Task 3:Harmonization and the optimisation of the acoustic methodology Involved participants: IFREMER, HCMR, CNR-Ancona, CNR-Sicily, IEO.

Introduction The acoustic target strength (TS) is an important metric in fisheries and plankton acoustics to inform on fish characteristics and to convert the acoustic energy in biomass units. TS = 20 log L + b 20 σ bs = 10 TS/10

Subtask Target strength equations for anchovy and sardine WP objectives: 1.To decide a common protocol for analysis. 2.Literature review of existing TS equations (Mediterranean and elsewhere) concerning sardine and anchovy. 3.To apply different TS equations in past acoustic data from each area and comparisons of the resulting abundant estimates will be made. 4.To estimate in situ TS equations for each target species ( ).

1.- To decide a common protocol for analysis. To apply the same TS (sardine & anchovy) to all the Mediterranean acoustic surveys? To estimate sardine (Sardina pilchardus) and anchovy (Engraulis encrasicolus) TS “in situ” in every area (Adriatic, WMed; EMed…) and to apply each one to its respective area…?

b 20 PILANE IFREMER-71.2 IEO /-71.2 IPIMAR AZTI dB (Diner & Marchand, 1995; ICES 1997) dB (Degnbol et al., 1985) (Herring, Clupea harengus) 2.- Literature review of existing TS equations (Mediterranean and elsewhere) concerning sardine and anchovy.

b 20 PILANE IFREMER-71.2 IEO-72.6 IPIMAR-72.6 AZTI dB (Diner & Marchand, 1995; ICES 1997) dB (Degnbol et al., 1985) (Herring, Clupea harengus) 2.- Literature review of existing TS equations (Mediterranean and elsewhere) concerning sardine and anchovy.

b 20 PILANE HCMR IFREMER-71.2 SICILIA ANCONA IEO-72.6

2.- Literature review of existing TS equations (Mediterranean and elsewhere) concerning sardine and anchovy. b 20 PILANE HCMR IFREMER-71.2 IAMC ISMAR IEO-72.6

2.- Literature review of existing TS equations (Mediterranean and elsewhere) concerning sardine and anchovy. b 20 PILANE HCMR IFREMER-71.2 SICILIA ANCONA IEO dB4.1 dB Barange et al., 1996; PIL (Sardinops ocellatus): ; ANE (Engraulis capensis/encrasicolus): (South Africa)

3.- To apply different TS equations in past acoustic data from each area and comparisons of the resulting abundant estimates will be made. AbundanceBiomass TS= -72.6TS= -71.2dif (%)TS= -72.6TS= -71.2dif (%) Anchovy Sardine S. colias TOTAL , , Relative Abundance (%)Relative Biomass (%) TS= -72.6TS= -71.2dif (%)TS= -72.6TS= -71.2dif (%) Anchovy43,5239,79-3,7318,6316,33-2,30 Sardine44,7547,853,1047,4449,081,64 S. colias11,7412,360,6233,9234,580, EcoCádiz 2004: TS anchovy = -72.6, TS sardine = -72.6, TS S. colias = EcoCádiz 2004R: TS anchovy = -71.2, TS sardine = -72.6, TS S. colias = -68.7

3.- To apply different TS equations in past acoustic data from each area and comparisons of the resulting abundant estimates will be made.

4.- To estimate in situ TS equations for each target species ( ). Fishing hauls selection: – Frequency: 38 kHz. – At nigth, dispersed. – High percentage of one species, 70, 80, 90%? – Other species? Different length distribution. – Better not bimodal. – Echosounder performance? (Soule et al, 1995; Jech et al, – In situ target strength measurements. Preliminary data of sardine (Sardina pilchardusW.) from the Mediterranean Sea Carrera, P., J. Miquel & M. Iglesias. Working paper. ICES FAST Working Group. Gothenburg, April

Fishing trawls with species percentage = or > to 87% ECOMED

Fishing trawls with species percentage = or > to 87% Green: raw data from EK60 (SIMRAD)

PESMA software