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
Published / External
30208
Protected Resources Marine Mammals (Beaufort)
Project
Completed
1999
2020-01
2020
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
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
Theme
NODC DATA TYPES
STOMACH CONTENTS - FULLNESS
Theme
NODC DATA TYPES
STOMACH CONTENTS - PREY COUNT
Theme
NODC DATA TYPES
ANIMALS - INDIVIDUAL - STOMACH CONTENTS
Theme
NODC DATA TYPES
BIOLOGICAL DATA
Theme
NODC DATA TYPES
STOMACH CONTENTS - CONTENT WEIGHT
Theme
NODC DATA TYPES
STOMACH CONTENTS - DIGESTION
Theme
NODC DATA TYPES
STOMACH CONTENTS - PREY TAXONOMY
Theme
NODC OBSERVATION TYPES
fish examination
Theme
NODC OBSERVATION TYPES
biological
Theme
NODC OBSERVATION TYPES
in situ
Theme
NODC OBSERVATION TYPES
laboratory analyses
Theme
Tursiops
Theme
common bottlenose dolphin
Temporal
1996-2012
Spatial
NODC SEA AREA NAMES
Coastal Waters Of North Carolina
Spatial
NODC SEA AREA NAMES
North Atlantic Ocean
Southeast Fisheries Science Center
Miami
FL
USA
SEFSC PARR Data Server
Data Set
MS Excel Spreadsheet
None Planned
Document (digital)
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.
None
Barbie Byrd and Aleta Hohn
58642
Stranded_Bottlenose_Dolphins.csv
Published / External
Provides a list of the stranded dolphins
Data Table
Provides a list of the stranded dolphins
10
Field ID Number
Character
8
7
Yes
Yes
Active
Individual identification number assigned to each specimen.
20
Species
Character
25
Yes
No
Active
Scientific name of the fish species.
It was Tursiops truncatus for all data items
30
Stranding Date
Date
10
Yes
No
Active
The date a stranded dolphin was found.
mm/dd/yyyy
40
County
Character
15
Yes
No
Active
County in North Carolina where the stranding occurred
50
Sex
Character
1
Yes
No
Active
The sex of a stranded dolphin, male (M) or female (F).
60
Length (cm)
Numeric
5
Yes
No
1
Active
The length of a stranded dolphin in cm
cm
###.#
70
Length Category: Actual or Minimum
Character
10
Yes
No
Active
Indicates if the length was actual or was a minimum.
Actual
Minimum
80
ForeStomach Code
Character
60
Yes
No
Active
Indicates whether or not the forestomach had contents.
58643
Reference_Collection_Otoliths.csv
Published / External
Contains length measurements and mass collected from the stomach of the stranded dolphin
PLease note that one or more length columns originally contained the word broken instead of a missing value in about 3% of the records.
Since these are numeric columns, the value broken was moved to the newly added Column comments with the comment being Broken Length Measurement when
the word broken was in a length column. All comments were concatenated when there were multiple broken measurements on the same record.
Data Table
Contains length measurements and mass collected from the stomach of the stranded dolphin
10
Common name
Character
Yes
No
Active
Common name of the fish species in the Stomach. (Always Weakfish)
20
Field ID Number
Character
20
Yes
Yes
Active
Individual identification number assigned to each specimen.
30
Left Otolith Length (mm)
Numeric
7
No
No
4
Active
Measured length of the left otolith.
mm
##.####
40
Left-Sulcus Length (mm)
Numeric
7
No
No
4
Active
Measured length of the left sulcus.
50
Left-Cauda Length (mm)
Numeric
7
No
No
4
Active
Measured length of the left cauda.
mm
##.####
60
R Otolith Length (mm)
Numeric
7
No
No
4
Active
Measured length of the right otolith.
mm
##.####
70
Right-Sulcus Length (mm)
Numeric
7
No
No
4
Active
Measured length of the right sulcus
mm
##.####
80
Right-Cauda Length (mm)
Numeric
7
No
No
Active
Measured length of the right cauda
mm
##.####
90
Fish Mass (g)
Numeric
No
No
Active
The mass of the whole fish.
gm
100
Fish SL (mm)
Numeric
No
No
Active
The standard length of the fish.
mm
110
Fish TL (mm)
Numeric
No
No
Active
The total length of the fish.
mm
##.####
120
Nodules Present (Y/N/ reduced)
Character
No
No
Active
Yes indicates nodules were present on the otolith, reducted indicates nodules are present but reduced in size, and no means nodules were absent.
130
Comments
Character
120
No
No
Active
Any extra investigator supplied comments about this record.
This was added afterwards to keep certain columns only numeric and move the word broken to this column
58645
Otolith_Data_From_Strandings.csv
Published / External
Contains Data collected from the Otoliths of the stomach of the stranded dolphins
Data Table
Contains Data collected from the Otoliths of the stomach of the stranded dolphins
10
Field ID Number
Character
7
Yes
No
Active
Individual identification number assigned to each specimen.
