Sanctuary Integrated Monitoring Network
Monitoring Project

Marine Life Studies' Research Scientist Program

Principal Investigator(s)

  • Peggy Stap
    Marine Life Studies, Whale Entanglement Team (WET)®
Start Date: May 15, 2006

The overall research mission of Marine Life Studies is to study the foraging strategies of transient and offshore killer whales as well as investigate the abundance, distribution, movement and frequency of occurrence of other whale and dolphin species in Monterey Bay National Marine Sanctuary. We collect photographic ID’s, along with written data and video footage of animal behavior. Our research facilitates a better understanding of the animals inhabiting and visiting the bay and central California, provides the baseline data necessary to implement effective conservation strategies, is shared with other researchers and students, and is used to develop educational programs.

Summary to Date

As of April 2016:

We have had numerous interesting encounters with the diversity of dolphin species. It was intriguing to see different species interacting with each other compared to finding the species alone. One of the objectives of our project was to observe the differences in behavior and percentages of species interacting.

Out of 183 sightings of Risso’s dolphins:
1] Risso’s were sighted alone 137 times (74.9%)
2] Risso’s sighted together with only northern right whale dolphins 12 times (6.6%)
3] Risso’s sighted together with only Pacific white-sided dolphins 15 times (8.2%)
4] Risso’s sighted in mixed species group including both northern right whale dolphins and Pacific white-sided dolphins 17 times (9.3%) and
5] Risso’s sighted with humpback whales 2 times (1.1%). They seemed to be harassing the humpback.

Out of 39 sightings of northern right whale dolphins (Lb’s):
1] Lb’s sighted alone 7 times (17.9%)
2] Lb’s sighted with Risso’s dolphins 12 times (30.8%)
3] Lb’s were sighted with Pacific white-sided dolphins 3 times (7.7%)
4] Lb’s sighted in mixed species group including both Risso’s dolphins and Pacific White-sided dolphins 17 times (43.6%).

Out of 52 sightings of Pacific white-sided dolphins (Lo’s):
1] Lo’s sighted alone 16 times (30.8%)
2] Lo’s sighted with Risso’s dolphins 15 times (28.8%)
3] Lo’s were sighted with northern right whale dolphins 3 times (5.8%)
4] Lo’s sighted in mixed species group including both Risso’s dolphins and northern right whale dolphins 17 times (32.7%) and
5] Lo’s sighted with humpback whales 1 time (1.9%).

Monitoring Trends

  • It was interesting to see that we encountered common dolphins frequently after our first sighting of them in July of 2014. There were 57 sightings total. Many of the common dolphins were feeding opportunistically with California sea lions and humpbacks. There was one occasion where the dolphins were bow riding in front of a gray whale. According to Benson et al. (2002) the warm-temperate common dolphin species was sighted at its greatest during El Niño periods, such as in 1997. This could be a reflection of what we were observing in 2014 when common dolphins were sighted often during our boat surveys.
  • Out of 69 sightings of orca, 9 of the sightings (13.0%) humpback whales were observed traveling in to the area of the orca and interactions between the two species pursued. Some of the behaviors by the orca were tail slapping, spy hop, breach, bubble bursts and behaviors of humpbacks included breach, trumpet blows, and directional changes. We were a collaborator in Pitman et al. (2016) “Humpback whales interfering when mammal-eating killer whales attack other species: Mobbing behavior and interspecific altruism?”.


Although we had a record number of boat survey days, we did not reach our projected goal that we anticipated. We did not launch our research vessel in 2011 because of financial conditions in which we did not raise enough donations to compensate for fuel costs. In 2015, we were in the process of searching for a larger vessel and ended up purchasing it. The trip from Bellingham, Washington to Moss Landing, California along the coast took up time and funds, but we are happy with our investment and are continuing to do our research while training many more individuals because of the capacity the vessel can accommodate.

Study Parameters

  • Disturbance
  • Abundance
  • Distribution

Study Methods

We practiced systematic patrols in search of whales and dolphins from a 40' Albin. Upon sighting animals, they were slowly approached, identified (whenever possible), and monitored for behavioral dynamics within their environment. Pod composition, location, movement, directional bearing, behaviors, and photo-documentation references were recorded for each sighting we encountered.

During the course of our surveys, we also retrieved marine debris. We also participate in the California Department of Health Services, Environmental Management Branch, Phytoplankton Monitoring Program where we obtained water samples through plankton tow fieldwork practices throughout the Monterey Bay National Marine Sanctuary.

Figures and Images

Figure 1. Recording data on our research boat survey.

Figure 2. Humpback whale fluke identification photo.

Figure 3. Orca dorsal identification photo.

Figure 4. Whale Entanglement Team in action taking assessment on a whale disentanglement response in the Monterey Bay National Marine Sanctuary.

Figure 5. Inspecting a scoop of krill in the Monterey Bay National Marine Sanctuary.

Figure 6. Listening to the hydrophone.

Figure 7. Using a TR4 with VHF antenna to locate an entangled whale with a telemetry buoy attached to the trailing gear.