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1
Assessment of Risk to Marine Mammals from the Propose Installation of a
Submarine Fibre Optic Cable at Mosney, Co. Meath
Client: PiPier Infrastructure LTD.
Ecological Consultants: IWDG Ltd.
Author: Dr. Joanne O’Brien
Date: December 2016
Irish Whale and Dolphin Group,
Merchants Quay, Kilrush, Co. Clare, Ireland
www.iwdg.ie
Marine Mammal Risk Assessment: Fibre Optic Cable Installation, Mosney Co. Meath
2 Irish Whale and Dolphin Group (www.iwdg.ie)
Dr. Joanne O’Brien
Table of Contents Table of Contents ................................................................................................................................ 2
1.0 Introduction ................................................................................................................................ 3
2.0 Legal Status of Marine Mammals in Ireland ............................................................................... 4
3.0 Information on the Proposed Activity ........................................................................................ 6
4.0 Marine Mammal Activity Within the Area of Proposed Activity ................................................ 8
4.1 The National Biodiversity Data Centre’s online mapping system of species records ......... 9
4.2 The Irish Whale and Dolphin Group Online Database of Sightings of Cetacean Species . 11
4.3 Appendix 4 of NPWS Guidance Document (NPWS, 2014) ................................................ 15
4.4 Summary of Desktop Data Records of Marine Mammals ................................................ 17
5.0 Impact Assessment ................................................................................................................... 17
5.1 NPWS Assessment Criteria .................................................................................................... 17
5.2 Mitigation .............................................................................................................................. 19
5.3 Summary ............................................................................................................................... 20
6.0 References ................................................................................................................................. 21
Marine Mammal Risk Assessment: Fibre Optic Cable Installation, Mosney Co. Meath
3 Irish Whale and Dolphin Group (www.iwdg.ie)
Dr. Joanne O’Brien
1.0 Introduction
The Irish Whale and Dolphin Group (IWDG) were contracted by PiPier Infrastructure Ltd. to carry out
a review of marine mammal activity in the vicinity of Mosney Co. Meath, an area of interest for
proposed installation of a submarine fibre optic cable. The cable laying process will include laying of
fibre optic cable protected in a steel casing along the intertidal area. The operation will centre on a
narrow section of foreshore off the coast off Mosney, Co. Meath (Figure 1).
Figure 1. Location of the propose cable laying at Mosney, Co. Meath
As recommended under the NPWS Guidelines (NPWS, 2014), coastal and marine activities be subject
to a risk assessment for anthropogenic sound-related impacts on relevant protected marine mammal
species to address any area-specific sensitivities, both in timing and spatial extent, that would inform
the consenting process. This marine mammal risk assessment will consider the following based on the
NPWS guidance document (NPWS, 2014); 1) Source, 2) Species and 3) Environment.
1. Source; where the source of anthropogenic noise will come from the cable laying vessel itself while in the vicinity.
2. Species; based on assessment from various data sources on the species of marine mammals occurring within the proposed cable laying location as well as surrounding areas.
3. Environment; where cable laying is propose to take place, marine mammal occurrence within this area will be assessed.
Marine Mammal Risk Assessment: Fibre Optic Cable Installation, Mosney Co. Meath
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Dr. Joanne O’Brien
2.0 Legal Status of Marine Mammals in Ireland
In Ireland, cetaceans (whale, dolphins and porpoises), pinnipeds and the Eurasian otter (Lutra lutra)
are protected under a suite of national and international legislation. All cetaceans, as well as grey
(Halichoerus grypus) and harbour seals (Phoca vitulina) and our only species of otter are protected
under the Wildlife Act (1976) and amendments (2000, 2005, 2010 and 2012). Under the act and its
amendments, it is an offence to hunt, injure or wilfully interfere with, disturb or destroy the resting
or breeding place of a protected species (except under license or permit from the Department). The
act applies out to the 12 nm limit of Irish territorial waters. Additionally, all cetaceans, pinnipeds and
otter and are protected under the EU Habitats Directive, where all cetaceans are included in Annex IV
of the Directive as species ‘in need of strict protection’. Under this Directive, the harbour porpoise
(Phocoena phocoena), bottlenose dolphin (Tursiops truncatus), grey seal, harbour seal and Eurasian
Otter are listed under Annex II, which identifies these species of community interest and whose
conservation requires the designation of Special Areas of Conservation (SACs).