20
Stomach Chamber
Character
No
No
Active
The chamber within the stomach in which the contents were found.
30
Removed from head
Character
No
No
Active
Yes if the otolith was found in the head of the fish.
40
Common name
Character
No
No
Active
Common name of the fish species.
50
Species
Character
25
No
No
Active
Scientific name of the fish species.
60
Number left otoliths
Numeric
2
No
No
Active
Number of otoliths from the left side counted from stomach contents.
70
Number right otoliths
Numeric
No
No
Active
Number of otoliths from the right side counted from stomach contents.
80
Otoliths Unknown Side
Numeric
No
No
Active
Number of otoliths for which it was unknown if they were from the left or right side.
90
Side Graded
Character
No
No
Active
Which otolith was graded for erosion - L for left or R for right.
100
Grade
character
No
No
Active
The erosion grade of the otolith:0, undamaged; 1, barely degraded, sulcus fully visible; 2, slightly degraded, somewhat chalky appearance, sulcus is still fully visible; 3-5, moderately to severely degraded, broken, erosion affecting sulcus edge.
110
Count of Minimum Number
Numeric
No
No
Active
Minimum number of fish meeting the criteria of the prior fields
120
Otolith Length (mm)
Numeric
No
No
Active
Measured length of the otolith (left or right).
130
Sulcus Length (mm)
Numeric
No
No
Active
Measured length of the suculus (left or right).
140
Cauda length (mm)
Numeric
No
No
Active
Measured length of the cauda (left or right).
150
Nodules present (Yes/No/ reduced)
Character
No
No
Active
Yes indicates nodules were present on the otolith, reducted indicates nodules are present but reduced in size, and no means nodules were absent.
58646
Byrd Hohn Krause 2020 Otolith Sulcus paper_data and data attributes
Byrd Hohn Krause 2020 Otolith Sulcus paper_data and data attributes.xlsx
Published / External
Completed
Investigator Supplied Multi Tabbed .xlsx File Containing The Data Files and documentation used in the Byrd Hohn Krause 2020 Otolith Sulcus paper
Spreadsheet
Yes
Investigator Supplied Multi Tabbed .xlsx File Containing The Data Files and documentation used in the Byrd Hohn Krause 2020 Otolith Sulcus paper
10
Attributes
.xlsx tab
No
No
Active
.xlsx tab containing field definition information
20
Reference Collection Otoloiths
.xlsx tab
No
No
Active
Contains length measurements and mass collected from the stomach of the stranded dolphins
30
Stranded Bottlenose Dolphin
.xlsx tab
No
No
Active
Contains information on each of the dolphin Strandings
40
Otolith Data From Strandings
.xlsx tab
No
No
Active
Contains Otolith Data From The Strandings Data
58647
attributes.csv
Published / External
Completed
Investigator supplied metadata table listing the column names and their definitions (attributes) for the three data tables in the data set.
All fields with text are character fields, all fields with numbers only are numeric.
Data Table
Investigator supplied metadata table listing the column names and their definitions (attributes) for the three data tables in the data set.
10
Field Name
Character
120
Yes
Yes
Active
Name of field/column that is being documented.
20
Explanation
Character
150
Yes
No
Active
Description of the column in question
Data Steward
2017
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
Distributor
2020
Organization
Southeast Fisheries Science Center
SEFSC
75 Virginia Beach Drive
Miami
FL
33149
USA
(305)361-5761
https://www.fisheries.noaa.gov/about/southeast-fisheries-science-center
About SEFSC
Online Resource
8:00 a.m. - 4:30 p.m. EST
Metadata Contact
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
Yes
Unclassified
Open to everyone
Download From Provided url
None
Please cite appropriately
None
Please cite appropriately
2020
https://grunt.sefsc.noaa.gov/parr/58439.zip
2020
Organization
Southeast Fisheries Science Center
58439.zip
Zip
Zip
58440
Document
Using the otolith sulcus to aid in prey identification and improve estimates of prey size in diet studies of a piscivorous predator
58441
Document
readme file
58646
Entity
Byrd Hohn Krause 2020 Otolith Sulcus paper_data and data attributes
58645
Entity
Otolith_Data_From_Strandings.csv
58643
Entity
Reference_Collection_Otoliths.csv
58642
Entity
Stranded_Bottlenose_Dolphins.csv
58647
Entity
attributes.csv
gov.noaa.nmfs.inport:58439
Lee Weinberger
2020-01-08T00:11:16
SysAdmin InPortAdmin
2023-09-27T12:04:58
2021-04-29
Southeast Fisheries Science Center
SEFSC
75 Virginia Beach Drive
Miami
FL
33149
USA
(305)361-5761
www.sefsc.noaa.gov
8:00 a.m. - 4:30 p.m. EST
1001
Public
No
2021-04-29
1 Year
2022-04-29