Growing up in southeastern Pennsylvania, there was neither an ocean nor was the term biodiversity ever used. But I was fascinated with fish. Like my Dad and Grandpa Grove, I loved to go fishing in the local streams and the Susquehanna River for rainbow trout, shad, and bass. During summer vacations on the Atlantic coast, croaker, blue fish, and flounder danced in my dreams, and sometimes on the end of my line. I was also enthralled watching fish in aquariums; I even had one of my own in those days. The fish in my tank were usually named after family members. Millie and Jim, for example, were the freshwater, "Kissing Gourami;" their lip-to-lip contact behavior reminded me of an affectionate aunt and uncle.
My Icthyo-fascination has followed me throughout my life. It led to a degree in marine biology, marine research studies, world travel, and the writing of books about fish. And, given my choice of a waterside home base, it remains an important part of my daily life. This morning for instance, over my breakfast cereal, I watched as young sergeant majors (a kind of damselfish) removed parasites from the parrotfish among the rocks next to the dock here in Key Largo, Florida. The cleaner-fish remain in the same area day after day, and the larger fish, which occasionally need to have their parasites removed, come by, change color, and advertise their willingness in being worked over... a wonderful, symbiotic interaction in which everybody benefits, except the parasitic copepods.
I've noted 32 kinds of fish (Caribbean species) here around the dock, a meager comparison to what awaits me on upcoming expeditions to the tropical seas of the Pacific—home to more than 1,500 species of fish. Perhaps the most rewarding job I've netted is playing an active leader-lecturer role on our voyages...that is, being able to show our travelers the wonders of the undersea world in some of the most diversified fish habitats on the planet. Among these Pacific realms are the "nesias:" Poly-, Mela-, Micro-, and Indo-. To put it in visual perspective, a cleaning station in the tropical Pacific, similar to the one next to my Florida dock, would be situated in a coral reef habitat, surrounded by, not ten or twenty species, but literally hundreds of different kinds of fish, colorful corals, and other fascinating invertebrates.
Which brings us to the concept of biodiversity. Webster's definition is simple: "variety in the living things in a particular area or region." To witness biodiversity up-close and personal, a journey to a coral reef is in order. Entering the waters with mask and snorkel, even at first glance, there is a sense of awe—certainly missing in Webster's austere definition. As you swim through shoals of fish in an emerald sea, a reef below you bejeweled in an array of colorful soft corals and fairy basselets, damselfish, angelfish, and butterflyfish...this is the first-hand, awe-inspiring experience of a snorkeler or diver "visualizing biodiversity." And once you've made that connection, absorbed that moment of sheer wonder, you'd be hard-pressed to ever forget it. Biodiversity—in all its biological, evolutionary glory—is magical.
During more than three decades of traveling around the world, leading snorkelers and scuba divers from Palau to the Galápagos, I have discovered that one of my greatest joys is sharing the experience of visualizing biodiversity in the sea—by training the observer how to use behavioral differences in the fish world to help identify the species. For example, the keen snorkeler or diver will soon learn that rainbow wrasse spawn in swarms and that their reproduction depends on the mixing of the gametes in a cloud in the water column, a process called gamete launching. In contrast, damselfish are primarily bottom nesters. Their eggs are deposited by a single female, accompanied by only one male whose job it is to deposit milt on top of the eggs left by the female on the sea floor. By the end of a trip even the newest underwater explorers will know that needlefish live at the surface, well above the reef itself, and that sand darters and lizardfish lay motionless on the bottom. They will recognize that many fish change color when they are involved in sexual courtship and, with some species, they will be able to distinguish males from females based on their color and size, and which ones are predators and which ones prey.
If biodiversity is something that you haven't yet "visualized," then join me for an experience that will open your eyes to a whole new world of wonders.