The blurred line between photic and aphotic environments: a large Mexican cave with almost no dark zone

Sistema Muévelo Rico is a 1.2 km long cave in Quintana Roo, less than 2 km from the Caribbean Sea. We measured illuminance to a level of 0.1 lux, organic matter (weight loss on ignition), temperature, and relative humidity. The last two were measured at hourly intervals for nearly one year. Approxim...

Full description

Bibliographic Details
Main Authors: Luis M. Mejía-Ortíz, Tanja Pipan, David C. Culver, Peter Sprouse
Format: Article
Language:English
Published: University of South Florida Libraries 2018-01-01
Series:International Journal of Speleology
Subjects:
Online Access:http://scholarcommons.usf.edu/ijs/vol47/iss1/6/
Description
Summary:Sistema Muévelo Rico is a 1.2 km long cave in Quintana Roo, less than 2 km from the Caribbean Sea. We measured illuminance to a level of 0.1 lux, organic matter (weight loss on ignition), temperature, and relative humidity. The last two were measured at hourly intervals for nearly one year. Approximately one-third of the cave has illuminance values greater than 0.01 lux, and most of the rest of the cave has light as well. Temperature and relative humidity were relatively constant, but they showed a daily cycle at all stations, albeit with different strengths. Organic matter averaged 8%, intermediate in value between surface and aphotic zones. Both eyeless species and eyed predators occurred throughout the cave. Their occurrence can best be explained by their foraging for organic matter and incurring an increased risk of predation.
ISSN:0392-6672
1827-806X