Efficacy of pingers in North Pacific salmon and squid gillnet fisheriesTomonari Akamatsu1

National Research Institute of Fisheries Engineering, Hasaki, Kamisu, Ibaraki 314-0408, JapanNational Research Institute of Fisheries Engineering, Fisheries Research Agency

7620-7 Hasaki, Kamisu, Ibaraki 314-0408, JapanTEL:+81-479-445954 FAX:+81-479-441875

E-mail: akamatsu@affrc.go.jpURL: http://nrife.fra.affrc.go.jp/akamatsu/

ABSTRACTReactions of bottlenose dolphins, Pacific white-sided dolphins, false killer whales, Risso's dolphins, Dall's porpoises to underwater sounds were observed for countermeasures to reduce damages to long line fisheries and by-catch on gill nets. Various sound projectors having dominant frequencies from 2 kHz to 200 kHz with source levels reached up to 200dB re 1μPa. Reactions of dolphins and porpoises to the sounds were observed in a pool, a net enclosure or an open sea. Clear escaping reactions from a sound source were observed by sounds with exposed level above 170dB at the subject animal. Reactions to sounds below 160dB were not stable. The dolphins got accustomed to the sound after multiple projections. On the other hand, frequency and amplitude modulated sounds seemed to be effective even if the sound pressure level was about 120dB. Efficacy of acoustic pingersto control wild dolphins and porpoises were limited. The effective range was estimated above 170dB exposure level that depends on the source level of a device and sound propagation. Acclimation for the sounds by dolphins and porpoises were not negligible. Avoiding successive transmission and amplitude/frequency modulations were recommended. Keywords: gill net, by-catch, dolphin, porpoise, underwater sounds, echolocation.

Efficacy of pingers in North Pacific salmon and squid gillnet fisheries

Tomonari Akamatsu

National Research Institute of Fisheries Engineering, Hasaki, Kamisu, Ibaraki 314-0408, Japan

Yoshimi Hatakeyama

April 1st, 1993

CONTENTS OF THIS TALK

1. REVIEW: Works of my ex-boss

2. DISCUSSION: Why dolphins and porpoises miss to detect gill nets?

Hatakeyama, Y., Ishii, K. and Akamatsu, T. (1995), Studies on the reduction of entanglement of dall'sporpoise, Phocoenoides dalli, in the Japanese salmon gillnet, Rept. Int. Whal. Commn. (Special Issue 15),549-563.Hatakeyama, Y., Ishii, K., Akamatsu T., Soeda, H., Shimamura, T. and Kojima T.(1994) A review of studies on attempts to reduce the entanglement of the Dall‘s porpoise, Phocoenoides dalli, in the Japanese salmon gillnet fishery. Rept. Int. Whal. Commn.15, 549-563.Hatakeyama, Y. (1992), The hearing ability of fish, Fisheries Engineering 28(2)111-119Ishii K., Akamatsu T. and Hatakeyama Y. (1992), Design of the biosonar simulator for dolphin's clicks waveform reproduction, Bull. Nat. Res. Inst. Fish. Engin.,13,95-128Hatakeyama, Y. and Soeda, H. (1990), Studies on echolocation of porpoises taken in salmon gillnet fisheries, In: Thomas JA, Kastelein RA (eds) Sensory abilities of cetacenas :laboratory and field evidence. Plenum press, New York, pp269-281Hatakeyama, Y., Ishii, K., Soeda, H., Shimamura, T., and Tobayama, T., (1988) Observation of Harbor porpoise's behavior to salmon gill net," "Document submitted to the meeting of the Scientific Subcommittee of the Ad Hoc Committe on Marine Mammals, INPFC,Tokyo, Japan, January 21, INPFC Document 3261.Hatakeyama, Y. and Shimizu, H. (1985) Feeding trial and acoustic studies on Dall‘s porpoise captured alive. “Document submitted to the meeting of the Scientific Subcommittee of the Ad Hoc Ｃommitte on Marine Mammals, INPFC, Tokyo, Japan, INPFC Document 2860.Hatakeyama, Y. and Shimizu, H. (1985) Feeding trial and acoustic studies on Dall's porpoise captured alive. Document submitted to the meeting of the Scientific Subcommittee of the Ad Hoc Committe on Marine Mammals, INPFC, Tokyo, Japan, INPFC Document 2860.Hatakeyama, Y., Ishii, K. and Maniwa Y. (1980), On the dispersion of dolphins by underwater ultrasonic waves: Proceedings of 1st Symposium on ultrasonic electronics, Tokyo, 1980, Japanese Journal of Applied Physics, Vol.20Supplement 20-3,pp.241-245 Hatakeyama, Y., Ishii, K. and Maniwa Y. (1980) On the dispersion of dolphins by underwater ultrasonic waves: Proceedings of 1st Symposium on ultrasonic electronics, Tokyo, 1980. Japanese Journal of Applied Physics, 20Supplement 20-3, 241-245.

