GMIT GALWAY-MAYO INSTITUTE OFTECHNOLOGY INSTITIÙID TEICNEOLAlOCHTA NA GAILLIMHE-HAIGH EO Impacts of the parasitic dinoflagellate Hematodinium sp. on Irish crustacean fisheries. By Ciara Ni Chualain B.Sc Degree of Doctor of Philosophy Galway-Mayo Institute of Technology Supervisors of Research: Dr. Martin Robinson Dr. Pauline King Submitted to Galway-Mayo Institute of Technology Bord lescaJgh Klhara Irish Sea Fisheries Board NATIONAL DEVELOPMENT PLAN Declaration 1 hereby declare that this thesis is my own work, unless otherwise slated and has not been previously submitted here or to any other university. I also give my permission to the library of the Galway- Mayo Institute of Technology to lend or copy this thesis on request for the purpose of scholarly research. CLvOcrt Q- vCvT Ciara Ni Chualdin POSTGRADUATE CANDIDATE STATEMENT - THESIS PRESENTATION/AWARD HETAC/GMIT Postgraduate Research Degree Policy and Procedures require that a hardbound copy of the thesis be prepared in accordance with HETAC postgraduate research degree policy and procedures. Accordingly, there is a requirement for “A Statement, signed by the candidate and the supervisor(s), indicating that the thesis represents the candidate's own work, or, in the case o f a thesis based on a group project, indicating the extent of the candidate’s individual contribution and making reference to any other theses submitted or material published by each collaborator in the project, should also be submitted at this time. ” Candidate Name: Ciara Ni Chualain MRA Ref. Register/Award PhD Thesis Title: Impacts of the parasitic dinoflagellate Hematodinium sp. on Irish crustacean fisheries. Supervisor (1): Dr. Martin Robinson Supervisor (2): Dr. Pauline King I, the above named, certify that the thesis wholly represents my own work. Signature: Date: (Student) I/We, the above m Signature: (Supervisor 1) Signature Date: (Supervisor 2) ACKNOWLEDGEMENTS I would like to express my gratitude and appreciation to my supervisor, Dr. Martin Robinson for his time and support throughout this process even from afar in the Shetlands. His guidance and direction have ensured that I have remained (mostly!) motivated until the end. Thank you also to my co-supervisor Dr. Pauline King for her assistance particularly at the final stressful stages. I gratefully acknowledge Bord Iascaigh Mhara who funded this project under the National Development Plan 2000 - 2006 through the programme for Innovation and Sustainability in the Fisheries Sector. I would like to give special thanks to Shelltechians Ed, Dave and Rebecca for their friendship and for all the laughs and support in the office over the years. To Roisin, Blaithin, Sonya, Donal, Jenni and John 1 thank you all for creating such a warm, friendly environment in Shelltec. Thank you to Brendan for all the road trips over the years and thank you Mary for help with the early project. To Eugene, I would like to say thanks for all the advice (hunting, fishing and otherwise) and for being a great boss and friend during my time in GMIT. To Bernie, I’m glad you made it to GMIT when you did! Without the fishermen and managers who provided crab samples or who facilitated me onboard their vessels over the years; Danny Farren, Mickey Farren, Thomas Miskella, Joe O’Regan, Gerry Sweeney and Charlie O’Donnell from the Malin Head Fisheries Co-op Ltd., this work would not have been possible. I would like to express ray appreciation to Professor Jim Wilson and Dr. Martyn Linnie from the Zoology Department in Trinity College Dublin for providing me with a much needed work space away from home during my write-up time in Dublin. Thank you to everyone who kept me reminded me of life on the ‘outside’; my friends both from home and from college and also my diving buddies. Thank you Helen & Diarmuid, for all the lovely Sunday dinners and for giving me a home away from home. To Donal, how you put up with me still amazes me but I express my love and gratitude that you still do and I thank you for your love, patience and support (and bribes!) these past few years. Gra mo chroi thu. Agus ta buiochas o chroi le glacadh agam do mo mhuintir Padraic agus Geraldine. Murach an tacaiocht agus gra ata taispeainte acu dom le linn na blianta fada seo ag foghlaim, ni bheadh an la seo sroichte go brach. v TABLE OF CONTENTS INTRODUCTION........................................................................................................................ 1 CHAPTER 1 DISTRIBUTION AND SEASONALITY OF HEM A TODINIJJM SP. IN IRISH CRUSTACEAN FISHERIES ABSTRACT............................................................................................................................... 16 INTRODUCTION......................................................................................................................17 METHODS....................................................................................................................... 18 RESULTS................................................................................................................................... 20 DISCUSSION............................................................................................................................30 CHAPTER 2 INVESTIGATION INTO HEM A TODINIJJM SP. PREVALENCE AND INFECTION INTENSITY IN CANCER PAGURUS FROM MALIN HEAD, IN RELATION TO HABITAT AND HOST FACTORS ABSTRACT...............................................................................................................................35 INTRODUCTION......................................................................................................................35 METHODS................................................................................................................................. 39 RESULTS................................................................................................................................... 46 DISCUSSION............................................................................................................................56 CHAPTER 3 COMPARISON OF ASSESSMENT METHODS USED TO DIAGNOSE HEM A TODINIUM SP. INFECTIONS IN CANCER PAGURUS L. ABSTRACT...............................................................................................................................62 INTRODUCTION..................................................................................................................... 62 METHODS.................................................................................................................................66 RESULTS................................................................................................................................... 69 DISCUSSION............................................................................................................................81 CHAPTER 4 PRELIMINARY INVESTIGATION INTO HEM A TODINIUM SP. TRANSMISSION PATHWAYS AND DISEASE PROGRESSION IN CANCER PAGURUS ABSTRACT...............................................................................................................................87 INTRODUCTION......................................................................................................................87 METHODS.................................................................................................................................91 RESULTS................................................................................................................................... 95 DISCUSSION............................................................................................................................99 GENERAL DISCUSSION...................................................................................................... 104 REFERENCES, 103 LIST OF FIGURES Figure 1.1. Sex-specific size-frequency distribution of Hematodinium sp. -infected (black bars) and non-infected (grey bars) from (a) southwest, (b) north and (c) southeast Ireland. Note scale change on y-axis of (c)................................................... p 24 Figure 1.2. Sex-specific size-frequency distribution and prevalence of Hematodinium sp. infection for all locations pooled. Only size classes containing > 30 individuals are included...................................................................................................................................p 25 Figure 1.3. Seasonal variation in prevalence (bars) and mean intensity (lines) (+SD) of Hematodinium sp. infection from a) southwest, b) north and c) southeast Ireland. Male and female samples pooled. Only one side of the standard deviation is shown for clarity. Arrows indicate sampling when Hematodinium was not encountered.............................................................................................................................p 27 Figure 1.4. Mean intensity (+SD) of Hematodinium sp. infection in relation to seawater temperature. Only one side of the standard deviation is shown for clarity. Samples are grouped by quarters of the year (Ql: January to April; Q2: May to June; Q3: July to September; Q4: October to December).................................................................................p 28 Figure 1.5. Cancer pagurus. Seawater temperature profile from November 2004 - December 2007 and mean percentage of plasmodial cells present in Hematodinium sp. - infected individuals. Sampling dates are indicated by month and year and grouped by quarter (Q1-Q4). Associated errors are not shown here for clarity