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Projected changes to freshwater fish habitats and stocks. Solomon Islands Government. Based on. Outline. Importance of flow Connectivity of freshwater habitats Effects of climate change on: habitats fisheries production Importance of catchment management.
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Projected changes to freshwater fish habitats and stocks Solomon Islands Government
Outline • Importance of flow • Connectivity of freshwater habitats • Effects of climate change on: • habitats • fisheries production • Importance of catchment management
Freshwater fisheries in the region • Catch 24,000 tonnes per year • 4% of GDP derived from fisheries Photo Jacob Wani
Flow responses to rainfall Daily flow, Nabukavesi Creek, Fiji
Fish migration and habitat connectivity Source: Gehrke et al 2011
Effects on freshwater are different! • Climate change will affect the quantity of freshwater habitat available to fisheries • Changes in water quality and habitat quality will be secondary to changes in flow
Effects of altered rainfall • Climate change will affect the quantity of freshwater habitat available to fisheries
Temperature and CO2 Photo: David Boseto • Increasing CO2 will promote growth of aquatic and riparian vegetation
Sea level • Barriers (waterfalls, weirs, culverts) may block retreat of freshwater habitats
Interactions in disturbed catchments Source: Google Earth
Effects on fisheries Photo: Erin Michelle Smith
Adaptation recommendations • Maintain vegetation in catchments to avoid sediments and nutrients entering waterways Photo: Joanna Ellison
Management recommendations • Build capacity of local communities to manage habitats and fisheries resources Photo: Joanna Ellison
Management recommendations • Adopt more efficient fishing methods and limit fishing effort Photo: Boga Figa Photo: Boga Figa
Adaptation recommendations • Manage threats from invasive species Photo: Boga Figa
Adaptation recommendations • Monitor catches and measure the success of management interventions Photo: Jacob Wani
Putting climate change in perspective ‘In tropical systems it is possible that the effects of global climate change will be overshadowed by other, larger disturbances such as deforestation and land-use changes.’ (Ficke et al. 2007) Photo: Jacob Wani
Summary • Increased rainfall will increase freshwater habitats in tropical regions • Freshwater fish production may increase by 5-10% • Disturbed catchments restrict production • Ridge to reef management is needed to maximise positive outcomes and minimise negative effects