In 2007, the National Parks and Wildlife Service (NPWS) of the Department of Arts, Heritage
and the Gaeltacht produced a ‘Code of Practice for the Protection of Marine Mammals during Acoustic
Seafloor Surveys in Irish Waters (NPWS, 2007). These were reviewed and amended to produce
‘Guidance to manage the risk to marine mammals from man-made sound sources in Irish waters’
(NPWS, 2014). This guidance document sets out the potential risks to marine mammals from man-
made sounds. It states that “An assessment of risk forms an important part of the decision-making
framework for mitigating the effects of anthropogenic sound in the marine environment. It is
recommended that … [certain] coastal and marine activities undergo a risk assessment for
anthropogenic sound-related impacts on relevant protected marine mammal species, to inform the
consenting process.”
The NPWS draft guidance states:
“A risk assessment for each marine mammal species of relevance to the proposed works area
needs to consider the nature of the sound source, its likely and/or potential effects on individuals
and/or populations and on their likely habitat…
Where an assessment identifies the likelihood of a risk to protected marine mammal species,
either by virtue of (a) the proposed operation or activity and/or (b) the sensitivity of a particular
site in which the sound-producing operation or activity is proposed, it is recommended that
appropriate risk management measures are pursued by the relevant Regulatory Authority.”
The guidance goes on to state:
“Following the initial identification and assessment of risk arising from an operation or activity
… a menu of management options is available to Regulatory Authorities in their decision making
process and it includes:
A1. Consent without mitigation (e.g., where the risk of any adverse effects has been ruled out)
Marine Mammal Risk Assessment: Fibre Optic Cable Installation, Mosney Co. Meath
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Dr. Joanne O’Brien
A2. No consent given for the activity
A3. Avoid critical habitats for marine mammals (e.g., designated sites or other locations
identified as sensitive via the risk assessment process)
A4. Avoid operations during key periods of the species’ life cycle (e.g., breeding/resting,
migration)
A5. Avoid time periods when effective impact mitigation is not possible, and/or
A6. Risk minimisation measures, namely
A6.1. Minimise the duration over which the sound-producing activity is intended to take
place;
A6.2. Minimise the individual and cumulative sound pressure and exposure levels delivered
into the environment by the activity. If necessary the use of alternative, lower impact
equipment and methods should be explored (e.g., vibratory hammer, gravity base piles).
A6.3. Incorporate the use of clear “ramp-up” or “soft-start” procedures, whereby sound
energy input to the marine environment is gradually or incrementally increased from levels
unlikely to cause significant behavioural impact on marine mammals to the full output
necessary for completion of the activity.
A6.4. Incorporate the use of fully enclosing or confined bubble curtains, encircling absorptive
barriers (e.g., isolation casings, cofferdams) or other demonstrably effective noise reduction
methods at the immediate works site, in order to reduce underwater sound propagation
from on-site operations. Studies have shown that such methods can provide a significant
reduction in sound input to the wider aquatic environment in the order of 10-30 dB.
A6.5. The use of trained marine mammal observers (MMO’s) provides effective means of
detecting marine mammals in the vicinity of coastal and marine operations. Associated
operational considerations should also be taken into account.”
Figure 2. Flow diagram illustrating the staged process towards managing risk (NPWS, 2014).
Risk
Characterisatio
n
Risk
Assessment
Risk
Management
Consent
without
mitigation (A1)
No Consent
(A2)
Risk avoidance
Risk
minimisation
(A6)
Marine Mammal Risk Assessment: Fibre Optic Cable Installation, Mosney Co. Meath
6 Irish Whale and Dolphin Group (www.iwdg.ie)
Dr. Joanne O’Brien
3.0 Information on the Proposed Activity
Cable laying is expected to take place in February/March 2017 during which time it is envisaged that
vessel traffic in the area will be restricted along the cable laying route. Some shore based preparation
will be carried out prior to the time of cable laying. During cable landing operations, excavators, cable
winch, and rigging will be moved on site. The beach landing party will have deployed quadrants on
the beach to assist in guiding the cable along the designated installation pathway. The main lay vessel
will transfer a messenger line to a small boat, which will either tow the cable in or pull the messenger
rope in to the beach party. The messenger line will be connected to an excavator doing beach pulls
(if not using a large winch). When connected, the beach pull will start and the “vessel crew” will add
floats to the cable as it is deployed from the vessel (see example, Figure 3).
