The Canadian landscape is dotted with thousands  of lakes; mighty rivers and countless streams run through it; and three oceans border it.  Most Canadians take this supply of clean, readily available water for granted: it is used, with little thought, for transport, hydro power,  consumption and recreation. However, in recent years, the impact of human activities on this vast resource has become more clearly visible: many rivers are polluted and their flow regime altered; algal blooms destroy lake ecosystems; invading species threaten native species assemblages; and oceans, lakes and rivers are over fished.   These events are not isolated, nor are they unconnected: introduced species, pollutants and nutrients drift and move through a network of lakes, rivers, tributaries, and marine habitats;  these multiple-stressors connected through the network pave the way for invasive species, pests and disease-agents impacting local ecosystems.  Although most impacts must be dealt with locally,  the problem must be studied on the larger, network, scale.  

Many initiatives are under way to understand and manage aquatic ecosystems in a sustainable way. Given the many transport and migration pathways that connect species locally, regionally and beyond, this task requires a network perspective. For example, invasive species in the lakes in Ontario and the American Midwest can spread through recreational boating. Which measures should be taken at what locations to most effectively limit this spread? A single large river hosts many local communities connected by river flow. How do upstream sources and changes in flow patterns impact downstream ecosystems? Watersheds form dentritic networks in which fish live.Which parts of these networks can we impact by agricultural, housing or industrial development before the fish are threatened? In the ocean, networks of marine protected areas are established for conservation of biodiversity.Individual protected areas are linked to one another by larval transport and adult migration. How should these networks be designed, given the changing ocean circulation conditions and the requirement of different species? Worldwide shipping transportation networks have facilitated the spread of invasive species through a network of ports. How could practices be changed to reduce the invasion pressure on coastal aquatic ecosystems? Aquaculture sites have sprung up to meet the demand of a growing human population. How do diseases and invasive species spread through these sites and affect native aquatic life?

The goal of this workshop is to create a cross-disciplinary platform to foster exchange and synergy between different groups to tackle these pressing questions at  regional, national and international scales. In particular, this workshop will present recent mathematical and theoretical advances to ecologists and managers, it will bring mathematicians ecologists and resource managers together to formulate testable models for the most pressing concerns, and it will create new opportunities and challenges for modellers and mathematicians. Workshop themes and talks will be grouped according to topic with an emphasis on freshwater systems during the first two days (22./23.) and on marine systems in the second half (24./25.)