Relatively visible works

Ｈａｔａｋｅｙａｍａ 畠山良己 1988 音波発生器の効果試験 1月7日 "１９８８年３月, 北太平洋漁業国際委員会, 生物調査常設小委員会海産哺乳動物科学会議提出文書, 水産庁水産工学研究所"Hatakeyama 畠山良己, 石井憲 , 添田秀男, 嶋村哲哉 " 1988 イロワケイルカに関する音響学的調査 1月21日 "１９８８年３月, 北太平洋漁業国際委員会, 生物調査常設小委員会海産哺乳動物科学会議提出文書, 水産庁水産工学研究所・日本大学農獣医学部"Hatakeyama 畠山良己, 石井憲 , 添田秀男, 嶋村哲哉, 鳥羽山照夫 " 1988 ネズミイルカの流網認知に関する研究 1月21日 " １９８８年３月, 北太平洋漁業国際委員会, 生物調査常設小委員会海産哺乳動物科学会議提出文書, 水産庁水産工学研究所"Hatakeyama 畠山良己, 石井憲 " 1987 バンドウイルカの対網行動の観察. "北太平洋漁業国際委員会海産哺乳動物特別小委員会, 科学分科会１９８７年３月提出文書 ,水産庁"atakeyama 畠山良己 1987 音波発生器の効果試験 "北太平洋漁業国際委員会海産哺乳動物特別小委員会, 科学分科会１９８７年３月提出文書 ,水産庁"Hatakeyama 畠山良己, 石井憲, 添田秀男, 嶋村哲哉, 榊原茂, 清水宏 " 1987 イシイルカの捕獲と音響学的実験 "北太平洋漁業国際委員会海産哺乳動物特別小委員会, 科学分科会１９８７年３月提出文書,水産庁"Hatakeyama 畠山良己, 石井憲, 清水宏, 前田義秋, 添田秀男, 嶋村哲哉 " 1986 イルカ類の流網の認知に関する実験 "北太平洋漁業国際委員会海産哺乳動物特別小委員会, 科学分科会１９８６年３月提出文書 ,水産庁"Ｈatakeyama 畠山良己 1986 新式音波発生装置の効果試験 "北太平洋漁業国際委員会海産哺乳動物特別小委員会, 科学分科会 １９８６年３月提出文書 ,水産庁"Hatakeyama 畠山良己 1986 イルカ類の漁具素材の認知に関する基礎的考察 "北太平洋漁業国際委員会海産哺乳動物特別小委員会, 科学分科会 １９８６年３月提出文書,水産庁"Hatakeyama 畠山良己 1986 混獲防止の技術開発試験 "北太平洋漁業国際委員会海産哺乳動物特別小委員会, 科学分科会 １９８６年３月提出文書,水産庁""Hatakeyama 畠山良己, 清水宏 " 1985 生け捕りイシイルカの飼育と音響学的調査. "北太平洋漁業国際委員会海産哺乳動物特別小委員会, 東京１９８５年３月提出文書,水産庁""Hatakeyama 畠山良己, 清水宏 " 1985 サケマス流網の素材の超音波反射指向性の測定 "北太平洋漁業国際委員会海産哺乳動物特別小委員会, 東京１９８５年３月提出文書,水産庁 浮子, フロート, ロープの反射率"Hatakeyama 畠山良己 1985 水中音に対する魚の反応 騒音制御 9(2) 100-104 "Hatakeyama 畠山良己, 石井憲, 武富一 " 1985 ベーリング海におけるイシイルカのサケ・マス流網への羅網の防止に関する音響的研究（第１報.） 水産工学研究所研究報告 6 264-288 Hatakeyama 畠山良己 1984 カツオ竿釣り漁業における水中音 月刊海洋科学 16(5) 303-307 "Hatakeyama 畠山良己, 嶋村哲哉 " 1984 ベーリング海におけるイシイルカの音響的調査 "北太平洋漁業国際委員会海産哺乳動物特別小委員会 １９８４年３月提出文書,水産庁"Hatakeyama 畠山良己 1984 音波発生器の有効距離 6 "９８４年３月北太平洋漁業国際委員会 海産哺乳動物特別小委員会科学分科会提出文書,水産庁"Hatakeyama 畠山良己 1984 水中の音と魚について 漁船 249 39-46 Journal of Fishing Boat Association of JapanHatakeyama 畠山良己 1984 流網の反射損失とイルカの検知可能最大距離 15 "１９８４年３月北太平洋漁業国際委員会 海産哺乳動物特別小委員会科学分科会提出文書,水産庁"Hatakeyama 畠山良己 1984 リクゼンイルカの鳴音分析 5 "１９８４年３月北太平洋漁業国際委員会 海産哺乳動物特別小委員会科学分科会提出文書,水産庁"Hatakeyama 畠山良己 1983 水産工学研究所漁業生産工学部 イルカ駆逐技術開発研究報告（昭和５７年度）

