Fishbelt Data Checks

Published 14 Jan 2026, Updated 14 Jan 2026
3
By Iain R. Caldwell - Lead Data Analyst, MERMAID,
Fishbelt
Quarto
R
Bar Plot
Scatterplot
Histogram
Donut plot/ Pie chart

Context

These additional data quality checks can be run on MERMAID projects with fish belt data to test and visualize differences among observers, detect outliers, and explore family diversity and biomass patterns.

In this example I export a public project - in this case a project tagged with "Blue ventures" called "Northern Belize Coastal Complex". However, I also provide some example code in the full resource (see link above) that can be used to get a project that is not public but for which you are a member.

Observer comparisons

Data checks for observers includes tables and plots to compare biomass, abundance, and taxonomic identification among observers.

Outlier detection

The data checks include identifying sites that have the highest and lowest biomass in the project and visualizing the spread of fish biomass and fish abundance across sites.

Since sharks can represent a large proportion of biomass within a site, the code also includes checking the abundance and biomass of shark families within the project.

Fish families

Data checks for taxonomic spread include tables and plots to compare the numbers of fish families across sites and their proportional representation within the project more generally.

Trophic categories

The final data check is a plot showing the average and spread of biomass for trophic groups across sample events.

Data summary

In addition to the individual data checks, there are parts of the code that present overall summaries of the project data.