TY - JOUR
T1 - Microplastics in Eurasian otter (Lutra lutra) spraints and their potential as a biomonitoring tool in freshwater systems
AU - O'Connor, James D.
AU - Lally, Heather T.
AU - Mahon, Anne Marie
AU - O'Connor, Ian
AU - Nash, Róisín
AU - O'Sullivan, John J.
AU - Bruen, Michael
AU - Heerey, Linda
AU - Koelmans, Albert A.
AU - Marnell, Ferdia
AU - Murphy, Sinéad
N1 - Publisher Copyright:
© 2022 The Authors. Ecosphere published by Wiley Periodicals LLC on behalf of The Ecological Society of America.
PY - 2022/7
Y1 - 2022/7
N2 - The ubiquitous nature of microplastics in aquatic ecosystems may have serious implications for aquatic biota. While microplastic research in freshwater ecosystems is increasing, very few studies have assessed the physical presence of microplastics among top predators. The Eurasian otter (Lutra lutra), a top predator of aquatic ecosystems, is one of the most widely distributed otter species and has a broad habitat niche. The opportunistic collection of otter spraints (i.e., feces) presents a valuable opportunity to assess pollutants of freshwater ecosystems through noninvasive means. Here, we assessed the prevalence, abundance, and concentration of microplastics (100 μm to 5 mm), as well as dietary remains, in 53 spraint samples collected over eight river catchments spanning three regions of Ireland. We found microplastics present in 57% of spraints at an abundance of 1.2 ± 0.1 microplastics (MPs)/spraint (mean ± SE) and a concentration of 3.8 ± 0.6 MPs/g (dry weight). Fibers were the dominant particle type recovered (85%), followed by film (10%). No significant differences in microplastic concentrations were detected between the three regions assessed, or between spraints collected from areas upstream (i.e., “lower” exposure) or downstream (“higher” exposure) of putative microplastic sources, which were defined using spatial vector data. While microplastic concentrations were not explained by spraint condition (i.e., fresh, drying, or dry), spraints collected in autumn had a significantly higher concentration than spring and summer. Furthermore, microplastic abundance or concentration could not be linked to dietary composition based on the items identified. From a trophic perspective, this study showed that the presence of microplastics in the feces of otter is most likely being obtained through its prey (i.e., secondary ingestion). While there may be limitations associated with using spraints as a biomonitoring tool for microplastics in freshwater systems, particularly with respect to otter home range and dietary niche breadth, they could still be employed for a regional assessment of microplastic levels.
AB - The ubiquitous nature of microplastics in aquatic ecosystems may have serious implications for aquatic biota. While microplastic research in freshwater ecosystems is increasing, very few studies have assessed the physical presence of microplastics among top predators. The Eurasian otter (Lutra lutra), a top predator of aquatic ecosystems, is one of the most widely distributed otter species and has a broad habitat niche. The opportunistic collection of otter spraints (i.e., feces) presents a valuable opportunity to assess pollutants of freshwater ecosystems through noninvasive means. Here, we assessed the prevalence, abundance, and concentration of microplastics (100 μm to 5 mm), as well as dietary remains, in 53 spraint samples collected over eight river catchments spanning three regions of Ireland. We found microplastics present in 57% of spraints at an abundance of 1.2 ± 0.1 microplastics (MPs)/spraint (mean ± SE) and a concentration of 3.8 ± 0.6 MPs/g (dry weight). Fibers were the dominant particle type recovered (85%), followed by film (10%). No significant differences in microplastic concentrations were detected between the three regions assessed, or between spraints collected from areas upstream (i.e., “lower” exposure) or downstream (“higher” exposure) of putative microplastic sources, which were defined using spatial vector data. While microplastic concentrations were not explained by spraint condition (i.e., fresh, drying, or dry), spraints collected in autumn had a significantly higher concentration than spring and summer. Furthermore, microplastic abundance or concentration could not be linked to dietary composition based on the items identified. From a trophic perspective, this study showed that the presence of microplastics in the feces of otter is most likely being obtained through its prey (i.e., secondary ingestion). While there may be limitations associated with using spraints as a biomonitoring tool for microplastics in freshwater systems, particularly with respect to otter home range and dietary niche breadth, they could still be employed for a regional assessment of microplastic levels.
KW - aquatic pollutants
KW - dietary analysis
KW - food webs
KW - mustelids
KW - plastic pollution
KW - secondary ingestion
KW - semi-aquatic mammals
KW - top predators
UR - http://www.scopus.com/inward/record.url?scp=85135192146&partnerID=8YFLogxK
U2 - 10.1002/ecs2.3955
DO - 10.1002/ecs2.3955
M3 - Article
AN - SCOPUS:85135192146
SN - 2150-8925
VL - 13
JO - Ecosphere
JF - Ecosphere
IS - 7
M1 - e3955
ER -