US Navy

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Marine Species Monitoring

Mid-Atlantic Humpback Whale Monitoring

Introduction & Objectives

The endangered North Atlantic humpback whale (Megaptera novaeangliae) migrates from six northern feeding grounds to Caribbean Sea waters during the winter months (Waring et al. 2013). Understanding the occurrence and behavior of humpback whales in the vicinity of U.S. Navy training and vessel transiting activities off the coast of Virginia is important in mitigating potentially harmful impacts on the species.

Humpback whale sighting information off the Virginia Beach area has been collected with various methods and sporadic field effort, with shore-based counts in 1991 and vessel-based photo-identification efforts in 1992 (Swingle et al. 1993), and further cataloging efforts using photos taken on whale-watching excursions and from stranded whales (Barco et al. 2002). Data have shown some individuals returning in subsequent years, and it is suggested that the area may act as a supplemental winter feeding grounds for the returning whales (Barco et al. 2002). Photos of whales sighted off Virginia were matched to cataloged whales from the Gulf of Maine, Newfoundland, and the Gulf of St. Lawrence regions (Barco et al. 2002). Information on the movements of individuals within this region are very limited, and these data are important to assess the potential for disturbance to humpback whales found the U.S. Navy training operations and high-traffic areas in the Chesapeake Bay and coastal waters.

The objectives of this pilot project under the Navy’s Marine Species Monitoring Program are to establish baseline occurrence and behavior data for humpback whales in the Hampton Roads mid-Atlantic region by addressing the following questions:

• What age classes (juveniles, sub-adults, adults) are utilizing the waters within and adjacent to the mouth of the Chesapeake Bay?       

• Do humpback whales exhibit site-fidelity over periods of days to years?

• Do humpback whales congregate in specific high-traffic and/or high-use Navy training areas?

• Do humpback whales spend significant time within or move through areas of U.S. Navy live-fire and mine neutralization exercises (Year 2)?

• What are the relative sound levels humpback whales are exposed to from vessel traffic and/or Navy training exercises (Year 3)?

LITERATURE CITED

Barco, S.G., McLellan, W.A., Allen, J.M., Asmutis-Silia, R.A., Mallon-Day, R., Meagher, E.M., Pabst, D.A., Robbins, J., Seton, R.E., Swingle, W.M., Weinrich, M.T., and Clapham, P.J. (2002) Population identity of humpback whales (Megaptera novaeangliae) in the waters of the US mid-Atlantic states. Journal of Cetacean Research Management, 4(2), 135-141. 

Swingle, W.M., Barco, S.G., and Pitchford, T.D. (1993) Appearance of juvenile humpback whales feeding in the nearshore waters of Virginia. Marine Mammal Science, 9(3), 309-315. 

Waring, G.T., Josephson, E., Maze-Foley, K., and Rosel, P.E. (2013) U.S. Atlantic and Gulf of Mexico marine mammal stock assessments -- 2012. NOAA Technical Memorandum NMFS-NE-221. National Marine Fisheries Service, Woods Hole, MA. 319 pp.

Technical Approach

This project focuses on nearshore non-systematic visual surveys from a small vessel with associated photo identification, biopsy sampling and tagging using Smart Position and Temperature (SPOT-6) Argos-linked satellite tags in the Low Impact Minimally Percutaneous Electronic Transmitter (LIMPET) configuration. Primary objectives of this project include:

1. Collect baseline occurrence data (location, sex, group size, etc) of humpback whales (and other species of baleen whales opportunistically)

2. Obtain identification photographs of humpback whales for inclusion in regional and local catalogs.

3. Conduct focal follows of humpback whales with an emphasis on priority U.S. Navy training areas, such as the W-50 MINEX zone, and shipping channels.

4. Collect biopsy samples of humpback whales for sex determination, mitochondrial control region sequencing, and microsatellite genotyping of tissue samples, and stable isotope analysis to determine foraging related to prey consumption.

5. Conduct satellite tagging to document seasonal humpback whale movement patterns in the nearshore waters off Virginia Beach, specifically whether the whales spend significant time in areas of high shipping traffic and/or areas of Navy training exercises.

