Article 17 web tool

Scientific name used in original MS report if different than recommended: "Margaritifera margaritifera"
Information provided in the field 2.8.2: Reported additionnal information: ||
->Range: N/A ||
->Population: Number of localities is number of occupied rivers ||
->HabInfo: N/A ||
->Future: N/A ||
->Conclusion: N/A ||
->JustificationThreshold: N/A ||
->Other: N/A

Open Original Report  

Scientific name used in original MS report if different than recommended: "Margaritifera margaritifera"
Information provided in the field 2.8.2: Reported additionnal information: ||
->Range: The river-dwelling mussel Margaritifera margaritifera has declined dramatically during the past 100 years due to water regulations, hydropower dams, forestry and acidification, both the habitats and the host species Salmo salar/Salmo trutta has declined due to these factors. Unlike other species the decline is not just loss of individuals but also loss of reproduction in still living individuals. In roughly half of the populations (rivers with M. margaritifera) in Sweden the individuals are not reproducing.

Red listed as EN (Endangered) in Sweden 2015. Data for this species largely from the National Monitoring Program of M. margaritifera. This program makes figures on range, the evaluation of status, number ef rivers with reproducing mussels solid and is supporting the construction of figures on number of populations and quality of habitat. A well-studied species with few changes since last report. ||
->Population: N/A ||
->HabInfo: See 5.12, 6.15 and 6.17 ||
->Future: See 5.12, 6.15 and 6.17 ||
->Conclusion: See 5.12, 6.15 and 6.17 ||
->JustificationThreshold: N/A ||
->Other: See 5.12, 6.15 and 6.17

Open Original Report  

Scientific name used in original MS report if different than recommended: "Margaritifera margaritifera"
Information provided in the field 2.8.2: Reported additionnal information: ||
->Range: N/A ||
->Population: Methodik zur Ermittlung der Populationsgröße in EU-Einheit: 1. Auswahl besiedelter Gewässerabschnitte durch Verschneidung der GIS-Koordinaten der Stichprobenflächen (Puffer 100 m) mit Gewässershape und Pufferung des ausgewählten Gewässers mit 500 m Radius
2. Verschneidung der besiedelten Gewässerabschnitte mit dem 1x1km-Raster
3. Ermittlung der besetzten grids1x1 ||
->HabInfo: N/A ||
->Future: N/A ||
->Conclusion: N/A ||
->JustificationThreshold: N/A ||
->Other: N/A

Open Original Report  

Scientific name used in original MS report if different than recommended: "Margaritifera margaritifera"
Information provided in the field 2.8.2: Reported additionnal information: ||
->Range: The monitoring program for M. margaritifera only contains a couple of sites, and so far it has not been possible to verify its presence based on traditional surveylance methods. However living specimens have been found by local anglers. A new method for registering the presence of M. margaritifera using eDNA is currently in progress. ||
->Population: N/A ||
->HabInfo: N/A ||
->Future: N/A ||
->Conclusion: N/A ||
->JustificationThreshold: N/A ||
->Other: N/A

Open Original Report  

Scientific name used in original MS report if different than recommended: "Margaritifera margaritifera"
Information provided in the field 2.8.2: Reported additionnal information: ||
->Range: Se ha encontrado una población en Navarra recientemente. Se conocía un solo resto, hallado en 2009, y tras trabajos realizados en 2014-2015 se encuentran varios restos más a lo largo de 22 kilómetros del río Bidasoa.
En 2015 se halla un resto reciente de un individuo, aún con el cuerpo carnoso en su interior. Ello certifica la presencia actual de la especie en Navarra. La especie es potencial en los ríos Bidasoa, Urumea y Baztán. ||
->Population: Se incluyen las cuadrículas correspondientes a Navarra, donde recientemente se ha localizado la especie. ||
->HabInfo: Se desconoce si el hábitat ocupado actualmente es suficiente para la supervivencia a largo plazo, dadas las existentes amenazas y la incertidumbre en el éxito de las acciones llevadas a cabo para la mejora del hábitat y las repoblaciones con almejas juveniles y con salmónidos infestados con gloquidios.
Siendo una especie muy exigente con los factores abióticos y bióticos del hábitat, que deben ser óptimos, se desconoce que exista un área suficiente de hábitat no ocupado que pueda garantizar la supervivencia a largo plazo, conocidas las amenazas y la regresión que ha sufrido la especie en todos los cursos fluviales donde históricamente se distribuía.

Sin embargo, en Navarra, algunos ríos están incrementando su calidad ecológica y conectividad con el derribo de presas y el aumento de la calidad del agua, proporcionando un hábitat cada vez más adecuado para esta especie. ||
->Future: Se espera un declive continuado para esta especie debido a la alteración del hábitat por efectos del cambio climático y las amenazas de origen antrópico.
La mayor recurrencia de las sequías, la subida de la temperatura de las aguas fluviales, la contaminación de las aguas por intensificación de la agricultura, la pérdida de poblaciones de salmónidos hospedadores de las larvas gloquidio, o la expansión de especies invasoras son algunos de los factores que se esperan incrementar en el futuro. ||
->Conclusion: N/A ||
->JustificationThreshold: N/A ||
->Other: N/A

