Symposium 2007: Non-native fishes: integrated biology of establishment success and dispersal, University of Exeter, 23-27 July

Translocations and introductions of fish species into areas outside their native range have a long history, with deliberate introductions for sport and food production intensifying during the last 100 to 150 years. The impacts of non-native fish introductions range from negligible to devastating, with the extinction of native species such as cichlids in Lake Victoria following the introduction of Nile perch. Only a small proportion of introduced species succeed in establishing a self-sustaining population, and consequently the probability of establishment is one of the central themes addressed in risk assessments of non-native species. Establishment in a novel environment is influenced by many interacting processes, including tolerance of environmental conditions (e.g. temperature, oxygen, salinity), human alteration of the environment, and species-specific adaptability (behavioural, physiological, reproductive, dietary, growth). Acclimatisation processes may be rapid or gradual, and establishment may be permanent or temporary, depending upon the genetic make-up of the founding populations - influenced by the frequency and size of introductions, and possibly facilitated by the presence of other non-native organisms, including parasites and pathogens, as well as by changes in environmental conditions (e.g. climate change, river regulation). Once established, the rates and routes for subsequent dispersal of introduced species are of particular interest for limiting or mitigating impacts. Knowledge of a species' dispersal patterns in its native range is not necessarily relevant to its introduced range. Therefore, research has been needed on the physiological and behavioural processes associated with dispersal in novel environments, especially integrated field (e.g. tracking) and laboratory studies of physiological tolerances and behaviour.

The Symposium will focus on the factors involved in the establishment success of non-native species and their subsequent dispersal, with emphasis on research that addresses these interactions through integrated studies of the development, life-history tactics, genetics, behaviour, biochemistry, ecological interactions and parasitology of non-native marine and freshwater fishes in novel environments.

THEMES AND INVITED SPEAKERS

In each of the 3 themes there will be an invited 'State of the Art' lecture and an invited Plenary lecture.

Theme 1

Ecological interactions will discuss the biology of interspecific interactions among fish and between non-native fish and their prey, humans, predators, parasites and pathogens and their impacts on establishment and dispersal.

• Jack Jones Lecturer - Kurt Fausch (Colorado State, US)
  Invasions, establishment, and effects of non-native salmonida: considering the risk of rainbow trout invasion in the British Isles
• Emili García-Berthou (University of Girona, Spain)
  The characteristics of invasive fish: what have we learned so far?

Theme 2

Ontogenetic aspects and life-history strategies will explore integrated studies of developmental processes (e.g. variations in age at maturity and size at maturity), encompassing morphology, physiology, behaviour and ecological interactions, and how these influence establishment and dispersal of introduced species.

• Michael G. Fox (Trent University, Canada)
  Life history and morphological strategies leading to invasion success: the case of pumpkinseed (Lepomis gibbosus) on the Iberian Peninsula
• Vladimír Kovác (Comenius University, Slovakia)
  Invasive fishes: from morphology, ontogeny and epigenesis towards ecology and evolution

Theme 3 

Physiological, behavioural and genetic constraints will examine such aspects as environmental tolerances and habitat suitability, and the interactions between growth and reproduction (e.g. allocation of somatic and gonadal growth) and the role of genetic diversity in determining successful establishment and subsequent dispersal in non-native species.

• Peter Sorensen (University of Minnesota, USA)
  Identification and use of a potent migratory pheromone in the invasive sea lamprey, Petromyzon marinus
• Bernd Hänfling (University of Hull, UK)
  Understanding establishment success of non-indigenous fishes: lessons from evolutionary genetics