Acoustic monitoring of Japanese anchovy Engraulis japonicus post larvae shirasu

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Amberly Bryant
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1 Title Acoustic monitoring of Japanese anchovy Engraulis japonicus post larvae shirasu K. Miyashita,, A. Watanabe, S. Morioka, Y. Ikewaki,, R. Matsukura,, and H. Yasuma Engraulis japonicus Shirasu fishery vessels

2 Recruitment estimation for small pelagic fish Background Present methods of the recruitment estimation Egg-larvae sampling using a net gear Catch of the adult fish Characteristics of the fishing ground In-situ measuring of the quantitative abundance efficiently in its early life stage Acoustic monitoring!!

adult fish Characteristics of the fishing ground In-situ measuring of the

3 Objectives Goal (our mission) and objective Long term goal Development and providing the practical quantitative monitoring system for early life stage of pelagic fish species Short term objective Development of a recruitment monitoring system for Japanese anchovy post larvae, shirasu, using acoustics

of pelagic fish species Short term objective Development of a recruitment

4 Approach Objectives 1. Refer useful information of shirasu with acoustic technology our background knowledge 2. Identify shirasu echoes using the obtained knowledge with a commonly used dual quantitative echo sounder 3. Visualize the horizontal distribution of shirasu using GIS

5 Background knowledge (Shirasu fishery I I) knowledge Day time fishery

6 Background knowledge (Shirasu fishery II) knowledge Use of a dual frequency echo sounder to find a shirasu fishing ground (50kHz and 200kHz) 50kHz 200kHz 50kHz 200kHz Shirasu Adult anchovy

ground (50kHz and 200kHz) 50kHz 200kHz 50kHz 200kHz

7 Background knowledge (Swim bladder condition I I) knowledge Day: No gas in the swim bladder Night: Fill gas in the swim bladder Japanese anchovy (E. japonicus), Japanese sardine (Sardinops melanosticta), and round herring (Etrumeus teres) ;(Uotani, 1973) Northern anchovy (E. mordax);(hunter and Sanchez, 1976)

japonicus), Japanese sardine (Sardinops melanosticta), and round herring

8 Background knowledge (Swim bladder condition II) 1)Day: All had NO gas in the swim bladder knowledge 2)Night: More than 90% of individuals had gas in the swim bladder Day Night Swim bladder

9 Target Strength (db) Background knowledge (Frequency characteristics) Size range of shirasu NO difference in TS Large difference in TS knowledge 38kHz(Day) 120kHZ(Day) 38kHZ(Night) 120kHz(Night) Total lengh (mm) Miyashita: ICES J. Mar. Sci., 60: (2003)

difference in TS knowledge 38kHz(Day) 120kHZ(Day) 38kHZ(Night) 120kHz(Night)

10 Background knowledge (Summary) Day knowledge Night Swim bladder condition No gas Fill gas School characteristics Dense Dispersion Frequency characteristics Large difference No difference Day time is suitable for the acoustic survey!! Miyashita: ICES J. Mar. Sci., 60: (2003)

Frequency characteristics Large difference No difference Day time is

11 Echograms in a fishing ground (Shirasu) Example 38kHz Shirasu school Shirasu school 120kHz Shirasu school Shirasu school 2000/07/19

12 Echograms in a fishing ground (Adult) Example 38kHz Adult schools Adult school 120kHz Adult school Adult school 2000/07/19

13 2000 年 7 月 19 日 Echograms in a fishing ground 38kHz (Shirasu and adult) Example Adult school Shirasu school Shirasu school Adult school 120kHz Adult school Shirasu school Shirasu school Adult school

14 Field survey (Survey area) Field test Kii channel Kuroshio Current

15 Date and cruise Oct. 2003~ July 2004 Monthly marine environment monitoring survey around Kii-channel (day time) Echo sounder KFC3000 (kaijo) 38kHz and 120kHz Sampling Plankton net Surface temp. Satellite Field survey (Survey contents) Vessel R/V Tokushima Field test

around Kii-channel (day time) Echo sounder KFC3000 (kaijo) 38kHz

16 Surface school (near shore) Identification of the shirasu school echoes Analysis Mid-water school (near shore) 38kHz 120kHz 38kHz 120kHz Bottom school (near shore) Pelagic school (off shore) 38kHz 120kHz 38kHz 120kHz

shore) 38kHz 120kHz 38kHz 120kHz Bottom school (near

17 The GIS mapping Analysis SA map SA+SST map White map SST map

18 Horizontal distribution of shirasu (Autumn to winter) Results Oct Dec Jan. 2004

19 Horizontal distribution of shirasu (Winter to spring) Results Feb Mar Apr. 2004

20 Horizontal distribution of shirasu (Spring to summer) Results May 2004 June 2004 July 2004

21 Summary (Shirasu school distribution) Results Winter Spring Summer Autumn Dec.- Feb. Mar. May June- Aug. Sep.-Nor. Fish. season Fish. season Near shore Near shore Near shore Near shore Acoustics Off shore Off shore Off shore Off shore Near shore Near shore Near shore Near shore Net Off shore Off shore Off shore Off shore

22 Conclusions Conclusion The distribution of shirasu schools estimated by acoustics is similar to those estimated by net at offshore areas, but different at near-shore areas. With the background knowledge, this result suggests that acoustics are more robust and reliable method to capture the quantitative distribution of shirasu schools than net. With the net used this study we did not catch shirasu in spite of its fine performance to catch larvae stage of anchovy. In contrast, acoustics helped to distinguish the wide range of anchovy size (also researchers can identify shirasu school).

23 Future works Development of automatic post processing system for shirasu school identification Software development Accuracy improvement Ground truth using quantitative sampling tools Routine the monitoring Near future? Posting to our homepage Contribution for sustainable shirasu fishery Propagation of shirasu acoustic monitoring Estimate the standing stock Contribution for the resources management

Hydroacoustic surveys of Otsego Lake, 2007

Hydroacoustic surveys of Otsego Lake, 2007 Thomas E. Brooking 1 and Mark D. Cornwell 2 INTRODUCTION In 2007, we sampled Otsego Lake (Otsego County, NY) with acoustics to estimate abundance of pelagic fishes