LevelPressureEnvironment

ImpactPressureWaterColumn

ImpactPressureSeabedHabitats

ImpactPressureFunctionalGroup

NIS2_1

NISWaterColumnHabitat2_2

NISSeabedHabitats2_2

NISFunctionalGroups2_2

NotReported

NotReported

NotReported

NotAssessed

NotAssessed

NotAssessed

NotAssessed

Unknown_NotAssessed

Unknown_NotAssessed

Unknown_NotAssessed

Unknown_NotAssessed

NotRelevant

NotRelevant

NotRelevant

NotRelevant

Ireland will consider how best to improve our understanding of the presence, distribution, trends and impacts of NIS in Irish marine waters. These will be considered when developing our monitoring programmes and may include: - the production of taxonomic guides and the development of websites with clear colour pictures, descriptions and keys to species that will enable non-specialists recognise many unfamiliar and potentially non-indigenous species; - the use of genetic methods to enable the deduction of some species origins thus improving the ability to identify NIS and potential pathways; - the targeting of species that cause impacts within specific habitats; - the targeting of high risk hubs such as marinas, ports, consignments of aquaculture species and dry docks, and - the adaptation of existing programmes, such as larval fish surveys and young fish survey, to include the presence/absence of NIS occurrences.

Ireland will consider how best to improve our understanding of the presence, distribution, trends and impacts of NIS in Irish marine waters. These will be considered when developing our monitoring programmes and may include: - the production of taxonomic guides and the development of websites with clear colour pictures, descriptions and keys to species that will enable non-specialists recognise many unfamiliar and potentially non-indigenous species; - the use of genetic methods to enable the deduction of some species origins thus improving the ability to identify NIS and potential pathways; - the targeting of species that cause impacts within specific habitats; - the targeting of high risk hubs such as marinas, ports, consignments of aquaculture species and dry docks, and - the adaptation of existing programmes, such as larval fish surveys and young fish survey, to include the presence/absence of NIS occurrences.

Ireland will consider how best to improve our understanding of the presence, distribution, trends and impacts of NIS in Irish marine waters. These will be considered when developing our monitoring programmes and may include: - the production of taxonomic guides and the development of websites with clear colour pictures, descriptions and keys to species that will enable non-specialists recognise many unfamiliar and potentially non-indigenous species; - the use of genetic methods to enable the deduction of some species origins thus improving the ability to identify NIS and potential pathways; - the targeting of species that cause impacts within specific habitats; - the targeting of high risk hubs such as marinas, ports, consignments of aquaculture species and dry docks, and - the adaptation of existing programmes, such as larval fish surveys and young fish survey, to include the presence/absence of NIS occurrences.

Ireland will consider how best to improve our understanding of the presence, distribution, trends and impacts of NIS in Irish marine waters. These will be considered when developing our monitoring programmes and may include: - the production of taxonomic guides and the development of websites with clear colour pictures, descriptions and keys to species that will enable non-specialists recognise many unfamiliar and potentially non-indigenous species; - the use of genetic methods to enable the deduction of some species origins thus improving the ability to identify NIS and potential pathways; - the targeting of species that cause impacts within specific habitats; - the targeting of high risk hubs such as marinas, ports, consignments of aquaculture species and dry docks, and - the adaptation of existing programmes, such as larval fish surveys and young fish survey, to include the presence/absence of NIS occurrences.

Current information suggests that the majority of NIS occupy areas close to the coastline, with most occurring within embayment’s and estuaries, where conditions appear to be most suitable for reproduction and where there are coastal features likely to enable containment of their progeny. Ship ballast discharges also have the potential to introduce NIS but the subsequent fate of NIS discharged within ballast water remains unknown. Little is known on NIS occurrences offshore but there have been isolated occurrences reported e.g. the Japanese prawn, Masupenaeus japonicus, but it is unlikely that this species is established in Irish offshore waters. Few directed studies on NIS have taken place in Irish waters and those that have relate mainly to single species studies associated with aquaculture or man-made structures. Some species that have been introduced at an early time have only recently been recognised, e.g. the bamboo worm Clymenella torquata in 2006 (Minchin, 2007) most probably arises from the imports of American oysters over the period ~ 1880-1920 (AFBI/NIEA, 2011). Zooplankton studies have taken place but generally these have been in conjunction with egg and larval fish surveys and NIS have not been a priority in these studies. These surveys could be a source of information on NIS for future investigations. Gelatinous zooplankton can be difficult to monitor in such surveys, as these can be damaged during sampling to such an extent that their identification presents difficulties. Similarly, trawl surveys that are undertaken for pre-recruiting fishes have not been used to record or monitor NIS that might occur in samples. Overall knowledge on the distribution of many NIS species in Ireland is limited due to an absence of survey data. All indications suggest an increase over time in the numbers of NIS arriving to Ireland (Minchin, 2007). For some NIS their arrival in Ireland is preceded by large scale expansion in Northern Europe. It is difficult to determine the number of NIS largely due to identification uncertainties that surround some poorly-studied taxonomic groups. Subsequently, there is a high degree of uncertainty around trends estimations. This uncertainty is raised because estimates are based on the compilation of results from different sources of data, collected for different purposes and frequencies. Many NIS will go unrecorded and for others their status as NIS may be unclear for a variety of reason including their small size, presence in difficult habitats to study, or because of a similarity with other recognised species. There is also a high degree of uncertainty in relation to the principal pathways and actual vectors involved in the spread of NIS. Better monitoring of the relevant activities, particularly if there is direct evidence of transmission, is required to resolve this. Improved knowledge of pathways will result in better risk-assessment, more focused inspections of potential vectors and improved monitoring systems. The proportion of assessment area (%) where non-indigenous species are present is not available, due to the lack of monitoring data.