Open Original Report  

Scientific name used in original MS report if different than recommended: "Margaritifera margaritifera"
Information provided in the field 2.8.2: Reported additionnal information: ||
->Range: Contrairement à d'autres espèces de bivalves, l'aire de répartition actuelle de la Mulette perlière reste similaire à celle historique, telle que décrite par la littérature ancienne. Cette aire de répartition est fortement contrainte par la nature géologique, la mulette perlière ne vivant que dans les cours d'eau cristallins acides des têtes de bassin.Contrairement à d'autres espèces de bivalves, l'aire de répartition actuelle de la Mulette perlière reste similaire à celle historique, telle que décrite par la littérature ancienne. Cette aire de répartition est fortement contrainte par la nature géologique, la mulette perlière ne vivant que dans les cours d'eau cristallins acides des têtes de bassin. ||
->Population: N/A ||
->HabInfo: N/A ||
->Future: N/A ||
->Conclusion: N/A ||
->JustificationThreshold: N/A ||
->Other: N/A

Open Original Report  

Scientific name used in original MS report if different than recommended: "Margaritifera margaritifera"
Information provided in the field 2.8.2: Reported additionnal information: ||
->Range: The range was based on the distribution, i.e. the Range Tool was not used, as the current distribution is considered to be accurate and the species is unlikely to occur outside the mapped 10 km grid squares. For a lotic species or habitat, occupying linear features in the landscape, the Range Tool is likely to include 10 km squares without rivers or with unsuitable river types.
Trends were estimated based on monitoring survey results; specifically evidence of population extinctions or contractions of the species’ distribution within a river system:
- A single extinction was documented during the reporting cycle, leading to the loss of one 10 km grid square from the distribution. The only record of a live specimen in the Larah River was made in 1988 and it is likely that the population extinction occurred before the short-term trend period and, possibly, before the Directive came into force;
- Monitoring surveys found no evidence of contractions of the species’ range within individual rivers, despite significant decreases in population size, mussel density, habitat occupancy and recruitment. This demonstrates that range is slow to change and is, therefore, not a sensitive measure of changes in the size or viability of freshwater pearl mussel populations, at either population or national scales;
- As a result, the short-term trend was assessed as stable, and the long-term trend was assessed as decreasing, based on the evidence of the extinction of the Larah population.
No values were provided for long- or short-term trend magnitude in the range of freshwater pearl mussels as, based on the available data, these would be speculative.
The reasons for the changes in the range were:
- improved knowledge/more accurate data:
Records of living mussels were made in an additional four 10 km grid squares;
Documentation of the extinction in the Larah, leading to the loss of one 10 km grid square;
A review of the 2007-2012 distribution led to the removal of seven 10 km grid squares owing to the absence of records for live mussels;
Genetic research concluded that the Nore population lies within the Margaritifera margaritifera taxon (Feind et al., 2016; Geist et al., 2018);
- different methods:
The inclusion of the Nore population led to an increase of 300 km2 in the area of the range and a 400 km2 increase in the FRR.
In line with the guidance, and as for previous reporting cycles, the ‘Favourable Reference Range’ (FRR) was based on the reported current range. This approach does not consider the following challenges:
- For widespread, cryptic or otherwise difficult to survey species, the reported current range will inevitably be based on a sub-sample and/or historical data and, therefore, may not accurately represent the actual range;
- In addition, for species, such as Margaritifera margaritifera, with documented declines in population and habitat condition, the range will inevitably decline in the future, unless the species’ habitat and populations are restored throughout the reported range.
Maintenance/restoration of a freshwater pearl mussel range that is smaller than the FRR would be sufficient to allow the long-term survival of the species in Ireland. Establishing such a (smaller) national target for Range is advisable and achieving it would be highly ambitious, but would not allow, under the current Article 17 reporting format, the national conservation status of the Range to return to Favourable.
In 2007, the Favourable Reference Population was set as 13 viable populations of Margaritifera margaritifera (including two viable, self-sustaining populations of the Nore mussels). A Range target of circa 20 x 10 km grid squares (2,000 km2) would support this Population target. The National Conservation Strategy for the species (NPWS, 2011) prioritised eight populations for restoration. The distribution of these eight priority populations occupies 15 x 10 km grid squares (1,500 km2). The reported FRR (152 x 10 km grid squares, or 15,200 km2) is therefore considered unrealistic and unnecessary to secure the future of the species in Ireland. ||
->Population: The population was based on the distribution. All 1 x 1 km squares intersected by positive records of living mussels (Margaritifera_Records feature class) and/or a freshwater pearl mussel habitat line (FPM_Habitat_Classification) were selected. The result is that both Range and Population report the distribution of the species, Range using a 10 x 10 km scale grid and Population a 1 x 1 km scale grid. The 1 x 1 km unit is not a reliable measure of either the species’ distribution or its population size:
- Point records are observations in space and time that reflect the distribution of survey effort, rather than the species itself and, therefore, are not a reliable, repeatable measure of the species’ current distribution or population.
- The distribution is based on all available records. It is not practically possible to survey every occupied 1 x 1 km square in a reporting cycle and, in the absence of evidence to the contrary, it must be assumed that this long-lived species continues to occupy each 1 x 1 km square in its distribution. Therefore, the distribution, and hence the population, will not change between reporting cycles, other than where a population has been declared to be extinct through a comprehensive, repeat survey. As a result, the population based on the 1 x 1 km unit will not illustrate the documented decline in population size and/or viability.
- The 1 x 1 km grid unit is not a measure of the size or viability of the freshwater pearl mussel population. The 1 x 1 km unit masks variation in the abundance and density of mussels, and in the carrying capacity of habitat, among squares. To illustrate, one 1 x 1 km square in the Bundorragha is estimated to contain more than 1 million adult mussels. By contrast, five transects counted in a 1 x 1 km square (X2186) in the Licky had only 11 mussels in 2016, and the entire stretch within that square is unlikely to contain more than 200 mussels.
