Nutrient enrichment of east Australian coastal waters. II. Laurieton upwelling

Abstract

An oceanographical investigation of coastal waters off Laurieton, N.S.W. (31º 39'S.) during August 1968 to March 1974 has shown that upwelling was a regular feature of the spring and summer season.

This upwelling was confined to a 5-mile zone against the coast, occurred at intervals between 12 and 57 days, was of short duration (9-15 days complete cycle) and originated in offshore 15-17º C waters around 125-275 m depth. Upwelling velocities during the final stzges of development were between 17 and 34 m per day. Causes of the upwelling could not be determined. However, it is possible that the narrowing of the shelf width just north of Laurieton is a local factor of importance.