...
use Encode;
...
my $fetch = $dbh->prepare("SELECT `id`,`bezeichnung` FROM `system` ORDER BY `bezeichnung` ASC");
$fetch->execute();
my @system = ();
#while ( ($system[scalar @system]{id},$system[scalar @system-1]{name}) = $fetch->fetchrow_array()){}
while ( ($system[scalar @system]{id},$system[scalar @system-1]{name}) = $fetch->encode('utf8',fetchrow_array())){}