TITLE:
A Biological Restoration Model for Contaminated Coastal Marshes and Islands Using the Life Cycle of Acheta domesticus to Establish Environmental Sustainability
AUTHORS:
Anna Leyrer, Edward Bush, James Geaghan, Buffy Meyer
KEYWORDS:
Entomology, Contamination, Oil, Insects, Sustainability, Marsh
JOURNAL NAME:
Computational Water, Energy, and Environmental Engineering,
Vol.9 No.2,
January
20,
2020
ABSTRACT: Insects such as Acheta domesticus account for over half of marsh fish and migratory bird diet. Therefore, insects
are very important to marsh and island ecosy stems and are susceptible to oil
contamination, but little research has been done to study the effects of oil
spills on cricket populations. The purpose of this experiment was to determine
the effects of an oil spill event on Acheta
domesticus mortality and hatch rate to establish environmental
sustainability. The treatment groups included 0% oil contamination, 5% oil
contamination and 10% oil contamination. The scientist counted the number of
deaths in two-week, four-week, and six-week-old
crickets after oil contamination. In addition, the scientist counted the number
of hatchlings among treated cricket eggs. Error bar lines in the results
section supported the scientist’s hypothesis that the crickets would be
affected by oil contamination. In fact, over 90% of the 10% oil treatment group
died and over 80% of the 5% oil treatment group died after five days of oil
contamination in the six-week-old experiment. The scientist used a Gas
Chromatography Mass Spectrometer to determine if benzene, toluene,
ethylbenzene, or xylene (total) were present in the sediment samples. BTEX
exposure is suspected to possibly cause insect mortality. These volatile
organic compounds were present in the samples and were found in higher
quantities in samples with higher concentrations of oil. The highest quantity
of volatile organic compounds present was xylene. After studying the population
dynamics of the tested Acheta domesticus, the scientist found that the two-week and four-week-old crickets’
survivability could fit a linear model while the six-week-old crickets fit an
exponential model. The scientist used these models to observe how long it took
each treatment group to approach zero, and the oiled groups grew closer to a
population of zero significantly faster. For example, it took about
twenty-seven days for the 10% treatment group’s population to approach zero
whereas the control, 0% treatment group, took about seven days in the two-week-old cricket
experiment. Overall, the six-week-old crickets had the highest mortality, and
the cricket egg experiment resulted in extremely low hatch rate. Specifically,
the highest number of crickets that hatched in an oiled replication either 5%
or 10% oil was eight out of the five thousand eggs laid. Since the adult
crickets are the most physically able to reproduce and the cricket eggs had low
hatch rates, the cricket population would significantly decrease after an oil
spill with 5% or more soil contamination. However, if the plant matter that
crickets consume is still present in their environment, they may be able to
recover.