The BBC, reporting from the Ocean Sciences Meeting in Salt Lake City, says Norwegian scientists are becoming concerned about dumping huge amounts of tailings in the country's fjords.

Reporter Jonathan Amos in Scrutiny for Norwegian fjord rock disposal says for decades some Norwegian mining companies have been using pipes at 23 sites to dump tailings as far down as 200 metres in Norway's deep fjords.  Companies are seeking permits to do more dumping.

However, there have been no major scientific studies of the consequences of dumping tailings into the deep fjords. Now the Norwegian Institute for Ocean Research (Niva) is embarking on a three year study to look at the consequences of tailing dumping on the deep ocean bottom.

The BBC quotes Prof Andrew Sweetman, a research scientist with Niva as saying,

The mining companies send these tailings down a long pipe, down below the euphotic zone, below 200m, and essentially smother everything on the seafloor...

All the animals that live in the sediments that provide food for larger invertebrates and fish, for example, will be killed off.

Potentially, you are also going to kill off a lot of deep water corals.

And you can get extremely turbid water columns, and it can stay turbid for long periods of time. So, it's a big deal"

Amos also quotes Lisa Levin, from the Scripps Institution of Oceanography in La Jolla, California, as saying that the Norwegian tailings story was a classic example of an activity being undertaken without fully understanding its consequences.