When sufficient cable is on the beach, it will be secured (on the beach), and the
floating cable will be adjusted to suit the route while divers will start to remove the cable
floats and the cable will sink to the seabed. When the cable is on seabed, the divers will
inspect the cable and may do some minor slack adjustment where possible/required. Once
the test has been successfully carried out, the ship will commence laying the cable. The cable
across the beach will have articulated pipe installed to the Low Water Mark (possibly further
if required). After the articulated pipe has been installed, a trench will be dug at the side of
the cable and the cable will be lowered into the trench. This will continue towards the low
water line, and the cable may be hand jetted (using water pressure) to lower it to 1m below
the seabed. As soon as the cable has been installed in the trench, it will be backfilled, and the
beach will be restored to the original profile. All equipment will be removed from the site.
Marine Mammal Risk Assessment: Fibre Optic Cable Installation, Mosney Co. Meath
7 Irish Whale and Dolphin Group (www.iwdg.ie)
Dr. Joanne O’Brien
Figure 3. Example of a Fibre Optic cable being installed in a similar environment.
All vessels used over the duration of the process will conform to MARPOL, including general
requirements over the control of waste oil, engine oil discharges and grey and black waste water
discharges; prevention of pollution by garbage from ships and prevention of air pollution; and
maintain operating procedures for dealing with incidents such as oil and waste spillages that
potentially may threaten the marine environment. Plough burial of cable is usually performed in water
depths of less than 1000m where the seabed conditions allow. An industry-standard cable plough
weighs approximately 12 tonnes in water. It is deployed from the stern of the installation vessel and
towed behind the ship, burying the cable into the seabed, usually to a depth of 1 m, as it progresses
along the route.
As the plough is towed through the seabed its share blade and inclined cutting disk lift a wedge
of substrate. As the plough progresses forwards, this sediment is dropped back into the trench,
emplacing the cable at the bottom of a relatively undisturbed sediment wedge. It is expected that the
sand will have resorted to a natural state after one tidal cycle. The intertidal cable laying works will
take one day to complete. This type of activity (cable-laying) is not covered by the NPWS guidance
document to “Manage the Risk to Marine Mammals from Man-made Sound Sources in Irish Waters”.
Hence, this proposed work qualifies under the category - Consent without mitigation (A1) and does
not require an MMO on site during the process. Additionally, the area is not an enclosed harbour, bay
or inlet, so if side-scan sonar techniques are employed over the duration, an MMO is not required.
However, as good practice the soft start procedure should be undertaken.
Marine Mammal Risk Assessment: Fibre Optic Cable Installation, Mosney Co. Meath
8 Irish Whale and Dolphin Group (www.iwdg.ie)
Dr. Joanne O’Brien
Figure 4. An exampleof a plough to be towed behind the ship to bury and infill cable.
4.0 Marine Mammal Activity Within the Area of Proposed Activity
To date 25 species of cetaceans have been recorded in Irish waters and two regularly occurring seal
species, the Grey Seal and Harbour/Common Seal. Of the 25 cetacean species recorded in Irish waters,
one species is known only from strandings (Gervais beaked whale (Mesoplodon europaeus (Gervais
1855)), three species are known only from sightings (beluga (Delphinapterus leucas), northern right
whale (Eubalaena glacialis), and Bowhead whale (Balaena mysticetus)), while 21 species have been
recorded both stranded and sighted (Berrow 2001; O’Brien et al., 2009). This high number (around a
quarter of the world’s total number of species) reflects the diversity of habitats from the relatively
shallow (<200m) continental shelf, to the deep water (>2000m) to the west (including the shelf edge).
