Plenary Lecture “Challenges and achievements in rebuilding
fisheries: uncertainty, prescriptions and scientific advice”
Ana Parma, Centro Nacional Patagónico, Argentina
Abstract
Global evaluations of fish stock status indicate that a more positive
outlook for fisheries is beginning to emerge in many regions in response
to new, stronger mandates to curve overfishing and to rebuild depleted
stocks. Legal frameworks have become increasingly prescriptive, requiring implementation of rebuilding
plans and specifying clear benchmarks for tracking progress. Effective reductions in fishing pressure have
been achieved in response to stringent management regulations, leading in many cases to a reversal of
declining trends in stock size. While successful on many accounts, however, prescriptive frameworks have
forced reliance on specific management approaches, often inadequate for specific fisheries, restricting the
range of acceptable options and discouraging innovation. In the US, for example, a legal management
framework built around the concept of maximum sustainable yield (MSY) mandates rebuilding to the MSY
level within a predefined time frame once a stock has been classified as overfished. Such policy dependency
on uncertain determinations of stock status relative to thresholds and targets often causes abrupt changes
in management, exacerbating the impact of the inherent variability of stock assessments.
While these problems manifest themselves even in fisheries that can be classified as “data-rich”, the
limitations of prescriptive frameworks are much more severe in data-poor situations. Major technical
challenges still remain for rebuilding many world fisheries for which quantitative assessments are not
available. For those fisheries, prescriptive management frameworks based on MSY exacerbate the
consequences of data deficiencies and distract resources away from due consideration of alternative
innovative approaches. Empirical decision rules for adjusting regulations (input or output controls), based
on simple indicators of resource status and trends, may prove adequate to support “direction-oriented”
strategies aimed at improving resource status. Although progress in evaluating performance of such rules is
underway and useful guidelines are emerging, data limitations often go hand in hand with other structural
features that hamper centralized management capabilities. In those cases, the most pressing challenges are
not in resource assessment but in broader issues of fisheries governance.
Biography
Ana Parma is an expert in fisheries modeling, assessment, and management. Her interests focus on
fisheries from different angles, ranging from stock assessment and the design of harvest control rules, to
the institutional aspects of decision-making and fisheries governance. She earned a PhD in Fisheries at the
University of Washington in 1989 and worked for 10 years at the International Pacific Halibut Commission,
while she became involved in the assessment of several data-rich, industrial fisheries. In 2000 she returned
to Argentina, her home country, to become a research scientist with Argentina’s National Scientific and
Technical Research Council, working at a coastal research centre in Patagonia. With this move, the focus of
her work broadened to include coastal reef and shellfish fisheries. Over recent years she has been involved
with the analysis of spatially explicit management approaches, and the evaluation of formal and informal
rules to regulate fishing access privileges in small-scale fisheries. Ana has participated in many scientific and
policy advisory groups in different countries and international organizations. In particular, she coordinated
the design of the stock rebuilding strategy recently adopted by the Commission for the Conservation of
Southern Bluefin Tuna, and co-chaired a committee that evaluated the effectiveness of fish stock rebuilding
plans in the United States.