The new, required reporting unit 1 x 1 km grid squares is not comparable with previous reports (leading to a change between reporting periods owing to the use of a different method). For the 2000-2006 and 2007-2012 reporting cycles, the recommended unit was number of mature individuals, which itself had significant limitations, not least that the challenges of underwater survey mean the full extent and abundance of a population can seldom be recorded (NPWS, 2013). Despite this, the number of mature individuals is reported again for the 2013-2018 cycle in order to illustrate the decline in freshwater pearl mussel Population size over time.
The size of adult populations of Margaritifera margaritifera can be estimated based on sub-samples and length or area of available habitat. All available population estimates, plus expert opinion, were used in 2007 to provide a national population estimate for Ireland of 12 million adult mussels (Moorkens et al., 2007). For the 2007-2012 cycle, it was estimated that the population had declined from 12 million to 10,990,320 (a decline of 8% over the reporting period) (NPWS, 2013). During the 2013-2018 cycle, 27 freshwater pearl mussel populations were monitored. 21 of these are SAC populations listed on S.I. 296 of 2009 as amended by S.I. 355 of 2018. For one population, the Allow, more extensive baseline survey by the IRD Duhallow project led to the upwards revision of the population estimate. The Bundorragha population has been in Favourable condition in most years and its population was assumed to be stable overall. The remaining 25 populations all demonstrated significant population declines and monitoring data were used to produce population-specific revised estimates (e.g. the 2013-2018 estimates were 1.5-2.1 million adult mussels for the Caragh population and 145-1,064 for the Clodiagh population). The individual estimates for the 27 monitored populations summed to 6,416,958-8,625,931 adult mussels. Revised estimates were produced for the six unmonitored SAC populations. Five were assumed to have declined by 18% over the reporting cycle, while the Bandon was assumed to have declined by between 18% and 28% owing to damage to the river bank. 18%, or 3% per year, was the estimated decline used for the 2007-2012 cycle and was based on a combination of survey data and expert opinion (NPWS, 2013). The individual estimates for the six unmonitored populations summed to 45,253-49,353. An estimate of 932,623 was used for the remaining unmonitored populations, based on an assumed 18% decline over the reporting cycle (as per NPWS, 2013). The figures summed to the Minimum and Maximum population size estimates of 7,394,834-9,607,907.
The estimated population is significantly (20-38%) below the Favourable Reference Population of 12 million assumed to be close to the number of mature individuals present when the Directive came into force (Moorkens et al., 2007). The estimated decline between the 2007-2012 and 2013-2018 cycles was 12.6-32.7%.
In Ireland, routine surveillance of the freshwater pearl mussel evaluates changes in adult mussel numbers using three main measures: numbers of dead shells; changes in adult numbers in permanent count areas; and, in particular, population age profiles (Moorkens, 2016; Moorkens and Killeen, in prep.). Data are assessed against targets established in S.I. 296 of 2009, site-specific conservation objectives (NPWS, 2011, 2012, 2015, 2016, 2017) and NSAI (2017). These detailed demographic data were used to assess the conservation status and trends in the population of Margaritifera margaritifera. Population viability is the key measure of the conservation status of Margaritifera populations. The percentage of the population of approximately five years of age and under (≤30mm in shell length), and the percentage of the population of approximately 10-15 years of age and under (≤65mm in shell length) demonstrate whether the population is reproducing and recruiting young mussels, and are particularly important to the assessment of population viability.
Based on the data from the 27 monitored populations, there has been a significant, genuine decline in the species’ population during the reporting cycle, both in terms of a decline in the number of individuals and decreased population viability. Only one population, the Budorragha, was in Favourable condition. This is significantly below the recommended Favourable Reference Population target of 13 viable populations. One population, the Larah River in the Upper Erne catchment, was declared to be extinct. The conservation condition of the other 25 populations was assessed as Unfavourable, and an attempt was made to further categorise Unfavourable condition as Inadequate, Bad and extinction imminent:
1. No populations were assessed as ‘Inadequate’ (i.e. inadequate recruitment - both juvenile (≤30 mm) and young mussels (≤65 mm) present but below targets. AND At least some areas of habitat are in favourable condition (i.e. passed all habitat attributes). No kills or other evidence of accelerated mortalities.)
2. Four populations were assessed as Inadequate/Bad (i.e. either:
(a) juvenile and young mussels present, but habitat in Poor to Bad condition, or
(b) no juvenile and young mussels, but substantial areas (>40% of quadrats on habitat transects) of habitat in Favourable condition
AND population large (hundreds of thousands or more). There may be evidence of accelerated mortalities in some stretches.
3. 14 were in Bad conservation condition (i.e. no juvenile mussels present (small numbers of young mussels may occur) and most/all of habitat is in Unfavourable (Poor to Bad) condition).
4. Eight populations were considered to be in imminent danger of extinction (i.e. the population is predicted to go extinct over the short-to-medium term, based on small population size, absence of recruitment, rapid decline in adult numbers and Bad habitat condition).
Only four of the monitored populations had juvenile mussels (≤30 mm) (Bundorragha, Caragh, Kerry Blackwater and Currane). Eleven populations had one or more young mussels of ≤65 mm, two of these (Recess and Deel) were not within SACs for the species.
In populations with no recruitment and few extant individuals, declines were severe and consistent across permanent monitoring stations, e.g. in the Clodiagh only 67 mature individuals were counted at five stations, declines ranged from 55.9% to 93.8%, or an average decline of 67.3% between 2006 and 2016. Similarly, in the Licky seven permanent monitoring stations showed declines of 66.7%, 37.1%, 65.2%, 92.3%, 80%, 100% and 100% between 2005 and 2016.
Kills (recently dead and moribund adult mussels) were recorded in 12 of the 27 monitored populations during the reporting cycle (2013-2018), including the Bundorragha, Kerry Blackwater (Kealduff) and Owenriff. Large declines in adult numbers over the short-term trend period (2007-2018) indicated possible kills in another six populations, including the Glaskeelan and Caragh. In addition, kills were reported from unmonitored rivers, including the Bandon.
