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Allelopathy of Invasive Brazilian Pepper
(Schinus terebinthifolius) on Mobile
Invertebrates from the Indian River Lagoon

By Lori Konar, Tiffany Sheldon, Stephanie Garvis, Melinda Donnelly
Mentor: Linda Walters

Abstract

Brazilian pepper Schinus terebinthifolius is a highly invasive plant species that can be found in many different ecosystems, including the edges of estuaries in south and central Florida. Brazilian pepper fruits contain chemicals that are toxic to native salt marsh plants. Previous researchers found that high densities of crushed Brazilian pepper fruits negatively impacted growth and final biomass of the black mangrove Avicennia germinans and the red mangrove Rhizophora mangle. Here, we investigated the impact of S. terebinthifolius on the viability of mobile estuarine invertebrates commonly found in the Indian River Lagoon, as well as the brine shrimp, a test organism commonly used in aquatic ecotoxicology bioassays. Our null hypothesis was that S. terebinthifolius would have no effect on the survival of all tested invertebrates. Our alternative hypothesis was that S. terebinthifolius would have a significant negative impact on the survival of the test invertebrates. Specifically, percent survival would decrease as the density of fruits increased, and crushed fruits would result in a lower percent survival than intact fruits. Bioassays containing 0 fruits (control), 5 crushed fruits, 5 intact fruits, 10 crushed fruits, or 10 intact fruits were tested on a variety of mobile invertebrates. We found that contact with any fruits of S. terebinthifolius significantly reduced survival in some trials (Sphaeroma quadridentata, Artemia salina Trial 1), significantly reduced survival of some trials only at the highest density of crushed fruits (Ilyanassa obsoleta, Artemia salina Trial 3) and had no effect on some trials (Petrolisthes armatus, Artemia salina Trial 2).

Hypotheses