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Are SA’s fisheries at the End of the Line?

Are SA’s fisheries at the End of the Line? Colin Attwood, Zoology Dept. and Marine Research Institute, UCT. End of the Line Mechanisms of over-fishing, and their consequences. Massive declines in fish abundance Excessive investment in gear The effects of subsidies Discarding

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Are SA’s fisheries at the End of the Line?

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  1. Are SA’s fisheries at the End of the Line? Colin Attwood, Zoology Dept. and Marine Research Institute, UCT

  2. End of the LineMechanisms of over-fishing, and their consequences Massive declines in fish abundance Excessive investment in gear The effects of subsidies Discarding Ignoring scientific advice Ecosystem alteration and degradation Exploitation of Africa by 1st world nations

  3. Linefish Survey data: Arniston and Struisbaai Carpenter Red stumpnose Roman 1931 to 1933 1987 to 1993 Red steenbras Seventy-four Dageraad Santer Other

  4. Dageraad “74” These species dominated our temperate reefs. They briefly supported a fishery. Now they are very rare! Red steenbras

  5. Not all is bad news

  6. Australia’s south-east trawl fishery (R.J. Gowers 2008. Environ. History 14: 265–287 )

  7. Catch of north-sea cod (tonnes)ICES Advice. Cod in Subarea IV (North Sea), Division VIId (Eastern Channel), and IIIa West (Skagerrak)

  8. Fisheries management 1.01 Maximum sustainable yield Sustainable harvest Extinction(?) Zero catch Effort (# boats, or sea-days)

  9. ? Let’s add a few other species Sustainable harvest Effort (# boats, or sea-days)

  10. A MDS plot of the similarity of each fish species’ contribution to different fisheries N=507

  11. A MDS plot of the similarity of each fish species’ contribution to different fisheries Trawl Pelagic longline Handline Purse-seine Beach-seine Shore angling Prawn trawl Estuarine angling

  12. A MDS plot of the similarity of each fish species’ contribution to different fisheries Trawl Pelagic longline Handline Purse-seine Beach-seine Shore angling Prawn trawl Estuarine angling

  13. It looks as if we are doing OK for 11 fish species. Lets hope the other 496 are OK too.

  14. Final thoughts • We need to consider cheap and robust mechanisms to protect our incredible diversity of fishes. I consider MPAs (or closed areas) to be in this category. • The small-scale fisheries policy is pushing co-management. It is backed by some nice theory (reducing the commons, encouraging buy-in), but can we make it work?

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