As 96% of the monitored extant populations were in Unfavourable condition, the conservation status of the Population was assessed as Unfavourable-Bad.
As 96% of the monitored extant populations showed strong evidence of decline in the number of individuals and decreased population viability, the short- and long-term trends in Population were assessed as decreasing.
Trend magnitudes cannot be provided owing to the high uncertainties, both in estimating overall population size and the changes in numbers of mussels at individual sites (see NPWS, 2013). As an example, while the Caragh population showed an average loss of 24% across seven stations between 2004 and 2014, six showed declines in numbers (-13% to -92.7%) and one showed an increase (+51.5%). Mussels do not move when conditions are favourable and, based on the evidence of insufficient recruitment and habitat deterioration, this increase in numbers is considered likely to indicate stress and disturbance.
The observed acceleration of population decline and further decreases in recruitment rates are alarming and raise questions as to the restorability not only of the small populations on the verge of extinction, but also of some priority populations with hundreds of thousands or millions of mussels. ||
->HabInfo: The freshwater pearl mussel is found in the oligotrophic, soft to neutral waters of fast-flowing rivers and, occasionally, in lakes. It is a benthic, largely sedentary species, living partially buried in gravels stabilised with larger clast-sizes such as cobbles and boulders. Juvenile mussels live fully buried between gravel particles, where oxygen is freely exchanged. The species is highly sensitive to alterations to the hydrology, morphology and benthic communities of its river habitat.
The standard methods employed for monitoring the conservation condition of the freshwater pearl mussel require detailed monitoring of the species’ habitat (Moorkens, 2016; Moorkens and Killeen, in prep.). Measurements for assessing habitat condition are typically taken in 1 m x 1 m quadrats, and largely relate to the river substratum: physical substrate parameters (composition and redox), plant colonisation (algae and macrophytes) and decomposing organic matter. Habitat condition is assessed using the attributes (‘elements’) and targets (‘objectives’) on the Fourth Schedule to the Freshwater Pearl Mussel Regulations (S.I. 296 of 2009), site-specific conservation objectives (NPWS, 2011, 2012, 2015, 2016, 2017) and NSAI (2017).
Monitoring data demonstrated that habitat condition was Favourable in only one of the 26 monitored extant populations. Siltation was the most common impact observed on mussel habitat, with 19 of the 26 failing the silt target (“No artificially elevated levels of siltation”) and 20 failing the redox target (“Average redox potential loss at 5cm <20%”). 17 and 14 rivers, respectively, failed the macroalgae and macrophyte targets (“Absent or Trace (<5%)”).
As 96% of the monitored extant populations had Unfavourable habitat condition, the conservation status of the Habitat for the species was assessed as Unfavourable-Bad.
The short- and long-term trends in freshwater pearl mussel habitat quality were assessed as declining for the 2007-2012 cycle (NPWS, 2013). This assessment was based on repeat monitoring of the species’ habitat from 2004, which showed continuous Bad condition and/or further deterioration in the habitat condition. Survey and monitoring during the 2013-2018 cycle confirmed these general trends and also documented episodes of severe impact, in some cases associated with specific, identifiable incidents of anthropogenic pressure, e.g.:
1. heavy sedimentation (including with organic matter) in the Currane (agricultural drainage and ‘re-contouring’), Ownagappul (agricultural practices including cattle entering the river), Bandon (woodland clearance), Licky (clear-felling), Glaskeelan (forest thinning), Clodiagh (multiple sources: even fast riffles had extremely heavy silt plumes);
2. low flow velocity in the Ownagappul (drinking water abstraction from up-stream lake combined with altered river morphology owing to agricultural activities), Clady (hydroelectric impoundment), Cloon (catchment drainage), Kerry Blackwater (catchment drainage), Owenriff (angling weirs and catchment drainage);
3. heavy macroalgal growth in the Licky (agriculture and forestry, including removal of tree shade), Dawros (nutrient sources uncertain, but a tourist attraction with over half a million visitors in 2017 is one potentially significant source), Kerry Blackwater (agriculture and forestry), Owenriff (urban wastewater and agriculture are likely nutrient sources, algal biomass acts in combination with low flows and on-going abundant macrophytes);
4. heavy macrophyte growth in the Bandon (removal of tree shade), Currane, Owenriff.
The decline in the habitat condition in priority catchments (Ownagappul, Currane, Glaskeelan, Owenriff, Kerry Blackwater and Caragh) is particularly concerning.
The development of more detailed habitat mapping methods (Moorkens, 2016; Moorkens and Killeen, in prep.) is providing additional data on the area of available habitat, including its potential to support juvenile mussels, as well as its conservation condition (Good, Moderate and Poor) (populations where these methods have been used include the Caragh, Kerry Blackwater, Owenriff, Bundorragha, Allow, Dawros, Deel). These data will inform future national assessments of the area of the habitat in Favourable, Inadequate and Bad condition. ||
->Future: The Future prospects of the Range, Population and Habitat for the species were assessed by reference to pressures and threats and conservation measures, as well as each parameter’s ‘future trends’ and current status:
Pressures and threats: Five pressures of high importance and five of medium importance were listed as pressures and threats. Many sectors give rise to impacts on the freshwater pearl mussel and longer lists of pressures and threats could have been provided. These pressures and threats impact on the species habitat through changes in hydrological regime, river substratum and plant biomass. They also impact more directly on the species leading to stress, loss of condition and, ultimately, premature death.
Conservation measures: Species-specific, concrete conservation measures are currently being implemented in parts of two SAC catchments (Caragh and Kerry Blackwater) through the KerryLIFE project. Work has also commenced on the implementation of a European Innovation Partnership in all eight priority SAC catchments. These conservation measures are voluntary and focused on agriculture and so do not address all of the pressures and threats impacting on the target populations. Identification and implementation of field and farm-specific measures takes time and there will be a significant time-lag before they take effect. The extent of restoration of terrestrial habitats required in order to restore the species’ habitat to Favourable condition is not yet known. Such catchment restoration must provide sufficient resilience to maintain the species and its habitat at Favourable condition long-term in order to fulfil the conservation objectives. Given the lack of measures for other pressures, particularly the lack of mechanisms to deal with existing conifer plantations on peat soils, as well as the number of incidents of damage recorded in the reporting cycle, it can be concluded that the conservation measures will not halt or reverse the negative influence of the threats in the next 12 years.
