How did UV light and climate change stressors affect oil toxicity in grass shrimp larvae?

Cheldina Jean, American University


Collecting samples at Leadenwah Creek (Photo credit: Katy Chung)

Findings: In my first post I outlined the uniqueness of estuaries, the importance of grass shrimp as a prey species and in the food chain, and how environmental conditions such as UV light, salinity and temperature can affect the toxicity of crude oil in the environment. The objective of my research this summer was to determine the effect of UV light and climate stressors such as temperature and salinity on oil toxicity in grass shrimp larvae. We hypothesized that:

1) UV light would increase the toxicity of oil to the grass shrimp larvae,

2) oil combined with high temperature and low salinity would increase the toxicity of oil and mortality of the larvae, and

3) combining UV light, oil, and these climate change stressors would further increase the toxicity of oil to the larvae, leading to greater mortality. 

In my second post, I highlighted the methods we would use to test these hypotheses under combinations of different environmental conditions:  oil or no oil, UV or no-UV light, salinities of 10 ppt, 20 ppt, and 30 ppt, and temperatures of 32 degrees Celsius and 25 degrees Celsius. 

2018-06-25 09.36.41

Creating the HEWAF (phot credit: Katy Chung)

Over the ten week period, our results showed that UV light alone altered the chemical composition of the oil as a HEWAF leading to greater toxicity to the larvae in all of the tests. The lower salinity of 10 ppt and the higher temperature of 32 degrees Celsius were the most stressful climate conditions for larval grass shrimp in both the UV and non UV conditions. The high salinity of 30 ppt did not significantly alter oil toxicity. Combining UV light with high temperature and low salinity significantly altered the toxicity of oil and further increased the mortality of larval grass shrimp.

In conclusion, understanding how climate change stressors such as salinity, temperature, and UV light modify the toxicity of oil to estuarine species will help resource managers predict environmental change and recovery following an oil spill. Some future directions of this research include testing earlier grass shrimp life stages, such as embryos, and other estuarine larval organisms under these conditions.

I have been interested in environmental toxicology ever since I was in middle school, and this summer I was finally able to finally immerse myself in toxicological research. I am glad that I was able to partake in this research experience because it made me realize that this is a field that I am interested in pursuing. I got to meet and work with a lot of great people and I gained valuable skills in research, and science communication. I am looking forward to my next research experience and what the future holds for me!

grass shrimp larvae gif

grass shrimp larvae being released from female grass shrimp. (Credit:

I can not thank my awesome and supportive mentors Marie DeLorenzo and Katy Chung enough for helping me with my research project. Working with them and everyone at NOAA’s National Centers for Coastal Ocean Science was an amazing opportunity. This project is supported by the Fort Johnson REU Program, NSF DBI: 1757899.

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