Seal species have been found to breed around all shorelines of Ireland and use the coastal and offshore
waters in their daily lives for foraging, transit between terrestrial resting places (known as haul-out
sites), and other behaviours linked to their annual life cycles (e.g., social behaviour, territoriality).
The following record sources for marine mammals were accessed to assess their occurrence
within and around the area of the proposed cable laying area. These sources included;
1. The National Biodiversity Data Centre (NBDC) online database of species (accessed at
www.biodiversityireland.ie on November 13, 2016)
2. The Irish Whale and Dolphin Group (IWDG) online database of sightings of primarily cetaceans
but other marine megafauna, including basking sharks and turtles (www.iwdg.ie, November
12, 2016)
Marine Mammal Risk Assessment: Fibre Optic Cable Installation, Mosney Co. Meath
9 Irish Whale and Dolphin Group (www.iwdg.ie)
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3. Appendix 4 of the National Parks and Wildlife Service guidance document (NPWS, 2014) which
provides generalised maps of marine mammal distribution and habitat in Irish waters.
This risk assessment was based on a review of available literature and data sources. Maps of the
distribution of cetacean sightings the Co. Meath coastline were prepared using data from the Irish
Whale and Dolphin Group’s casual sightings database (IWDG, 2016). Results from searches of the
NBDC database are provided in Tables below. However, it is acknowledged that absence of records
does not provide conclusive evidence that marine mammals are absent from an area.
4.1 The National Biodiversity Data Centre’s online mapping system of species records
The National Biodiversity Data Centres’ (NBDC) online database was accessed for grey and harbour
seal records, as well as European otter records in the vicinity of the proposed works at Mosney. The
cable laying operations will take place within National Grid Squares (NGS, 10km) O16 and O26. These
NGSs as well as the surrounding NGSs; for records of all three species.
(i) Harbour seal (Phoca vitulina)
Some of the most important haul-out sites for harbour seals are along the west coast of Ireland,
including; Bantry Bay, Kenmare River, Galway Bay, Sligo Bay and the Donegal Coast and Carlingford
Lough (Lyons, 2004). Harbour seals are less widespread and abundant in Ireland than grey seals, but
abundance estimates in 2004 were estimated at 2,905 common seals in total for the Republic of
Ireland (Cronin et al. 2004). More recently, counts were combined from 2011 and 2012 surveys, which
showed a total of 3,489 harbour seals, an increase of 18.1% from 2003 (Duck and Morris, 2013). No
records of harbour seals exist for the Mosney area within the NBDC database (O16), while a number
of sightings exist for sites at Balbriggan, c5km south of the proposed works. The last seal survey
undertaken on the East Coast was in 2012, when no harbour seals were counted off Co. Meath same
as the 2003 survey results (Duck and Morris, 2013; Figure 5).
(ii) Grey seal (Halichoerus grypus)
Grey seals are widespread and abundant in Ireland, with the greatest numbers found in the south-
western, western and northern coasts, but smaller populations are also found on the east and south
coasts. Previous work has shown the largest populations exist on the Blasket Islands, Inishkea Island
group and the Saltees (Lyons, 2004). A minimum estimate of 5,343 grey seals was recorded among
haul-out sites in the Republic of Ireland between 1-9 March, 2007, with over 45% of all grey seals
recorded on two islands, Inishkea North, Co. Mayo and the Great Blasket Island, Co. Kerry (O’Cadhla
Marine Mammal Risk Assessment: Fibre Optic Cable Installation, Mosney Co. Meath
10 Irish Whale and Dolphin Group (www.iwdg.ie)
Dr. Joanne O’Brien
et al. 2007). Grey seals are highly mobile and may remain at sea for extended periods, especially
outside the breeding season travelling distances of several hundred kilometres from breeding colonies
(Cronin et al. 2013). Six records of harbour seals exist for the Cardy Rocks area on the NBDC database,
which is approximately 7km south of the site of the proposed works. (O16 and O26; Table 1).