Range: The short-term trend of the Range was assessed as stable and the long-term trend as decreasing. The current range is 3% less than the Favourable Reference Range. Therefore, the Conservation Status of the Range was assessed as Unfavourable-Inadequate. Given the negative influence of the identified pressures and threats, the Bad condition of the Population and the Habitat for the species, and the insufficient conservation measures, the predicted future trend in Range is negative. As a result, the Future prospects of the Range were assessed as Poor.
Population: The short- and long-term trends of the Population were assessed as decreasing. The estimated minimum population is 38% smaller than the Favourable Reference Population. Only one individual population is considered to be viable. Therefore, the Conservation Status of the Population was assessed as Unfavourable-Bad. Given the negative influence of the identified pressures and threats on the species’ populations and their habitat, and the insufficient conservation measures, the predicted future trend in Population is negative. As a result, the Future prospects of the Population were assessed as Bad.
Habitat for the species: The short- and long-term trends in Habitat for the species were assessed as decreasing, owing to evidence of on-going and accelerated habitat decline, as well as documented episodes of severe impact. The decline in the condition of the habitat within six of the priority catchments was particularly concerning. 96% of the monitored extant populations had Unfavourable habitat condition. As a result, the Conservation Status of the Habitat for the species was assessed as Unfavourable-Bad. Given the negative influence of the identified pressures and threats on the species’ habitat, and the insufficient conservation measures, the predicted future trend in Habitat for the species is negative. As a result, the Future prospects of the ‘Habitat of the species’ were assessed as Bad.
As the Future prospects of the Range were assessed as Poor and the Future prospects of the Population and Habitat for the species as Bad, the overall Future prospects for Margaritifera margaritifera were assessed as Unfavourable-Bad. ||
->Conclusion: Range: The current range is 3% smaller than the Favourable Reference Range. As a result, the Range has been assessed as Unfavourable-Inadequate. This change from the 2007-2012 report is because the Nore pearl mussel population is now reported with other Margaritifera margaritifera populations. As no changes in the species’ range were recorded during the reporting cycle, the short-term trend was assessed as stable. The long-term trend was assessed as decreasing, owing to the extinction of the Larah population, however this extinction may have occurred before the Directive came into force. Given the recorded declines in Population, the Bad status of the Habitat for the species and the pressures and threats recorded, the Range of the species is predicted to decline significantly in the future. Securing the long-term viability of the species in Ireland does not require restoration of the full, reported species’ range, and it is highly unlikely that the habitat of many populations is restorable.
Population: The estimated population (number of mature individuals) is 20-38% smaller than the Favourable Reference Population of 12 million. Only one individual population is considered to be viable (in Favourable condition). The target is for 13 viable populations. Of the 27 populations monitored, one was declared extinct and 25 were found to be in Unfavourable condition: eight were considered in imminent danger of extinction, 14 were considered to be in Bad condition and four were Inadequate/Bad. Mussel kills were reported in 12 of the 27 populations monitored. Therefore, the Conservation Status of the Population was assessed as Unfavourable-Bad. The short- and long-term trends of the Population were assessed as decreasing, owing to failure to recruit young mussels, recorded kills and documented declines in numbers of adult mussels.
Habitat for the species: 96% of the monitored extant populations had Unfavourable habitat condition. 77% failed the redox target, 73% failed the silt target, 65% failed the macroalgae target and 54% failed the macrophyte target. Flow impacts were also recorded in many of the rivers. Episodes of severe impacts were documented in at least 12 populations. As a result, the Conservation Status of the Habitat for the species was assessed as Unfavourable-Bad.
The short-term trend in Habitat for the species was assessed as decreasing owing to evidence of on-going and accelerated habitat decline, as well as documented episodes of severe impact. The decline in the condition of the habitat within six of the priority catchments was particularly concerning.
Future prospects: The Conservation Status of the Range was assessed as Unfavourable-Inadequate, but its predicted future trend was negative, owing to the Bad condition of the Population and the Habitat for the species, the negative influence of the identified pressures and threats, and the insufficient conservation measures. As a result, the Future prospects for the Range were assessed as Poor. Population and Habitat for the species were assessed as Unfavourable-Bad and decreasing and, therefore, their Future prospects are Bad.
As Population, Habitat for the species and Future prospects were assessed as Unfavourable-Bad, the Overall Conservation Status of the freshwater pearl mussel was assessed as Unfavourable-Bad.
As for the 2007-2012 cycle, the overall trend was assessed as deteriorating, based on the overall Bad Conservation Status and the decreasing trends in Population and Habitat for the species. Despite the significant progress in identifying and implementing the necessary conservation measures for the species, particularly by the KerryLIFE project, relatively few practical conservation measures have yet been taken and only in a restricted area. Populations have continued to decline, many at alarmingly high and previously unpredicted rates, the condition of the habitat for the species has continued to deteriorate, new pressures have emerged and incidents of direct and indirect damage have occurred. There were delays with the implementation of relevant plans/programmes (e.g. FPM EIP, forestry and FMP, WFD RBMP), and there has been some poor policy integration, as well as insufficient consideration of the science, particularly in relation to the species’ ecological requirements. It is hoped that with the demonstration of conservation measures through the KerryLIFE project and the Pearl Mussel Project European Innovation Partnership, that the Future prospects of the species will improve in the next reporting cycle and that evidence of improvements in the Habitat for the species and in Population viability will be detected. ||
->JustificationThreshold: N/A ||
->Other: N/A

