Understanding biodiversity and the ecosystems representing nature on this planet is a complex task. It is slow to develop and guided largely by unproven hypotheses and uncertain theories rather than by well-behaved physical laws. Progress occurs in steps — steps made or taken by scientists working singly or in teams, focused on a particular portion of the natural world. The scientists must be supported by an institution — formal or informal — that embraces that focus. For we are, after all, social animals.

When the Stroud family and Dr. Ruth Patrick persuaded the Academy of Natural Sciences of Philadelphia to establish the Stroud Water Research Center 34 years ago, they germinated an institution devoted to understanding the ecology of streams and rivers and their watersheds. It was an institution whose scientists understood the critical importance of small steps. And yet growth and development of the Stroud Center has been remarkable.

The "field station" began by focusing on one small temperate watershed, White Clay Creek in Chester County, Pennsylvania. It soon metamorphosed into a large independent institution pursuing knowledge and understanding of temperate river systems far beyond the banks of the White Clay — to the Susquehanna, Potomac, Salmon, and Mississippi Rivers, to name a few. About 11 years ago, I urged the Stroud Center to expand its scientific horizons and program even further to include tropical streams and rivers. I particularly wanted the Stroud scientists to study the streams flowing through my backyard in the Area de Conservacion Guanacaste (ACG) in northwestern Costa Rica. Fortunately, they accepted my challenge.

I have enjoyed helping their tropical research program grow and develop during the past decade. It has been very supportive for the growing ACG to have this independent research program developing on site, something driven by its own motivation and not requiring substantial attention from us.I have learned so much from watching over their shoulders as they peer intently at the streams I have always ignored. I have seen them unravel the details of the ACG natural stream ecosystem in true academic fashion — molecule by molecule, species by species, bug by bug. And I have watched as they used the data they collect in the still relatively pristine streams of the ACG, to understand and interpret their findings on the disturbed and polluted tropical streams that have become far too common outside of the ACG in Costa Rica and elsewhere.

As you read through this history of the Stroud Center, you may find yourself wondering whether the Stroud Center is a kind of university, focused on basic research and education? Or is it a museum, focused on collecting and discovering new species and understanding their ecological and evolutionary relationships? Or is it an environmental consulting firm using its basic research findings to prescribe remedies for disturbed stream and river ecosystems? Well, it is none of these solely, but rather a unique, unusual and fortunate blend of them all.

Dan Janzen
Professor of Biology
University of Pennsylvania