Part of the Scientists in the Field series, this book centers around the issues involved in trying to protect and preserve the seahorse population, focused primarily on that in the coral reefs in the Philippines.  It does a good job of addressing the interconnected concerns of the biology of the seahorse itself, the health of its coral reef habitat, the needs of the community who make their livelihood from fishing these waters, and the wider world where seahorses are sought out for aquariums and medicines.  It does not over-simplify the issues, or support one cause at the expense of the others, but rather seeks to find ways to achieve sustainable balance that benefits all.  The photographs are absolutely lush.  The text understandable, but dense — definitely intended for older students.