In Sweden.
Sorry, mrostov, but the Daily Mail drives folks nuts because of it's terrible reporting. It's inclined to glance over a subject and give false emphasis to little 'bon mots' that might grab the attention.
We already know of the huge use of sea marsh resources, the wild fowling and the seasonal fish runs though, and the shellfish exploitation.
What evidence for 'violence' and 'fighting' ? there was no reference made to any injuries to the bones.
Mind, low population densities, and there are a heck of a lot of watery bits in Sweden.
We do get fish bone preservation, in shell middens. Everything organic rots, unless it's in an environment that preferentially preserves it. So, dessication, or encased in permanent ice, or in tannin rich bog waters, (good for leather, and wool, terrible for bones) or in mineral rich layers of shell middens where antler, and bone are preserved instead of leached out into the soil or water.
Better report of this kind of thing here......
http://www.uwhg.org.uk/reports/uwhg_meetings/01_apr_10/01_apr_10.html