use strict;
use warnings;
use XML::Simple;

my $xml_raw = <<XML_RAW;
<survey>
...
</survey>
XML_RAW

my $data = XMLin($xml_raw, ForceArray => [qw(river fish)], KeyAttr => []);

foreach my $Animal (@{$data->{animals}{fish}}) {
	print <<"*END*";
[ Survey information for: $Animal->{name} ]:

Saltwater:$Animal->{saltwater}
Freshwater:$Animal->{freshwater}
Rivers covered in survey:

*END*
	for (@{$Animal->{river}}) {
		print $_, "\n";
	}
	print "\n";
}