Passive acoustic monitoring of killer whales in the northern Gulf of Alaska

Hannah Myers, University of Alaska Fairbanks

Killer whales (Orcinus orca) are top predators throughout the world’s oceans. In the
North Pacific, the species is divided into three ecotypes—resident (fish-eating),
transient (mammal-eating), and offshore (largely shark-eating)—that are genetically
and acoustically distinct and have unique roles in the marine ecosystem. We deployed
hydrophones in the northern Gulf of Alaska to examine the year-round distribution of
killer whales from 2016 to 2020 using passive acoustic monitoring. Highest year-round
acoustic presence occurred in Montague Strait, with strong seasonal patterns in
Hinchinbrook Entrance and Resurrection Bay. Passive acoustic monitoring revealed
that both resident and transient killer whales used these areas much more extensively
than previously known and provided novel insights into high use locations and times
for each population. These results may be driven by seasonal foraging opportunities
and social factors, and have management implications for this species.

Year-round passive acoustic monitoring of killer whales

This dataset presents killer whale presence or absence based on acoustic detection.

The locations of the stationary acoustic devices are approximate.



Passive acoustic monitoring efforts were done during the following periods:

Montague Strait

Hanning Bay 10/1/2016 - 1/31/2017

Little Bay 9/14/2017- 5/7/2018

Little Bay 5/15/2018 - 9/17/2018

Little Bay 10/1/2018 - 9/24/2019

Little Bay 09/27/2019 - 5/31/2020



Hinchinbrook Entrance

Port Etches 10/1/2016 - 6/16/2017

Port Etches 9/7/2017 - 5/12/2018

Port Etches 5/15/2018 - 9/30/2018

Zaikof Bay 10/1/2018 - 7/25/2019

Zaikof Bay 10/1/2019 - 5/29/2020



Resurrection Bay

6/7/2018 - 10/2/2018

10/2/2018 - 5/27/2019

5/27/2019 - 9/22/2019

9/22/2019 - 5/31/2020

Overview

This section explains attributes included in the original dataset. OBIS-SEAMAP restricts the attributes available to the public to date/time, lat/lon and species names/counts only. Should you need other attributes described here, you are encouraged to contact the data provider.

Attributes described below represent those in the original dataset provided by the provider.
All attributes are included in the downloadable file (CSV or ESRI File Geodatabase) for "Complete Set of Dataset".

Attributes in dataset

Attribute (table column)	Description
oid	Unique ID number (generated by OBIS-SEAMAP)
location	Location
latitude	Approximate latitude of stationary acoustic device
longitude	Approximate longitude of stationary acoustic device
date	Date of the detection
time	Time is not recorded
killer_whales_detected	Flag to indicate killer whales detected (1) or not (0)
species	Species name
sp_tsn	Taxonomic Serial Number added by OBIS-SEAMAP
obs_count	Presence (blank) or absence (0)
geom	Geometry field added by OBIS-SEAMAP