Fish belt transect

The fish belt transect records observations of fish abundance.

Each transect requires a transect number, length surveyed (m), and transect belt width (options: 2m, 5m or 10m). Users can select how fish sizes are estimated underwater, using 1cm, 5cm or 10cm size bins. The “label” field can be used to indicate a special type of fish belt transect, such as long-swim.

Observations are recorded at the bottom of the page.

After typing any three letters of an observed fish family, genus, or species, MERMAID will provide a predictive dropdown with names. This ensures all spelling is correct and consistent. Select the fish observation by using the ‘up’ or ‘down’ arrow keys or entering more letters so that there is only one choice and press the Enter or Return key to select a name.

Indo-Pacific fish are included in this version of MERMAID and all fish names come from Fishbase. They can be found in the “Reference” icon at the header of any page. New fish family, genus, or species can be proposed to the MERMAID science team for approval and addition. Biomass will automatically be calculated in the last column.

To prevent errors in data entry, MERMAID will flag the following as a warnings and errors:

  • Total biomass less than 100 kg/ha or greater than 2,000 kg/ha
  • Total fish count less than 10
  • Total observations less than 5


Navigating through the observation fields is similar to navigating in Excel: use the ‘tab’ keys to move across to the Size and Count (abundance) columns; at the end of a row, press “Enter” to create a blank row to enter a new fish observation; press “Tab” at the end of a row to duplicate fish species from the