Recent Submissions

  • Dinophysis species in Irish waters 1990 - 1993

    Jackson, D.; Silke, J. (ICES, 1993)
    The distribution and abundance of Dinophysis species as recorded in the national phytoplankton monitoring programme are described. An apparent spread in the occurrence of Dinophysis to the west coast of Ireland is reported. The lack of correlation between the concentrations of Dinophysis in the water and DSP toxicity in shellfish is reported on and discussed.
  • The occurrence of DSP toxicity in Ireland

    Jackson, D.; Silke, J.; Doyle, J.; Nixon, E.; Taaffe, B. (ICES, 1993)
    The geographical and temporal variations in the occurrence of DSP in Ireland are presented and the implications of the resulting closures on aquaculture operations and fisheries are discussed. Prior to 1992 DSP toxicity had been confined to the southwest and south coasts but in 1992 a protracted occurrence of DSP was recorded in Killary Harbour on the west coast.
  • Cork Harbour PSP incident

    Doyle, J.; Dunne, T. (1985)
    Gonyaulax tamarensis is one of the principle organisms involved in Paralytic Shellfish Poisoning in Europe and North America. P.S.P. has not been described in Irish waters with the exception of one incidence in Belfast Lough and also in Kerry in the late 1800s, although this cannot be verified. G. tamarensis has only been recorded in Irish waters as individual organisms and no bloom has been described up to this.
  • The implications of Alexandrium tamarense resting cysts in an area of shellfish aquaculture in Ireland

    Silke, J.; McMahon, T. (1998)
    The Irish Marine Institute's Fisheries Research Centre carry out a monitoring programme for the detection of algal toxins in shellfish. This programme is carried out under EU Directive 91/492. During the course of this programme the North Channel area of Cork Harbour has been the only location in Ireland where toxins causing Paralytic Shellfish Poisoning (PSP) have been detected in shellfish above the regulatory limit. For short periods during each of the summers of 1996,1997 and 1998, PSP toxins were found in mussels{Mytilus edulis) from this area above the regulatory limit period necessitating a ban on harvesting. Oysters {Crassostrea gigas) from the same area remained below the regulatory threshold. The dinoflagellate Alexandrium tamarense, a known vector of PSP toxins, was observed in the area during each of the toxic events. The exact origin of the populations of A. tamarense was unknown. A. tamarense is known to produce a cyst stage as part of its life cycle. These cysts can remain viable in the sediments for several years. A survey of the distribution of cysts of A. tamarense in the surface sediments in Cork Harbour was carried out in order to determine if they were potentially seeding the area. They were detected in 6 sites, and successfully germinated to yield vegetative cells. The results of the survey are presented and discussed.
  • Amnesic shellfish poisoning in the king scallop, Pecten maximus, from the west coast of Scotland

    Campbell, D.A.; Kelly, M.S.; Busman, M.; Bolch, C.J.S.; Wiggins, E.; Moeller, P.D.R.; Morton, S.L.; Hess, P.; Shumway, S.E. (National Shellfisheries Association, 2001)
    The king scallop, Pecten maximus, is a valuable economic resource in the UK. The industry relies on supplying premium "roe-on" processed scallops to the continental market. In July 1999, king scallops harboring the amnesic shellfish poisoning (ASP) toxin, domnic acid (DA), in gonadal tissue at levels above the regulatory limit (20 μg DA g-1) were detected across a wide area of northern and western Scotland. In response, a survey of the southern extent of the closed harvest areas was initiated to describe variability of ASP toxin levels over varying spatial scales (<5 m to >5 km); determine the anatomical distribution of the toxin, and identify, isolate, and culture causative Pseudo-nitzschia species. Toxin analysis was conducted using a liquid chromatography-tandem mass spectroscopy (LC-MS/MS) procedure. The DA content of tissues followed the predictable rank order: all other tissue -1 gonad -1 adductor. The toxin levels within all other tissue (95% Cl = 580-760 μg DA g-1, n = 170) consistently accounted for 99% of the total individual toxin burden. DA levels in the gonad (95% CI = 8.2-11.0 μg DA g- 1, n = 170) were an order of magnitude below levels in all other tissue and contributed to less than 0.5% of the total individual toxin burden, although levels above the regulatory limit were detected in individual gonad samples. Adductor muscle tissue contained the lowest concentration of DA (95% Cl = 0.38-0.82 μg DA g- 1, n = 170), and was typically within two to three orders of magnitude below levels in all other tissue. None of the scallops examined had DA toxicities in adductor muscle tissue exceeding the regulatory limit. Toxin variability among individuals and sites was high (range of coefficients of variation (CV) in all other tissue = 29&-l20% and gonadal = 45%-85%). The results do give an indication of the scale on which microhabitat differences may influence ASP toxicity in P. maximus populations, because significant differences were found in all other and gonadal tissue toxin levels between groups of individuals only 25-m apart. In total, seven species of Pseudo-nitzschia were identified from west coast waters. A suspected causative species, P. australis, was found to produce high levels of DA, in culture. The high individual variation in toxicities and the occurrence of DA in the gonad at levels above the regula1ory limit clearly demonstrate the complexity of managing the king scallop fishery during ASP events.
  • Factors affecting the concentration of domoic acid in scallop, Pecten maximus

