Acoustic abundance estimation of the stock of Norwegian spring spawning herring, winter 1995- 1996

Standard echo integration methodology has been applied to the stock of Norwegian spring spawning herring (Clupea harengus) wintering in the Ofotfjord-Tysfjord-Vestfjord system during late autumn 1995 and early winter 1996. The primary instruments of acoustic data collection and processing were the SIMRAD EK500/38-kHz echo sounder and the Bergen Echo Integrator. Biological sampling was effected by means of a so-called MultiSampler pelagic trawl in addition to standard pelagic trawls. Compensation was made during postprocessing for the effect of acoustic extinction. The major complication of the survey and challenge of the analysis has been stratification. This is discussed in the context of (1) mixing of immature and mature year classes, each with its own behavioural characteristics apropos of diurnal vertical migration and outwards spawning migration, (2) degree of achieved survey coverage, depending on fjord geometry, navigational hazards, available time, and fish distribution, and (3) ongoing spawning migration. Because of various uncertainties, a series of abundance estimates is presented. These are accompanied by fitted variogram models and geostatistical variance estimates

Environmental information for stock evaluation and management advice purposes

This report summarizes the work of an internal working group appointed by the Institute of Marine Research's management group to evaluate inclusion of environmental parameters in stock evaluation. The report discusses the current and potential usage of environmental information and presents specific recommendation on how to increase the usage of environmental information for stock evaluation and management advice purposes. NORSK SAMMENDRAG: Rapporten sammenfatter arbeidet til et utvalg nedsatt av ledergruppen ved Havforskningsinstituttet for å evaluere bruk av miljøinformasjon i bestandsvurdering og rådgivning. Rapporten diskuterer dagens- og potensiell bruk av miljøinformasjon og gir konkrete anbefalinger for hvordan Havforskningsinstituttet kan øke bruken av miljøinformasjon i bestandsvurderinger og rådgivning

The added value of participatory modelling in fisheries management – what has been learnt?

How can uncertain fisheries science be linked with good governance processes, thereby increasing fisheries management legitimacy and effectiveness? Reducing the uncertainties around scientific models has long been perceived as the cure of the fisheries management problem. There is however increasing recognition that uncertainty in the numbers will remain. A lack of transparency with respect to these uncertainties can damage the credibility of science. The EU Commission's proposal for a reformed Common Fisheries Policy calls for more self-management for the fishing industry by increasing fishers' involvement in the planning and execution of policies and boosting the role of fishers' organisations. One way of higher transparency and improved participation is to include stakeholders in the modelling process itself. The JAKFISH project (Judgment And Knowledge in Fisheries Involving StakeHolders) invited fisheries stakeholders to participate in the process of framing the management problem, and to give input and evaluate the scientific models that are used to provide fisheries management advice. JAKFISH investigated various tools to assess and communicate uncertainty around fish stock assessments and fisheries management. Here, a synthesis is presented of the participatory work carried out in four European fishery case studies (Western Baltic herring, North Sea Nephrops, Central Baltic Herring and Mediterranean swordfish), focussing on the uncertainty tools used, the stakeholders' responses to these, and the lessons learnt. It is concluded that participatory modelling has the potential to facilitate and structure discussions between scientists and stakeholders about uncertainties and the quality of the knowledge base. It can also contribute to collective learning, increase legitimacy, and advance scientific understanding. However, when approaching real-life situations, modelling should not be seen as the priority objective. Rather, the crucial step in a science–stakeholder collaboration is the joint problem framing in an open, transparent way

The use of personal knowledge in stock assessment

The focus on the precautionary approach, sustainable fisheries and ecological management requires knowledge about the uncertainty of stock assessments. An increasing number of working groups in the ICES system include uncertainty estimates, and new reference points are being developed. When it comes to the quality or the uncertainty of uncertainty estimates and reference points, this is communicated by scarce comments in ACFM reports or working group reports. Uncertainty is difficult to estimate, and to get a picture of the quality of assessments it might be fruitful to study not only the data and models used, but also how the models are used by the participants of the ICES working groups. It seems that personal knowledge plays an important role when results from each run are evaluated and the program package is rerun with new options or other data. In this paper I discuss the role personal knowledge plays in stock assessment and how this can reflect the quality of the assessment

The ecosystem approach to fisheries – science driven or issue driven?

