Biology and invasion ecology of sessile animals

Suspension-feeding sessile invertebrates make a major contribution to benthic–pelagic coupling and create complex habitats exploited by numerous motile forms. Their adaptations to a static existence give these animals many similarities to land plants.

Sessile marine animals have lifestyles unseen in their terrestrial counterparts; studying their reproduction and development provides fascinating insights into the evolution of sex, gender allocation and ageing, while ascidians in particular can cast light on the origin of the vertebrates. Our work on reproduction has focussed on spermcast mating, a widespread process in sessile faunas that involves the release of sperm into the water to be taken up by conspecifics to fertilize eggs that have been retained rather than spawned, generally followed by brooding of the resulting embryos.  One group of sessile animals combines this with the splitting of each embryo into multiple genetically identical copies that develop independently, a process termed polyembryony which seems hard to explain in evolutionary terms—an apparent paradox that we are investigating.

Non-native species, introduced beyond their natural geographical range by human activities, pose serious threats to native species and ecosystems and can damage both human health and economic interests. Sessile marine organisms, living attached to solid surfaces, are easily transported from place to place as fouling, and accordingly feature prominently in inventories of marine non-natives.

Small scratch in antifoul coating on hull, colonised by several species

Development of a new antifouling assay

A bioassay of antifouling treatments is being developed based on the settlement and metamorphosis of bryozoan (moss animal) larvae.

In order to broaden the taxonomic range of testing used to assess new antifouling formulations, a bioassay using the responses of bryozoan larvae is being...

Inspecting pontoons managed by Milford Haven Port Authority

Biosecurity training and advice on non-native species

The MBA is working with partners in the provision of biosecurity training and advice along with the development of biosecurity plans for specific sites, areas and activities. Biosecurity here means taking steps to make sure that good practices are in place to minimise the risk of spreading...

Incubation chamber (Gonozooid) of the cyclostome Filicrisia geniculata

Reproductive biology of sessile animal species

A long-standing study has elucidated spermcast mating by sessile invertebrates, a widespread process involving the release of sperm into the water and its subsequent uptake by conspecific genetic individuals. 

This has involved long-term culturing of colonial ascidians...

Propellor with fouling including non-native species

Leisure boating and non-native species

The role of leisure boating and marinas in the secondary spread of non-natives along coastlines is being investigated.

This has involved survey work, monitoring and experimental investigations using settlement panels. The data also contributes baseline distribution information...

Mitochondrial haplotypes of global populations of the ascidian Ciona robusta

The introduction of marine species to new areas by human activities

The anthropogenic mechanisms and routes by which marine species are carried between remote biogeographic regions have been studied.

This has involved a combination of i) population-genetic approaches to infer population histories and ii) repeated monitoring of sites to document actual...


Identification guides

‘Identification Guide to Selected marine non-native species,’ now in its fourth edition and available in French and Welsh as well as English (Click on 'Guides' tab above)

‘Guide to early post-settlement stages of fouling marine invertebrates in Britain’ (Click on 'Guides' tab above).

Poster ‘Non-native sea-squirts and sea-mats’ (ascidians and bryozoans non-native in UK) (Download Poster 1.pdf [4.9MB])

GB Non-native Species Information Portal (GBNNSIP)

Contributors to GBNNSIP (Link here:, and use search window with green ladybird or ‘Species Information' drop-down):

  • species register entries
  • species information pages
  • horizon-scan exercises
  • input to biodiversity index based on non-native species
  • input to risk assessments.

Biosecurity planning for stakeholders

  • Developing templates for biosecurity planning by marinas, harbours and aquaculture sites etc.
  • Pilot study of whole-estuary biosecurity planning
  • Training workshops for stakeholders.

Marine Pathways Project - Managing marine non-native species

The main objectives of the project were:

  • Develop protocols for detection of NNS, both inshore and offshore
  • Identify locations at high risk of introduction of NNS, to enable risk-based monitoring and management
  • Raise awareness of NNS with stakeholders
  • With stakeholders, develop codes of practice reducing risk of introduction /spread of NNS
  • Develop strategies for control / eradication of NNS.

