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History of Marine Animal Populations

History of Marine Animal Populations. HMAP Executive Committee. Chair: Poul Holm Trinity Long Room Hub, Trinity College Dublin Andrew A. Rosenberg Institute for the Study of Earth, Oceans and Space and Department of Natural Resources, University of New Hampshire Brian R. MacKenzie

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History of Marine Animal Populations

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  1. History of Marine Animal Populations

  2. HMAP Executive Committee • Chair: Poul Holm • Trinity Long Room Hub, Trinity College Dublin • Andrew A. Rosenberg • Institute for the Study of Earth, Oceans and Space and Department of Natural Resources, University of New Hampshire • Brian R. MacKenzie • National Institute for Aquatic Resources, Department of Marine Ecology and Aquaculture, Technical University of Denmark, • Anne H. Marboe • Department of Environmental, Social and Spatial Change, Roskilde University, Denmark • Bo Poulsen • Department of Environmental, Social and Spatial Change, Roskilde University, Denmark

  3. Preliminary Synthesis Conclusions: Big conclusions Huge changes in marine life, regime shifts Human impact of ancient origin Few species have become extinct through overfishing But many species have become commercially extinct, some marine ecosystems have been depleted beyond recovery ’Pristine nature’ is lost But we may hope to ’rebuild’ ecosystems and historical baselines will inform us of potential

  4. Preliminary Synthesis Conclusions: key patterns or trends • Changes are attributed to climatic and human forces • Modelling and testing historical hypotheses are possible • Historical patterns of resource exploitation are key to identifying what has actually been lost in the habitat • An essential part of developing and implementing recovery plans for depleted marine ecosystems and ecosystem attributes

  5. Distribution • Atlantic and North Pacific right whales • Text book assumptions on distribution and abundance have been corrected • The causes of failure of North Pacific right whale to recover numerically and spatially after severe depletion of the 1840s unknown • North Atlantic range of Tuna • North Sea abundance revealed • Climate or human exploitation? • Global habitat changes • 2000 year trajectories • Detailed studies of recoveries are needed

  6. Abundance • Northwest Atlantic: 1850s Cod Biomass Estimate on the Scotian Shelf • total removals 200,000 t per year • 1850s adult cod biomass estimate of 1.26 million t • 1990s annual biomass estimate of 50 000 t • Baltic cod: • extension • of time-series to • 16th C

  7. Abundance North Sea herring 1600-2000 fishing power of North Sea herring fishing vessels from the 16th – 20th century measured as cpue of hoeker-units stock abundance ten times higher in the 1600s than in the 1950s by the 1800s it had dropped to 50–60% of the level of the 1600s Bo Poulsen, submitted

  8. Returns in yearly catch and money value per unit of capital, Denmark 1895-2000 Catch values relative to investments (V/C) declined steadily through 20th C Falling catch volumes relative to investments offset by industrial fisheries (fishmeal) by mid-20th C but stagnating / declining since 1980 Abundance Technology gains Economic gains Holm 2007

  9. Visualization & Communication • Nicolas De Larmessin, Fisherman’s dress. Detail. (18th century)

  10. Visualization & Communication Pieter Brueghel the Elder, Big Fish Eat Little Fish

  11. Societal Impact of Results to Date “… a desktop review of current and historical information … to assess the extent to which New Zealand marine ecosystems have been affected by fishing and other anthropogenic forcing over the past 1000 years. This should provide a realistic baseline against which current and future status can be gauged.” New Zealand Ministry of Fisheries, Aquatic Environment Medium Term Research Plan (2008)

  12. Societal Impact of Results to Date • “ high urgency to recover the historical information” • ICES Study Group on the history of fish and fisheries (SGHIST) • theme session at the ICES ASC 2010 to improve the understanding of the long-term dynamics of marine ecosystems

  13. Societal Impact of Results to Date • History may contribute to revise present targets for • Potential biodiversity • Potential distribution and biomass of species • Should be incorporated in nature conservation plans • Is a way to draw on users’ knowledge • And help bring about a sense of proportions

  14. Limits to Knowledge • Current limits to knowledge: • Data rescue • Digitisation • Disciplinary boundaries • Developing technologies: • advanced computer animations and GIS to show changes in abundances, distributions over time and how they could look in future (under recovery situations) • new quantitative approaches for modelling changes in biodiversity, species’ abundance and distribution

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