PhD graduand Steve Lamberth's thesis places a value of R490 million a year on the contribution of estuaries to marine fisheries.

Estuaries have become vital refuges for fish from otherwise catastrophic sea conditions, such as periodic low-level events.

Lamberth's thesis demonstrates how a Multi-Criterion Decision Analysis can prioritise line fish for research and management. It also identifies biogeographic situation and estuarine size as the most important factors influencing fish composition.

This research underpins his thesis on the status of nearshore and estuarine fish and fisheries and their responses to environmental change.

Lamberth has worked for Marine and Coastal Management for 10 years and was a commercial fisherman earlier in his career.