Revisions and Further Evaluations of the Right Whale Abundance Model: Improvements for Hypothesis Testing

Pace, Richard M.

doi:10.25923/3e01-q598

i

Revisions and Further Evaluations of the Right Whale Abundance Model: Improvements for Hypothesis Testing

2021
By Pace, Richard M.
Series: NOAA technical memorandum NMFS-NE 269

Details

Personal Author:

Pace, Richard M.
Corporate Authors:

Northeast Fisheries Science Center (U.S.)
NOAA Program & Office:

NMFS (National Marine Fisheries Service) ; NEFSC (Northeast Fisheries Science Center)
Description:

The National Marine Fisheries Service relies upon a published Bayesian state-space model to estimate annual abundance and uses that to characterize the status of the North Atlantic right whale (Eubalaena glacialis) population. I developed modifications to that model that differently characterize annual estimates of age-specific survival and may better represent population demography over time. In particular, I added an indicator variable within the survival process to test the hypothesis that mean survival changed following dramatic changes in right whale area-use patterns beginning in 2011, which I refer to as a regime change. A similar modification could be used to test if survival rates differ following some future mitigation measure(s) designed to reduce threats to right whales. I show that the addition of the “regime” parameter, while providing strong evidence of a change in mean survival, had little effect on 3 important estimates of the abundance model: population size, the number of new entrants, and adult female survival. I discuss future modification that should be accomplished that would allow testing other demographic effects over time.
Keywords:

Abundance Bayesian State-space Model North Atlantic Right Whale
Series:

NOAA technical memorandum NMFS-NE 269
DOI:

https://doi.org/10.25923/3e01-q598
Format:

PDF
Document Type:

Technical Memorandum
License:

https://creativecommons.org/publicdomain/zero/1.0/
Rights Information:

CC0 Public Domain
Compliance:

Submitted
Main Document Checksum:

urn:sha256:1dc52793ea4a8374e19b27ebdbd4cf1cb8b744b246120027bb76cef1e4857fb8
Download URL:

https://repository.library.noaa.gov/view/noaa/50567/noaa_50567_DS1.pdf
File Type:

[PDF - 1.22 MB ]

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