Open Original Report  

Scientific name used in original MS report if different than recommended: "Margaritifera margaritifera"
Information provided in the field 2.8.2: Reported additionnal information: ||
->Range: N/A ||
->Population: N/A ||
->HabInfo: N/A ||
->Future: N/A ||
->Conclusion: N/A ||
->JustificationThreshold: N/A ||
->Other: The reduction and fragmentation of habitats generated by dam construction on the Cávado River and human disturbances on the Neiva River do not allow conditions for their long-term viability, so it is considered that any investment in these areas will not be effective.

Open Original Report  

Scientific name used in original MS report if different than recommended: "Margaritifera margaritifera"
Information provided in the field 2.8.2: Reported additionnal information: ||
->Range: The short term trend direction is considered most likely to be 'decreasing <=1% (one percent or less) per year on average', based on the reported declines in Scotland and Wales.
Several known populations have been lost in the reporting period and therefore the number of sites, and the species range in northeast Scotland and southern Wales has particularly decreased. ||
->Population: The short term trend direction is considered most likely to be decreasing >1% (more than one percent) per year on average, based on the reported declines in Scotland, England, Wales and Northern Ireland. At the UK-level it is considered most likely that the FRP is no more than 25% above the current population, even though there are severe declines reported in Wales. In terms of age-structure, mortality and reproduction, there are severe juvenile recruitment problems reported in Scotland England, Wales and Norther Ireland, resulting in ageing populations. Therefore age-structure and reproduction is strongly deviating from normal. ||
->HabInfo: Poor river habitat quality (e.g. water quality, riparian and instream habitat (including the interstitial substrate quality) and host fish populations) remains the serious limiting factor in juvenile recruitment. The sufficiency of the area of occupied and unoccupied habitat is less of a problem. There have been some habitat improvements within the Natura 2000 network, with some populations now recovering, but not at a sufficiently wide scale to provide an overall improving short-term trend. There are long-term declines elsewhere. ||
->Future: Future trend of Range is Negative - decreasing <=1% (one percent or less) per year on average; Future trend of Population is Negative - decreasing <=1% (one percent or less) per year on average; and Future trend of Habitat for the species is Negative - slight/moderate deterioration. For further information on how future trends inform the Future Prospects conclusion see the 2019 Article 17 UK Approach document. ||
->Conclusion: Conclusion on Range reached because: (i) the short-term trend direction in Range surface area is decreasing by more than 1% per year; and (ii) the current Range surface area is more than 10% below the Favourable Reference Range.
Conclusion on Population reached because: (i) the short-term trend direction in Population size is decreasing by more than 1% per year; (ii) the current Population size is not more than 25% below the Favourable Reference Population; and (iii) age structure, mortality and reproduction are strongly deviating from normal.
Conclusion on Habitat for the species reached because: (i) the area of occupied and unoccupied habitat is sufficiently large and (ii) the habitat quality is not adequate for the long-term survival of the species; and (iii) the short-term trend in area of habitat is uncertain.
Conclusion on Future prospects reached because: (i) the Future prospects for Range are bad; (ii) the Future prospects for Population are bad; and (iii) the Future prospects for Habitat for the species are bad.
Overall assessment of Conservation Status is Unfavourable-bad because all of the conclusions are Unfavourable-bad.
Overall trend in Conservation Status is based on the combination of the short-term trends for Range - decreasing, Population - decreasing, and Habitat for the species - uncertain.
The Overall assessment of Conservation Status has not changed between 2013 and 2019. The Overall assessment is Unfavourable-bad.
The Overall trend in Conservation Status has not changed between 2013 and 2019. The overall trend is declining.
||
->JustificationThreshold: N/A ||
->Other: England
Translocation protocol produced for the movement of mussels for conservation purposes (Killeen, I. & Moorkens, E., 2016). Freshwater pearl mussels are taken for conservation purposes and captive breeding.

