Non Technical Summary

Research presented in this paper explores how characteristics of individual sea urchins, habitat and season, can be used to predict whether sea urchins are likely to contain roe of a high quality. Variability in roe quality is a problem common to sea urchin fisheries, and the decline of many fisheries around the world can be partly attributable to overfishing caused by non-selective harvest. Any assistance that can help direct fishers towards sea urchins that have high quality roe will make harvesting more efficient and reduce wastage. For example, we show that by collecting individuals with test diameters < 85 mm from fringe habitats outside the spawning period, the chances of obtaining the most preferred colour of roe increase substantially (i.e. from 65% to almost 95%). This is associated with a 40% increase in the mean roe weight of sea urchins at this time. The paper goes on to explore how other attributes of roe quality (texture and granularity) can be maximised by selecting individual sea urchin with the appropriate characteristics.