Posters shown at the Marine Pathways Conference, Cardiff, 25/03/2015:

  • ‘Comparison of methods for monitoring marine non-native fouling species in marinas and harbours’ (Download Poster 2.pdf [2.4 MB])
  • ‘Updating the distributions of marine non-native fouling species in Welsh and English marinas’ (Download Poster 3.pdf [3.2MB])

Channel Catchment Cluster (3C)

An MBA-led capitalization cluster part-funded by the EU ERDF focusing on communicating the outputs of Interreg IVa France (Channel) England and publicizing them to stakeholders, including two participatory meetings:

  • Discussion workshop ‘Marine non-native species surveillance: sharing best practice across the Channel’, MBA, Plymouth, 05 & 06/03/2014.
  • Symposium on water quality monitoring and management, Chambre du Commerce et Industrie, Le Havre, 17 & 18/09/2014.

Citizen science

Collaborators with Cornwall Wildlife Trust in pilot citizen science scheme in which stakeholders (marina operators and yacht owners, harbour authorities) deployed settlement panels and scored / photographed them to monitor non-native species, 2010-2014.


  • Annual contributors of session on sessile marine faunas to the University College London ‘Complex’ post-grad course.
  • Annual contributors of session on marine bio-invasions to University of Plymouth/MBA Marine Biology MRes course
  • Participators in MBA ‘Marina Aliens’ projects at three local schools.

    EU policy (invasive alien species)

    Co-lead expert (Marine) and co-authors, ENV.B.2/ETU/2014/0016 Invasive Alien Species - Prioritising prevention efforts through horizon scanning (Brussels, May 2015).

    Training workshops

    Workshops on marine non-native species and fouling faunas, including identification, survey techniques, recording, and biosecurity measures (NNS = non-native species; WT = Wildlife Trust):


    For ...



    Marine NNS awareness and biofouling

    Marina berthholders and visitors


    Plymouth Yacht Haven

    Marine NNS ID and recording

    North West WTs staff & volunteers


    Blackpool and the  Fylde College, Blackpool

    Marine NNS ID and recording; site biosecurity measures

    Stakeholders, volunteers, WT and agency staff


    Royal Southern Yacht Club, Hamble

    Marine NNS ID and recording; site biosecurity measures

    Stakeholders, volunteers, WT and agency staff


    Orielton Field Studies Centre, Pembroke

    Marine NNS ID and recording; site biosecurity measures

    Stakeholders, volunteers, WT and agency staff


    Menai Bridge (Bangor University)

    Native and non-native Bryozoa and their biology

    ERCCIS-funded and fee-paying delegates



    Marine NNS ID and recording

    Natural England staff



    Marine NNS ID and recording

    Stakeholders + volunteer recorders;  CWT/ERCCIS  /GBNNSIP-funded


    Falmouth Marine School

    Marine NNS ID and recording

    Devon and Cornwall Seasearch divers


    Falmouth Marine School

    Native and non-native Ascidiacea

    Environmental Records Centre for Cornwall and the Isles of Scilly (ERCCIS) & Cornwall WT


    Falmouth Marine School

    Marine NNS ID and recording

    Yorkshire and Lincolnshire WTs staff + volunteers


    Far Ings, Humberside (Lincolnshire WT)

    Identification of Carpet Seasquirt (Didemnum vexillum)

    CCW / Non-native Species Secretariat


    Menai Bridge (Bangor University)

    Marine NNS ID and recording

    Devon and Cornwall Seasearch divers


    Coxside Diving Centre (U. of Plymouth)

    Marine NNS in marinas, and student project options

    Falmouth Marine School




    Jersey Electric



    Marine NNS awareness

    CCW / Wales Biodiversity Partnership


    Menai Bridge (Bangor University)

    Scientific meeting (joint with SAMS, NHM)

    ‘Controlling Marine Invasive Species by Targeting Vectors of Dispersal’

    Stakeholders, academics, interested members of public


    Linnean Society, London


    Non-Native Species Guides

    The 2020 edition of our identification guide was produced by the MBA with funding from Natural England and The Bromley Trust.

    Waterproof copies of the guide are available at a cost to cover administration and p&p costs. For further information contact Chris Wood email:

    To download a low-resolution version of our  Identification Guide for Selected Marine Non-native Species (English) click here: ID NNS English.pdf (1.6 MB PDF)

    A high-resolution version is available at: 

    A version of the guide in French was produced with funding from the Interreg IVA ‘3C’ capitalization cluster.