Nearly invisible works

Experiment number correspond to the number indicted in the map (next slide). BND: Bottlenose dolphin, PWD: Pacific whiteｭsided dolphin, FKW: False killer whale, RSD: Risso'sdolphin, DLP: Dalli's porpoise, The number of dolphins are indicated shown after =. If the number was unknown, = was not indicated in the table.

Study sites and species for pinger experiments

Exp. 1.5.11 Taiji Port in Wakayama Pref. False killer whale, bottlenose dolphin

Exp. 2 Kamogawa Sea World in Chiba Pref.False killer whale, bottlenose dolphin, Pacific

white-sided dolphin

Exp. 3.4.6.7 Iki in Nagasaki Pref. False killer whale, bottlenose dolphin, Risso’s dolphin, Pacific white-sided dolphin

Exp. 8 Akkeshi in Hokkaido Dall’s porpoises, tank

Exp.9 Central Bering SeaDall’s porpoises, open ocean

Exp.10 The Sea of Okhotsk near ShiretokoDall’s porpoises, open ocean

Study sites and species for pinger experimentsTo drive porpoises away from gill nets

PE: Pseudo Echolocation, MT: Marine Transponda, Orca: Vocalization of a killer whale, Tursiops: Vocalization of a bottlenose dolphin, SL: source level (sound pressure level at 1m), PI: pulse interval, PD: pulse width, Pulse interval, pulse width and frequency were modulated as indicated PI, PD, FM in the right hand of the column respectively. ＊ Artificial frequencies, pulse intervals or pulse duration modulated sounds. ＋ The pulse interval was chosen among 250, 500 and 1000 ms.

Biological sounds

Simple pulse sounds

Impulse sounds

Modulated pulse sounds

PE: Pseudo Echolocation, MT: Marine Transponda, Orca: Vocalization of a killer whale, Tursiops: Vocalization of a bottlenose dolphin, SL: source level (sound pressure level at 1m), PI: pulse interval, PD: pulse width, Pulse interval, pulse width and frequency were modulated as indicated PI, PD, FM in the right hand of the column respectively. ＊ Artificial frequencies, pulse intervals or pulse duration modulated sounds. ＋ The pulse interval was chosen among 250, 500 and 1000 ms.

