Monitoring tropical freshwater fish with underwater videography and deep learning

Context

The application of deep learning to monitor tropical freshwater fish assemblages and detect potential anthropogenic impacts is poorly understood.

Aims

This study aimed to compare the results between trained human observers and deep learning, using the fish monitoring program for impact detection at Ranger Uranium Mine as a case study.

Methods

Fish abundance (MaxN) was measured by trained observers and deep learning. Microsoft’s Azure Custom Vision was used to annotate, label and train deep learning models with fish imagery. PERMANOVA was used to compare method, year and billabong.

Key results

Deep learning model training on 23 fish taxa resulted in mean average precision, precision and recall of 83.6, 81.3 and 89.1%, respectively. PERMANOVA revealed significant differences between the two methods, but no significant interaction was observed in method, billabong and year.

Conclusions

These results suggest that the distribution of fish taxa and their relative abundances determined by deep learning and trained observers reflect similar changes between control and exposed billabongs over a 3-year period.

Implications

The implications of these method-related differences should be carefully considered in the context of impact detection, and further research is required to more accurately characterise small-growing schooling fish species, which were found to contribute significantly to the observed differences.