    Pour télécharger le Guide d’identification pour quelques espèces marines non-indigènes (en français) cliquez ici: ID NNS francais.pdf (16MB PDF)

    A version of the guide in Welsh was produced with funding from the Resilient Ecosystems Fund (Welsh Assembly Government / Natural Resources Wales)

    I lawrlwytho’r Canllawiau I adnabod rhywogaethau morol anfrodorol dethol (Cymraeg) cliciwch yma: ID NNS Cymraeg.pdf (12MB PDF)


    Early Stages Guide

    This guide to early post-settlement stages was produced by the MBA with funding from the Welsh Resilient Ecosystems Fund and the Porcupine Marine Natural History Society.

    To download the Guide to Early Stages click here: Early Stages Guide v 1.pdf (7MB PDF).



    Staff List

    John Bishop
    John Bishop
    Associate Fellow

    John's research group at the MBA focuses on the ecology, reproduction and development of ‘sessile’ animals—those that, as adults, live permanently attached to a solid surface.

    Email: Telephone Number:
    +44(0)1752 426258
    Christine Wood
    Research Assistant

    Chris is a marine ecologist, with a particular interest in the discovery and study of the spread and phylogeography of non-native species (NNS) of ascidians and bryozoans in the UK and Europe.

    Email: Telephone Number:
    +(44)01752 426330

    1. Peer-reviewed papers (since 2006)

    • Jenkins H.L., Waeschenbach A, Okamura B., Hughes R.N., Bishop, J.D.D. (2017) Phylogenetically widespread polyembryony in cyclostome bryozoans and the protracted asynchronous release of clonal brood-mates. PLoS One DOI:10.1371/journal.pone.0170010.
    • Bouchemousse, S., Bishop, J.D.D., Viard, F., 2016. Contrasting global genetic patterns in two biologically similar, widespread and invasive Ciona species (Tunicata, Ascidiacea). Scientific Reports 6, 24875.
    • Fernandes J.A., Santos L., Vance T., Fileman T., Smith D., Bishop J., Viard F., Queirós A.M., Merino G., Buisman E., Austen M. 2016. Costs and benefits to European shipping of ballast-water and hull-fouling treatment: impacts of native and non-indigenous species. Marine Policy 64: 148-155. DOI: 10.1016/j.marpol.2015.11.015.
    • Jenkins, H. L., Bishop, J. D. D., & Hughes, R. N. 2015. Prudent female allocation by modular hermaphrodites: female investment is promoted by the opportunity to outcross in cyclostome bryozoans. Biological Journal of the Linnean Society, 116(3), 593-602.
    • Bishop, J.D.D., Wood, C.A., Yunnie, A.L.E., Griffiths, C.A. 2015. Unheralded arrivals: non-native sessile invertebrates in marinas on the English coast. Aquatic Invasions 10(3): 249-264. doi:
    • Wood, C.A., Bishop, J.D.D., Davies, C.J., Delduca, E.L., Hatton, J.C., Herbert, R.J.H. and Clark, P.F. 2015. Hemigrapsus takanoi Asakura and Watanabe, 2005 (Crustacea: Decapoda: Brachyura: Grapsoidea): first records of the brush-clawed shore crab from Great Britain. Bioinvasions Records, 4(2): 109-113.
    • Bishop, J.D.D., Wood, C.A., Lévêque, L., Yunnie, A.L.E., Viard, F. 2014. Repeated rapid assessment surveys reveal contrasting trends in occupancy of marinas by non-indigenous species on opposite sides of the western English Channel. Marine Pollution Bulletin doi:
    • Roy, H.E., Preston, C.D., Harrower, C.A., Rorke, S.L., Noble, D., Sewell, J., Walker, K., Marchant, J., Seeley, B., Bishop, J., Jukes, A., Musgrove, A., Pearman, D., Booy, O. 2014. GB Non-native Species Information Portal: documenting the arrival of non-native species in Britain. Biological Invasions 16, 2495-2505.
    • Nishikawa, T., Oohara, I., Saitoh, K., Shigenobu, Y., Hasegawa, N., Kanamori, M., Baba, K., Turon, X., Bishop, J.D.D. 2014. Molecular and morphological discrimination between an invasive ascidian, Ascidiella aspersa, and its congener A. scabra (Urochordata: Ascidiacea). Zoological Science 31(3): 180-185.
