What are we studying? | Why are we studying? | What are we finding? | What does it mean? | Where can I read more?

What are we studying?

Merritt Island National Wildlife Refuge include 140,000 acres. It’s an area of high Biological diversity with more than 1100 plant, 142 fish, 360 bird, 71 amphibian and reptile, and 29 mammal species on-site. Kennedy Space Center is located in and a large part of the refuge. Due to off-site commercial and agricultural development, Kennedy Space Center has been deemed critical for regional biodiversity. 39 plant and 33 wildlife species on Kennedy Space Center are either federally or state-listed endangered species, making it a critical area to prevent extinction for many populations. Thus, it is a unique reserve of regional and global biological importance.

One impact of climate change is likely to be increased pollutant exposure and toxicity, especially for aquatic species. This outcome is expected because as temperatures increase and waters become more acidic, the equilibrium for pollutants, particularly metals, shifts to favor increased solubility in water. This shift can release pollutants from sediments and other sources increasing their concentrations in the water column. The increased acidity will also likely affect the valence of metal pollutants. For example, lower pH (i.e. increased acidity) favors the more toxic hexavalent form of chromium (Cr) over the less toxic trivalent form. Thus, a critical, but often overlooked, need for understanding climate change is to monitor sentinel species for tissue levels of pollutants and toxic insult.

As a top predator, alligators serve as a sentinel species of ecosystem health as they accumulate and concentrate many environmental pollutants other species lower on the food chain encounter. Alligators do not migrate far, conducting their foraging and nesting habits in a relatively small area. Alligators are cold blooded (ectotherms); consequently, they rely on their environment to determine their body temperature. Ectotherms will be among the first species to experience the impacts of climate change and the impacts on them will have profound effects on the rest of the ecosystem. Thus, alligators are excellent sentinels for understanding climate change and other environmental insults. We want investigate the levels of metals and DNA damage in alligator tissues over time to better understand how they are changing with environmental changes. We also aim to evaluate potential risks of exposure to environmental contaminants to human health in our One Health approach using alligators as a sentinel species.

Why are we studying it?

Merritt Island National Wildlife Refuge include 140,000 acres. It’s an area of high Biological diversity with more than 1100 plant, 142 fish, 360 bird, 71 amphibian and reptile, and 29 mammal species on-site. Kennedy Space Center is located in and a large part of the refuge. Due to off-site commercial and agricultural development, Kennedy Space Center has been deemed critical for regional biodiversity. 39 plant and 33 wildlife species on Kennedy Space Center are either federally or state-listed endangered species, making it a critical area to prevent extinction for many populations. Thus, it is a unique reserve of regional and global biological importance.

 

What are we finding?

 

We have found that both particulate and soluble forms of chromium (VI) induce cell death and damage chromosomes in alligator skin cells.

 

What does it mean?

Our data support the suggestion that chromium (VI) poses a potential health risk to alligators who are exposed to it through either inhalation of chromium (VI) or other routes such as diet. Furthermore, because our data indicate that chromium (VI) damages chromosomes, chromium exposure may contribute to the development of cancer, developmental abnormalities and failure to reproduce.

 

Where can I read more?
  • Wise, S.S., Wise, C.F., Xie, H., Wise, Jr., J.P., Guillette, Jr., L.J., and Wise, Sr., J.P. Hexavalent Chromium Is Cytotoxic and Genotoxic to American Alligator Cells. Aquatic Toxicology, 171, 30-36, 2016. PMID: 26730726. PMCID: PMC4721530.