SAHFOS plankton recorder studies may be a useful source for the identification and distribution of some selected NIS species. But these surveys do not provide complete coverage by area or taxa for Irish marine waters. As a result the level of confidence as to the presence and knowledge of NIS within the water column, and any associated potential impacts, is low, especially for offshore regions.

The Irish seabed has been recently mapped to include the continental shelf and slope. Inshore areas have been surveyed by acoustic methods and a wide range of habitats mapped at a broad scale level, including bedrock, mobile sediments and biogenic reefs. The biological communities associated with these habitats have not been documented in detail and, as a result, the presence or absence of NIS remains generally unknown. In reduced salinity and estuarine waters there are known NIS distributions associated with seabed habitats, but their overall abundance, distribution, range (ADR) and impact have not been evaluated. It is possible, for some of these, that calculated abundance and distribution levels would attain high values for ADR indicating a potential to change benthic habitats. Man-made firm substrates are some of the most heavily colonised substrates by NIS. These tend to be in inshore areas such as aquaculture sites, ports and marina structures. However, offshore man-made structures such as renewable energy devices may also be important for the development of NIS populations and may aid in ‘stepping-stone’ transmissions to previously uncolonised regions. Species such as the amphipod Caprella mutica may have extended its range, in part, in this way. Seabed impacts resulting from an NIS would seem to relate to the abundance and the area/volume they occupy. Assessment of the abundance and distribution range (ADR) is seen as the first step in calculating an impact level. Although not assessed the extent of the seabed impacted by NIS would appear to be very minor, based on current knowledge. Few NIS are known to occur offshore. The area of seabed occupied by NIS is probably low with populations being concentrated within coastal estuaries and bays.

Invertebrates also endure impacts from NIS and make up a large proportion of the biomass in the pelagic and benthic realms. The great majority of invertebrate NIS are passive or active suspension feeders. Their relative abundance can result in competition should they be sufficiently abundant. Of the seventy-nine NIS recorded in Ireland 45% (N=36) are active and passive suspension feeders. At present there are no obvious competitive effects known with cultivated passive feeding species (Ostrea edulis, Crassostrea gigas, Mytilus edulis, M. galloprovincialis, Pecten maximus, Ruditapes philippinarum). Amphibalanus improvisus and Austrominius (Elminius) modestus dominate estuarine hard surfaces (e.g. Bandon estuary for E. modestus, and the Waterford estuary for A. improvisus; D. Minchin, personal observations) in otherwise free niches, with the latter frequent on the upper shore. Active suspension feeders consuming larger particles are often most abundant in areas where there are currents. Predatory NIS, which to-date in Ireland, are all crustacea, constitute 7% of the draft NIS Inventory for Ireland. However, no decapods are presently known to be established. Photoautotrophs (species which use light for energy) make-up a significant component of the draft NIS Inventory for Ireland, 24% (N=19), and generally have seasonal periods of abundance and a number of different life history stages. Some of these are difficult to identify. Records of chlorophyte and rhodophyte macroalgae NIS continue to increase and it is likely that their full distribution remains unrecorded. Locally these can dominate and probably exclude other species. Locally, Asparagopsis armata dominates alga communities and is not actively cropped, as it secretes bromo-acetic acid that deters grazers, and thereby provides a competitive advantage over native species. This species is presently in cultivation in Ireland (Kraan and Barrington, 2005). There is little available information of the impact of NIS upon marine vertebrates and cephalopods. Knowledge of marine diseases, and their origin, is still at a relatively early stage. Birds and fish (with the exception of eel), when considered as functional groups, are not extensively impacted by NIS. However, there are some studies that indicate that bird feeding areas may be affected. The degree of competitive interaction has not been established or quantified. Intertidal areas are known to be impacted as in the case of the range expansion of Spartina anglica, and can be evaluated from aerial photographs combined with ground-truthing. Aquaculture production can be affected by the cryptogen K. mikimotoi which can result in mortalities of cultured fish (Jenkinson and Connors, 1980). However, there are impacts upon other living groups that include the zooplankton (Minchin, 1985) and benthic invertebrates (Ottway et al., 1979).

