# 7. PROCESSING AND PRESENTATION

7.1 The codification system
7.2 Processing, tabulation, graphical presentation

For the consolidation of the results of an acoustic survey programme estimates of the survey magnitudes are required not only for the total population, but also for different parts of it which constitute domains of study. Final estimates of the survey magnitudes are calculated on an individual survey basis by daytime and night-time periods, and by the variety of fish and biomass totals. As far as space is concerned, estimates are calculated on the established space/depth domains, space domains (totals), depth domains (totals) and for the whole survey area.

The prepared tabulation system of an acoustic survey programme provides estimates of the following magnitudes:

1. Echo-integrator surveys

a) Estimated biomass indices (Area (n.mi2) × average integrator readings per ESDU, mm)
b) Estimated total biomass (m. tons)
c) Estimated biomass abundance (m. tons/n.mi2)
2. Sonar surveys
a) Estimated total number of schools
b) Estimated total area of schools (m2)
c) Estimated total volume of schools (m3)
d) Estimated total biomass (m. tons)
e) Estimated secondary magnitudes (= averages)
As an illustration, we present in the two sections below the following information (data of IND/75/038, Project):
Section 7.1: The codification system and source documents for lage-scale acoustic surveys
Section 7.2: Mechanical processing, tabulation and graphical presentation of the findings

## 7.1 The codification system

For the proper tabulation of the mass of the calculated estimates of the acoustic programme, we developed a compact system of coding for the analytical tables. The constructed code consists of two parts. The first part of the code (A digits) indicates:

 1. Kind of survey (1 digit) 1. Echo-integrator Surveys2. Sonar Surveys 2. Fishing year (1 digit) 2. Fishing year 1972/733. Fishing year 1973/74...8. Fishing year 1978/79 3. Serial number of the acoustic surveys within a given fishing year (2 digits). Specifically, four sets of chain code numbers have been introduced:(i) Serial number of individual surveys 01, 02,...(ii) Quarterly average estimates; 41, 42, 43, 44(iii) Fishing season, off-fishing season average estimates: 51, 52(iv) Yearly average estimates: 99 The Second part of the code (3 digits) indicates: 4. Reference period (1 digit) 1. Daytime2. Night-time3. Day + night-time 5. Variety of fish, Echo-integrator Surveys (2 digits) 01: Total02: Pelagic fish03: Bottom fish04: Whitebait05: Horse mackerel06: Cat fish/Ribbon fish07: Whitebait/Ribbon fish08: Horse mackerel/Tuna09: Shallow water mixture10: Other commercial fish11: Non-commercial fish12: Other schools13: Night recordings14: Other fish Variety of fish, Sonar Surveys 01: Total02: Oil sardine03: Mackerel04: Oil sardine/Mackerel05: Other fish

The overall format of the constructed code is given below:

THE CODE

Source documents

A source document is the initial form on which transaction data are transmitted. The types of source documents used in the acoustic programme reflect the nature of the obtained information at the measuring process of the surveys. Specifically, the following two kinds of information were obtained:

(i) Counts, providing the output of the acoustic instruments per survey unit (ESDU)
(ii) Observations, measurements obtained through the concurrent fishing programme
As it has been discussed, counts are converted into quantitative data by multiplying their values with the respective proportionality coefficient C (calibration experiments).

The following forms were used for data collection

 Hydroacoustic log sheets: (a) Echo-integrator form(b) Sonar form Fishing sheets: (c) Trawl Survey form(d) Purse seine form

The format of the source documents was designed for automatic data processing. Non-quantitative characteristics are precodified.

Each source document consists of two parts, the heading of the form and the body of the form. The heading of the form includes the type of survey and other identification particulars. The body of each form consists of a number of columns indicating the items of information obtained. One line is allocated for a single entry in the form.

## 7.2 Processing, tabulation, graphical presentation

Three main programmes (mini-computer) were developed for the processing of the sample observations of the acoustic surveys (IND/75/038):

a) Programme for the processing of the sample observation of echo-integrator surveys
b) Programme for the processing of the sample observations of sonar surveys
c) Programmes for the graphical presentation of the calculated estimates
Additional programmes were also prepared for the analysis and critical analysis of the findings.

On next pages 90-93 we present in a descriptive way the steps included in the above-mentioned programmes, a, b.

On pages 94-96 we present the format and textual content of prepared tables providing the calculated estimates based on the sample data of echo-integrator and sonar surveys.

On page 97 is an oblique projection graph (see also above c) providing a graphical presentation of the estimated total biomass. Specifically, the produced chart portrays both the size and spatial distribution (space/depth-wise) of the survey biomass.