    • Sato, A., Shimeld, S.M, Bishop, J.D.D. 2014. Symmetrical reproductive compatibility of two species in the Ciona intestinalis (Ascidiacea) species complex, a model for marine genomics and developmental biology.” Zoological Science 31(6): 369-374.
    • Fitzer, S.C., Bishop, J.D.D, Caldwell, G.S., Clare, A.S., Upstill-Goddard, R.C., Bentley, M.G. 2012. Visualisation of the copepod female reproductive system using confocal laser scanning microscopy and two-photon microscopy. Journal of Crustacean Biology 32(5): 685-692.
    • Bishop, J.D.D., Roby, C., Yunnie, A.L.E., Wood, C.A., Lévêque, L., Turon, X., Viard, F. 2012. The Southern Hemisphere ascidian Asterocarpa humilis is unrecognised but widely established in NW France and Great Britain. Biological Invasions doi: 10.1007/s10530-012-0286-x
    • Sato, A., Satoh, N & Bishop, J.D.D. 2012. Field identification of ‘types’ A and B of the ascidian Ciona intestinalis in a region of sympatry. Marine Biology 159: 1611-1619.
    • R. Pérez-Portela, R., Turon, X. & Bishop, J. D. D. 2012. Bottlenecks and loss of genetic diversity: spatio-temporal patterns of genetic structure in an ascidian recently introduced in Europe. Marine Ecology Progress Series 451, 93-105.
    • Romano, C., Sarà, G., Salvo, G., Bishop, J., Mazzola, A. & Widdows, J. 2011. Effect of the presence of the shore crab, Carcinus maenas, on burrowing behaviour and clearance rate of the common cockle, Cerastoderma edule. Marine Biology 158: 2685–2694.
    • Johnston, E. L., Marzinelli, E. M., Wood, C. A., Speranza, D. & Bishop, J. D. D. 2011 Bearing the burden of boat harbours: Heavy contaminant and fouling loads in a native habitat-forming alga. Marine Pollution Bulletin 62 2137-2144.
    • Hammerschmidt K, Pemberton AJ, Michiels NK & Bishop, JDD 2011. Differential maternal allocation following mixed insemination contributes to variation in oocyte size in a sea squirt. Marine Ecology Progress Series 422, 123-128.
    • Pistevos, J. C. A., Calosi, P., Widdicombe, S. & Bishop, J. D. D. 2011. Will variation among genetic individuals influence species responses to global climate change? Oikos, 120 (5): 675-689.
    • Ryland, J. S., Bishop, J. D. D., De Blauwe, H., El Nagar, A., Minchin, D., Wood, C. A. & Yunnie, A. L. E. 2011. Alien species of Bugula (Bryozoa) along the Atlantic coasts of Europe. Aquatic Invasions 6 (1): 17-31.
    • Sköld, H. N., Asplund, M. E., Wood, C. A. & Bishop, J. D. D. 2011. Telomerase deficiency in a colonial ascidian after prolonged asexual propagation. Journal of Experimental Zoology Part B: Molecular and Developmental Evolution 316, 276-283.
    • Sköld, H. N., Stach, T., Bishop, J. D. D., Herbst, E. & Thorndyke, M. C. 2011. Cell proliferation pattern during budding in the colonial ascidian Diplosoma listerianum. Biological Bulletin (Woods Hole, Massachusetts) 221, 126-136.
    • Goldstien, S. C., Dupont, L., Viard, F., Hallas, J. P., Nishikawa, T., Schiel, D. R., Gemmell, N. J. & Bishop, J. D. D. 2011. Global phylogeography of the widely introduced North West Pacific ascidian Styela clava. PLoS One 6 (2), e16755.
    • Pemberton, A. J., Hansson, L. J. & Bishop, J. D. D. 2011. Does sperm supply limit the number of broods produced by a polyembryonous bryozoan? Marine Ecology Progress Series, 430: 113-119.
    • Sewell, J., Bishop, J.D.D. & Seeley, R. 2010. Through the portal—Improving the flow of information on non-native species in Great Britain. Biologia Marina Mediterranea 17, 76-77.
    • Chenuil, A., Hoareau, T. B., Egea, E., Penant, G., Rocher, C., Aurelle, D., Mokhtar-Jamai, K., Bishop, J. D. D., Boissin, E., Diaz, A., Krakau, M., Luttikhuizen, P. C., Patti, F. P., Blavet, N. & Mousset, S. 2010 An efficient method to find potentially universal population genetic markers, applied to metazoans. BMC Evolutionary Biology 10, 276. doi:10.1186/1471-2148-10-276
    • Dupont, L., Viard, F., Davis, M. H., Nishikawa, T. &, Bishop, J. D. D. 2010. Pathways of spread of the introduced ascidian Styela clava (Tunicata) in Northern Europe, as revealed by microsatellite markers. Biological Invasions 12, 2707-2721.
