Parasite spill-over, spill-back and dilution effects of invasive oysters

Transcription

1 Royal Netherlands Institute for Sea Research Parasite spill-over, spill-back and dilution effects of invasive oysters M. Anouk Goedknegt R.W. Nauta, A. Schuster, M. Markovic, S.L. Bedolfe, D. Shoesmith, J.Havermans, J.E. Welsh, P. Luttikhuizen, C. Buschbaum, K.M. Wegner, J. Van der Meer, D.W. Thieltges

2 PhD project

3 Invasive species and parasites Invasive species Native species Co-introduction Enemy release Invasive parasites Established parasites Spill-over effect Spill-back effect Dilution effect

4 Pacific Oyster (Crassostrea gigas) Pacific oyster invasion

5 Pacific oysters and parasites Invasive species Native species Co-introduction Enemy release Invasive parasites Established parasites Spill-over effect Spill-back effect Dilution effect

6 Spill-over Mytilicola orientalis Crassostrea gigas 2-50 % M.orientalis M.orientalis Mytilus edulis 3-53 % Cerastoderma edule 2-18 % Macoma balthica 6-7 % Anne-Karin Schuster

7 Mussel culture plots Jarco Havermans Oosterom N = 155 Prev = 6,5% Int = 2 ± 1.5 Inschot N = 47 Prev = 2,1% Int = 4

8 Field work campaign Reinier Nauta Methods: 6 weeks 8 beds 4 plots per bed 20 hosts per plot Parasite/host data

9 Population size M. orientalis

10 Population size M. orientalis

11 True parasite? Dave Shoesmith

12 Effects on host Sarah Bedolfe On-going experiments: Effects of infection on: - Filtration capacity - Body condition - Attachment strength Additional stressors: - Oyster competition - Food limitation Bayne et al. 1978, J. Cons. Int. Explor. Mer.

13 Pacific oysters and parasites Invasive species Native species Co-introduction Enemy release Invasive parasites Established parasites Spill-over effect Spill-back effect Dilution effect

14 Spill-back effect Mytilicola intestinalis Polydora spp.

15 The enemy of the mussel culture De Telegraaf, 8 th August 1950 Leeuwarder Courant 28 th of March 1961 Leeuwarder Courant 12 th of December 1962

16 Spill-back Mytilicola intestinalis 0%

17 Spill-back of Polydora spp. NA NA

18 Pacific oysters and parasites Invasive species Native species Co-introduction Enemy release Invasive parasites Established parasites Spill-over effect Spill-back effect Dilution effect

19 Dilution effect

20 No. of recovered metacercariae (%) ±SD Pacific oysters dilute trematodes Thieltges et al. (2009) Biol invasions

21 Conclusions Invasive species Invasive parasites Native species Co-introduction Enemy release Established parasites Mytilicola orientalis Mytilicola intestinalis Polydora spp. Renicola roscovita Himastla elongata Spill-over effect Spill-back effect Dilution effect

22 Df Biorisks: impact of Pacific oysters Impacts of invasive species include effects on native parasite-host webs via spill-over, spill-back and dilution effects via parasite Disease risk assessment of Pacific oyster invasion Potential high risk: spill-over of M. orientalis No or low risk: spill-back of M. intestinalis & Polydora spp. Risk reduction for native hosts: dilution of infective stages of native trematodes

23 Thank you! David Thieltges, Jaap van der Meer, Pieternella Luttikhuizen, Kees Camphuysen, Mathias Wegner, Christian Buschbaum, Karsten Reise, Jennifer Welsh, Klemens Eriksson, Anneke Bol, Mirjana Markovic, Marc Engelsma, Anne-Karin Schuster, Karin Troost, Ad van Gool, Carola van Zweeden, Reinier Nauta, Jarco Havermans, David Shoesmith, Sarah Bedolfe, Annabelle Durain, Jonas Martin, Fokje Schaafsma, Samira Theis, Christian Einer

24 # of Population MO per size mussel in oysters per m2

25 Parasite population size in mussels

26 Mean prevalence parasites

27 Mean prevalence parasites

28 Mean intensities parasites

29 Mytilicola spp. Invasion Mathias Wegner

30 Maturation Sexual reproduction Juvenile Mature adult Eggs Hatching Copepodite II, III, IV, V Nauplius Infection Copepodite I Metanauplius Metamorphosis

31 Host specificity Crassostrea gigas Mytilus edulis Ostrea edulis Mytilus galloprovincialis Mytilus californianus Ostrea lurida Crepidula fornicata M.orientalis Mytilus crassestra Saxidomus giganteus Mytilus edulis Crassostrea gigas Mytilus galloprovincialis Ostrea edulis M.intestinalis Cerastoderma edule Paphia pullastra Protothaca staminea Macoma balthica Crepidula fornicata Tapes decussates Cerastoderma edule