The majority of NIS records relate to port regions and sites where aquaculture activities take place. These ‘hubs’ are sites where various pathways and vectors can overlap potentially leading to the local establishment and subsequent spread to other areas (Minchin, 2007). Currently there would appear to be range expansions of a number of species which have the potential to have an impact or are impacting within Irish waters (for example: Styela clava, Didemnum vexillum, Caprella mutica, Botrylloides violacues, Sargassum muticum, Crepidula fornicata). Some species such as the ‘shipworm’ Teredo navalis are still present in Irish marine waters but, in terms of impact, are no longer considered to be of importance with the change in hull designs to steel and fibre-glass and with more effective antifouling applications. Of the 35 marine species contained on the 100 worst list of invasive species identified by DAISIE (http://www.europe-aliens.org/speciesTheWorst.do), eight species are recorded in Ireland’s marine waters. These are, Anguillicola crassus, Amphibalanus improvisus, Bonnemaisonia hamifera, Codium fragile, Coscinodiscus wailesii, Crassostrea gigas, Ficopomatus enigmaticus, and Styela clava.

Few known NIS extend over the continental shelf. The cryptogen, Karenia mikimotoi is known to form spontaneous blooms in some years at the border of coastal and offshore water masses with inundations into coastal bays (Silke et al., 2005; Raine et al., 2001; McMahon et al., 1998). K. mikimotoi blooms can cause extensive localised invertebrate and fish mortalities either from toxins or possible inshore de-oxygenation events following bloom collapses. Blooms are known to result in declines of zooplankton, reduced recruitment in scallops and poor oyster growth (Minchin, 1985). The non-native introduced Asian eel swimbladder parasite Anguillicoloides crassus was first recorded in Ireland from eels captured in the Waterford Estuary in 1997 and since then it has become well established in several commercially exploited Irish eel fisheries such as those on the Shannon and Erne river systems, (Morrissey and McCarthy, 2007). In 2010, Upper Lough Erne and Upper Lough Derg had the highest percentage prevalence of A. crassus (66.7% and 62.1%, respectively) and Upper Lough Ree and Upper Lough Derg had the largest mean infection intensity (3.53 and 2.93 parasites per eel, respectively) (EIFAAC/ICES, 2011). The impact on the host population(s) as a whole is unclear, however, there is increasing evidence that the induced swim bladder degradation (Kennedy and Fitch, 1990) may compromise the eel’s spawning migration and reproduction, (Lefebvre et al., 2012). Recruitment of eel remains at an all time low since records began, the stock continues to decline and stock recovery will be, for biological reasons, a long-term process. Therefore, all negative anthropogenic factors impacting on the stock and affecting the production/escapement of silver eels should be reduced until there is clear evidence the stock is increasing (EIFAAC/ICES WGEEL, 2011). The eels captured in the Eel Management Plan and Water Framework Directive surveys were checked for the presence of A. crassus and these were summarised in the Irish Eel Report to the EU (Anon, 2012). Prevalence and intensity rates varied from east to west, but the northwest and southwest of the country show little to no infection by A. crassus. A number of catchments, such as the Munster Blackwater, the Laune and the Fergus, have shown low infection rates and patchy distribution which indicates recent introductions and continued spread. It should be noted that any transfer of water or fish, not only eels, can act as a vector for the spread of A. crassus. Therefore, any movements of fish or water between catchments should be undertaken with caution. This includes stocking programmes from hatcheries, transfers of coarse fish between water bodies and bilge water in boats.

Production of the native oyster Ostrea edulis in Ireland has declined due to bonamiosis (McArdle, 1991) leading to imports of unquarantined Pacific oysters Crassostrea gigas from France and the introduction of two copepods (Holmes and Minchin, 1995) and a possible ‘summer mortality disease’. C. gigas production is an important economic activity and is dependent on hatchery spat production and half-grown imports. There is now evidence indicating that C.gigas now recruits within some shallows of bays. The tunicates Styela clava (Nunn & Minchin, 2009) and Didemnum vexillum foul longlines (Fergal Guilfoyle, pers com., October 2008, Westport Bay), oyster bags and vessel hulls however their impacts upon the seabed have not been quantified. The barnacles Austrominius (Elminius) modestus and Amphibalanus improvisus (e.g. Bandon estuary for E. modestus, and the Waterford estuary for A. improvisus; D. Minchin, personal observations) dominate harbour and culture structures in some estuaries. Spartina anglica (Curtis and Sheehy-Skeffington, 1998) forms extensive monocultures on mud flats and marine algae Heterosiphonia japonica, and Colpomenia peregrina (Minchin, 1991) seasonally dominate shallows while Sargassum muticum (Kraan, 2009) can impair navigation in stony shallows for small craft. The wasting disease Labyrinthula zosterae (Whelan and Cullinane, 1987) reduced the extent of eel-grass nursery areas for fishes, the overall consequences of this are unclear but may have resulted in declines of Palaemon serratus in some areas. Native oysters will have suffered from shell disease induced by Ostracoblabe implexa (Colm Duggan, pers, Comm. 1963, Clew Bay) and mortalities as a result of gill damage observed in the 1980s was probably due to the grazing of the gills by the copepod Herrmannella duggani (Holmes & Minchin, 1991). The one-off event of gaffkaemia caused by Aerococcus viridans (Gibson, 1961), a bacterial disease of lobsters Homarus gammarus has not been recorded since. More recent establishment of the amphipod Caprella mutica (Tierney et al., 2004) and the slipper limpet Crepidula fornicata (McNeill et al., 2010) will probably cause inshore impacts on biodiversity as it spreads over greater areas.