Open Original Report  

Scientific name used in original MS report if different than recommended: "Margaritifera margaritifera"
Information provided in the field 2.8.2: Reported additionnal information: ||
->Range: N/A ||
->Population: N/A ||
->HabInfo: N/A ||
->Future: N/A ||
->Conclusion: N/A ||
->JustificationThreshold: N/A ||
->Other: N/A

Open Original Report  

Scientific name used in original MS report if different than recommended: "Margaritifera margaritifera"
Information provided in the field 2.8.2: Reported additionnal information: ||
->Range: N/A ||
->Population: Number of localities means number of occupied rivers ||
->HabInfo: N/A ||
->Future: N/A ||
->Conclusion: N/A ||
->JustificationThreshold: N/A ||
->Other: N/A

Open Original Report  

Scientific name used in original MS report if different than recommended: "Margaritifera margaritifera"
Information provided in the field 2.8.2: Reported additionnal information: ||
->Range: Species range has a significant long-term decline, because species is no longer present in areas outside Gauja river basin, where it was previously found (Rudzīte 2014). ||
->Population: N/A ||
->HabInfo: Data on habitat quality decreasing according to Rudzite 2015 ||
->Future: N/A ||
->Conclusion: N/A ||
->JustificationThreshold: N/A ||
->Other: N/A

Open Original Report  

Scientific name used in original MS report if different than recommended: "Margaritifera margaritifera"
Information provided in the field 2.8.2: Reported additionnal information: ||
->Range: The river-dwelling mussel Margaritifera margaritifera has declined dramatically during the past 100 years due to water regulations, hydropower dams, forestry and acidification, both the habitats and the host species Salmo salar/Salmo trutta has declined due to these factors. Unlike other species the decline is not just loss of individuals but also loss of reproduction in still living individuals. In roughly half of the populations (rivers with M. margaritifera) in Sweden the individuals are not reproducing.

Red listed as EN (Endangered) in Sweden 2015. Data for this species largely from the National Monitoring Program of M. margaritifera. This program makes figures on range, the evaluation of status, number ef rivers with reproducing mussels solid and is supporting the construction of figures on number of populations and quality of habitat. A well-studied species with few changes since last report. ||
->Population: N/A ||
->HabInfo: N/A ||
->Future: N/A ||
->Conclusion: N/A ||
->JustificationThreshold: N/A ||
->Other: See 5.12, 6.15 and 8.2

Open Original Report  

Scientific name used in original MS report if different than recommended: "Margaritifera margaritifera"
Information provided in the field 2.8.2: Reported additionnal information: ||
->Range: N/A ||
->Population: N/A ||
->HabInfo: N/A ||
->Future: N/A ||
->Conclusion: N/A ||
->JustificationThreshold: N/A ||
->Other: N/A

Open Original Report  

Scientific name used in original MS report if different than recommended: "Margaritifera margaritifera"
Information provided in the field 2.8.2: Reported additionnal information: ||
->Range: N/A ||
->Population: pollutions (Our, Sûre, Vierre) impacting major populations ||
->HabInfo: Increasing for the rivers Anlier and Rulles (Life). These two rivers contend 90% of the number of individuals present in Wallonia. On the other hand for the Sûre and the Vierre, following the pollution it is decreasing and for the Our it is stable (on the basis of the data of the DCE) ||
->Future: need for a new LIFE project ||
->Conclusion: N/A ||
->JustificationThreshold: N/A ||
->Other: N/A

Open Original Report  

Scientific name used in original MS report if different than recommended: "Margaritifera margaritifera"
Information provided in the field 2.8.2: Reported additionnal information: ||
->Range: N/A ||
->Population: Implementation of the rescue program. ||
->HabInfo: N/A ||
->Future: N/A ||
->Conclusion: N/A ||
->JustificationThreshold: N/A ||
->Other: Monitoring of limit values for the freshwater pearl mussel habitat. Mortality in 3% (under optimal conditions, up to 1%), pH (up to 7.1) Conductivity (50-70 μS), BASK5 - BOD5 (1.5 mg / L O2) Calcium - Ca (8 mg / l) , Mg: Ca (max. 1: 3.2), total phosphorus - P (20-35 mg / l), NH4 (0.1 mg / l), NO3 (up to 2.5 mg / l), chlorides - Cl (up to 10 mg / l). In addition, water turbidity (suspended solids) and water color (presence of humic substances). A major problem has happened in the last 50 years the total grassland acidification. All parameters for the maintenance of the population is virtually impossible due to the size and extent of the habitat area.

Open Original Report  

Scientific name used in original MS report if different than recommended: "Margaritifera margaritifera"
Information provided in the field 2.8.2: Reported additionnal information: ||
->Range: N/A ||
->Population: Methodik zur Ermittlung der Populationsgröße in EU-Einheit: Verschneidung der Vorkommenspunkt (Distribution) mit grids1x1 und Habitatmaskierung mit CorineLandCover-Klassen ||
->HabInfo: N/A ||
->Future: N/A ||
->Conclusion: N/A ||
->JustificationThreshold: N/A ||
->Other: N/A

Open Original Report  

Scientific name used in original MS report if different than recommended: "Margaritifera margaritifera"
Information provided in the field 2.8.2: Reported additionnal information: ||
->Range: Contrairement à d'autres espèces de bivalves, l'aire de répartition actuelle de la Mulette perlière reste similaire à celle historique, telle que décrite par la littérature ancienne. Cette aire de répartition est fortement contrainte par la nature géologique, la mulette perlière ne vivant que dans les cours d'eau cristallins acides des têtes de bassin. ||
->Population: N/A ||
->HabInfo: N/A ||
->Future: N/A ||
->Conclusion: N/A ||
->JustificationThreshold: N/A ||
->Other: N/A