The operating area for each survey is chosen depending on weather conditions and reports of humpback whales or other baleen whales in the area and there will always remain a focus on areas of high Navy use, such as the W-50a MINEX zone and shipping channels. If there are no reports of humpback whales or other baleen whales in the primary survey area, the research vessel will follow a pre-determined set of tracks that cover the high priority regions, although these will not follow line-transect survey methodology. During each encounter, every effort will be made to collect photo-identification photographs, perform focal follows, and collect  biopsy samples, as well as identify suitable individuals for satellite tagging and tracking.

Progress & Results

Year 1 of the Mid-Atlantic humpback whale monitoring project was a great success! Researchers from HDR and the U.S. Navy conducted fifteen inshore surveys during the first field season between January and May 2015. During these 15 surveys, there were 46 sightings of humpback whales totaling 61 individuals, as well as 3 sightings of fin whales (Balaenoptera physalus) totaling four individual whales. A total of 31 unique humpback whales and 4 fin whales were identified over the course of the season and approximately half (16/31) of all humpback whales were seen on multiple occasions with one whale spending a minimum of 53 days in the area based on photo-identification results. Of the 61 individual humpback whales seen, 35 (57.4 percent) were presumed to be juveniles based on their estimated size. Twenty-nine focal follow sessions (where detailed behaviors and animal locations were recorded over a 60-minute period) were conducted on 18 humpback whales and one fin whale. In addition, twelve biopsy samples were collected from humpback whales and enough skin was collected on nine of those samples for stable isotope analysis.

The photo-ID catalog includes 31 unique humpback whales as of June 2015. Of the 31 unique individuals, 24 whales include fluke identification photos as well as dorsal images. Images of flukes have been submitted to Allied Whale and the Virginia Aquarium for matching. Although matching for these images is still underway, preliminary results from Allied Whale indicate at least two known matches to Gulf of Maine individuals (GOM67 and GOM73), as well as one match to a Newfoundland animal (HWC#7799) and one match to a St. Pierre and Miquelon animal (HWC#7621/ WBR#958).

Results from Year 1 suggest that humpback whales - and some fin whales - are spending a considerable amount of time in and around Norfolk’s busy commercial shipping lanes. Just over half (33 of 60) of all sightings occurred in shipping lanes, with many more just outside these lanes. A smaller number of individuals (4 of 60) were sighted in U.S. Navy training areas (W-50 MINEX zone).

Beginning in December 2015 (year 2), a satellite-tagging component was incorporated into the project using to better address medium-scale movement patterns by humpback whales frequenting the waters off Virginia Beach.  Researchers are deployed location-only Smart Position and Temperature (SPOT-6) Argos-linked satellite tags in the Low Impact Minimally Percutaneous Electronic Transmitter (LIMPET) configuration (Andrews et al. 2008) on humpback whales to track their movements. These small tags measuring only 2 inches in length and height and less than an inch wide, attach to the dorsal fin or base of the dorsal fin by two sterilized darts. This placement allows frequent transmissions to the Argos satellites when the animals surface, providing locations throughout the day on the whereabouts of the tagged individuals. Tags are designed to eventually fall off the animal after a period of weeks. 

Twenty-seven nearshore surveys were conducted during the 2015/16 field season resulting in 96 sightings of humpback whales and 5 sightings of fin whales, totaling 135 individual humpback whales and 7 individual fin whales. Eleven biopsy samples were collected with enough skin on all samples to also be used for stable isotope analysis. Of the 135 total individual humpback whales seen, 103 (76.3 percent) were categorized as juveniles based on their estimated size. There were 37 individual humpback whales identified during the 2015/16 field season, six of which were also seen during the 2014/15 field season. Nine SPOT-6 satellite tags were deployed and transmitted between 3.3 and 21.4 days (mean = 13.0 days). Details of the tagging efforts and associated individual whale tracks can be found in the 2015/16 annual progress report.  The third field season of this project is currently underway and started off with the relatively early arrival of humpbacks in the area during the first week of November.  We hope to deploy as many as 25 satellite tags during the 2016/17 field season.

LITERATURE CITED Andrews, R.D., R.L. Pitman, and L.T. Ballance. 2008. Satellite tracking reveals distinct movement patterns for Type B and Type C killer whales in the southern Ross Sea, Antarctica. Polar Biology 31:1461-1468