The non-native introduced Asian eel swimbladder parasite Anguillicoloides crassus was first recorded in Ireland from eels captured in the Waterford Estuary in 1997 and since then it has become well established in several commercially exploited Irish eel fisheries such as those on the Shannon and Erne river systems, (Morrissey and McCarthy, 2007). In 2010, Upper Lough Erne and Upper Lough Derg had the highest percentage prevalence of A. crassus (66.7% and 62.1%, respectively) and Upper Lough Ree and Upper Lough Derg had the largest mean infection intensity (3.53 and 2.93 parasites per eel, respectively) (EIFAAC/ICES, 2011). The impact on the host population(s) as a whole is unclear, however, there is increasing evidence that the induced swim bladder degradation (Kennedy and Fitch, 1990) may compromise the eel’s spawning migration and reproduction, (Lefebvre et al., 2012). Recruitment of eel remains at an all time low since records began, the stock continues to decline and stock recovery will be, for biological reasons, a long-term process. Therefore, all negative anthropogenic factors impacting on the stock and affecting the production/escapement of silver eels should be reduced until there is clear evidence the stock is increasing (EIFAAC/ICES WGEEL, 2011). The eels captured in the Eel Management Plan and Water Framework Directive surveys were checked for the presence of A. crassus and these were summarised in the Irish Eel Report to the EU (Anon, 2012). Prevalence and intensity rates varied from east to west, but the northwest and southwest of the country show little to no infection by A. crassus. A number of catchments, such as the Munster Blackwater, the Laune and the Fergus, have shown low infection rates and patchy distribution which indicates recent introductions and continued spread. It should be noted that any transfer of water or fish, not only eels, can act as a vector for the spread of A. crassus. Therefore, any movements of fish or water between catchments should be undertaken with caution. This includes stocking programmes from hatcheries, transfers of coarse fish between water bodies and bilge water in boats. There is a reduction in the extent of bird feeding areas as a result of colonisation of the upper shore in sheltered bays and estuaries by the grass Spartina anglica.

Non related GES component

Non related GES component

Low

Non related GES component

Unknown_NotAssessed

Unknown_NotAssessed

NIS are frequently recorded in ports or at aquaculture sites. The significance of a pathway is often difficult to evaluate because the number of individuals needed to form a founder population is usually unknown and will depend on the reproductive opportunities presented on arrival at particular times (Campbell & Hewitt, 1999). It is accepted that the greater the volume and frequency associated with a pathway, the greater the probability that an introduction will take place; and areas where a large number of NIS have arrived in the past will be areas at high risk of invasion causing harm. Developments in ports, harbours and marinas have resulted in more vessels visiting and better conditions for the survival of NIS. Increased hard surfaces from buoyage, piles and service craft, with a trend of moving ship berthage into more marine conditions, means there are more overlaps with other activities, such as leisure craft at marinas and this increases the chances of NIS becoming established. The use of marina floating pontoons provide firm silt-free permanently submerged surfaces not found to the same extend elsewhere within a harbour region and are recognised as ‘hot-spots’ for NIS. With no road connections to the island of Ireland, the majority of Ireland’s trade passes through ports resulting in vessel movement to a wide range of geographical regions of the world, but mainly within Europe. This increases the risk of secondary introductions of NIS from other European ports where they have become established. Ships have two principal vectors for spreading NIS; ballast water and hull fouling, the importance of which is dependent on the life-history stages and the tolerance range of the carried biota (Hewitt et al., 2009). Ballast water is pumped to onboard tanks which also provide structural support for the ship. Tanks accumulate sediments when ballasting in ports with locally turbid waters, such as in estuaries, and can unintentionally take on board benthic infauna and resting cysts of harmful phytoplankton capable of surviving for months before germination. Free-living biota within tanks gradually expire over time. As a result discharges following short sea journeys are of high risk in creating new inoculations. Improved ballast water management is reducing the pressure of NIS from shipping and future technical developments and measures under IMO will further reduce this pressure. Hull fouling is accepted as being, as or more, important than ballast water in terms of the number of viable transmissions of NIS world-wide (Minchin and Gollasch, 2003). The degree of fouling is related to the age of the antifouling paint applied to the structure. Increased fouling occurs in areas of most paint wear or where no antifouling paint is applied, which can happen when ships have rested on wooden blocks during dry-dock maintenance. Paint efficacy has changed with time and following the cessation of the usage of TBT, less effective but less toxic methods are now employed. Organisms for aquaculture activities are maintained in optimal conditions during transit to improve their survival, but this also applies to any pests, parasites and diseases that have become associated with the cargo. Most of the unwanted spread from aquaculture is from introductions and stock movements of oysters distributed by plane, ferry and overland transport. This is a pathway that requires careful management and monitoring. Natural dispersal along coasts takes place with surface drift, including anthropogenic flotsam, driven by wind direction and strength and current movements. Many NIS are almost certainly spread from nearby regions this way but natural dispersal mechanisms are very much understudied. Activities contributing to the pressure: Activity: Vessels, principally ships and leisure craft (reported here as "UsesActivitiesOther"): Most introductions are associated with port regions or where there are moorings and marinas. There is good evidence for hull fouling being involved in transmissions with several species found being associated with this vector (Minchin and Gollasch, 2003). Arrivals by ballast water have been presumed in many cases and related to estimates of ballast water discharge (Minchin, 1996) with Cork Harbour having the greatest number of recognised arrivals (Minchin and Sheehan, 1998) with more having arrived since this study (Minchin 2007). Improved ballast water management is reducing the pressure of NIS from shipping and future technical developments and measures under IMO will further reduce this pressure. Activity: Aquaculture: Several species will have been intentionally introduced for cultivation including Rainbow trout (Oncorhynchus mykiss), Pacific oyster (Crassostrea gigas), Manila clam (Ruditapes philippinarum). The introduction of several non-native species have been associated with the importation of consignments of oyster species (Minchin, 2004). The bamboo worm, polychaete Clymenella torquata has only comparatively recently been identified in Ireland (O’Connor, 1981) and was most likely introduced with imports of the American oyster, C. virginica, from Long Island Sound, during the period 1880s -1930s. In January 1993 unquarantined oyster stock was clearly involved with the arrival from France of two non-native crustacean species (Holmes and Minchin, 1995). Unapproved consignments from the same source resulted in the arrival and subsequent spread of Bonamia ostreae (McArdle et al., 1991). In the majority of cases the pathway have involved deliberate introductions with a high level of certainty being ascribed to this pathway. This is a pathway that requires careful management and monitoring.

