Item Identification

Title: Monk Seal Ecosystem Model: observation data and output data hindcast
Status: Completed
Abstract:

Through hindcast (1998-2015) simulations we evaluated the importance of different drivers on the Laysan and French Frigate Shoals monk seal nesting populations. External drivers assessed were the Pacific Decadal Oscillation (PDO), the (cessation of) bottomfish fishery, and an additional external mortality factor to monk seals. We also evaluated combinations of these drivers. Importance of drivers was determined by the 'best-fit' model , i..e. the model where the simulated data best matched the observed data on monk seal and bottomfish biomass.

Purpose:

To understand what drivers were most important for the observed trend of monk seal nesting populations we simulated different drivers and compared model output data with observational data of bottomfish and monk seal biomass. The simulation that resulted in the best fit between these two time series was deemed to represent the actual driver in the decline of the monk seal best. In both the Laysan as well as the French Frigate Shoal nesting monk seal population, historical fishing for bottomfish with an additional unexplained mortality on monk seals best described the trend in monk seal and bottomfish biomass. The model output data shows the fishery only data (Fishery_only.csv) and the fishery plus an additional percentage of mortality on monk seals data

(Fishery_plus_percent_removal.csv) which we compared withe the observational data (Observation_data.csv).

Entity Information

Entity Type: Spreadsheet
Active Version?: Yes
Description:

Data used to create the figures in the Weijerman et al 2017 EwE monk seal manuscript: A comparative application of trophic ecosystem models to evaluate drivers of endangered Hawaiian monk seal populations

Data Attributes

Attribute Summary

Rubric Score Primary Key? Name Type Description
100
ISLANDCODE TEXT The 3-letter code for the island/atoll in the Northwestern Hawaiian Islands for which the model was run. FFS = French Frigate Shoals LAY = Laysan
100
Year NUMBER Year of the observation data, 1998 through 2015.
100
YEAR_MONTH NUMBER Monthly output of simulation run from 1998 through 2015, formatted as 4-digit Year + decimal month (3 months = 0.25, 6 months = 0.5, etc.).
100
3: Monk Seals NUMBER The biomass from the simulation runs for monk seals measured in tons/square kilometer.
100
9: Benthic bottomfish NUMBER The biomass from the simulation runs for benthic bottomfish measured in tons/square kilometer.
100
REMOVAL TEXT The percent of monk seal biomass removed from the area in the simulations (1% at Laysan, 7% at French Frigate Shoals).

Attribute Details

ISLANDCODE

CC ID: 839233
Seq. Order: 1
Data Storage Type: TEXT
Required: No
Primary Key: No
Status: Active
Description:

The 3-letter code for the island/atoll in the Northwestern Hawaiian Islands for which the model was run.

FFS = French Frigate Shoals

LAY = Laysan

Year

CC ID: 379786
Seq. Order: 2
Data Storage Type: NUMBER
Max Length: 11
Min Length: 4
Required: No
Primary Key: No
Status: Active
Description:

Year of the observation data, 1998 through 2015.

Unit of Measure: month

YEAR_MONTH

CC ID: 839230
Seq. Order: 2
Data Storage Type: NUMBER
Required: No
Primary Key: No
Status: Active
Description:

Monthly output of simulation run from 1998 through 2015, formatted as 4-digit Year + decimal month (3 months = 0.25, 6 months = 0.5, etc.).

3: Monk Seals

CC ID: 379787
Seq. Order: 3
Data Storage Type: NUMBER
Max Length: 19
Min Length: 16
Required: No
Primary Key: No
Status: Active
Description:

The biomass from the simulation runs for monk seals measured in tons/square kilometer.

Unit of Measure: t/km2

9: Benthic bottomfish

CC ID: 379788
Seq. Order: 4
Data Storage Type: NUMBER
Max Length: 18
Min Length: 16
Required: No
Primary Key: No
Status: Active
Description:

The biomass from the simulation runs for benthic bottomfish measured in tons/square kilometer.

Unit of Measure: t/km2

REMOVAL

CC ID: 839244
Data Storage Type: TEXT
Required: No
Primary Key: No
Status: Active
Description:

The percent of monk seal biomass removed from the area in the simulations (1% at Laysan, 7% at French Frigate Shoals).

Catalog Details

Catalog Item ID: 36658
Metadata Record Created By: Nicole P Kamalu
Metadata Record Created: 2017-02-06 15:34+0000
Metadata Record Last Modified By: SysAdmin InPortAdmin
Metadata Record Last Modified: 2019-06-04 13:14+0000
Metadata Record Published: 2019-05-08
Owner Org: PIFSC
Metadata Publication Status: Published Externally
Do Not Publish?: N
Metadata Next Review Date: 2020-05-08