Dr. Ian Fleming
ProfessorOcean Sciences CentreMemorial University of NewfoundlandSt. John's, Newfoundland, Canada,A1C 5S7 |
Research Laboratory of Dr. Ian A. Fleming
The research in our laboratory focuses on the behavioural and evolutionary ecology of fishes, with an emphasis on breeding system evolution, life history diversity, phenotypic plasticity maternal effects, survival strategies and habitat, cultured (i.e. hatchery, farmed and transgenic) and wild fish interactions, fisheries, and conservation. It examines the role of behavioural and life history diversity in the dynamics of fish populations and to study the links among reproductive patterns, early life history and population processes. It involves a range of approaches, from controlled laboratory experiments to large-scale field experiments, as well as more theoretical studies.
A long-term goal of the research program is to understand how ecological and evolutionary forces shape reproductive strategies and influence offspring performance, particularly in the context of environmental variability and human disturbance. Reproductive strategies are manifestations of breeding systems and are reflected in life history traits, such as age and size at maturity, residency versus anadromy, reproductive allocation, and number and size of offspring. Moreover, they can have tight, direct links to offspring success through maternal traits, such as egg size, breeding time and breeding location. What forces shape such traits and how they respond (genes, environmental plasticity, epigenetic effects or some combination thereof) are fundamental areas to evolutionary ecology and conservation biology. The forces acting and the source of trait expression will determine the form and speed of response to natural and anthropogenic environmental change.
(i) Mating system evolution - Our research has shown fishes, with their diverse mating systems, to be excellent models for the study of mating system evolution, particularly in the face of environmental variability and anthropogenic disturbance. Using a pluralistic approach, combining controlled laboratory and field experimentation, phylogenetically-based comparative methods, molecular parentage and kinship analyses, and other leading-edge techniques, the work addresses central issues within mating systems. These include exploring the forms of selection shaping both males and females and their interactions, the spatial and temporal variability the intensities of such selection, and the evolution of alternative reproductive phenotypes, sperm competition and cryptic female choice. This work also explores how anthropogenic change impacts mating structure and thus the response of fish populations.
(ii) Maternal and other effects on offspring performance - This research extends that on mating systems to explore the evolutionary significance of maternal effects (e.g., egg size, breeding time and location) and other forces (e.g., epigenetics) in shaping offspring performance and population dynamics. It attempts to resolve theoretical issues, such as why females of highly fecund species sacrifice offspring survival to maximize maternal fitness. It also explores norms of reaction in egg size to environmental quality, the evolutionary constraints imposed by oxygen availability for organisms with aquatic eggs, the potential for the maternal phenotype to determine offspring environment and the evolution of within-clutch variation in egg size.
(iii) Life history diversity - Resource allocation to offspring, as influenced by trade-offs between egg size and number, is a central theme of life history evolution. Our work in this area attempts to resolve not only long-standing controversies about “optimal” egg size, but also identify the relation between reproductive investment and other life history traits, such as semelparity/iteroparity. We also explore the role of life history diversity in population stability, the effects of phenotypic heterogeneity on intraspecific competition, and the evolution of the alternative life history strategies such as residency/anadromy and early maturity.
(iv) Invasion Biology and Consequences of the Escape of Cultured Fish - This issue has attracted considerable speculation and controversy, and our research has been at the forefront in attempts to resolve it. Using the theoretical underpinnings of conservation ecology combined with laboratory and large-scale field experiments, we were among the first to quantify the potential for farm salmon to invade and impact wild populations. Our work continues to identify the relative roles of environment and genetics (i.e. non-indigenous origins and domestication) and associated phenotypic plasticity in the potential for invasive fishes to establish both within native and non-native ranges, and to assess impacts on the productivity and genetic integrity of wild fish populations and the ecosystem they inhabit.
(v) Restoration and Fish Conservation - The laboratory’s research on restoration focuses on small population biology and involves theoretical and empirical analyses of the application of captive breeding. Using experiments, meta-analytic approaches and models we explore the array of behavioural, life history and morphological changes that captive breeding can impose on fish and impede their success after release. Captive breeding and release of fish, particularly salmonids, has long been a major tool of resource managers for supplementing wild populations, and more recently, for the recovery of endangered populations. Our research continues to address the critical question of whether such programs can successfully contribute to the recovery of populations, and under what circumstances.