Fisheries biology of short-spined sea urchins (Heliocidaris erythrogramma) in Tasmania: supporting a profitable harvest and appropriate management
University of Tasmania (UTAS)
Urchins have been fished in Tasmania since the 1980s, yet no significant research since a basic morphological description of the reproductive cycle in the 1970s has been conducted to support fisheries management. Spatial and habitat variability in urchin growth rates, maximum sizes and size at maturity across key harvesting regions are unknown. There is a need to understand the drivers of seasonal and spatial variability in roe quality to maximise returns of ‘A-grade’ roe in order to maximise industry probability. Variability in urchin roe coupled with competitive catch limits is leading to localised concentration in effort and subsequently catch caps being reached or areas being heavily exploited before roe has reached its highest quality or optimal recovery. This is decreasing product value and fishery profits. The lack of information on the biology, population structure and roe characteristics of the urchin not only continues to hinder the value of the wild fishery in Tasmania but also the capacity to manage it. There are regions where high concentrations of barren forming urchins are present and are not targeted by the wild fishery due to poor roe quality. Trials of Norwegian technologies to enhance roe quality of these urchins are being planned as a part of international trials. Gonad (roe) development and waste generation need be assessed in order to manage the developing industry, as well as to optimise feed-regimes ahead of moving to full commercialisation. Successful urchin farming will facilitate the expansion of the urchin industry, allow for diversification in the oyster industry given recent outbreaks of POMS and assist salmon growers move into IMTA practices. There is strong support from managers and industry for the proposed research that will guide the future profitability of the fishery and inform its management. The TasRAC has identified this as a high priority project. DPIPWE is bound by the Living Marine Resources Management Act 1995 to ensure that fisheries are managed in a sustainable manner. However, the Department has had to adopted a precautionary approach in management due to the lack of scientific knowledge on the species.
1. Assess Heliocidaris resource status and fisher perceptions on management and factors influencing roe quality
2. Assess regional and habitat variability in size at maturity and growth in Heliocidaris and the appropriateness of current size limits.
3. Determine biological and environmental drivers of roe quality.
4. Quantify roe enhancement and waste production of Heliocidaris fed on natural and formulated feeds