NIS are frequently recorded in ports or at aquaculture sites. The significance of a pathway is often difficult to evaluate because the number of individuals needed to form a founder population is usually unknown and will depend on the reproductive opportunities presented on arrival at particular times (Campbell & Hewitt, 1999). It is accepted that the greater the volume and frequency associated with a pathway, the greater the probability that an introduction will take place; and areas where a large number of NIS have arrived in the past will be areas at high risk of invasion causing harm. Developments in ports, harbours and marinas have resulted in more vessels visiting and better conditions for the survival of NIS. Increased hard surfaces from buoyage, piles and service craft, with a trend of moving ship berthage into more marine conditions, means there are more overlaps with other activities, such as leisure craft at marinas and this increases the chances of NIS becoming established. The use of marina floating pontoons provide firm silt-free permanently submerged surfaces not found to the same extend elsewhere within a harbour region and are recognised as ‘hot-spots’ for NIS. With no road connections to the island of Ireland, the majority of Ireland’s trade passes through ports resulting in vessel movement to a wide range of geographical regions of the world, but mainly within Europe. This increases the risk of secondary introductions of NIS from other European ports where they have become established. Ships have two principal vectors for spreading NIS; ballast water and hull fouling, the importance of which is dependent on the life-history stages and the tolerance range of the carried biota (Hewitt et al., 2009). Ballast water is pumped to onboard tanks which also provide structural support for the ship. Tanks accumulate sediments when ballasting in ports with locally turbid waters, such as in estuaries, and can unintentionally take on board benthic infauna and resting cysts of harmful phytoplankton capable of surviving for months before germination. Free-living biota within tanks gradually expire over time. As a result discharges following short sea journeys are of high risk in creating new inoculations. Improved ballast water management is reducing the pressure of NIS from shipping and future technical developments and measures under IMO will further reduce this pressure. Hull fouling is accepted as being, as or more, important than ballast water in terms of the number of viable transmissions of NIS world-wide (Minchin and Gollasch, 2003). The degree of fouling is related to the age of the antifouling paint applied to the structure. Increased fouling occurs in areas of most paint wear or where no antifouling paint is applied, which can happen when ships have rested on wooden blocks during dry-dock maintenance. Paint efficacy has changed with time and following the cessation of the usage of TBT, less effective but less toxic methods are now employed. Organisms for aquaculture activities are maintained in optimal conditions during transit to improve their survival, but this also applies to any pests, parasites and diseases that have become associated with the cargo. Most of the unwanted spread from aquaculture is from introductions and stock movements of oysters distributed by plane, ferry and overland transport. This is a pathway that requires careful management and monitoring. Natural dispersal along coasts takes place with surface drift, including anthropogenic flotsam, driven by wind direction and strength and current movements. Many NIS are almost certainly spread from nearby regions this way but natural dispersal mechanisms are very much understudied. Activities contributing to the pressure: Activity: Vessels, principally ships and leisure craft (reported here as "UsesActivitiesOther"): Most introductions are associated with port regions or where there are moorings and marinas. There is good evidence for hull fouling being involved in transmissions with several species found being associated with this vector (Minchin and Gollasch, 2003). Arrivals by ballast water have been presumed in many cases and related to estimates of ballast water discharge (Minchin, 1996) with Cork Harbour having the greatest number of recognised arrivals (Minchin and Sheehan, 1998) with more having arrived since this study (Minchin 2007). Improved ballast water management is reducing the pressure of NIS from shipping and future technical developments and measures under IMO will further reduce this pressure. Activity: Aquaculture: Several species will have been intentionally introduced for cultivation including Rainbow trout (Oncorhynchus mykiss), Pacific oyster (Crassostrea gigas), Manila clam (Ruditapes philippinarum). The introduction of several non-native species have been associated with the importation of consignments of oyster species (Minchin, 2004). The bamboo worm, polychaete Clymenella torquata has only comparatively recently been identified in Ireland (O’Connor, 1981) and was most likely introduced with imports of the American oyster, C. virginica, from Long Island Sound, during the period 1880s -1930s. In January 1993 unquarantined oyster stock was clearly involved with the arrival from France of two non-native crustacean species (Holmes and Minchin, 1995). Unapproved consignments from the same source resulted in the arrival and subsequent spread of Bonamia ostreae (McArdle et al., 1991). In the majority of cases the pathway have involved deliberate introductions with a high level of certainty being ascribed to this pathway. This is a pathway that requires careful management and monitoring.