    • Collin, S. B., Oakley, J. A., Sewell, J. & Bishop, J. D. D. 2010 Widespread occurrence of the non-indigenous ascidian Corella eumyota Traustedt, 1882 on the shores of Plymouth Sound and Estuaries Special Area of Conservation, UK. Aquatic Invasions 5, 175-179.
    • El Nagar, A., Huys, R. & Bishop, J. D. D. 2010. Widespread occurrence of the Southern Hemisphere ascidian Corella eumyota Traustedt, 1882 on the Atlantic coast of Iberia. Aquatic Invasions 5, 169-173.
    • Carter, M. C., Bishop, J. D. D., Evans, N. J. & Wood, C. A. 2010. Environmental influences on the formation and germination of hibernacula in the brackish-water bryozoan Victorella pavida Saville Kent, 1870 (Ctenostomata: Victorellidae). Journal of Experimental Marine Biology and Ecology 383, 89–95.
    • Perez-Portela, R., Bishop, J. D. D., Davis, A. R. & Turon, X. 2009 Phylogeny of the families Pyuridae and Styelidae (Stolidobranchiata, Ascidiacea) inferred from mitochondrial and nuclear DNA sequences. Molecular Phylogenetics and Evolution 50, 560-570.
    • Griffith, K., Mowat, S., Holt, R.H.F., Ramsay K., Bishop, J.D.D., Lambert, G. and Jenkins, S.R.  (2009). First records in Great Britain of the invasive colonial ascidian Didemnum vexillum Kott, 2002 Aquatic Invasions 4, 581-590.
    • Dupont, L., Viard, F., Dowell, M.J., Wood, C. & Bishop J.D.D. 2009 Fine- and regional-scale genetic structure of the exotic ascidian Styela clava (Tunicata) in south-west England, 50 years after its introduction. Molecular Ecology 18, 442-453.
    • Sato, A., Bishop, J. D. D. & Holland, P. W. H. 2008 Developmental biology of pterobranch hemichordates: History and perspectives. Genesis 46, 587-591.
    • Jacobs, M. W., Degnan, B. M., Bishop, J. D. D. & Strathmann, R. R. 2008 Early activation of adult organ differentiation during delay of metamorphosis in solitary ascidians, and consequences for juvenile growth. Invertebrate Biology 127, 217-236.
    • Pemberton, A.J., Hansson, L.J., Craig S.F., Hughes, R.N. & Bishop J.D.D. (2007) Microscale genetic differentiation in a sessile invertebrate with cloned larvae: investigating the role of polyembryony.  Marine Biology 153, 71-82.
    • Dupont, L., Viard, F., David, P. & Bishop, J. D. D. (2007) Combined effects of bottlenecks and selfing in populations of Corella eumyota (Tunicata), a recent introduction to the English Channel. Diversity and Distributions 13, 808–817.
    • Shalla, S. & Bishop, J.D.D. (2007) Lampropidae (Crustacea: Cumacea) from the deep North-East Atlantic and the North Sea, with two new species of Hemilamprops and Mesolamprops. Journal of the Marine Biological Association of the United Kingdom 87, 1191-1200.
    • Hodgson, A. N., Le Quesne, W. J. F., Hawkins, S. J. & Bishop, J. D. D. 2007. Factors affecting fertilization success in two species of patellid limpet (Mollusca: Gastropoda) and development of fertilization kinetics models. Marine Biology, 150, 415-426.
    • Arenas, F., Bishop, J. D. D., Carlton, J. T., Dyrynda, P. J., Farnham, W. F., Gonzalez, D. J., Jacobs, M. W., Lambert, C., Lambert , G., Nielsen, S. E., Pederson, J. A., Porter, J. S., Ward, S. & Wood, C. A. 2006. Alien species and other notable records from a rapid assessment survey of marinas on the south coast of England. Journal of the Marine Biological Association of the United Kingdom, 86, 1329-1337.
    • Dixon, D. R., Dixon, L. R. J., Bishop, J. D. & Pettifor, R. A. 2006. Lunar-related reproductive behaviour in the badger (Meles meles). Acta Ethologica, 9, 59-63.
    • Bishop, J.D.D. & Pemberton, A.J. 2006.  The third way: spermcast mating in sessile marine invertebrates.  Integrative and Comparative Biology, 46, 398-406.
    • Dupont, L., Viard, F. & Bishop, J . D. D. 2006. Isolation and characterization of twelve polymorphic microsatellite markers for the invasive ascidian Styela clava (Tunicata), Molecular Ecology Notes, 6, 101-103.

