BioPerl doesn't come with ActivePerl, so it's not installed. Here's a little install script that'll do it for you:

#!/usr/bin/perl

use strict;
use warnings;
use CPAN;

CPAN::Shell->install(

"Bundle::BioPerl",
"Bio::Seq",
"Bio::SeqIO::staden::read",
"Bio::Factory::EMBOSS",
"Bio::Tk::SeqCanvas",
"Bio::DB::Annotation");
[download]

There will be a bunch of test failures, so be prepared to spend some time working it. A good way to learn BioPerl:).

Update: Here's a newer version. Note that BioPerl::DB requires BioSQL. Install that before you run the script.

#!/usr/bin/perl

use strict;
use warnings;
use CPAN;

CPAN::Shell->force(qw(
install 
Bundle::BioPerl
Bio::DB::ESoap
CJFIELDS/BioPerl-Network-1.006900.tar.gz
CJFIELDS/BioPerl-DB-1.006900.tar.gz));
[download]