ECHO INTEGRATOR SURVEYS
Processing/Surveyed Magnitudes

 1. SURVEY YEAR/No. Survey year and serial number of Survey 2. AVERAGE ECHO INTEGRATOR READINGS (per EDSU, mm) On a space/depth domain basis [rows: space (1°Lat.); columns: depth] 3. BIOMASS INDICES = [Area (n.mi2) × average integrator readings per EDSU] On a space/depth domain basis 3.1 MARGINAL BIOMASS INDICES: by row Totals on a space domain basis 3.2 MARGINAL BIOMASS INDICES: by column Totals on a depth domain basis 4. CALIBRATION COEFFICIENT Given 5. ESTIMATED TOTAL BIOMASS (m.t) On a space/depth domain basis 5.1 MARGINAL TOTAL BIOMASS: by row Total biomass on a space domain basis 5.2 MARGINAL TOTAL BIOMASS: by column Total biomass on a depth domain basis 6. BIOMASS DENSITY (m.t/n.mi2) On a space/depth domain basis 6.1 MARGINAL BIOMASS DENSITY: by row Biomass density on a space domain basis 6.2 MARGINAL BIOMASS DENSITY: by column Biomass density on a depth domain basis 7. MARGINAL PROBABILITIES: 7.1 SPACE MARGINAL PROBABILITIES Express the occurrence of ESDUs with traces of fish in a given space domain 7.2 DEPTH MARGINAL PROBABILITIES Express the occurrence of ESDUs with traces of fish in a given depth domain 8. CUMULATIVE TOTAL BIOMASS BY DEPTH/1° LAT. Cumulative total biomass by depth domain within the established space domains (1° Lat.) 9. RELATIVE DISTRIBUTION OF TOTAL BIOMASS BY DEPTH/1° LAT. Relative distribution (%) of total biomass in the depth domains within the established space domains 10. CUMULATIVE RELATIVE DISTRIBUTION OF TOTAL BIOMASS BY DEPTH/1° LAT. Cumulative relative distribution (%) of total biomass in the depth domains within the established space domains 11. CUMULATIVE TOTAL BIOMASS BY SPACE/DEPTH Cumulative total biomass by space domain (1° Lat.) within the established depth domains 12. RELATIVE DISTRIBUTION OF TOTAL BIOMASS BY SPACE/DEPTH Relative distribution (%) of total biomass in the space domains within the established depth domains 13. CUMULATIVE RELATIVE DISTRIBUTION OF TOTAL BIOMASS BY SPACE/DEPTH Cumulative relative distribution (%) of total biomass in the space domains within the established depth domains

SONAR SURVEYS
Processing/Surveyed Magnitudes

 1. PACKING DENSITIES OF SCHOOLS (kg/m3) Given 2. SAMPLE DENSITY OF SCHOOLS (Number of Schools/EDSU) Sample average number of schools per EDSU within the established space/depth domains 3. SAMPLE TOTAL AREA OF SCHOOLS (m2) Sample total area of Schools (m2) within the established space/depth domains (sample totals were calculated by considering both circular and elliptical shapes of schools) 4. SAMPLE TOTAL VOLUME OF SCHOOLS (m3) Sample total volume of Schools (m3) within the established space/depth domains (sample totals were calculated by considering both circular and elliptical shapes of schools) 5. AVERAGE SIZE (SAMPLE) OF THE OBSERVED SCHOOLS 1. Average area (m2) per observed sample school within the established space/depth domains and marginal space, depth domains (circular and elliptical)2. Average volume (m3) per observed sample school within the established space/depth domains and marginal space, depth domains (circular and elliptical) 6. ESTIMATED DENSITIES 1. Average total number of Schools per n.mi2 within the established space/depth domains and space, depth marginal domains2. Average total area of Schools (m2) per n.mi2 within the established space/depth domains and space, depth marginal domains (circular, elliptical)3. Average total volume of Schools (m3) per n.mi2 within the established space/depth domains and space, depth marginal domains (circular, elliptical)4. Average total absolute biomass of Schools (m.t) per n.mi2 within the established space/depth domains and marginal space, depth domains (circular, elliptical) 7. ESTIMATED TOTALS 1. Estimated total number of Schools within the established space/depth domains and marginal space, depth domains2. Estimated total area of Schools (m2) within the established space/depth domains and marginal space, depth domains (circular, elliptical)3. Estimated total volume of Schools (m3) within the established space/depth domains and marginal space, depth domains (circular, elliptical)4. Estimated total biomass of Schools (m.t) within the established space/depth domains and marginal space, depth domains (circular, elliptical) 8. ESTIMATED PROBABILITIES Express the occurrence of ESDUs with traces of schools in a given space/depth domain and a marginal space, depth domain 9. CUMULATIVE TOTAL BIOMASS BY DEPTH/1° LAT. Cumulative total biomass by depth domain within the established space domains (1° Lat.) 10. RELATIVE DISTRIBUTION OF TOTAL BIOMASS BY DEPTH/1° LAT. Relative distribution (%) of total biomass in the depth domains within the established space domains 11. CUMULATIVE RELATIVE DISTRIBUTION OF TOTAL BIOMASS BY DEPTH/1°LAT. Cumulative relative distribution (%) of total biomass in the depth domains within the established space domains 12. CUMULATIVE TOTAL BIOMASS BY SPACE/DEPTH Cumulative total biomass by space domain (l° Lat.) within the established depth domains 13. RELATIVE DISTRIBUTION OF TOTAL BIOMASS BY SPACE/DEPTH Relative distribution (%) of total biomass in the space domains within the established depth domains 14. CUMULATIVE RELATIVE DISTRIBUTION OF TOTAL BIOMASS BY SPACE/DEPTH Cumulative relative distribution (%) of total biomass in the space domains within the established depth domains

Table

Table

Table (cont’d)