Sometimes the data considered to determine stock status can be temporally or spatially limited, whereas considering a modern fishery in a broader temporal and/or spatial context can be very informative. The South Australian fishery for southern sea garfish (Hyporhamphus melanochir) experienced a significant downturn in the early 2000s. Two alternative hypotheses were proposed to account for this, i.e. natural population dynamics or recruitment over-fishing. This study helped to differentiate between these by: considering the history of the fishery; determining the level of exploitation in the modern fishery; and describing the contemporary population structure and assessing whether population truncation had occurred due to fishing.

Catch records indicated that the fishery had sustained substantial catches for at least 60 years. Exploitation rates for the modern fishery, estimated using a complex, computer fishery model, have generally exceeded 50% of the fishable biomass. Population structure in 2005/06, determined by market-sampling and fish ageing, was dominated by one- and two-year old fish. There is strong evidence of population truncation, compared with results from similar sampling in 1954/55 as well as lightly-fished, geographically-separated populations. In 2005, the fishery status reflected; its long history, high exploitation rates and population truncation.