58440
Using the otolith sulcus to aid in prey identification and improve estimates of prey size in diet studies of a piscivorous predator
Document
Published / External
58439
Using the otolith sulcus to aid in prey identification and improve estimates of prey size in diet studies of a piscivorous predator
Data Set
Completed
2020-03-23
Diet studies are fundamental for understanding trophic connections in marine ecosystems. In the southeastern US, the common bottlenose dolphin Tursiops truncatus is the predominant marine mammal in coastal waters, but its role as a top predator has received little attention. Diet studies of piscivorous predators, like bottlenose dolphins, start with assessing prey otoliths recovered from stomachs or feces, but digestive erosion hampers species identification and underestimates fish weight (FW). To compensate, FW is often estimated from the least affected otoliths and scaled to other otoliths, which also introduces bias. The ulcus, an otolith surface feature, has a species-specific shape of its ostium and caudal extents, which is within the otolith edge for some species. We explored whether the sulcus could improve species identification and estimation of prey size using a case study of four sciaenid species targeted by fisheries and bottlenose dolphins in North Carolina. Methods were assessed first on otoliths from a reference collection (n=421) and applied to prey otoliths (n=5308) recovered from 20 stomachs of dead stranded dolphins. We demonstrated in reference collection otoliths that cauda to sulcus length (CL:SL) could discriminate between spotted seatrout (Cynoscion nebulosus) and weakfish (Cynoscion regalis) (classification accuracy=0.98). This method confirmed for the first time predation of spotted seatrout by bottlenose dolphins in North Carolina. Using predictive models developed from reference collection otoliths, we provided evidence that digestion affects otolith length more than sulcus or cauda length, making the latter better predictors. Lastly, we explored scenarios of calculating total consumed biomass across degrees of digestion. A suggested approach was for the least digested otoliths to be scaled to other otoliths iteratively from within the same stomach, month, or season as samples allow. Using the otolith sulcus helped overcome challenges of species identification and fish-size estimation, indicating their potential use in other diet studies.
To explore whether the sulcus could improve species identification and estimation of prey size using a case study of four sciaenid species targeted by fisheries and bottlenose dolphins in North Carolina
Byrd, BL, Hohn, AA, Krause, JR. Using the otolith sulcus to aid in prey identification and improve estimates of prey size in diet studies of a piscivorous predator. Ecol Evol. 2020; 10: 3584-3604. https://doi.org/10.1002/ece3.6085
(actual Journal article)
ECE-2019-07-00864.R2_Proof_for inport.pdf is the pre-publication version of the paper found on the SEFSC PARR Data Server
Information on the published paper has been added to this record.
10.1002/ece3.6085
Wiley Online Library
Journal article
Acrobat Portable Document Format
Published
Author
2020
Person
Byrd, Barbie
barbie.byrd@ncdenr.gov
252-726-7021
Co-Author
2020
Person
Hohn, Aleta
aleta.hohn@noaa.gov
101 Pivers Island Road
Beaufort
NC
28156
252-728-8797
252-728-8784
https://scholar.google.com/citations?user=wd1SXSQAAAAJ
Aleta Hohn Google Scholar Page
Online Resource
https://doi.org/10.1002/ece3.6085
Byrd, BL, Hohn, AA, Krause, JR. Using the otolith sulcus to aid in prey identification and improve estimates of prey size in diet studies of a piscivorous predator. Ecol Evol. 2020; 10: 3584-3604.
Online Resource
Online version of article
gov.noaa.nmfs.inport:58440
Lee Weinberger
2020-01-08T08:11:49
SysAdmin InPortAdmin
2023-09-27T12:04:58
2021-04-29
Southeast Fisheries Science Center
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1001
Public
No
2021-04-29
1 Year
2022-04-29