Slide Menu
Search Help Show/Hide Menu
Short Citation:
Southeast Fisheries Science Center, 2022: Using the otolith sulcus to aid in prey identification and improve estimates of prey size in diet studies of a piscivorous predator, https://www.fisheries.noaa.gov/inport/item/58439.

Item Identification

Title: Using the otolith sulcus to aid in prey identification and improve estimates of prey size in diet studies of a piscivorous predator
Status: Completed
Creation Date: 1999
Revision Date: 2020-01
Publication Date: 2020
Abstract:

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.

Purpose:

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

Supplemental Information:

Complete List of Authors: Byrd, Barbie; Riverside Technology, Inc, Contractor for:

Hohn, Aleta; National Marine Fisheries Service, Southeast Fisheries

Science Center, Beaufort Laboratory

Krause, Jacob; NC State University, Department of Applied

Ecology/Center for Marine Sciences and TechnologyComplete List of Authors: Byrd, Barbie; Riverside Technology, Inc, Contractor for:

Hohn, Aleta; National Marine Fisheries Service, Southeast Fisheries

Science Center, Beaufort Laboratory

Krause, Jacob; NC State University, Department of Applied

Ecology/Center for Marine Sciences and Technology

Keywords

Theme Keywords

Thesaurus Keyword
UNCONTROLLED
NODC DATA TYPES STOMACH CONTENTS - FULLNESS
NODC DATA TYPES STOMACH CONTENTS - PREY COUNT
NODC DATA TYPES ANIMALS - INDIVIDUAL - STOMACH CONTENTS
NODC DATA TYPES BIOLOGICAL DATA
NODC DATA TYPES STOMACH CONTENTS - CONTENT WEIGHT
NODC DATA TYPES STOMACH CONTENTS - DIGESTION
NODC DATA TYPES STOMACH CONTENTS - PREY TAXONOMY
NODC OBSERVATION TYPES fish examination
NODC OBSERVATION TYPES biological
NODC OBSERVATION TYPES in situ
NODC OBSERVATION TYPES laboratory analyses
None common bottlenose dolphin
None Tursiops

Temporal Keywords

Thesaurus Keyword
UNCONTROLLED
None 1996-2012

Spatial Keywords

Thesaurus Keyword
UNCONTROLLED
NODC SEA AREA NAMES Coastal Waters Of North Carolina
NODC SEA AREA NAMES North Atlantic Ocean

Physical Location

Organization: Southeast Fisheries Science Center
City: Miami
State/Province: FL
Country: USA
Location Description:

SEFSC PARR Data Server

Data Set Information

Data Set Scope Code: Data Set
Data Set Type: MS Excel Spreadsheet
Maintenance Frequency: None Planned
Data Presentation Form: Document (digital)
Entity Attribute Overview:

Data used in the study, including data on stranded dolphins, data on reference-collection fish and associated otolith measurements, and measurements of otoliths taken from dolphin stomachs.

Distribution Liability:

None

Data Set Credit: Barbie Byrd and Aleta Hohn

Support Roles

Data Steward

CC ID: 890856
Date Effective From: 2017
Date Effective To:
Contact (Person): Hohn, Aleta
Address: 101 Pivers Island Road
Beaufort, NC 28156
Email Address: Aleta.Hohn@noaa.gov
Phone: 252-728-8797
Fax: 252-728-8784

Distributor

CC ID: 894610
Date Effective From: 2020
Date Effective To:
Contact (Organization): Southeast Fisheries Science Center (SEFSC)
Address: 75 Virginia Beach Drive
Miami, FL 33149
USA
Phone: (305)361-5761
URL: https://www.fisheries.noaa.gov/about/southeast-fisheries-science-center
Business Hours: 8:00 a.m. - 4:30 p.m. EST

Metadata Contact

CC ID: 894612
Date Effective From: 2020
Date Effective To:
Contact (Person): Hohn, Aleta
Address: 101 Pivers Island Road
Beaufort, NC 28156
Email Address: Aleta.Hohn@noaa.gov
Phone: 252-728-8797
Fax: 252-728-8784

Extents

Currentness Reference: Ground Condition

Spatial Information

Spatial Representation

Representations Used

Text / Table: Yes

Access Information

Security Class: Unclassified
Data Access Policy:

Open to everyone

Data Access Procedure:

Download From Provided url

Data Access Constraints:

None

Data Use Constraints:

Please cite appropriately

Metadata Access Constraints:

None

Metadata Use Constraints:

Please cite appropriately

Distribution Information

Distribution 1

CC ID: 894609
Start Date: 2020
End Date: Present
Download URL: https://grunt.sefsc.noaa.gov/parr/58439.zip
Distributor: Southeast Fisheries Science Center (SEFSC) (2020 - Present)
File Name: 58439.zip
File Type: Zip
Compression: Zip

Catalog Details

Catalog Item ID: 58439
GUID: gov.noaa.nmfs.inport:58439
Metadata Record Created By: Lee M Weinberger
Metadata Record Created: 2020-01-08 00:11+0000
Metadata Record Last Modified By: Lee M Weinberger
Metadata Record Last Modified: 2022-06-17 02:21+0000
Metadata Record Published: 2021-04-29
Owner Org: SEFSC
Metadata Publication Status: Published Externally
Do Not Publish?: N
Metadata Review Frequency: 1 Year