Additional records listed are for Lambay Island, more than 30km from the proposed works. During the
2012 aerial survey, no grey seals were recorded off Co. Meath (Duck and Morris, 2013; Figure 6).
Figure 5 and 6. The number and distribution of harbour (orange) and grey seals (blue) counted in west,
south-west, south and east Ireland in August-September 2012 (From Duck and Morris, 2013).
Table 1. Records of Harbour and Grey seals within and surrounding NGS Q40, V49.
Grid square Species Date Location Precision Source
O16 Grey seal 20/08/2003 Cardy Rocks 2km NBDC
O16 Grey seal 20/08/2003 Cardy Rocks 2km NBDC
O26 Grey seal 20/08/2003 Cardy Rocks 2km NBDC
O26 Grey seal 20/08/2003 Cardy Rocks 2km NBDC
O26 Grey seal 20/08/2003 Cardy Rocks 2km NBDC
O26 Grey seal 31/08/2012 Baily Lighthouse 2km NBDC
Marine Mammal Risk Assessment: Fibre Optic Cable Installation, Mosney Co. Meath
11 Irish Whale and Dolphin Group (www.iwdg.ie)
Dr. Joanne O’Brien
(iii) Eurasian Otter (Lutra lutra)
Otters are found across a variety of aquatic habitats, including; rivers, lakes, estuaries, canals, marsh
and along the coast. Coastal dwelling otters require access to fresh water to regularly rinse their fur
to avoid problems with insulation. No records exist for the site of the proposed works, and the closest
sightings are for Balbriggan and Skerries, Co. Dublin, some 10km south east.
4.2 The Irish Whale and Dolphin Group Online Database of Sightings of Cetacean
Species
The Irish Whale and Dolphin Group (IWDG) operate an online validated database of cetacean sightings
and other megafauna including basking sharks and sea turtles. This database was accessed to map the
sighting records off the Co. Meath coastline from 2000-2016. A total of 14 cetacean records exist for
this time frame off the coastline of Co. Meath (stretching 10.4km), accounting for two species, and a
total of 86 individuals, including; Bottlenose dolphin and Harbour porpoise (Figure 7). Two Basking
shark records also exist for Co. Meath, but of the 14 cetacean sightings, 10 were not identified to
species level.
Figure 7. Map of cetacean distribution off Co. Meath 2000-2016.
Marine Mammal Risk Assessment: Fibre Optic Cable Installation, Mosney Co. Meath
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(i) Bottlenose dolphin (Tursiops truncatus)
Bottlenose dolphins are widespread and relatively abundant off the Irish coast with most sightings
along the western seaboard (Berrow et al. 2010). Recent genetic evidence (Mirimin et al. 2011)
suggests the existence of three discrete populations of bottlenose dolphins in Ireland, the Shannon
Estuary, a coastal inshore population and a putative offshore population. The “putative offshore
population” that was suggested by Mirimin et al. (2011) has recently been confirmed by Louis et al.
(2014) who showed offshore dolphins in Ireland are genetically discrete from the Inshore population
and part of a large wide-ranging group that includes dolphins from the Bay of Biscay and the Azores.
O’Brien et al. (2009) showed that the “Inshore population” (referred to as the Connemara-Mayo
population by Ingram et al. 2001 and Mirimin et al. 2011) which is regularly recorded off Connemara
is highly mobile with re-sightings of individual bottlenose dolphins from around the entire Irish coast.
IJsseldijk et al. (2012) carried out a more recent analysis which included 50 individual dolphins
photographed off Connemara and showed a very high overall re-sighting rate of c.28%. These results
suggest that this highly mobile population is relatively small and exhibits high local site fidelity.
Recently individuals from this “Inshore population” in Ireland have been matched to the northeast
and west coast of Scotland (Robinson et al. 2012) and to southwest England (Ryan et al. 2010). Two
sighting records exist off Co. Mosney for bottlenose dolphins (Figure 8), with group sizes ranging from
4-50 individuals.
Figure 8. Map of bottlenose dolphin distribution off Co. Meath 2000-2016.
