Projected changes to freshwater fish habitats and stocks
Download
1 / 26

Projected changes to freshwater fish habitats and stocks - PowerPoint PPT Presentation


  • 53 Views
  • Uploaded on

Projected changes to freshwater fish habitats and stocks. Presented by Peter Gehrke. Authors.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Projected changes to freshwater fish habitats and stocks' - kaoru


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

Authors
Authors

This presentation is based on Chapter 7 ‘Vulnerability of freshwater and estuarine fish habitats in the tropical Pacific to climate change’ and Chapter 10 ‘Vulnerability of freshwater and estuarine fisheries in the tropical Pacific to climate change’ in the book Vulnerability of Tropical Pacific Fisheries and Aquaculture to Climate Change, edited by JD Bell, JE Johnson and AJ Hobday and published by SPC in 2011.

The authors of Chapter 7 are: Peter C Gehrke, Marcus J Sheaves, James P Terry, David T Boseto, Joanna C Ellison, Boga S Figa and Jacob Wani. The authors of Chapter 10 are: Peter C Gehrke, Marcus J Sheaves, David T Boseto, Boga S Figa and Jacob Wani.


Key messages
Key messages

  • Freshwater fisheries are important!!!

  • Increased rainfall will increase freshwater habitats in tropical regions, less in subtropics

  • Freshwater fish production may increase by ~12%

  • Disturbed catchments restrict production

  • Five adaptations to maximise positive outcomes and minimise negative effects


Importance of freshwater fisheries
Importance of freshwater fisheries

  • Catch 24,000 tonnes per year

  • 4% of GDP derived from fisheries

  • Consumption up to 100 kg per year

  • Part of culture and language

Photo Jacob Wani




Effects on freshwater are different
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


Freshwater habitats
Freshwater habitats

Photo Boga Figa


Fish migration and habitat connectivity
Fish migration and habitat connectivity

Source: Gehrke et al 2011


Flow responses to rainfall
Flow responses to rainfall

Daily flow, Nabukavesi Creek, Fiji

Episodic flow, Tontouta River, New Caledonia

Seasonal flow, Ba River, Fiji



Temperature
Temperature

Photo: David Boseto

  • Increasing CO2 will promote growth of aquatic and riparian vegetation


Sea level
Sea level

  • Barriers (waterfalls, weirs, culverts) may block retreat of freshwater habitats


Rainfall
Rainfall

2050

2050

Source: Lough et al. (2011)


Effects of altered rainfall
Effects of altered rainfall

Source: Gehrke et al 2011




Effects on fisheries
Effects on fisheries

Photo: Erin Michelle Smith



Adaptation recommendations
Adaptation recommendations

  • Maintain vegetation in catchments to avoid sediments and nutrients entering waterways

Photo: Joanna Ellison


Adaptation recommendations1
Adaptation recommendations

  • Build capacity of local communities to manage habitats and fisheries resources

Photo: Joanna Ellison


Adaptation recommendations2
Adaptation recommendations

  • Adopt more efficient fishing methods and limit fishing effort

Photo: Boga Figa

Photo: Boga Figa


Adaptation recommendations3
Adaptation recommendations

  • Manage threats from invasive species

Photo: Boga Figa


Adaptation recommendations4
Adaptation recommendations

  • Monitor catches and measure the success of management interventions

Photo: Jacob Wani


Putting climate change in perspective
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


ad