The Long-term Killer Whale Database project is part of
North Gulf Oceanic Society's
long-term study of killer whales in Prince William Sound, Alaska. Database
development and data analyses were supported during 1995-1998 by funding
from the Exxon Valdez Oil Spill Trustee Council as a component of restoration
research designed to monitor and promote the recovery of the damaged ecosystem
in the area impacted by the 1989 Exxon Valdez oil spill (EVOS).
Results of these analyses were
published in July 2001 in Marine Mammal Science.
The database is now housed in the GIS lab at Alaska Pacific University.
New records are added annually by NGOS personnel.
NGOS continues to conduct killer whale research and long-term monitoring
in Prince William Sound and Resurrection Bay. New research in Kodiak or further
west may be undertaken beginning in 2002 to investigate killer whale behavior at
Steller sea lion haul-outs. Collaborations are underway for APU Master's students
in Environmental Science to conduct portions of this work, if funding becomes
available. Interested students or prospective students should contact
Dr. David Scheel
(dscheel@alaskapacific.edu)
at Alaska Pacific University.
Background, Database project 1995-1998
The killer whale was injured by EVOS and as of September 1996 was listed as "Not Recovered (AB pod)" (see
Press release from January 1996).
Staple prey species of these whales are listed as injured and not recovering. Prey species include harbor seals and pink salmon At least for harbor seals, predation by killer whales is considered an alternative to the hypothesis that food limitation constrains population growth. The unrecovered status of these species may alter whale feeding patterns and behaviors. The recovery of these species may be impacted by predation by killer whales.
Project Description
Data on killer whales were available from North Gulf Oceanic Society (NGOS) for the period
1984-1996. This thirteen-year span includes five years of pre-EVOS data, and provides the
best available record of how killer whale habits may have changed following the oil spill.
The goal of this project was to enter this data into a geographic information database;
and to analyze this database to address questions of interest to restoration management.
(Database design and entry of the first thirteen years of data was completed by 1998.
Since that time, the database has been maintained and additional years of data entered
by NGOS and Dr. David Scheel. The database currently contains data from 1984 to the
present.)
The long-term records on killer whales may provide answers to questions about the impact of oil on whale diet or habitat use, be used to examine the impact of whales on other injured species (especially harbor seals), to maximize the utility of currently planned data collection efforts through improved sampling protocol, and to corroborate results from studies of whale biology relying on alternative methods (i.e. stable isotope and fatty acid analysis).
However, while demographic information from these data have been computerized and utilized for both damage assessment and ecological studies, at the start of this project (1995) much of the distribution and behavioral data remained in file drawers in a relatively inaccessible state. Entry of this data into a computerized, geographically referenced database was the first step to making the knowledge contained in the data available to answer questions raised by restoration management.
Available Data
Data were recorded during summer months each year from 1984 to the present. Only one or a few sightings were recorded on any field day, but encounters with whales averaged from 3-6 hours, providing considerable behavioral information (travel rates, duration of feeding bouts, etc.). In addition to the thousands of frames of film already computerized for demographic analyses, NGOS has numbers, IDs, and pods of whales present at each sighting, as well as the location of encounters. Basic behavioral information (resting, feeding, traveling, etc.) is available for each sighting. Scale samples and bits of marine mammal flesh were collected when possible during feeding bouts, providing positive evidence of predation and of prey type.
Project Activities
Database design & management
Data are stored in ESRI Arc/Info format. A graphical user interface to the database was designed using Arc Macro Language. The interface consists of a series of menu forms that the user fills in to store, peruse or edit a record.
Data entry has been completed up to the present year and additional records from each summer's field work will be added in the Fall of each year. For the period from 1984 to 1996, NGOS records contain 663 encounters recorded during nearly 10,000 hours and 112,000 kilometers of searching. These data have been entered into the database and form the basis for our analyses.
