Icelandic Fish Kill...

[Lucky_Phill]

Fish Kills – a Natural Phenomenon?

with Dr John Thorogood, Managing Principal 11 February 2013

Breaking news: Thousands of tonnes of fish die in Icelandic lake.


Iceland has recently experienced some of the largest fish-kills ever recorded, with between 25 000 and 30 000 tonnes of dead fish found floating on Kolgrafafjorour, a small fjord on the west coast. Needless to say, local authorities are receiving complaints about the smell of rotting fish from local residents. While investigations are on‑going, landfill and the recent construction of a bridge are being blamed.

Fish are utterly dependent on the quality of the water in which they swim, particularly the oxygen content, pH and toxicant status.In nature, the oxygen content of a waterbody can rapidly decline to critical levels as deposited nutrients consume oxygen through chemical and biological processes. Fish also suffer from disease epidemics: the mass mortality of sardines in southern Australian waters in 1995 and 1998 was the result of a herpes virus. While the definitive cause was not determined, the stocks recovered over the subsequent years. The estimated biomass of herring found dead on Kolgrafafjorour earlier this month, roughly equates to the total annual harvest of sardine from Australia's southern waters (sardines are Australia's highest volume, single‑species fishery).

Fish-kills (events where fish die en masse over a short period) are often natural and not uncommon events


Land use can increase the frequency and severity of fish-kills, through influencing flow, water quality and 'stocking density'. Discerning the cause or trigger of a fish-kill can be challenging and it commonly requires a holistic approach and a deeper understanding of ecology, rather than just a simple interpretation of symptoms (symptoms may show what ultimately killed the fish, but rarely explain what caused their death).

Recent fish-kills on the Queensland coast were attributed to TC Oswald washing large amounts of organic matter into waterways, leading to critically low concentrations of dissolved oxygen. Low dissolved oxygen killed the fish, but how land use across the various catchments may have contributed is a far more complex and meaningful question.

copyright........ FRC Environment.


FYI>


cheers LP

[manta man]

Hi Lucky Phil just wondering if you heard anymore on this particular issue. Have they come too any conclusions thus far.?

[manta man]

Hi Lucky Phil any updates on this particular thread?

[Lucky_Phill]

Nothing has come through to me.

No idea how long the investigation will take, but will follow it up in a month.

cheers LP

[manta man]

Cheers Manta Man

[Fillet`n`Release]

Iceland is one of the most seismologically active regions in the world. I'd be looking at the water chemistry and parameters and any recent geologic events preceeding the kill.