Dipl. Biol. Sven Koschinski Nehmten, Germany Bonn, 22-23 April 2015 - - PowerPoint PPT Presentation

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Dipl. Biol. Sven Koschinski Nehmten, Germany Bonn, 22-23 April 2015 - - PowerPoint PPT Presentation

Sep 05, 2023 123 likes •225 views

Dipl. Biol. Sven Koschinski Nehmten, Germany Bonn, 22-23 April 2015 32.000 tonnes of chemical warfare materials have been dumped northeast of Bornholm between 1945 and 1965 Thereby one of the most important cod spawning areas in the Baltic

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  • Dipl. Biol. Sven Koschinski

Nehmten, Germany

Bonn, 22-23 April 2015

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32.000 tonnes of chemical warfare materials have been dumped northeast of Bornholm between 1945 and 1965

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Thereby one of the most important cod spawning areas in the Baltic was contaminated with highly toxic materials such as sulphur mustard or arsenic containing agents (arsine oil, Clark I & II, Lewisite, Adamsite)

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Today, the same area sustains a cod fishery with high commercial value. The main fishing gear used is the bottom trawl

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Mustard gas is persistent in lumps and frequently caught by fishing vessels operating around Bornholm. Trawling and emergency redumping relocates warfare

  • material. The contaminated

area gets bigger.

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etc.

5 10 15 20 25 30 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 tear gas Clark Adamsite sulfur mustard number of incidents (HELCOM reporting system)

Large salt water inflow

(www.smhi.de)

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etc.

Large salt water inflow

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  • Cod are dispersed and not present at

the bottom in stagnation years

  • Salt water inflows produce favourable

conditions for cod eggs

  • Cod are concentrated at and below

halocline in inflow years

  • Fishermen fish at cod concentrations

and use gear optimized for cod (i.e. bottom trawl)

  • CHEMSEA and MERCW studies

done in stagnation phase when fish were not present close to the bottom

Halocline

CHEMSEA: Such inflows may lead to a re- development of benthic fauna, on which fish like cod feed on, creating a shortcut for pollutants into the food chain

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Graphs taken from Hinrichsen et al. 2007, Storr-Paulsen et al. 2012, HELCOM 2013

Conclusions

  • Environmental effects of salt water inflows on chemical

warfare not well studied

  • Side effects not studied (e.g. fishermen‘s behaviour)
  • Fishermen knowingly put themselves at a high risk
  • Catch loss compensation for Danish fishermen due to

contamination may be a wrong incentive

  • High trawling activity further disperses chemical warfare
  • Fishing bans may result in a better protection of the

environment, fishers and fish consumers

  • Work of HELCOM MUNI on chemical munitions must be

continued