Full Description

"The sound levels of amberjack were 109.4-110.2 dB in the swimming activi ty and 115.3-121.9 dB in the bait-eating activity."

"The overall underwater sound level of the amberjack was 109.2-121.9 dB. The sound levels were 109.4-110.2 dB in the swimming activity and 115.3-121.9 dB in the bait-eating activity.The sound level in the bait-eating activ ity was higher than that in the swimming activity."

"According to Matsuno et al (8) the main frequency range of the swimming sound was be low 130 Hz for the amberjacks.(7)"

"When the amberjacks swam slowly, the main sound component was below 125 Hz, and with the increase of speed, their sounds contained higher frequencies (400 Hz, 1.6 kHz-3.15 kHz) which were especially distin guished from the other high frequency bands.(8)"

"Graphs of one-third octave band analysis of the underwater sounds in the two activities could be classified in four specific patterns. The curve patterns indicated some relationship with sizes of the fish. Frequencies at the minimum sound level in a concave part of the pattern and at the maximum level in the swimming and bait-eating activities were higher for the small-sized fish and vice versa. Both frequen cies of the amberjack sounds were lower than those of the yellowtail sounds in the respective sizes and activities."

"Swimming sound curve patterns of the yellowtails and amberjacks show three curve patterns in accordance with fish weights (Table 5). Each pattern was related with the fish size."

"The minimum level frequency and maximum level frequency are higher for the small sized ones, and are lower for the big-sized ones."

"The present study confirmed that the middle-size yellowtails produced the maximum level at 63 Hz-100 Hz and the amberjacks at be low 160 Hz in the swimming activity."

"One-third octave band analysis curve patterns of the yel lowtails and amberjacks bait-eating sounds show three curve patterns related to fish weights (Table 5)."

"The minimum and maximum level frequencies during bait-eating activity of the yellowtails and amberjacks are shown in Tables 3 and 4. The maximum level frequencies are higher for the small-sized ones and lower for the big sized ones."

"The maximum sound emitted by feeding fish was registered at around 12kHz, but this figure varied with the kinds of bait as well as with the feeding posture of the fish.(12)"

Observation Environment Quotes

"This experiment was carried out on middle Kagoshima Bay in Kagoshima prefecture. Data were collected at the two marine culture grounds, i.e., Tarumizu marine culture in Tarumizu city and Furue marine culture in Furue city.È

Full Description

"The sound levels of yellowtail were 102.8-116.0 dB during swimming and 113.4 124.8 dB during bait-eating."

"The overall underwater sound level of the yellowtail was 102.8-124.8 dB (Table 2). The sound levels were 102.8 116.0 dB in the swimming activity and 113.4-124.8 -dB in the bait-eating activity."

"According to Fujieda et al. (3) 1.5 kg yellowtails produced the maximum level at 64 Hz."

"According to Takemura et al.(10) the natural feeding sound of the yellowtail (Buri) shows the maximum level frequency at 2 kHz-5 kHz."

"The present study confirmed that the bait-eating sounds of the yellowtail also have the second maximum level frequen cies, i.e., 3.15 kHz for the small-sized ones, about 1 kHz for the middle-sized ones and 500 Hz for big-sized ones, which are slightly different from Takemura's results be cause of the different experimental conditions. The sound intensity is greatest when the fish takes the bait foreefully, and vice versa. (12)"

"Graphs of one-third octave band analysis of the underwater sounds in the two activities could be classified in four specific patterns. The curve patterns indicated some relationship with sizes of the fish. Frequencies at the minimum sound level in a concave part of the pattern and at the maximum level in the swimming and bait-eating activities were higher for the small-sized fish and vice versa. Both frequen cies of the amberjack sounds were lower than those of the yellowtail sounds in the respective sizes and activities."

"Swimming sound curve patterns of the yellowtails and amberjacks show three curve patterns in accordance with fish weights (Table 5). Each pattern was related with the fish size."

"The minimum level frequency and maximum level frequency are higher for the small sized ones, and are lower for the big-sized ones."

"The present study confirmed that the middle-size yellowtails produced the maximum level at 63 Hz-100 Hz and the amberjacks at be low 160 Hz in the swimming activity."

"One-third octave band analysis curve patterns of the yel lowtails and amberjacks bait-eating sounds show three curve patterns related to fish weights (Table 5)."

"The minimum and maximum level frequencies during bait-eating activity of the yellowtails and amberjacks are shown in Tables 3 and 4. The maximum level frequencies are higher for the small-sized ones and lower for the big sized ones."

"The maximum sound emitted by feeding fish was registered at around 12kHz, but this figure varied with the kinds of bait as well as with the feeding posture of the fish.(12)"

Observation Environment Quotes

"This experiment was carried out on middle Kagoshima Bay in Kagoshima prefecture. Data were collected at the two marine culture grounds, i.e., Tarumizu marine culture in Tarumizu city and Furue marine culture in Furue city."

"The Tarumizu culture ground is situated about 0.8 nauti cal mile offshore with depth of 60-70 m. "

"The Furue culture ground (in the afternon on July 10, 1996) is situated about 1.5 nautical miles offshore with depth of 70 m."