Open Original Report  

Scientific name used in original MS report if different than recommended: "Margaritifera margaritifera"
Information provided in the field 2.8.2: Reported additionnal information: ||
->Range: Species extinct in the wild, meanwhile; last wild individuals were recorded in 2013 ||
->Population: Species extinct in the wild, meanwhile; last wild individuals were recorded in 2013 on 2 sites in the upper Our ||
->HabInfo: Physico-chemical conditions of the habitat decreased during the same period as species numbers decreased;
Species extinct in the wild, meanwhile; last wild individuals were recorded in 2013 on 2 sites in the upper Our ||
->Future: Species extinct in the wild, meanwhile; last wild individuals were recorded in 2013 ||
->Conclusion: Although survey and conservations measures were undertaken, physico-chemical conditions of the habitat decreased during the same period as species numbers decreased;
Species extinct in the wild, meanwhile; last wild individuals were recorded in 2013 ||
->JustificationThreshold: N/A ||
->Other: N/A

Open Original Report  

Scientific name used in original MS report if different than recommended: "Margaritifera margaritifera"
Information provided in the field 2.8.2: Reported additionnal information: ||
->Range: The river-dwelling mussel Margaritifera margaritifera has declined dramatically during the past 100 years due to water regulations, hydropower dams, forestry and acidification, both the habitats and the host species Salmo salar/Salmo trutta has declined due to these factors. Unlike other species the decline is not just loss of individuals but also loss of reproduction in still living individuals. In roughly half of the populations (rivers with M. margaritifera) in Sweden the individuals are not reproducing.

Red listed as EN (Endangered) in Sweden 2015. Data for this species largely from the National Monitoring Program of M. margaritifera. This program makes figures on range, the evaluation of status, number ef rivers with reproducing mussels solid and is supporting the construction of figures on number of populations and quality of habitat. A well-studied species. ||
->Population: N/A ||
->HabInfo: N/A ||
->Future: See 5.12 and 6.15 ||
->Conclusion: See 5.12 and 6.15 ||
->JustificationThreshold: N/A ||
->Other: See 5.12, 6.15 and 8.2

Open Original Report  

Scientific name used in original MS report if different than recommended: "Margaritifera margaritifera"
Information provided in the field 2.8.2: Reported additionnal information: ||
->Range: El rango de distribución de la especie es conocido en Galicia y se ha mantenido estable desde la década de los 90. No así en Castilla y León, donde se han descubierto nuevas localidades, al igual que poblaciones recientemente extintas, por lo que la tendencia del rango de distribución décadas atrás es incierta dado el desconocimiento de la especie en esta región, aunque podría valorarse como en descenso. ||
->Population: Las poblaciones de este molusco han sido escasamente estudiadas en las últimas décadas. Se valora una tendencia global en declive de la especie a largo plazo en la región Mediterránea. Estudios y evaluaciones llevados a cabo en Europa Central evidencian un declive poblacional muy drástico de esta especie. Además, teniendo en cuenta la degradación del hábitat y las presiones y amenazas, se podría inferir un deterioro y retroceso de las posibles poblaciones remanentes en esta región biogeográfica. ||
->HabInfo: El hábitat de los ríos mediterráneos se ha visto deteriorado en décadas recientes, con un empeoramiento de la calidad de las aguas, una grave alteración de los regímenes hídricos por obstáculos transversales y construcción de presas, o la expansión de especies exóticas invasoras. Todo esto, sumado a los efectos del cambio climático como el aumento de las temperaturas y las sequías recurrentes, reduce la disponibilidad del hábitat óptimo necesario para esta especie, con unos muy escasos y localizados efectivos en la región Mediterránea. ||
->Future: Son numerosos los problemas que a medio y largo plazo amenazan las últimas poblaciones mediterráneas. El cambio climático es el factor preponderante, y del que derivan otros como las sequías cada vez más recurrentes, la falta de salmónidos hospedadores en los ríos, la aparición de los incendios cada vez más habituales, etc. Las perspectivas futuras obtenidas de la aplicación de modelos poblacionales predicen que los eventos estocásticos antes enumerados agravan significativamente el proceso de extinción, anticipando el presumible colapso demográfico teóricamente esperable para 2027-2032 (Morales & Lizana, 2014). ||
->Conclusion: N/A ||
->JustificationThreshold: N/A ||
->Other: N/A

Open Original Report  

Scientific name used in original MS report if different than recommended: "Margaritifera margaritifera"
Information provided in the field 2.8.2: Reported additionnal information: ||
->Range: 5.7 - Although it is not known how many populations before 2003, it is known that at that time six populations were known, of which only two remain (Joaquim Reis com. pess.). However, others were discovered in the meantime. ||
->Population: N/A ||
->HabInfo: N/A ||
->Future: N/A ||
->Conclusion: N/A ||
->JustificationThreshold: N/A ||
->Other: In Portugal M. margaritifera occurs in rivers Beça, Cávado, Mente, Neiva, Paiva, Rabaçal, Terva e Tuela (Varandas et al. 2013, Sousa et al. 2013, Sousa et al. 2015), the majority integrated in two SAC: Montesinho/Nogueira and Rio Paiva.
River Terva presented very low abundances and showed acute signs of ageing, calling into question the future survival of these populations. Although abundances were low in Rivers Beça, Paiva and Mente, juveniles were present and populations may improve their conservation status in the future, if appropriate management measures are applied. The highest abundances of pearl mussels (adults and juveniles) were found in Rivers Rabaçal and Tuela, with the species being present in all surveyed sites except in the areas subjected to the influence of dams (Amorim 2013, Sousa et al. 2015).
The evidence of recent juvenile recruitment in the Rabaçal, Tuela, Paiva, Mente and Beça Rivers, make these water courses extremely important for the conservation of M. margaritífera in the south of Europe.

Open Original Report