The messages you've quoted do NOT
support your supposition that "the problem is that it needs to use the NCBI BLAST installed components, which it cannot find.
" They address themselves solely to what choroba
pointed out: that the first use of each needs to be declared with a "my" as, for one possibility,
my ($blast_obj, $seq_obj, $report_obj, $result_obj);
If Perl couldn't find something you tried to use, it would have provided an additional message specifically stating that it can't find it (by name).