    Bogan, Y. (2006)
    Domoic acid, a neurotoxin produced by some Pseudo-nitzschia species, can accumulate in shellfish, consumption of which can result in Amnesic Shellfish Poisoning. Since its detection in Irish king scallop, Pecten maximus, regulatory monitoring of toxin levels in product entering the human food chain has been undertaken. Only limited data exist on factors that may influence variability in scallop DA concentration in the field. DA concentration in scallop tissues from a range of sites around Ireland, analysed using HPLC-PDA, exhibited high concentrations in hepatopancreas (max. 3834.4 (μg.g-1), much lower in gonad (max. 61.3 μg.g-1) and even lower concentrations in adductor muscle (max. 31.8 μg.g-1). Toxin concentration in hepatopancreas and scallop size usually exhibited no relationship and there was little support for the hypothesis that shellfish size influenced toxin concentration. DA concentration exhibited site-specific relationships with water depth. Toxin concentration in suspended scallops compared to seabed scallops exhibited a statistically significant difference on only one sampling occasion. Attempts to correlate the occurrence of DA in bivalves with the abundance of cells of Pseudo-nitzschia species were unsuccessful. Given the extent of field variability in DA concentration, a landings-based approach to toxin management rather than an area-based approach would reduce the risks of poisoning.
  • Report on analysis of shellfish samples for the presence of Yessotoxins (YTX)

    Marine Institute (Marine Institute, 2001)
    In order to determine the cause of the positive mouse bioassay results obtained in mussel samples from several shellfish production areas (including Bantry Bay, Kenmare Bay, Cromane and Lough Foyle), samples were sent in December 2000 and January 2001 for analysis. Positive mouse bioassay results were obtained, using the Yasumoto (1978) assay, in the EU Reference Laboratory and using the Yasumoto (l 984) assay in the Italian Reference Laboratory. ASP toxins, Azaspiracid, Okadaic acid and DTXs were not detected. Yessotoxin, homoYessotoxins and analogues of Yessotoxins were not detected in the samples sent to the EU Reference Laboratory or the Italian Reference Laboratory. Prof. Yasumoto detected the presence of Yessotoxin and 45-hydroxyYessotoxin at the Japan Food Research Laboratory. 45-hydroxyYessotoxin is a shellfish metabolite of Yessotoxin, which occurs with time as the YTX is oxidised by the shellfish. The shellfish samples in which Yessotoxin and 45-hydroxy Yessotoxin were detected were taken from Bantry Bay, Roaring Water Bay (Summer 2000) and Mulroy Bay. If the initial detection of Yessotoxin and 45-hydroxyYessotoxin is confirmed in other samples, the Irish biotoxin management regime and the production cycles for shellfish (in particular mussels) will have to be adapted to encompass YTX.
  • Morphological and molecular characterization of the small armoured dinoflagellate Heterocapsa minima (Peridiniales, Dinophyceae)

    Salas, R.; Tillmann, U.; Kavanagh, S. (Taylor and Francis, 2014)
    The dinophycean genus Heterocapsa is of considerable interest as it contains a number of bloom-forming and/or harmful species. Fine structure of organic body scales is regarded as the most important morphological feature for species determination but currently is unknown for the species H. minima described by Pomroy 25 years ago. Availability of a culture of H. minima collected in the south-west of Ireland allowed us to provide important information for this species, including cell size, cell organelle location, thecal plate pattern, body scale fine structure and molecular phylogeny. Light microscopy revealed the presence of one reticulate chloroplast, an elongated centrally located nucleus, and the presence of one pyrenoid surrounded by a starch sheath. Scanning electron microscopy (SEM) of the thecal plate pattern indicated that Pomroy erroneously designated the narrow first cingular plate as a sulcal plate. In addition, SEM revealed as yet unreported details of the apical pore complex and uncommon ornamentations of hypothecal plates. Organic body scales of H. minima were about 400 nm in size, roundish, with a small central hole and one central, six peripheral and three radiating spines. They differ from other body scales described within this genus allowing for positive identification of H. minima. Heterocapsa minima shares gross cell morphological features (hyposome smaller than episome, elongated nucleus in the middle of the cell, one pyrenoid located in the episome on its left side) with H. arctica (both subspecies H. arctica subsp. arctica and H. arctica subsp. frigida), H. lanceolata and H. rotundata. These relationships are reflected in the phylogenetic trees based on LSU and ITS rDNA sequence data, which identified H. arctica (both subspecies), H. rotundata and H. lanceolata as close relatives of H. minima.
  • Real-time PCR detection of Dinophysis species in Irish coastal waters

