Managed and unmanaged whale mortality in the California Current Ecosystem

This repository includes data source, analysis, and methods for the following manuscript

Authors: Helen Julia Killeen*, Eliza Oldach*, Priya Shukla, Ellie Brauer, Nick Carter, Jennifer Fields, Alexandra Thompsen, Cassidy Cooper, Leah Mellinger, Kaiwen Wang, Carl Hendrickson, Anna Neumann, Pernille Sporon Bøving, Nann Fangue

Abstract: Whales serve important biological and cultural functions in the California Current ecosystem (CCE). Due to recent concerns regarding anthropogenic impacts on whales, the California Ocean Protection Council recently articulated a goal to achieve zero mortality for CCE whales, with a target of creating a statewide plan by 2022. Achieving zero mortality is a laudable but difficult goal to achieve as success depends on understanding the existing sources of mortality, the opportunities for policy change, and coordination of activities across the entire CCE. This review synthesizes the available research on drivers of mortality for nine whale species in the CCE and existing policy that addresses those drivers. Five main threats contribute to whale mortality in the CCE and are currently targeted through relevant policy responses: entanglement, vessel strikes, noise, water quality, and marine debris. Three threats remain largely unaddressed in management, despite their contribution to lethal and sublethal impacts on whales: nutritional stress, disease, and predation. Ultimately, sources of whale mortality are interconnected and their impacts span both geographic and jurisdictional boundaries, necessitating a holistic approach to managing whale mortality in the CCE.

Journal:

Link:

Funding and permit support: This work was supported by the UC-Davis Sustainable Oceans program, a National Science Foundation Research Traineeship (NSF DGE -1734999).

Contents: There are two folders, R project, and a README.md file.

Data

This project used a total of four data sets from the NOAA NMFS Marine Mammal Health and Stranding Response Program (MMHSRP) and Entanglements Dataset and NOAA NMFS Marine Mammal Health and Stranding Response Program (MMHSRP)-StrandingsDataset, including: Entangled Whale dataset for Washington, Oregon, and California from 1982-2019, Strandings dataset for California 1982-2005, Strandings dataset for California 2006-2019, and Strandings dataset for Washington and Oregon 1974-2019

These datasets can be obtained through contacting Justin Greenman, California Assistant Stranding Coordinator NOAA Marine Mammal Health and Stranding Response Program (justin.greenman@noaa.gov)

Coding scripts

Contains all code for project. Within this folder there are two files:

Study area map script

Whale mortality data and graphs script

Final figures

Contains Figure 1-3 and supplemental figure of the manuscript