NIS are frequently recorded in ports or at aquaculture sites. The significance of a pathway is often difficult to evaluate because the number of individuals needed to form a founder population is usually unknown and will depend on the reproductive opportunities presented on arrival at particular times (Campbell & Hewitt, 1999). It is accepted that the greater the volume and frequency associated with a pathway, the greater the probability that an introduction will take place; and areas where a large number of NIS have arrived in the past will be areas at high risk of invasion causing harm. Developments in ports, harbours and marinas have resulted in more vessels visiting and better conditions for the survival of NIS. Increased hard surfaces from buoyage, piles and service craft, with a trend of moving ship berthage into more marine conditions, means there are more overlaps with other activities, such as leisure craft at marinas and this increases the chances of NIS becoming established. The use of marina floating pontoons provide firm silt-free permanently submerged surfaces not found to the same extend elsewhere within a harbour region and are recognised as ‘hot-spots’ for NIS. With no road connections to the island of Ireland, the majority of Ireland’s trade passes through ports resulting in vessel movement to a wide range of geographical regions of the world, but mainly within Europe. This increases the risk of secondary introductions of NIS from other European ports where they have become established. Ships have two principal vectors for spreading NIS; ballast water and hull fouling, the importance of which is dependent on the life-history stages and the tolerance range of the carried biota (Hewitt et al., 2009). Ballast water is pumped to onboard tanks which also provide structural support for the ship. Tanks accumulate sediments when ballasting in ports with locally turbid waters, such as in estuaries, and can unintentionally take on board benthic infauna and resting cysts of harmful phytoplankton capable of surviving for months before germination. Free-living biota within tanks gradually expire over time. As a result discharges following short sea journeys are of high risk in creating new inoculations. Improved ballast water management is reducing the pressure of NIS from shipping and future technical developments and measures under IMO will further reduce this pressure. Hull fouling is accepted as being, as or more, important than ballast water in terms of the number of viable transmissions of NIS world-wide (Minchin and Gollasch, 2003). The degree of fouling is related to the age of the antifouling paint applied to the structure. Increased fouling occurs in areas of most paint wear or where no antifouling paint is applied, which can happen when ships have rested on wooden blocks during dry-dock maintenance. Paint efficacy has changed with time and following the cessation of the usage of TBT, less effective but less toxic methods are now employed. Organisms for aquaculture activities are maintained in optimal conditions during transit to improve their survival, but this also applies to any pests, parasites and diseases that have become associated with the cargo. Most of the unwanted spread from aquaculture is from introductions and stock movements of oysters distributed by plane, ferry and overland transport. This is a pathway that requires careful management and monitoring. Natural dispersal along coasts takes place with surface drift, including anthropogenic flotsam, driven by wind direction and strength and current movements. Many NIS are almost certainly spread from nearby regions this way but natural dispersal mechanisms are very much understudied. Activities contributing to the pressure: Activity: Vessels, principally ships and leisure craft (reported here as "UsesActivitiesOther"): Most introductions are associated with port regions or where there are moorings and marinas. There is good evidence for hull fouling being involved in transmissions with several species found being associated with this vector (Minchin and Gollasch, 2003). Arrivals by ballast water have been presumed in many cases and related to estimates of ballast water discharge (Minchin, 1996) with Cork Harbour having the greatest number of recognised arrivals (Minchin and Sheehan, 1998) with more having arrived since this study (Minchin 2007). Improved ballast water management is reducing the pressure of NIS from shipping and future technical developments and measures under IMO will further reduce this pressure. Activity: Aquaculture: Several species will have been intentionally introduced for cultivation including Rainbow trout (Oncorhynchus mykiss), Pacific oyster (Crassostrea gigas), Manila clam (Ruditapes philippinarum). The introduction of several non-native species have been associated with the importation of consignments of oyster species (Minchin, 2004). The bamboo worm, polychaete Clymenella torquata has only comparatively recently been identified in Ireland (O’Connor, 1981) and was most likely introduced with imports of the American oyster, C. virginica, from Long Island Sound, during the period 1880s -1930s. In January 1993 unquarantined oyster stock was clearly involved with the arrival from France of two non-native crustacean species (Holmes and Minchin, 1995). Unapproved consignments from the same source resulted in the arrival and subsequent spread of Bonamia ostreae (McArdle et al., 1991). In the majority of cases the pathway have involved deliberate introductions with a high level of certainty being ascribed to this pathway. This is a pathway that requires careful management and monitoring.