Marine Mammal Risk Assessment: Fibre Optic Cable Installation, Mosney Co. Meath
13 Irish Whale and Dolphin Group (www.iwdg.ie)
Dr. Joanne O’Brien
(ii) Harbour porpoise (Phocoena phocoena)
Harbour porpoises are recorded year round and at high densities off the east coast (Wall et al.
2013). Two porpoise records exist for the Co. Meath coastline (Figure 9), but the location is of the
works is over 10 km from the Rockabill to Dalkey SAC boundary, where porpoise abundance was
estimated as 391±25 (344-445) individuals in 2014 (Berrow and O’Brien, 2014).
Figure 9. Map of harbour porpoise distribution off Co. Meath 2000-2016.
(iii) Other cetacean species
10 of the total 14 cetacean records for Co. Meath were not identified to species level, but were
most likely harbour porpoise and bottlenose dolphins (Figure 10).
Marine Mammal Risk Assessment: Fibre Optic Cable Installation, Mosney Co. Meath
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Dr. Joanne O’Brien
Figure 10. Map of un-identified cetacean species distribution off Co. Meath, 2000-2016.
(iv) Basking shark (Cetorhinus maximus)
Basking sharks are seasonally abundant off the west coast, with most sightings recorded during late
spring and early summer (Figure 11). Sighing records are not as abundant on the east coast, and a
total of two records exist for the Co. Meath coastline.
Figure 11. Map Basking Shark distribution off Co. Meath, 2000-2016.
Marine Mammal Risk Assessment: Fibre Optic Cable Installation, Mosney Co. Meath
15 Irish Whale and Dolphin Group (www.iwdg.ie)
Dr. Joanne O’Brien
4.3 Appendix 4 of NPWS Guidance Document (NPWS, 2014)
This NPWS publication provides generalised maps of marine mammal distribution and habitat in Irish
waters. These maps indicate that there is habitat suitable for the following species in waters adjacent
to the proposed works.
Marine Mammal Risk Assessment: Fibre Optic Cable Installation, Mosney Co. Meath
16 Irish Whale and Dolphin Group (www.iwdg.ie)
Dr. Joanne O’Brien
Harbour seal Grey seal
Marine Mammal Risk Assessment: Fibre Optic Cable Installation, Mosney Co. Meath
17 Irish Whale and Dolphin Group (www.iwdg.ie)
Dr. Joanne O’Brien
The maps presented in the NPWS guidance document show that a large amount of habitat offered is
available to a variety of marine mammals along the east coast. However, these maps are presenting
data for the entire EEZ so are not suitable for assessing fine spatial occurrence such as that achieved
through the IWDG and NBDC databases.
4.4 Summary of Desktop Data Records of Marine Mammals
In summary, evidence from the data sources accessed suggest that cetaceans occur infrequently off
the Co. Meath coastline. Species most likely to be encountered include bottlenose dolphins and
harbour porpoises. Both species of seal have been recorded at locations adjacent to the works but
not at the actual site. Therefore, the vast majority of cetacean and seal activity is located away from
the area of the proposed works.
5.0 Impact Assessment
5.1 NPWS Assessment Criteria
This Marine Mammal Risk Assessment is based on the NPWS guidance document (NPWS, 2014); and
assessment was carried out in order to address 1) Source, 2) Species and 3) Environment. A detailed
description of the proposed works is included as well as detailed maps and tables of marine mammal’s
distribution in the vicinity of the proposed work at Mosney, Co. Meath. Data from the IWDG sightings
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Dr. Joanne O’Brien
database (IWDG, 2016), NBDC database (NBDC,2016) and using the NPWS generalised maps of marine
mammal distribution (NPWS, 2014) were used to carry out the assessment.
1. Do individuals or populations of marine mammal species occur within the propose area?
From the three data sources accessed, the most likely species to be encountered at the site
include; bottlenose dolphin and harbour porpoise. As the proposed works includes ploughing
through soft sediment with immediate infilling, the impact of such work does not deem to
propose a threat to marine mammals in the area.
2. Is the plan or project likely to result in death, injury or disturbance of individuals?
There is some potential for direct or indirect impact from the cable-laying work on marine
mammals in the area. The potential impacts would arise from the cable-laying vessel itself
through;
• Noise
• Visual disturbance
• Interaction with vessels/cable.
