History of Marine Animal PopulationsHistory of Marine Animal Populations

HMAP Executive CommitteeHMAP 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

Preliminary Synthesis Conclusions: Big conclusions Preliminary Synthesis Conclusions: Big conclusions

Huge changes in marine life, regime shiftsHuman 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

Preliminary Synthesis Conclusions: key patterns or trends

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

DistributionDistribution

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

AbundanceAbundance

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

AbundanceAbundance

North Sea herring 1600-2000North Sea herring 1600-2000fishing power of North Sea herring fishing vessels from the 16th – fishing power of North Sea herring fishing vessels from the 16th –

20th century measured as cpue of hoeker-units 20th century measured as cpue of hoeker-units

stock abundance ten times higher in the 1600s than in the 1950sstock 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 1600sby the 1800s it had dropped to 50–60% of the level of the 1600s

Bo Poulsen, submittedBo Poulsen, submitted

AbundanceAbundance

• Returns in yearly Returns in yearly catch and money catch and money value per unit of value per unit of capital, Denmark capital, Denmark 1895-20001895-2000

• Catch values relative to Catch values relative to investments (V/C) declined investments (V/C) declined steadily through 20steadily through 20thth C C

• Falling catch volumes relative Falling catch volumes relative to investments offset by to investments offset by industrial fisheries (fishmeal) industrial fisheries (fishmeal) by mid-20by mid-20thth C but stagnating / C but stagnating /

declining since 1980declining since 1980

Holm 2007Holm 2007

0,10

1,00

10,00

100,00

1895

1905

1915

1925

1935

1945

1955

1965

1975

1985

1995

Returns in total catch per unit ofcapital

Returns in value per unit ofcapital

Technology gains

Economic gainsEconomic gains

Visualization & CommunicationVisualization & Communication

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

Visualization & CommunicationVisualization & Communication

Pieter Pieter BrueghelBrueghelthe Elder, the Elder, Big Fish Big Fish Eat LittleEat LittleFishFish

“… 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)

Societal Impact of Results to DateSocietal Impact of Results to Date

Societal Impact of Results to DateSocietal Impact of Results to Date

• “ “ high urgency to recover the historical high urgency to recover the historical information”information”

• ICES Study Group on the history of fish ICES Study Group on the history of fish and fisheries (SGHIST)and fisheries (SGHIST)

• theme session at the ICES ASC 2010 to theme session at the ICES ASC 2010 to improve the understanding of the long-term improve the understanding of the long-term dynamics of marine ecosystemsdynamics of marine ecosystems

Societal Impact of Results to DateSocietal Impact of Results to Date

• History may contribute to revise present History may contribute to revise present targets fortargets for• Potential biodiversityPotential biodiversity• Potential distribution and biomass of speciesPotential distribution and biomass of species

• Should be incorporated in nature Should be incorporated in nature conservation plansconservation plans• Is a way to draw on users’ knowledge Is a way to draw on users’ knowledge

• And help bring about a sense of And help bring about a sense of proportionsproportions

Limits to KnowledgeLimits 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