    Kavanagh, S.; Brennan, C.; O’Connor, L.; Moran, S.; Salas, R.; Lyons, J.; Silke, J.; Maher, M. (Springer Verlag, 2010)
    Diarrhetic shellfish toxin-producing Dinophysis species occur in Irish coastal waters throughout the year. Dinophysis acuta and Dinophysis acuminata are the most commonly occurring species and are responsible for the majority of closures of Irish mussel farms. This study describes the development of a qualitative real-time polymerase chain reaction (PCR) assay for identification of D. acuta and D. acuminata in Irish coastal waters. DNA sequence information for the D1-D2 region of the large ribosomal sub-unit (LSU) was obtained, following single-cell PCR of D. acuta and D. acuminata cells isolated from Irish coastal locations. PCR primers and hybridization probes, specific for the detection of D. acuta, were designed for real-time PCR on the LightCycler™. The LightCycler™ software melt curve analysis programme determined that D. acuta was identified by a melt-peak at 61°C, while D. acuminata cells produced a melt peak at 48°C. The limit of detection of the real-time PCR assay was determined to be one to ten plasmid copies of the LSU D1-D2 target region for both species and one to five D. acuminata cells. Lugol's preserved water samples were also tested with the assay. The real-time PCR assay identified Dinophysis species in 100% of samples found to contain Dinophysis species by light microscopy and had a greater than 90% correlation with light microscopy for identification of D. acuta and D. acuminata in the samples. The assay can identify and discriminate D. acuta and D. acuminata at low numbers in Irish waters and has the potential to add value to the Irish phytoplankton monitoring programme.
  • Novel azaspiracids produced by Amphidomataceae

    Krock, B.; Tillmann, U.; Jeong, H.J.; Potvin, E.; Salas, R.; Kilcoyne, J.; Gu, H. (Alfred-Wegener-Institut für Polar- und Meeresforschung, 2012)
  • A multi-year comparison of Spirolide profiles in planktonic field samples from the North Sea and adjacent waters

    Krock, B.; Tillmann, U.; Alpermann, T.; Salas, R.; Cembella, A.D. (Alfred-Wegener-Institut für Polar- und Meeresforschung in der Helmholtz-Gemeinschaft, 2010)
    Alexandrium ostenfeldii isolates from distinct geographical locations showed almost identical profiles, primarily consisting of 20-methyl spirolide G (20-meG). Whereas the Scottish isolate produces only this variant, the Irish isolate additionally yields slight amounts of 13-desmethyl spirolide C (13-desmeC). These profiles were also reflected in the field data, where 20-meG was the most abundant spirolide throughout all samples and years.
  • The dinophycean genus Azadinium and related species – morphological and molecular characterization, biogeography, and toxins

    Tillmann, U.; Elbrächter, M.; Gottschling, M.; Gu, H.; Jeong, H.J.; Krock, B.; Nézan, E.; Potvin, E.; Salas, R.; Soehner, S. (International Society for the Study of Harmful Algae, 2014)
    Azaspiracids (AZAs) are the most recently discovered group of lipophilic marine biotoxins of microalgal origin. It took about twelve years from the first human poisoning event until a culprit for AZA production was unambiguously identified and described as a novel species, Azadinium spinosum, within a newly created genus. Since then, knowledge on the genus has increased considerably, and an update on the current circumscription of the genus is presented here including various aspects of morphology, phylogeny, biogeography, and toxin production. There are currently five described species: A. spinosum, A. obesum, A. poporum, A. caudatum, and A. polongum. As indicated by molecular sequence variation detected in field samples, there are probably more species to recognize. Moreover, Amphidoma languida has been described recently, and this species is the closest relative of Azadinium based on both molecular and morphological data. Amphidoma and Azadinium are now grouped in the family Amphidomataceae, which forms an independent lineage among other monophyletic major groups of dinophytes. Initially, azaspiracids have been detected in A. spinosum only, but AZA production within the Amphidomataceae appears complex and diverse: A new type of azaspiracid, with a number of structural variants, has been detected in A. poporum and Amphidoma languida, and AZA-2 has now been detected in Chinese strains of A. poporum.