Cetacean and Seabird Data Collected During the Winter Hawaiian Islands Cetacean and Ecosystem Assessment Survey (Winter HICEAS), January-March 2020

The Winter Hawaiian Islands Cetacean and Ecosystem Assessment Survey (referred to as "Winter HICEAS") of 2020 was a ship-board survey for cetaceans and seabirds within offshore waters surrounding the main Hawaiian Islands (MHI). This project used many of the same methods as the previous HICEAS projects which occurred in 2002 (Barlow 2006), 2010 (Bradford et al. 2017), and 2017 (Yano et al. 2018).

The Winter HICEAS 2020 project represents the third cetacean and ecosystem assessment survey conducted as part of the Pacific Marine Assessment Program for Protected Species (PacMAPPS), a partnership between NOAA Fisheries, Bureau of Ocean Energy Management (BOEM), and U.S. Navy. PacMAPPS includes rotational ship surveys in regions of joint interest throughout the Pacific designed to estimate the abundance of cetaceans and seabirds and to assess the ecosystems supporting these species. The previous PacMAPPS surveys include the 2017 HICEAS and 2018 California Current Ecosystem Survey. The HICEAS project was a collaborative effort between the Pacific Islands and the Southwest Fisheries Science Centers (PIFSC and SWFSC) and surveyed the U.S. waters surrounding the northwestern and main Hawaiian Islands from July through December 2017, whereas the 2018 California Current Ecosystem Survey, led by the SWFSC, surveyed waters offshore from the U.S. West Coast from June through December 2018 (Henry et al. 2020).

Winter HICEAS 2020 sailed aboard the NOAA Ship Oscar Elton Sette (hereafter referred to as the Sette) for 51 days-at-sea. The project was conducted during 2 survey "legs"; Leg 1 sailed on 18 January to 12 February and Leg 2 sailed on 17 February to 12 March.

The primary goals of Winter HICEAS 2020 were to collect data required to estimate the abundance and distribution, examine the population structure, and understand the habitat of cetaceans around the main Hawaiian Islands during the winter months (January-March). There were 5 major research components to the project:

-visual observations for cetaceans following a line-transect survey design;

-passive acoustic monitoring for cetaceans using towed hydrophone arrays, sonobuoys, and autonomous drifting acoustic recorders;

-collection of photographs and tissue samples and deployment of satellite tags for select cetacean groups;

-visual observations for seabirds following a strip-transect survey design; and

-ecosystem measurements for assessment of cetacean and seabird habitat.

Yano, K.M., E.M. Oleson, J.L.K. McCullough, M.C. Hill, and A.E. Henry. 2020. Cetacean and Seabird Data Collected During the Winter Hawaiian Islands Cetacean and Ecosystem Assessment Survey (Winter HICEAS), January-March 2020. U.S. Department of Commerce, NOAA Technical Memorandum NOAA-TM-NMFS-PIFSC-111, 72 p. https://doi.org/10.25923/ehfg-dp78

The Winter HICEAS 2020 study area was delineated as a convex hull around a 100-nmi (185.2-km) radius of the MHI, truncated to the northwest at the easternmost edge of the Papahānaumokuākea Marine National Monument