NIS are frequently recorded in ports or at aquaculture sites. The significance of a pathway is often difficult to evaluate because the number of individuals needed to form a founder population is usually unknown and will depend on the reproductive opportunities presented on arrival at particular times (Campbell & Hewitt, 1999). It is accepted that the greater the volume and frequency associated with a pathway, the greater the probability that an introduction will take place; and areas where a large number of NIS have arrived in the past will be areas at high risk of invasion causing harm. Developments in ports, harbours and marinas have resulted in more vessels visiting and better conditions for the survival of NIS. Increased hard surfaces from buoyage, piles and service craft, with a trend of moving ship berthage into more marine conditions, means there are more overlaps with other activities, such as leisure craft at marinas and this increases the chances of NIS becoming established. The use of marina floating pontoons provide firm silt-free permanently submerged surfaces not found to the same extend elsewhere within a harbour region and are recognised as ‘hot-spots’ for NIS. With no road connections to the island of Ireland, the majority of Ireland’s trade passes through ports resulting in vessel movement to a wide range of geographical regions of the world, but mainly within Europe. This increases the risk of secondary introductions of NIS from other European ports where they have become established. Ships have two principal vectors for spreading NIS; ballast water and hull fouling, the importance of which is dependent on the life-history stages and the tolerance range of the carried biota (Hewitt et al., 2009). Ballast water is pumped to onboard tanks which also provide structural support for the ship. Tanks accumulate sediments when ballasting in ports with locally turbid waters, such as in estuaries, and can unintentionally take on board benthic infauna and resting cysts of harmful phytoplankton capable of surviving for months before germination. Free-living biota within tanks gradually expire over time. As a result discharges following short sea journeys are of high risk in creating new inoculations. Improved ballast water management is reducing the pressure of NIS from shipping and future technical developments and measures under IMO will further reduce this pressure. Hull fouling is accepted as being, as or more, important than ballast water in terms of the number of viable transmissions of NIS world-wide (Minchin and Gollasch, 2003). The degree of fouling is related to the age of the antifouling paint applied to the structure. Increased fouling occurs in areas of most paint wear or where no antifouling paint is applied, which can happen when ships have rested on wooden blocks during dry-dock maintenance. Paint efficacy has changed with time and following the cessation of the usage of TBT, less effective but less toxic methods are now employed. Organisms for aquaculture activities are maintained in optimal conditions during transit to improve their survival, but this also applies to any pests, parasites and diseases that have become associated with the cargo. Most of the unwanted spread from aquaculture is from introductions and stock movements of oysters distributed by plane, ferry and overland transport. This is a pathway that requires careful management and monitoring. Natural dispersal along coasts takes place with surface drift, including anthropogenic flotsam, driven by wind direction and strength and current movements. Many NIS are almost certainly spread from nearby regions this way but natural dispersal mechanisms are very much understudied. Activities contributing to the pressure: Activity: Vessels, principally ships and leisure craft (reported here as "UsesActivitiesOther"): Most introductions are associated with port regions or where there are moorings and marinas. There is good evidence for hull fouling being involved in transmissions with several species found being associated with this vector (Minchin and Gollasch, 2003). Arrivals by ballast water have been presumed in many cases and related to estimates of ballast water discharge (Minchin, 1996) with Cork Harbour having the greatest number of recognised arrivals (Minchin and Sheehan, 1998) with more having arrived since this study (Minchin 2007). Improved ballast water management is reducing the pressure of NIS from shipping and future technical developments and measures under IMO will further reduce this pressure. Activity: Aquaculture: Several species will have been intentionally introduced for cultivation including Rainbow trout (Oncorhynchus mykiss), Pacific oyster (Crassostrea gigas), Manila clam (Ruditapes philippinarum). The introduction of several non-native species have been associated with the importation of consignments of oyster species (Minchin, 2004). The bamboo worm, polychaete Clymenella torquata has only comparatively recently been identified in Ireland (O’Connor, 1981) and was most likely introduced with imports of the American oyster, C. virginica, from Long Island Sound, during the period 1880s -1930s. In January 1993 unquarantined oyster stock was clearly involved with the arrival from France of two non-native crustacean species (Holmes and Minchin, 1995). Unapproved consignments from the same source resulted in the arrival and subsequent spread of Bonamia ostreae (McArdle et al., 1991). In the majority of cases the pathway have involved deliberate introductions with a high level of certainty being ascribed to this pathway. This is a pathway that requires careful management and monitoring.

