Small-boat Cetacean Surveys- Guam/CNMI EEZ (Marianas)

OBIS SEAMAP: http://seamap.env.duke.edu

The Guam/CNMI EEZ including Guam, Saipan, Tinian, Aguijan, Rota and offshore submerged reefs.

Surveys were conducted around Guam between 9 and 18 February. Tracklines covered at total of 387 nmi. The observer team encountered 11 groups of cetaceans (10 identified to species). A total of 2,769 photos and 8 biopsy samples were collected. Surveys were conducted around Saipan and Tinian between 22 February and 3 March. Tracklines covered 325 nmi. Seven cetacean groups were encountered and all were identified to species. A total of 971 photos and 4 biopsy samples were collected

During eight days, between 26 August and 5 September, nine surveys were completed within the waters surrounding Guam (< 20 km from shore). A total of 968 km were covered. There were eight cetacean sightings including bottlenose dolphins (Tursiops truncatus), spinner dolphins (Stenella longirostris), pantropical spotted dolphins (Stenella attenuata), and short-finned pilot whales (Globicephala macrorhynchus).

Between 7 and 29 September, a total of 21 cetacean surveys were conducted in the waters surrounding Saipan, Tinian, Aguijan, and Rota. The surveys covered 2,165 km of trackline. There were 30 on-effort sightings of cetaceans including bottlenose dolphins, spinner dolphins, pantropical spotted, short-finned pilot whales, pygmy killer whales (Feresa attenuata), a dwarf sperm whale (Kogia sima), and unidentified medium and small delphinids.

Between 25-28 May and 26 June – 3 July, 11 surveys were completed within the waters surrounding Guam (< 45 km from shore). A total of 1,323 km were covered. There were 17 cetacean sightings during the 11 surveys off of Guam including bottlenose dolphins (Tursiops truncatus), spinner dolphins (Stenella longirostris), pantropical spotted dolphins (Stenella attenuata), and short-finned pilot whales (Globicephala macrorhynchus). A total of 6,264 photos were collected from fifteen of the seventeen cetacean groups encountered.

Between 29 May and 24 June, a total of 20 cetacean surveys were conducted in the waters surrounding Saipan, Tinian, Aguijan, and Rota. The surveys covered 2,169 km of trackline . There were 22 on-effort sightings of cetaceans. The species encountered around Rota included bottlenose dolphins, spinner dolphins, pantropical spotted dolphins, and unidentified Mesoplodon whales. A total of 1,221 photos were collected during the sightings off of Rota. The species encountered in the waters surrounding Saipan, Tinian, and Aguijan included bottlenose dolphins, spinner dolphins, pantropical spotted dolphins, short-finned pilot whales, and an unidentified Ziphiid whale. A total of 4,034 photos were collected during the study period off of Saipan, Tinian, and Aguijan.

Surveys were conducted during 30 days (Guam: 10 d, Rota: 6 d, Saipan/Tinian/Aguijan: 14 d), and a total of 3208 km of trackline were surveyed. There were a total of 42 sightings of 8 cetacean species (bottlenose dolphin, false killer whale, pantropical spotted dolphin, pygmy killer whale, rough-toothed dolphin, short-finned pilot whale, sperm whale, and spinner dolphin). Three of the sightings were mixed species groups of pilot whales and bottlenose dolphins; false killer whales and bottlenose dolphins; and rough-toothed dolphins, bottlenose dolphins, and spinner dolphins. More than 18,500 photos were taken. A total of 76 biopsy samples were collected during 28 sightings of the 8 cetacean species and 8 sloughed skin samples were collected from sperm whales (Table 5). The biopsy samples are currently being processed. Ten satellite tags were deployed (2 bottlenose dolphins, 4 false killer whales, 1 rough-toothed dolphin and 3 short-finned pilot whales).

Surveys were conducted during 15 days (Saipan/Tinian/Aguijan: 9 d; Guam: 6 d), and a total of 1194 km of trackline were surveyed. There were a total of 15 encounters of 6 cetacean species (bottlenose dolphin, melon-headed whale, pantropical spotted dolphin, pygmy killer whale, rough-toothed dolphin, and spinner dolphin). One of the encounters was a mixed species group of bottlenose dolphins and rough-toothed dolphins. More than 10,200 photos were taken. A total of 19 biopsy samples were collected during 2 encounters with melon-headed whales. Three satellite tags were deployed during the first encounter with melon-headed whales.

Surveys were conducted during 30 days (Guam: 10 d; Saipan/Tinian/Aguijan: 15 d; Rota: 5 d), and a total of 3090 km of trackline were surveyed. There were a total of 41 encounters of 7 cetacean species (Blainville’s beaked whale, bottlenose dolphin, Cuvier’s beaked whale, false killer whale, pantropical spotted dolphin, short-finned pilot whale, and spinner dolphin). In addition, there were 2 encounters with unidentified Mesoplodonts, 1 encounter with an unidentified beaked whale, and 1 encounter with an unidentified small whale. More than 22,200 photos were taken. A total of 36 biopsy samples were collected from 3 species (bottlenose dolphin, false killer whale, and short-finned pilot whale). Thirteen satellite tags were deployed on 3 species (bottlenose dolphin, false killer whale, and short-finned pilot whale).

Small-boat cetacean surveys off Saipan and Tinian primarily focused on finding humpback whales. All cetacean groups encountered were approached for species confirmation, group size estimates, photo-identification, biopsy sampling (when possible).

There were a total of 29 encounters with 3 cetacean species including humpback whale, bottlenose dolphin (Tursiops truncatus), and pygmy killer whale (Feresa attenuata). All but 2 of the encounters were on CK Reef. We confirmed with photographs that we encountered 4 humpback whale mom/calf pairs and 4 other individuals. Other individuals may have been present but we were unable to confirm with photographs. We collected 4 biopsy samples.

