Use of genetic methods for determining patterns and processes during marine biological invasions
Smith, K. F. (2012). Use of genetic methods for determining patterns and processes during marine biological invasions (Thesis, Doctor of Philosophy (PhD)). University of Waikato, Hamilton, New Zealand. Retrieved from http://hdl.handle.net/10289/6630
Permanent Research Commons link: http://hdl.handle.net/10289/6630
Invasive species are widely recognised as one of the major threats to marine biodiversity worldwide. With increasingly faster and more frequent transoceanic shipping, propagule pressure in the marine environment is likely to further increase, leading to a need for effective strategies for the early detection, prevention and control of marine invasive species. However, such strategies are often difficult to implement as many marine species cannot be accurately categorised as either native or non-native. For these reasons molecular genetic methods have increasingly been utilised for the study of marine invasive species. The potential for molecular data to enhance traditional morphology-based information is recognised and there has been huge progress in the application of molecular genetic methods to the study of marine bioinvasions in the last two decades. This work aims to build on and extend current advances in the use of molecular techniques for understanding marine bioinvasions, and in particular invasive ascidians. Part One (Chapters Two and Three) contains chapters that focus on the detection and identification of marine invasive species with molecular methods. Part Two (Chapters Four, Five and Six) examines how molecular methods can aid in understanding marine invasions and the affect of genetic diversity on invasive populations. The research in this thesis demonstrates the usefulness of molecular genetics for marine invasive species research. Chapter Two describes the development of a highly sensitive assay for rapid and accurate identification of an invasive clam from environmental samples and has the ability to enhance current marine pest surveillance methods. Chapter Three demonstrates the power of molecular methods for invasive species identification. To effectively monitor and / or control the ongoing anthropogenic spread of invasive marine species there is also a need for extensive molecular inventories of the extant marine invertebrate biodiversity. An understanding of the genetic diversity of invasive species populations is also required and will increase understanding of the species biology and lead to more effective management strategies. Chapters Four and Five highlight the applications of molecular genetic methods for identifying the invasive species / variants present and elucidating particular populations that served as the source of an introduction. This information can contribute to effective national and international policies and management strategies. Chapters Five and Six also show how molecular genetic data can aid in understanding why some species are invasive. The results from these two chapters add to growing evidence that, for colonial organisms, reductions in population level genetic diversity may alter colony interaction dynamics and enhance the invasive potential of newly colonising species. In the future, invasive species research will increasingly utilise metagenomics / next-generation sequencing (NGS) technologies. Such applications will provide the ability to not only detect specific invasive species but also the native species present in a sample to assess environmental health. Studies of invasive species are increasingly using functional markers to identify physiologically and ecologically important traits. Future gene expression experiments can utilise NGS technology to identify the genes involved in producing invasive phenotypes and species. Such studies may provide findings which could be of both evolutionary and importantly, practical interest for guiding invasive species management decisions. The application of molecular genetic methods to understanding the biology of invasive species is an extremely promising area of research and such knowledge should be utilised to guide and inform management decisions.
University of Waikato
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