The ecosystem approach to fisheries (EAF) represents a multi-objective aiming at 1) broadening the management perspectives from single species to including ecosystems considerations, 2) maintaining a precautionary approach and 3) increasing the involvement of stakeholders. ICES, as a science community and provider of advice, has a particular responsibility in these respects, but developing advice in accordance with the EAF has proven difficult and time consuming. In this paper, I discuss the role of science for the EAF in terms of applied versus basic research and in terms of type-I, II and III errors. I argue that the science community augment two problems in our demand for political attention to knowledge gaps, often in our own field of interest. First, the managers are implicitly advised to postpone the EAF until the knowledge gaps are filled, which is in contradiction with the precautionary approach. Second, this may take attention away from more urgent ecosystem issues. One solution to this problem is to consider scientists as stakeholders and involve all interested parties when deciding what should be the present priority of ecosystem issues. As ICES is not in power to arrange this, an alternative is that ICES carries out this exercise itself among its own scientists. I briefly discuss how this can be done. Keywords: EAF, participation, transparency, uncertaint

The Fragility of Precautionary Reference Points

A basic idea in fisheries management is that a fishery should be managed so that there is sufficient spawning stock biomass left to reproduce after the following year’s fishing. An essential task for the scientists has thus been to predict spawning stock one to two years ahead. The focus on precautionary approach in fisheries management is an expression of a will to be careful with the marine resources by taking into account the uncertainty in science. The fisheries science community has responded by designing precautionary reference points to reflect the state of the stock and the uncertainty in the predicted spawning stock biomass and fishing mortality rate. However, experience has shown that this has not become the intended success. In this paper I argue that the precautionary reference points do not communicate uncertainty adequately. The system of reference points is static regarding the communication of uncertainty, it is an inefficient way of communicating uncertainty, it only reflects part of the total uncertainty in advice and it is value-laden as it is not transparent regarding underlying assumptions. In addition, the ACFM advice on catch options communicates an incorrect precision level and contradicts the precision level reflected by the reference points. ICES should therefore rethink the concept on how to communicate fisheries related advice that is more robust and more in accordance with the precautionary approach. The solution to the mismatch between quantified uncertainty and the total uncertainty could be to partly move the focus from quantified uncertainty to qualitative perspectives of the uncertainty. I include some suggestions that can be further explored

Fisheries scientists` struggle for objectivity

Traditionally, objectivity and neutrality along with testability and significance have been important standards of science. However, science has changed profoundly from small-scale experiments to large-scale problems of societal concern. Thus a revised set of scientific standards and ideals of quality is necessary. Fisheries scientists are educated at universities where traditional ideals are essential. In this paper I discuss objectivity and neutrality as measures of quality and how fisheries scientist relate to these ideals. Scientific ideals are challenged, and examples are discussed within fish stock assessment, whale counting and fisheries data

Hermod, a single species model for the Norwegian spring spawning herring stock

HERMOD is a model for the population dynamics and migration of the Norwegian Spring spawning herring that is being developed with the double purpose of being an independent single species model and of being integrated into the Multispecies Model for the Barents Sea (MULTSPEC). This paper describes and discusses the presently used algorithms for maturation, recruitment, growth and migration, as well as the model's input and output options. A brief outline is given of the plans for further development

FiSHU@LiS, a Computer Game on a General Pelagic Fish

Experience has shown that making political decisions that ensure sustainable use of natural resources is difficult. This has raised the question on how to include stakeholders and citizens in decision processes. ViRTU@LiS (social learning on enVIRonmental issues with the inTeractive information and commUnicAtion technoLogIeS) is an EU project that aims at developing ICTs (information and communication tools) for participatory processes. One of the outcomes of this project is an Internet game on a general pelagic fishery, FiSHU@LiS. The aim of the game is to let any citizen learn and judge information in an interactive way. The player can choose to be a migratory pelagic fish, a predator (a shark), a fisherman, a fisheries scientist or a politician. Through these characters, the player can learn in an interactive way about resource problems and societal aspects in the fisheries. An important part of the project, including this Internet game, is to undertake an extended peer-review. Stakeholders of different categories will be invited to evaluate the information presented: the information itself, how it is presented and how uncertainty is presented. The software will then be adjusted. This paper describes in short the dynamics of the game, indicates what kind of information will be available and how the extended peer-review will be carried out