DOES SEA LEVEL RISE ENHANCE FISH HABITAT IN SALT MARSHES?

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  • Impacts of Sea Level Rise on Fishes

    Insightful

    GeoInformatics

    www.insightfulgeo.

    ca

  • Source: IPCC, 2013

    Sea level is expected to rise past historical levels in the next 100

    years.

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    2000 2009 2018 2027 2036 2045 2054 2063 2072 2081 2090 2099

    Sea

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    Year

    SL Hist SL .5

    SL 1 SL 1.5

  • Recent study show that sea level rise can drown and shrink

    wetlands because of coastal squeeze.

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    Projected distribution of salt marsh areas at Year 2100 sea levels (m)

    Source: Torio & Chmura, 2013

  • How will a shrinking marsh surface affect fish habitats within the

    salt marsh?

    Image source: http://ian.umces.edu/imagelibrary/displayimage-4192.html

  • To examine the impacts sea level rise on salt marsh as fish habitats,

    the size, configuration and connectivity of salt marsh patches were

    evaluated.

    Patch size and configuration Connectivity

  • Results indicate that at moderate sea level rise, salt marsh area

    increased resulting in more available fish habitats.

    -At high sea level, 40% of the future marshes will be in

    private properties!

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    0.00 0.32 0.50 1.00 1.50

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    Constant Accretion

    Accretion = SLR

    Carrying Capacity (ESLI)

  • Not only the size but also the variability of marsh patches increased

    with moderate sea level rise.

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    Are

    a (

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    0.00 0.32 0.50 1.00 1.50

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    Sea Level (m)

    Constant Accretion

    Accretion = SLR

    Patch size standard deviation Mean Patch Size

  • Apart from habitat size and variability, complexity of marsh edges

    which provide refuge for small fishes also increased.

    Edge Density Fractal Dimension

  • Furthermore, moderate flooding from sea level rise increased

    connectivity between habitat patches.

  • Summary and conclusion

    Moderate sea level rise resulted in

    expansion of fish habitats. Moderate means

    sea levels not exceeding 1 meter. Sea

    levels exceeding this threshold resulted in

    reduced habitat size, configuration and

    fragmentation.