food web

Fish in ponds can be a flowering plant’s best friend, according to WUSTL ecologists.Fish and flowering plants would seem to have as much in common as pigs and beauty soap. But ecologists at Washington University in St. Louis and the University of Florida have found an amazing relationship between the different species that provides a new direction for understanding how ecosystems “hook up.” A team of researchers, headed by Tiffany Knight, Ph.D., Washington University assistant professor of biology in Arts & Sciences, has shown a correlation between the presence of fish in ponds and well-pollinated St. John’s wort (Hypericum fasciculatum, Hypericaceae) at a Florida research station.

Copyright Pieter JohnsonEutrophication is caused by higher phosphorous and nitrogen that create a profound impact on the food web, threatening the frogs’ existence.A collaboration involving ecologists at WUSTL and the University of Wisconsin strongly points to farming practices and development, two factors that create a condition called eutrophication in ponds and wetlands, as factors behind the high incidence of deformed frogs. Eutrophication is caused by higher phosphorus and nitrogen (prime components of agricultural fertilizer) levels in wet ecosystems. Higher levels of these nutrients cause a profound impact on the food web that imperils the frogs’ existence.

New evidence has linked deformities to the presence of a parasite that has been noted in scientific literature for a century and a half.