.

Post construction the noise and disturbance issues associated with theconstruction phase will no longer exist and so present residing birds may returnto the island. This is likely to occur during quiet periods with no humanpresence.

Noise impacts associated with the proposed development are likely to beminimal and short term in nature and mainly restricted to the constructionphase.(OES Consulting. 2007)

Pollutants and Waste

During the construction phase of the proposed development chemicals i.e.hydrocarbons, cement could contaminate the area and adversely impact marinesediments and marine organisms. These materials are toxic to marineorganisms and could also inhibit recolonisation of the area after construction.The water pollutants can also bioaccumulate and affect apex predators withinthe area such as Seals and Otters.

Post construction there is potential for sewage pollution to contaminate the waterif left untreated.No vulnerable habitats that might be affected by the development were notedon the islands of Inishkeragh. However the habitats of Otter, Common Seal,and resident birds are vulnerable to disturbances from construction activity andresidual impacts of thedevelopment.

In general the impacts associated with the development are largely temporaryin nature, as the area would be recolonised post construction.(OES Consulting. 2007)

Proposed Mitigation

The following mitigation measures are recommended in order to avoid, reduceor remedy the adverse environmental effects associated with the proposeddevelopment.

Potential Impact: Temporal loss of feeding habitat during construction.

Proposed Mitigation

  • Undertake construction outside the breeding and molting season for the Common Seal and when birds are not feeding along the foreshore areas.
  • It is recommended that a fully annotatedlandscaping plan is developed for the site toinclude native tree species which are local andrepresentative of the area be submitted to Kerry County Council.

Potential Impact:Permanent loss and disturbance of habitat.

Proposed Mitigation

  • Specific construction activities will be timed to avoid sensitive periods such as spawning, nursing and migratory periods, where possible. The programme of construction activities will be developed in consultation with National Parks and Wildlife Services and Kerry County Council by an appropriately qualified ecologist. The purpose of this consultation will be to determine specific constraints for specific activities. This would be particularly important for bird species such as Cormorant, and Common Gull, and also Common Seal, Otter, Salmonids, and shellfish. The programme should also include a comprehensive approach for water quality protection during construction phase of the development.
  • To minimise habitat and species loss and disturbance, efforts will be made to keep thearea disturbed by construction activities to a minimum.

Potential Impact:Pollution of waters as a result of construction activities.

Proposed Mitigation

  • Construction activities close to sensitive watercourses should be programmed during drier months to minimise the risk of potential erosion.
  • Construction of sediment traps (fences) and basins will occur before other land disturbance activities are implemented. Sediment traps will be regularly inspected, maintained and cleaned as necessary.
  • Phasing of works will be undertaken wherever possible to minimise erosion potential.
  • All fuels or chemicals kept on the construction site will be stored in bunded containers.
  • All refuelling and maintenance will be carried out in ramped containment areas away from sensitive environments.
  • Oil interceptors will also be installed in appropriate locations (i.e. refuelling locations) such that surface water which could become contaminated with hydrocarbons is afforded appropriate treatment.
  • Equipment will be regularly maintained and leaks repaired immediately.
  • Accidental spillages will be contained and cleaned up immediately. Remediation measures will be carried out in the unlikely event of pollution of adjacent watercourses in accordance with recommendations from suitability qualified and experienced personnel.

Potential Impact:Chemical pollution of waters and waste water operation of the proposed development.

Proposed Mitigation

  • Self-contained chemical toilets will be used for the treatment of all 'domestic nature' sewage generated onsite.
  • The waste from these toilets will be removed from site by an appropriate permitted contractor for treatment/disposal in accordance with best environmental practice (ensuring that no sewage is directly discharged to watercourses).
  • An advanced waste water treatment unit and percolation area will be installed to ensure that the waste water is sufficiently treated before it enters the groundwater.
  • Specialist contractors will be employed to installing the guides for the floating pier and will use materials that have been approved for use in the marine environment. Construction methods should be applied to minimise the release of polluting materials into the water column.

Supervision of mitigation measures should be undertaken by a qualified environmental scientist to ensure they are correctly implemented, and where required, make alterations to same if considered necessary to improve their effectiveness.(OES Consulting 2007)

Impact on the Integrity of the Site

All species, including those of high conservation importance, such as the Otter and Common Seal are expected to continue to occur in the area after theconstruction is complete.

The proposed landscape plan will in the long term, lessen the residual impacts with regard to the removal of bracken, dry heath and shingle and gravel shores.

The island is bounded by a SAC and consequently all works will be discussedwith the National Parks & Wildlife Service in advance and provision should bemade for a qualified ecologist to supervise works on these islands if required. Ifsuitable precautions are taken and best practice for the storage, handling anddisposal of such material are followed, impacts should be minimal. Theproduction of a Programme of Works to include agreed scheduled constructiondates and include mitigation measures outlined above to be fullyimplemented will ensure compliance with the various National and EuropeanUnion legislative instruments relating to habitats and species.

It is anticipated that if best construction practices are implemented the scaleand negative impacts of the development as a result of construction activitieswill be minimal in nature.(OES Consulting 2007)

On the basis of the above it is considered that the integrity of the Kenmare River SAC will not be adversely impacted by the proposed construction of a slipway and concrete pad with ladder to access floating pontoon and gangway at Inishkeragh Island, Sneem, Co. Kerry.

Prepared by

Barry Mc Donald M.Eng. M.I.E.I.,

Engineer & EngineeringInspector

Department of Environment Heritage & Local Government

09/02/2012

References

NPWS (2004) SiteSynopsisKenmareRiver SAC Site Code: 002158

NPWS (2010) DraftGenericConservationObjectivesKenmareRiver SAC Site Code: 002158

OES Consulting (2007) Ecological Assessment, OES Consulting, FBD House, Fels Point, Tralee, Co. Kerry