Observation Environment Quotes

"Data were collected at the outer bay exhibit of the Monterey Bay Aquarium (MBA) on 26 and 27 August, 2000, and at offshore aquaculture farm, Maricultura del Norte in Ensenada, Baja California, Mexico (MNE), on 18–19 November and on 10 and 17 December 2000. "

"Table 1 Species and quantities of animals present in the Outer Bay Tank at Monterey Bay Aquarium on August 26 and 27, 2000"

Observation Environment Quotes

"Data were collected at the outer bay exhibit of the Monterey Bay Aquarium (MBA) on 26 and 27 August, 2000, and at offshore aquaculture farm, Maricultura del Norte in Ensenada, Baja California, Mexico (MNE), on 18–19 November and on 10 and 17 December 2000. "

"Table 1 Species and quantities of animals present in the Outer Bay Tank at Monterey Bay Aquarium on August 26 and 27, 2000"

Full Description

"At both locations, the most prevalent sounds seemingly associated with tuna were low-frequency pulses varying from 20 to 130 Hz, lasting about 0.1 s, and usually single and apparently unanswered."

"Because these measurements were made in noisy environments, this study should be repeated under more controlled conditions before tuna vocalizations can be claimed with certainty."

"Coughing or yawning behaviors were visually observed in both yellowfin and bluefin tuna. Their mouths would open wide and the area about the operculum and abdomen would contract slightly and convulsively. Five such incidents were observed from the observation deck shortly after 0800 PST on 26 August. Apparently associated underwater sounds were short (_0.1 s), low-frequency pulses (20–130 Hz; mean = 64.1 Hz; S.D. = 38.4 Hz). The estimated SLs were between 110.9 and 128.9 dB re 1 uPa at 1 m. Most sounds were single and unanswered (Fig. 4), but double pulses and a quadruple pulse train were also recorded. In addition to the low-frequency pulses, there were also a few high frequency (jaw snap sounds). The source of the jaw snap sounds is unknown at this time."

"The acoustical signals recorded in the presence of these tuna are short (_0.1 s), narrow-bandwidth pulses of low frequency (20–130 Hz) and amplitude (_117.5 dB re 1 Pa at 1 m), possibly caused by contraction of muscles about the swim bladder. Because these sounds were recorded in the presence of other species and in noisy tank and open ocean environments, the results of this study should be considered tentative rather than definitive."

Observation Environment Quotes

"Data were collected at the outer bay exhibit of the Monterey Bay Aquarium (MBA) on 26 and 27 August, 2000, and at offshore aquaculture farm, Maricultura del Norte in Ensenada, Baja California, Mexico (MNE), on 18–19 November and on 10 and 17 December 2000. "

"The Outer Bay exhibit of the MBA is oval shaped and approximately 11 m deep, 30 m long and 13 m wide. Tuna in the exhibit included bluefin (13) and yellowfin (48) as well as a skipjack (1) (Table 1)."

Behaviour Description Quotes

"Coughing or yawning behaviors were visually observed in both yellowfin and bluefin tuna. Their mouths would open wide and the area about the operculum and abdomen would contract slightly and convulsively. Five such incidents were observed from the observation deck shortly after 0800 PST on 26 August. Apparently associated underwater sounds were short (_0.1 s), low-frequency pulses (20–130 Hz; mean = 64.1 Hz; S.D. = 38.4 Hz). The estimated SLs were between 110.9 and 128.9 dB re 1 uPa at 1 m. "

"It is unknown whether the tuna sounds are generated as a by-product of some biological function such as clearing of the gills, or an intentional form of communication. The sound and associated behavior recorded on audio and video tape at MNE occurred less than 1 h after feeding, but the observations at MBA occurred throughout the day with no detectable correlation with feeding."

Sound Name Quotes

"At both locations, the most prevalent sounds seemingly associated with tuna were low-frequency pulses varying from 20 to 130 Hz, lasting about 0.1 s, and usually single and apparently unanswered. "

" Coughing or yawning behaviors were visually observed in both yellowfin and bluefin tuna. Their mouths would open wide and the area about the operculum and abdomen would contract slightly and convulsively. Five such incidents were observed from the observation deck shortly after 0800 PST on 26 August. Apparently associated underwater sounds were short (_0.1 s), low-frequency pulses (20–130 Hz; mean = 64.1 Hz; S.D. = 38.4 Hz). The estimated SLs were between 110.9 and 128.9 dB re 1 uPa at 1 m. Most sounds were single and unanswered (Fig. 4), but double pulses and a quadruple pulse train were also recorded. In addition to the low-frequency pulses, there were also a few high frequency (jaw snap sounds). The source of the jaw snap sounds is unknown at this time."

Observation Environment Quotes

"Data were collected at the outer bay exhibit of the Monterey Bay Aquarium (MBA) on 26 and 27 August, 2000, and at offshore aquaculture farm, Maricultura del Norte in Ensenada, Baja California, Mexico (MNE), on 18–19 November and on 10 and 17 December 2000. "

"Table 1 Species and quantities of animals present in the Outer Bay Tank at Monterey Bay Aquarium on August 26 and 27, 2000"

Observation Environment Quotes

"Data were collected at the outer bay exhibit of the Monterey Bay Aquarium (MBA) on 26 and 27 August, 2000, and at offshore aquaculture farm, Maricultura del Norte in Ensenada, Baja California, Mexico (MNE), on 18–19 November and on 10 and 17 December 2000. "

"The Outer Bay exhibit of the MBA is oval shaped and approximately 11 m deep, 30 m long and 13 m wide. Tuna in the exhibit included bluefin (13) and yellowfin (48) as well as a skipjack (1) (Table 1)."