Impulse sounds

Simple pulse sounds

Modulated pulse sounds

Biological sounds

Sound projections

Method of observation

Positive reaction ●

Sound source

Positive reaction ●

Sound source

Positive reaction ●

Sound source

D is the maximum reacted distance between sound source and dolphins. <D indicate that the reacted distance was under D(m). Min. SPL is the minimum reacted sound pressure level. SL is source level (0dB=1μPa). PI and PW are pulse interval and pulse width respectively. ●indicate that the dolphins escaped from the sound source or swam high speed. △ indicated that the dolphins increased the swimming speed or change direction slightly. × indicated that the dolphins did not changed their behavior. ＊ indicates the modulated sounds. ●＋ : Only Pacific whiteｭsided dolphin approached to the sound source, △＋: Dalli'sporpoise shook head slightly.

RESULTS overview, unsorted

1

3

4

5

6

8

7

9

10

11

2

RESULTS Sound pressure levels and reactions of dolphins

Simple pulse sounds

Impulse sounds

Modulated sounds

Biological sounds

RESULTS Sound types and reactions of dolphins

Simple pulse sounds

Impulse sounds

Modulated sounds

Biological sounds

RESULTS acclimation to simple pulse sounds

Serial number of experiment

Exp

osed

sou

nd p

ress

ure

leve

l at t

he

targ

et a

nim

al (d

B re

1uP

a) Simple pulse sounds

RESULTS acclimation to simple pulse sounds cont.

Serial number of experiment

Exp

osed

sou

nd p

ress

ure

leve

l at t

he

targ

et a

nim

al (d

B re

1uP

a) Simple pulse sounds

RESULTS acclimation to modulated pulse sounds cont.

Serial number of experiment

Exp

osed

sou

nd p

ress

ure

leve

l at t

he

targ

et a

nim

al (d

B re

1uP

a)

Modulated sounds

RESULTS acclimation to modulated pulse sounds cont.

Serial number of experiment

Exp

osed

sou

nd p

ress

ure

leve

l at t

he

targ

et a

nim

al (d

B re

1uP

a)

Modulated sounds

Tentative summary

Aversion to AttentionLet dolphins and porpoises know there are gill nets.

1. Clear escaping reactions from a sound source were observed by sounds with exposed level above 170dB at the subject animal.

2. Modulated sounds were effective to keep animals away even with low exposure level and less acclimated.

Detection distance of a gill net by echolocation

Hataeyama et al. 1994

Detection distance of a gill net by echolocation

Hataeyama et al. 1994

Au 1988

Let dolphins and porpoise know gill nets are there

For example, ping interval 5 seconds is suitable assuming 10m detection distance to a net by echolcation assuming 2m/s swimming speed.

A-tag: L=112 mm, Φ21 mm VHF

Suction cup Φ80 mm

Float materialHydrophone BHydrophone A

Weight 77gHigh Pass Filter 100kHz<Recording (CR2) 40 hoursMemory size 128MB

How frequently they produce sonar sounds?

31

80

400

180

90

0

0

IPI (

ms)

Bea

ring

angl

e

SP

(Pa)

120

80

40

How frequently they produce sonar sounds?

White-beaked dolphin@IcelandRasmussen in prep

Harbor porpoise@DenmarkDeep-Sea Research II, 54,290-297 (2007)

Finless porpoise @ChinaProc. Roy. Soc. B, 272, 797-801 (2005)J. Exp. Biol. 213, 146-152 (2010)

Even though they produce sonar sounds frequently…..

Click train production every 5-12 sec. for finless porpoises was observed.

Histogram of inter-click train intervals obtained from 15 tagged porpoises. Total observation duration was 279 hours.

Distribution of inter-click train intervals

Kimura et al. (2010), JASA

Odotocetes stop using sonar for a while occasionally.

Resolution is not so simple

Sound could attract dolphins

Shrimp trawler and an Indo-Pacific humpback dolphin in Hong Kong

SUMMARY

1. Clear escaping reactions from a sound source were observed by sounds with exposed level above 170dB at the subject animal.

2. Modulated sounds were effective to keep animals away even with low exposure level and less acclimated.

3. Acoustic pinger to attract attention of dolphins is one of the choices for countermeasures. Echolocation effort with/without pinging should be observed.

4. Acoustically visible but not too attractive sounds. Gill nets could be unfamiliar with dolphins and porpoises.