Discipline: Ecology Environmental and Earth Sciences
Subcategory: Pollution/Toxic Substances/Waste
Abraham J. Smith - Florida International University
Co-Author(s): Gary M. Rand, Florida International University, North Miami, FL
The assessment of impacts of chemical and nonchemical stressors frequently involves the use of ecotoxicology studies with standard organisms for natural resource damage assessment and ecological risk analysis procedures. Classical toxicological work has generated toxicity data in fresh water and marine ecosystems but considerably less in estuarine systems using native species. This work addresses the use of native estuarine organisms in ecotoxicology studies to make more relevant conclusions on potential adverse biological effects from cadmium and copper. It is hypothesized that native species such as the starlet anemone, Nematostella vectensis, may be more sensitive than standard organisms used in classical ecotoxicology studies.
Well-developed animal husbandry and laboratory techniques for N. vectensis make it an excellent candidate for ecotoxicology and risk assessment studies. Cadmium and copper are two common metals used in agricultural and industrial applications and are contaminants of concern in estuarine systems. Therefore, our research used juvenile anemones to investigate short-term acute exposures of cadmium and copper and generated reproducible mortality estimates using a newly developed standardized laboratory protocol. Species sensitivity distributions also illustrate the sensitivity of cadmium and copper to N. vectensis and other estuarine organisms. Cnidarians are not a commonly used in toxicity studies and definitive determination of mortality can be difficult. Recovery (post-exposure to cadmium and copper) was used to facilitate the creation of a stress-response index. This index was used to determine at which stress level an anemone would be likely to recover. Macroscopically observable responses were used for the development of the index such as anemone column shape, color, and condition; mesentery visibility and condition; tentacle shape and level of retraction; tissue color and level of opaqueness; and response to physical and optical stimuli. Ecotoxicology studies are generally designed to use the most sensitive life stage of an organism, we furthermore developed an early life stage study with N. vectensis embryos/planulae larvae. Inhibition of larval survival, development, and metamorphosis were endpoints used in these 14-day studies. N. vectensis is an excellent model organism to use in estuarine or marine (water only or sediment exposures) ecotoxicology studies and has great potential for the integration of genetic techniques. In addition, the availability of data on embryological development, genetic pathways, epigenetics, and the annotated genome, as well as tools including gene knockdown, in situ hybridization, stable transgenic lines, and CRISPR/Cas9-mediated genome editing add to the value of using N. vectensis as a non-standard native organism in future aquatic ecotoxicology investigations.
Funder Acknowledgement(s): This material is based upon work supported by the National Science Foundation under Grant No. HRD-1547798. This NSF Grant was awarded to Florida International University as part of the Centers of Research Excellence in Science and Technology (CREST) Program. Partial funding was provided by miscellaneous funds available through Dr. Gary M. Rand to cover analytical chemistry costs.
Faculty Advisor: Gary M. Rand, firstname.lastname@example.org
Role: I modified culture protocols in the literature to create a husbandry routine to induce weekly spawning of anemone cultures. I developed all laboratory toxicity testing methods and turned them into a standard protocol for the FIU Ecotoxicology & Risk Assessment Laboratory. I conducted or was involved in hands-on training with all of the toxicity studies included in this presentation. I trained one graduate and two undergraduate students to assist me in some of the toxicity studies when there was more than I could handle at one time.