With regards to these potential impacts, the cable laying is expected to be completed over a
short timeframe, keeping potential disturbance to a minimum. The east coast is a busy shipping
and fishing area so the presence of the cable laying vessel will essentially be an extra vessel in
the area for this time, producing similar noise. With respect to interactions with the cable laying
equipment, the vessel is extremely slow moving and has minimal moving parts underwater.
The activity has previously been described as similar to laying lobster pots. Literature on the
noise emissions from cable laying activities are sparse, and therefore it is difficult to ascertain
what levels are associated or how fast the sound attenuates. Previous work in the UK found an
SPL of 123 dB re 1 mPa recorded at a range of 160 m from the trenching with the work been
undertaken in very shallow water (Newell et al., 2003). This compares with piling sound
pressure levels of 197 – 207 dB re 1 mPa at 103m from the source (Abbott, 2001). Given the
activity is likened to laying lobster pots, the associated anthropogenic noise levels are
insignificant. Therefore, there are no concerns for this activity negatively impacting on marine
mammals at the site.
Marine Mammal Risk Assessment: Fibre Optic Cable Installation, Mosney Co. Meath
19 Irish Whale and Dolphin Group (www.iwdg.ie)
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3. Is it possible to estimate the number of individuals of each species that are likely to be affected?
The number of sightings available for the Co. Meath coastline are extremely low (14 sightings
over a 16 year period), so the number of cetaceans likely to be encountered on any given day
could range from zero to a large group of dolphins, as previously up to 50 bottlenose dolphins
have been recorded off Bettystown, Co. Meath.
4. Will individuals be disturbed at a sensitive location or sensitive time during their life cycle?
No sensitive areas are evident within the vicinity of the proposed work at Mosney, Co. Meath.
The Rockabill to Dalkey Harbour porpoise SAC is over 10km from the proposed works.
5. Are the impacts likely to focus on a particular section of the species’ population, e.g., adults vs. juveniles, males vs. females?
It is impossible to assess this impact/risk as the data available does not permit. Marine
mammal sightings off the Co. Meath coastline are sporadic and irregular.
6. Will the plan or project cause displacement from key functional areas, e.g., for breeding,
foraging, resting or migration?
Based on the datasets available, it is unlikely that the proposed works will cause displacement
from key functional areas. Marine mammal sightings are very infrequent.
7. How quickly is the affected population likely to recover once the plan or project has ceased?
Marine Mammals along the Co. Meath coastline should already have a high tolerance to vessel
and shipping noise. It is expected that if animals are displaced from the vicinity of the cable
laying activity that they would re-establish quickly once the works cease.
5.2 Mitigation
Referring to the NPWS document ‘Guidance to manage the risk to marine mammals from man-made
sound sources in Irish waters (NPWS, 2014) and the detailed risk assessment matrix it documents, it
is clear that the prosed work falls under the category A1, “Consent without mitigation” (NPWS, 2014).
The proposed works are considered unlikely to present a risk to cetaceans or seals and therefore are
not considered to require specific mitigations.
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20 Irish Whale and Dolphin Group (www.iwdg.ie)
Dr. Joanne O’Brien
5.3 Summary
Based on the NPWS risk assessment matrix, this work falls under the category A1, “Consent without
mitigation” (NPWS, 2013). The proposed works are considered unlikely to present a risk to cetaceans
or seals and therefore are not considered to require specific mitigations.
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6.0 References
Berrow, S. (2001) Biological diversity of cetaceans (whales, dolphins and porpoises) in Irish
waters. In Marine Biodiversity in Ireland and adjacent waters. Ed. Nunn, J. Pages, 115-119.
Berrow, S., Whooley, P., O’Connell, M. and Wall, D. (2010) Irish Cetacean Review (2000-2009).
Irish Whale and Dolphin Group, 60pp. ISBN 0-9540552-4-1.
Berrow and O’Brien. (2013) Harbour Porpoise Survey 2013. Final Report to the National Parks
and Wildlife Service. Irish Whale and Dolphin Group. 24 pp.
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