Surveys were conducted during 21 days (Guam: 14 d; Rota: 6 d; Rota-Guam transit: 1 d), and a total of 2179 km of trackline were surveyed. There were a total of 28 encounters with cetacean groups. Species identity was confirmed during 26 of the encounters. There were 7 different species (Blainville’s beaked whale, bottlenose dolphin, Bryde’s whale, false killer whale, pantropical spotted dolphin, pygmy killer whale, and spinner dolphin). In addition, there was an encounter with a Sei/Bryde’s whale that was likely Bryde’s whale (genetic analysis will determine) and an encounter with an unidentified small whale (Table 2, Figs. 1-2). More than 8,000 photos were taken (Table 2). A total of 20 biopsy samples were collected from 3 species (bottlenose dolphin, false killer whale, and Bryde’s whale). One location-dive satellite tag was deployed on a bottlenose dolphin.

Small-boat cetacean surveys off Saipan, Tinian, and Aguijan primarily focused on finding humpback whales. All cetacean groups encountered were approached for species confirmation, group size estimates, photo-identification, biopsy sampling (when possible).

There were a total of 15 encounters with 3 cetacean species including humpback whale, bottlenose dolphin (Tursiops truncatus), and spinner dolphins (Stenella longirostris). We collected 7 biopsy samples. We confirmed with photographs that we encountered 5 humpback whale mom/calf pairs.

Small-boat visual surveys were conducted in the waters surrounding Saipan, Tinian, Aguijan, Rota, and Guam on 24 days during 7 May-5 June 2016.

A total of 42 cetacean groups were encountered during the small-boat surveys resulting in the collection of approximately 11,000 photos, 43 biopsy samples, 3 acoustic recordings, and the deployment of 9 satellite tags. All but 2 of the cetacean groups were identified to species. The confirmed species include bottlenose dolphins, spinner dolphins, pantropical spotted dolphins (Stenella attenuata), rough-toothed dolphins (Steno bredanensis), short-finned pilot whales (Globicephala macrorhynchus), sperm whales (Physeter macrocephalus), and dwarf sperm whales (Kogia sima). The two other groups were Mesoplodon beaked whales.

Small-boat surveys for humpback whales conducted off Saipan. The small-boat surveys were conducted during 6 days between 11-22 February. There were a total of 23 encounters with 4 cetacean species including humpback whales, short-finned pilot whales, bottlenose dolphins (Tursiops truncatus), and spinner dolphins (Stenella longirostris). Photographs were used to confirm that we encountered 25 humpback whales including two mother-calf pairs. Both mother-calf pairs were encountered on the south end of CK Reef on February 22. Biopsy samples were collected from 11 humpbacks including both mothers. Fluke images were collected from 19 humpbacks. A satellite tag was deployed on an adult short-finned pilot whale and a biopsy sample was collected from the same individual. No sea turtles were observed outside of the boat channel.

Small-boat surveys for cetaceans conducted off Saipan, Tinian, and Guam. The small-boat surveys were conducted during 17 days between 6-26 May. There were a total of 12 encounters with 4 confirmed cetacean species including a Bryde’s whale (Balaenoptera edeni), melon-headed whales (Peponocephala electra) bottlenose dolphins (Tursiops truncatus), and spinner dolphins (Stenella longirostris), as well as an unidentified beaked whale. We collected approximately 6,000 photos, 16 biopsy samples and deployed four satellite tags. In addition, we had 29 turtle sightings.

Small-boat surveys for humpback whales off Saipan. The small-boat surveys were conducted during 8 days between 17¬−26 February. There were a total of 12 encounters with 4 cetacean species including humpback whales, rough-toothed dolphins (Steno bredanensis), bottlenose dolphins (Tursiops truncatus), and spinner dolphins (Stenella longirostris). Photographs were used to confirm that we encountered 15 humpback whales including three mother-calf pairs. Biopsy samples were collected from 6 humpbacks including two mothers. Fluke images were collected from 10 humpbacks. Four sea turtles were observed outside of the boat channel.

Small-boat surveys off Saipan, Tinian, Aguijan, and Guam. Small-boat surveys were conducted during 14 days between 23 August and 9 September. There were a total of 20 encounters with 5 cetacean species including spinner dolphins (Stenella longirostris), pantropical spotted dolphins (Stenella attenuata), bottlenose dolphins (Tursiops truncatus), short-finned pilot whales (Globicephala macrorhynchus), and sperm whales (Physeter macrocephalus). A total of 6,437 photos and 33 biopsy samples were collected and 5 satellite tags were deployed. A total of 30 sea turtles were observed.

Small-boat surveys were conducted for humpback whales off Saipan. The small-boat surveys were conducted during 11 days between 9¬−26 January. There were a total of 12 encounters with 4 cetacean species including humpback whales, rough-toothed dolphins (Steno bredanensis), bottlenose dolphins (Tursiops truncatus), and spinner dolphins (Stenella longirostris). A total of 377 photos were collected. Fluke images were collected from 3 humpback whales. No biopsy samples were collected. Twenty-one sea turtles were observed outside of the boat channel. Six were identified as green sea turtles (Cheloni mydas) and the others were unidentified.

Survey tracklines and cetacean sighting location and associated data are available as downloadable .csv files. Includes data collected 2010-2015 during PIFSC small-boat surveys off the southernmost islands (Guam to Saipan)

Survey tracklines and cetacean sighting data collected during PIFSC small-boat surveys within the southern portion of the Mariana Archipelago (Guam to Saipan) between 2010-2019.