Effects of Exotic Species and Nutrient Pollution on Native Aquatic Communities

EPA Grant Number: FP917353
Title: Effects of Exotic Species and Nutrient Pollution on Native Aquatic Communities
Investigators: Meza-Lopez, Maria M
Institution: Rice University
EPA Project Officer: Lee, Sonja
Project Period: September 1, 2011 through August 31, 2014
Project Amount: $126,000
RFA: STAR Graduate Fellowships (2011) RFA Text |  Recipients Lists
Research Category: Academic Fellowships , Fellowship - Ecosystem Services: Aquatic Systems Ecology


Exotic herbivores often are found co-occurring at high densities with exotic plants in eutrophic aquatic ecosystems but very little is known about the effects of eutrophication and the interactions between invasive species and the impact that they have on natural freshwater ecosystems. This study will investigate if nutrient enrichment enhances the effects of competition between exotic and native aquatic plants, herbivory of the exotic snail on native plants and whether an exotic snail increases the success of exotic plants.


This study will quantify the individual and combined impact of exotic plants and exotic herbivores on a native community by establishing native communities in mesocosms and then introducing exotic species into the communities while varying environmental conditions (nutrient levels). The study will collect data on the native community before and after each exotic species introduction. At the end, the study will collect plant diversity and biomass and snail abundance and biomass.

Expected Results:

Study predictions are that exotic snail herbivory on the native plant is going to have greater negative effects compared to competition between native and exotic plants. Herbivory by the exotic snail may facilitate the establishment of exotic plants. The predictions above will be magnified by nutrient enrichment contributing to the success of exotic aquatic species.

Potential to Further Environmental/Human Health Protection

Investigating the biotic interactions between native and exotic species that determine native community composition and the effects that nutrient pollution may have on those biotic interactions is critical to determine if it is beneficial to manage and control exotic plants and/ or exotic herbivores, and whether regulation of nutrient influx in aquatic ecosystems is important to protect native biodiversity. This study will provide information on how nutrient pollution may synergistically lead to declines in native species. This also will provide information on the relative importance of focusing on managing nutrient pollution and/or species invasions. This would be directly applicable to the conservation of freshwater ecosystems in Texas and also has economic and agricultural implications.

Supplemental Keywords:

exotic species, biotic interactions, nutrient enrichment, freshwater, community,

Progress and Final Reports:

  • 2012
  • 2013
  • Final