    2. Recent Government Agency & NGO reports:

    • Wood, C.A., Bishop, J.D.D., Rennocks, L., Crundwell, R. (2016). RAS 2015: Non-Native Species Rapid Assessment Surveys in English Marinas (E Anglia & W coast). Report to the Bromley Trust. 34 pp.
    • Roy, H.E., Adriaens, T., Aldridge, D.C., Bacher, S., Bishop, J.D.D., Blackburn,T.M., Branquart, E., Brodie, J., Carboneras, C., Cook, E.J., Copp, G.H., Dean, H.J., Eilenberg, J., Essl, F., Gallardo, B., Garcia, M., García-Berthou, E., Genovesi, P., Hulme, P.E., Kenis, M., Kerckhof, F., Kettunen, M., Minchin, D., Nentwig, W., Nieto, A., Pergl, J., Pescott, O., Peyton, J., Preda, C., Rabitsch, W., Roques, A., Rorke, S., Scalera, R., Schindler, S., Schönrogge, K., Sewell, J., Solarz, W., Stewart, A., Tricarico, E., Vanderhoeven, S., van der Velde, G., Vilà, M., Wood, C.A., Zenetos, A. 2015. Invasive Alien Species – Prioritising Prevention efforts through horizon scanning ENV.B.2/ETU/2014/0016. European Commission. doi: 10.2779/096586
    • Wood, C.A., Bishop, J.D.D., Yunnie, A.L.E. 2015. Plotting the current distribution of NNS in English marinas. Report to Natural England and the Bromley Trust. 37pp
    • Wood, C.A., Bishop, J.D.D., Yunnie, A.L.E. 2015. Comprehensive reassessment of NNS in Welsh marinas. Report to Natural Resources Wales. 42pp
    • Lucy Morris; Nick Pope; Jonathan Richir; Jennifer Pini; Shannon White; Gordon Watson; Awantha Dissanayake; Awadhesh N. Jha; Christine A. Wood; Anna L.E. Yunnie; John D.D. Bishop; Nick Paling; Sarah Wigley; Sarah Purnell; Paulina Lopez; Laurence Couldrick. 2014. Channel Catchments Cluster: Atlas. Westcountry Rivers Trust. 22pp
    • Roy, H.E., Bacon, J., Beckmann, B., Harrower, C.A., Hill, M.O., Isaac, N.J.B., Preston, C.D., Rathod, B., Rorke, S.L., Marchant, J.H., Musgrove, A., Noble, D., Sewell, J., Seeley, B., Sweet, N., Adams, L., Bishop, J.D.D, Jukes, A.R., Walker, K.J., Pearman, D. 2012. Non-Native Species in Great Britain: establishment, detection and reporting to inform effective decision making. NERC Centre for Ecology & Hydrology, 110 pp.
    • Maggs, C., Mineur, F., Bishop, J.D.D.,  McCollin, T. 2010. Non-natives. In: Annual Report Card 2010-2011 (Marine Climate Change Impacts Partnership).
    • Bishop, J.D.D., Wood, C.A., Yunnie, A.L.E. 2010a. Surveys of marinas and harbours on the south and east coasts of England for the invasive ascidian Didemnum vexillum (October-December 2009). Report to Defra, February 2010.
    • Bishop, J.D.D., Wood, C.A., Yunnie, A.L.E. 2010b. Surveys for the invasive ascidian Didemnum vexillum in the Dart and Kingsbridge-Salcombe estuaries, Devon, in October 2009. Report to Defra, February 2010.
    • Hill, M.O., Beckmann, B.C., Bishop, J.D.D., Fletcher, M.R., Lear, D.B., Marchant, J.H., Maskell, L.C., Noble, D.G., Rehfisch, M.M., Roy, H.E., Roy, S., Sewell, J. 2009. Developing an indicator of the abundance, extent and impact of invasive non-native species. Final report. Defra, 49pp. (WC0718)
    • Sewell, J., Pearce, S., Bishop, J.D.D., Evans, J.L. 2008. Investigations to determine the potential risk for certain non-native species to be introduced to North Wales with mussel seed dredged from wild seed beds. CCW Policy Research Report No. 06/3, pp. 82.
    Tab not in use


    John Bishop



    The Marine Biological Association of the UK

    The Laboratory

    Citadel Hill


    Devon PL1 2PB


    Email: jbis [at]

    Telephone: +44 (0) 1752 426258