Poly-
and perfluoroalkyl substances (PFAS) are ubiquitous contaminants across the
globe, can bioaccumulate in aquatic taxa, and potentially biomagnify in food
webs. Consequently, research examining the influence of PFAS on wildlife is warranted.
Amphibians are sensitive to contaminants such as PFAS because of their porous
skin and associations with aquatic habitats where contaminants accumulate. Because
PFAS tend to bioaccumulate and can adversely affect the endocrine system, there
is a need to examine uptake rates to inform ecotoxicology studies, as well as a
need to examine sublethal effects. To address these knowledge gaps I conducted
two experiments. First, I exposed larval northern leopard frogs (<i>Rana
pipiens</i>), American toads (<i>Anaxyrus
americanus</i>), and eastern tiger
salamanders (<i>Ambystoma tigrinum</i>) to PFAS chemicals
perfluorooctanoic acid (PFOA) or perfluorooctane sulfonate (PFOS) at
concentrations of 10 or 1000 ppb for 10 days and sampled them every 48 hours during
the exposure period. In the next experiment, I examined the effects of PFAS exposure via
contaminated substrate on the survival and growth of post metamorphic amphibians of the same species. I
found that, for all species, body burdens often reached steady state within 48
to 96 h of exposure. Steady-state body burdens of PFOA ranged from 3,819–16,481
ng/g dry weight among treatments and species (corresponding BCFs of 0.5 to 2.5),
while PFOS body burdens ranged from 6,955–489,958 ng/g dry weight
(corresponding BCFs of 47–259) among treatments and species. These data suggest
that steady state is rapidly reached in larval amphibians exposed to PFAS,
particularly regarding PFOS. This reflects a high potential for trophic
transfer of PFAS within food webs because amphibians are often low in trophic
position and are important prey for many aquatic and terrestrial species. In post-metamorphic
amphibians, there
was no influence of PFAS on survival or mass. However, significant effects on snout-vent
length were observed in all species, and body condition differences were
observed for two of my species. I found that all leopard frogs increased in
scaled mass index (SMI) when exposed to a PFAS treatment, indicating an
increased body condition. Toads exhibited a more variable SMI pattern across
treatments, with no outstanding trends, and tiger salamanders did not differ
significantly across treatments. These data suggest that sublethal effects vary
greatly depending on the species, possibly due to life history traits. Future research examining biomagnification
potential is warranted to determine the influence of PFAS on food webs. Additionally,
there is a need to determine the physiological mechanisms underlying the
observed effects of PFAS exposure.<br>
| Identifer | oai:union.ndltd.org:purdue.edu/oai:figshare.com:article/7413236 |
| Date | 17 January 2019 |
| Creators | Sarah A. Vaughn (5930915) |
| Source Sets | Purdue University |
| Detected Language | English |
| Type | Text, Thesis |
| Rights | CC BY 4.0 |
| Relation | https://figshare.com/articles/THE_UPTAKE_AND_EFFECTS_OF_POLY-_AND_PERFLUOROALKYL_SUBSTANCES_ON_LARVAL_AND_JUVENILE_AMPHIBIANS/7413236 |
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