SEA - Stock Evaluation of Abalone: Towards a sustainable fishery

  • Team: Island Aquatic Ecology
  • Type: DRCT Azores
  • Category:Regional Research Project
  • 2012 to 2015


The view that the sea is an infinite source of resources is slowing changing as the number of over-exploited populations increases. Global catches of marine fish and invertebrates are approaching its upper limit with the number of over-exploited or collapsed stocks showing an exponential increase over the last decades. In addition to the dramatic and obvious loss of targeted populations, over-fishing has also led to profound changes to the structure of marine communities via indirect effects and is impacting marine ecosystems as a whole. Overall, these results indicate that management of marine biotic resources has largely failed to achieve its primary role – sustainability. Such a failure is mostly a consequence of the continually increasing harvest rates in response to an increasing socio-political pressure for greater harvests coupled with the intrinsic uncertainty to predict sustainable harvesting levels. A common drawback in predicting the consequences of harvest rates is that there is no a priori information regarding the status of exploited populations. That is, most studies are done only when there is a perceived impact upon the targeted populations. In most situations, this means that fishing has already caused dramatic reductions in populations sizes and changes in the population structure so that no longer exists a reference state against which to compare and predict the resilience or recovery of target populations. In the Azores there is a long tradition of exploiting coastal marine resources. Common catches include numerous finfish, lobsters, barnacles, crabs and limpets. Unlike other locations worldwide where the abalone fishery has led to severe stock depletions, there has been little impact on the stocks of the abalone Haliotis tuberculata. However, H. tuberculata is a valuable and highly regarded resource and there is now evidence that it is slowly being introduced into the regional gastronomy. Although Azorean abalone stocks may be considered relatively virgin, there is yet no information regarding the local abundance, biology or ecology of this species. Similarly, there is no regional legislation regarding the exploitation of this shellfish. The present project aims to provide a reference state to which future studies can be compared and thus accurately assess the impact of a potential fishery. This will involve examining the biology and ecology of H. tuberculata and creating a dynamic population model that will inform the authorities and provide valuable information that fosters sustainable harvest rates. The present project will also provide recommendations for the future management of the fishery, based on a literature review and the field information collected.

Funding Institution

Direcção Regional da Ciência e Tecnologia. M2.1.2/F/004/2011.


Armindo dos Santos Rodrigues - Centro de Vulcanologia e Avaliação de Riscos Geológicos (CVARG), Universidade dos Açores.