Lee Newman, of Vancouver BC, has been keeping and studying freshwater fish for over 45 years, especially the geophagines from South America. Currently the Curator of Tropics with the Vancouver Aquarium, Lee is also an award-winning photographer and writer, contributing over sixty published articles.
Since earning his full cave diver certification in 2010, he has been a little distracted by the topic of the talk he will present for us this month:
Cenote Fishes of the Yucatan Peninsula is an overview of a very complex ecosystem. The peninsula is built of very porous limestone and therefore cannot hold surface waters such as rivers and lakes. However, that porosity has allowed rain and atmospheric carbon dioxide to hollow out the layers of rock below giving rise to an intricate network of flooded cave passages. Cave ceiling collapses form cenotes and exposes the ground water to sunlight and the surrounding forest. Residing in each cenote is an aquatic community - including fishes. The presentation looks at the geology of the peninsular and the effects of glaciation on the flooded cave passages - now a Mecca for cave divers worldwide. It also looks at how the fishes got there and why there are differences in the aquatic community structure of the cenotes. Given such a unique ecosystem, the presentation also covers some of the efforts being made to conserve the cenotes and their fishes.