• Aquaculture
• UsesActivitiesOther

• Aquaculture
• UsesActivitiesOther

• Aquaculture
• UsesActivitiesOther

• Aquaculture
• UsesActivitiesOther

The total number of known NIS presently recognised in Ireland is seventy-nine (as per draft NIS Inventory), and like all lists worldwide it should be considered as being incomplete. Taxonomists need to recognise whether a species is non- native and to be able to distinguish NIS from vagrants and other species spreading as a result of natural expansion. In addition, there is a component of the biota whose status is not fully known, referred to as cryptogens, sensu Carlton (1996). For completeness, known impacting cryptogens have been included in Ireland’s MSFD reporting. While the early records of NIS arrivals have originated from records by naturalists, it is likely that many NIS will remain unrecorded. This is also the situation in recent decades, as many taxonomic groups still have not been fully documented; and where recorded, the status of a specimen as an NIS is often left unrecognised. Ireland will consider how best to improve our understanding of the presence, distribution, trends and impacts of NIS in Irish marine waters. These will be considered when developing our monitoring programmes and may include: - the production of taxonomic guides and the development of websites with clear colour pictures, descriptions and keys to species that will enable non-specialists recognise many unfamiliar and potentially non-indigenous species: - the use of genetic methods to enable the deduction of some species origins thus improving the ability to identify NIS and potential pathways; - the targeting of species that cause impacts within specific habitats; - the targeting of high risk hubs such as marinas, ports, consignments of aquaculture species and dry docks, and - the adaptation of existing programmes, such as larval fish surveys and young fish survey, to include the presence/absence of NIS occurrences.

The total number of known NIS presently recognised in Ireland is seventy-nine (as per draft NIS Inventory), and like all lists worldwide it should be considered as being incomplete. Taxonomists need to recognise whether a species is non- native and to be able to distinguish NIS from vagrants and other species spreading as a result of natural expansion. In addition, there is a component of the biota whose status is not fully known, referred to as cryptogens, sensu Carlton (1996). For completeness, known impacting cryptogens have been included in Ireland’s MSFD reporting. While the early records of NIS arrivals have originated from records by naturalists, it is likely that many NIS will remain unrecorded. This is also the situation in recent decades, as many taxonomic groups still have not been fully documented; and where recorded, the status of a specimen as an NIS is often left unrecognised. Ireland will consider how best to improve our understanding of the presence, distribution, trends and impacts of NIS in Irish marine waters. These will be considered when developing our monitoring programmes and may include: - the production of taxonomic guides and the development of websites with clear colour pictures, descriptions and keys to species that will enable non-specialists recognise many unfamiliar and potentially non-indigenous species: - the use of genetic methods to enable the deduction of some species origins thus improving the ability to identify NIS and potential pathways; - the targeting of species that cause impacts within specific habitats; - the targeting of high risk hubs such as marinas, ports, consignments of aquaculture species and dry docks, and - the adaptation of existing programmes, such as larval fish surveys and young fish survey, to include the presence/absence of NIS occurrences.

The total number of known NIS presently recognised in Ireland is seventy-nine (as per draft NIS Inventory), and like all lists worldwide it should be considered as being incomplete. Taxonomists need to recognise whether a species is non- native and to be able to distinguish NIS from vagrants and other species spreading as a result of natural expansion. In addition, there is a component of the biota whose status is not fully known, referred to as cryptogens, sensu Carlton (1996). For completeness, known impacting cryptogens have been included in Ireland’s MSFD reporting. While the early records of NIS arrivals have originated from records by naturalists, it is likely that many NIS will remain unrecorded. This is also the situation in recent decades, as many taxonomic groups still have not been fully documented; and where recorded, the status of a specimen as an NIS is often left unrecognised. Ireland will consider how best to improve our understanding of the presence, distribution, trends and impacts of NIS in Irish marine waters. These will be considered when developing our monitoring programmes and may include: - the production of taxonomic guides and the development of websites with clear colour pictures, descriptions and keys to species that will enable non-specialists recognise many unfamiliar and potentially non-indigenous species: - the use of genetic methods to enable the deduction of some species origins thus improving the ability to identify NIS and potential pathways; - the targeting of species that cause impacts within specific habitats; - the targeting of high risk hubs such as marinas, ports, consignments of aquaculture species and dry docks, and - the adaptation of existing programmes, such as larval fish surveys and young fish survey, to include the presence/absence of NIS occurrences.

The total number of known NIS presently recognised in Ireland is seventy-nine (as per draft NIS Inventory), and like all lists worldwide it should be considered as being incomplete. Taxonomists need to recognise whether a species is non- native and to be able to distinguish NIS from vagrants and other species spreading as a result of natural expansion. In addition, there is a component of the biota whose status is not fully known, referred to as cryptogens, sensu Carlton (1996). For completeness, known impacting cryptogens have been included in Ireland’s MSFD reporting. While the early records of NIS arrivals have originated from records by naturalists, it is likely that many NIS will remain unrecorded. This is also the situation in recent decades, as many taxonomic groups still have not been fully documented; and where recorded, the status of a specimen as an NIS is often left unrecognised. Ireland will consider how best to improve our understanding of the presence, distribution, trends and impacts of NIS in Irish marine waters. These will be considered when developing our monitoring programmes and may include: - the production of taxonomic guides and the development of websites with clear colour pictures, descriptions and keys to species that will enable non-specialists recognise many unfamiliar and potentially non-indigenous species: - the use of genetic methods to enable the deduction of some species origins thus improving the ability to identify NIS and potential pathways; - the targeting of species that cause impacts within specific habitats; - the targeting of high risk hubs such as marinas, ports, consignments of aquaculture species and dry docks, and - the adaptation of existing programmes, such as larval fish surveys and young fish survey, to include the presence/absence of NIS occurrences.