Full Description

"At both locations, the most prevalent sounds seemingly associated with tuna were low-frequency pulses varying from 20 to 130 Hz, lasting about 0.1 s, and usually single and apparently unanswered."

"Because these measurements were made in noisy environments, this study should be repeated under more controlled conditions before tuna vocalizations can be claimed with certainty."

"Coughing or yawning behaviors were visually observed in both yellowfin and bluefin tuna. Their mouths would open wide and the area about the operculum and abdomen would contract slightly and convulsively. Five such incidents were observed from the observation deck shortly after 0800 PST on 26 August. Apparently associated underwater sounds were short (_0.1 s), low-frequency pulses (20–130 Hz; mean = 64.1 Hz; S.D. = 38.4 Hz). The estimated SLs were between 110.9 and 128.9 dB re 1 uPa at 1 m. Most sounds were single and unanswered (Fig. 4), but double pulses and a quadruple pulse train were also recorded. In addition to the low-frequency pulses, there were also a few high frequency (jaw snap sounds). The source of the jaw snap sounds is unknown at this time."

"During three visits to the site, 47 sounds thought to be associated with tuna were recorded that were similar to those from MBA (Fig. 5). The mean center frequency was 62.4 Hz (S.D. = 6.2 Hz). The smaller standard deviation in center frequency was consistent with more uniform fish sizes in the aquaculture pen relative to the aquarium. The SLs were estimated to be between 103.4 and 126.9 dB re 1 uPa at 1 m."

"Less than 1 h after a feeding, a bluefin tuna was simultaneously recorded on video and audio tape (Fig. 6). The cough-like behavior produced a low amplitude sound centered at 58.6 Hz with a phase difference indicating an angle of approximately 40_ from a normal to the hydrophone pair. This azimuth is reasonable with respect to the visual image. The estimated SL was between 110.8 and 117 dB re 1 uPa at 1 m. In every instance where the sounds were observed, there was no obvious impetus for the sound and no discernable reaction to the sound from nearby animals."

"However, from an arbitrary threshold (0.65) on the time-series of the maximum correlation coefficients (Fig. 7), the sounds thought to be from tuna were generally distributed randomly in time, suggesting that the tuna were not answering each other’s sounds."

"The acoustical signals recorded in the presence of these tuna are short (_0.1 s), narrow-bandwidth pulses of low frequency (20–130 Hz) and amplitude (_117.5 dB re 1 Pa at 1 m), possibly caused by contraction of muscles about the swim bladder. Because these sounds were recorded in the presence of other species and in noisy tank and open ocean environments, the results of this study should be considered tentative rather than definitive."

Observation Environment Quotes

"Data were collected at the outer bay exhibit of the Monterey Bay Aquarium (MBA) on 26 and 27 August, 2000, and at offshore aquaculture farm, Maricultura del Norte in Ensenada, Baja California, Mexico (MNE), on 18–19 November and on 10 and 17 December 2000. "

"The Outer Bay exhibit of the MBA is oval shaped and approximately 11 m deep, 30 m long and 13 m wide. Tuna in the exhibit included bluefin (13) and yellowfin (48) as well as a skipjack (1) (Table 1)."

"The MNE is in open water, on the south side of Punta Banda (a narrow, 8 mile long peninsula forming the southern boundary of Bahia Todos Santos). Acoustical recordings were made on three occasions inside one of the farm’s 12 floating cages (Northern Plastics) containing bluefin tuna of fork lengths approximately 80 cm."

Behaviour Description Quotes

"Coughing or yawning behaviors were visually observed in both yellowfin and bluefin tuna. Their mouths would open wide and the area about the operculum and abdomen would contract slightly and convulsively. Five such incidents were observed from the observation deck shortly after 0800 PST on 26 August. Apparently associated underwater sounds were short (_0.1 s), low-frequency pulses (20–130 Hz; mean = 64.1 Hz; S.D. = 38.4 Hz). The estimated SLs were between 110.9 and 128.9 dB re 1 uPa at 1 m. "

"It is unknown whether the tuna sounds are generated as a by-product of some biological function such as clearing of the gills, or an intentional form of communication. The sound and associated behavior recorded on audio and video tape at MNE occurred less than 1 h after feeding, but the observations at MBA occurred throughout the day with no detectable correlation with feeding."

Sound Name Quotes

"At both locations, the most prevalent sounds seemingly associated with tuna were low-frequency pulses varying from 20 to 130 Hz, lasting about 0.1 s, and usually single and apparently unanswered. "

" Coughing or yawning behaviors were visually observed in both yellowfin and bluefin tuna. Their mouths would open wide and the area about the operculum and abdomen would contract slightly and convulsively. Five such incidents were observed from the observation deck shortly after 0800 PST on 26 August. Apparently associated underwater sounds were short (_0.1 s), low-frequency pulses (20–130 Hz; mean = 64.1 Hz; S.D. = 38.4 Hz). The estimated SLs were between 110.9 and 128.9 dB re 1 uPa at 1 m. Most sounds were single and unanswered (Fig. 4), but double pulses and a quadruple pulse train were also recorded. In addition to the low-frequency pulses, there were also a few high frequency (jaw snap sounds). The source of the jaw snap sounds is unknown at this time."