Fisheries management in one of the most crowded marine area. Does spatial planning help?

The Adriatic Sea is one of the most crowded marine area. Several fishing activities operate simultaneously in the area, and the need to minimize conflicts among them is also a social concern. We applied a spatially and temporally explicit fish and fisheries model to assess the impact of a suite of spatial plans suggested by practitioners that could reduce the pressure on the four demersal stocks of high commercial interest in the northern Adriatic and that could promote space sharing between mutually exclusive activities.

Check out the open access paper for more information in Ecosphere


DISPLACE is a spatial impact assessment tool that can be used to evaluate the consequences of spatial fisheries closures on the sustainability and the economy of fisheries. The model simulates individual vessels and how they will redistribute their fishing effort given spatial or temporal closures. By applying the model that fit the local fisheries of the Adriatic region, practitioners could further develop tailored applications to their area for both understanding the fine dynamic of the interlinked fish and fisheries here, and, in the meantime, acquire a helicopter view of the outcomes when the small-scale (fishing) operations at sea are aggregated. Ultimately, the framework applied to the Adriatic or other areas should analyse and provide data with thematic reports/scenario on which the practitioners can rely on to project the fish stock population levels and fishery economy relevant to the ecoregion. The model contributes to the coordination and integration of different spatial activities in marine areas and reduces potential inefficient management and use of space in accordance with the aims of the EU MSP and other Directives. In the project the model is used to estimate the consequences of closing specific areas to fishing.

DISPLACE in the Adriatic Sea

We are setting the first steps in developing a fish and fisheries DISPLACE application for the northern Adriatic Sea DISPLACE4AdriaticSeain support of maritime spatial planning and management issues, especially from the perspective of the Italian coastal fisheries. The model provides a test platform for running Monte-Carlo simulations that project scenarios of alternative spatial management scenarios and fishing effort distributions. We evaluate how fisheries revenues and environmental benefits are affected. This first application to the Adriatic Sea DISPLACE4AdriaticSea2should provide technical inputs for the development of a bio-economic model in order to guarantee effective science based inputs allowing policy improvement and better governance at cross-border level for fisheries management and marine spatial planning.


(Attached screenshots in this margin are very preliminary outcomes and should not be used to give any kind of advice)



How individual fishermen´s micro-decision-making affects the overall performance of fisheries

Fishermen´s micro-decision-making is challenged by fishery management and marine spatial plans and affects the overall performance of fisheries. Because of individual decisions and tactics for fishing (e.g. selection of gears, place and time) influence catching power, the fishermen have individual footprint on the harvested stocks and benthic communities.

Also, fishermen have different objectives and strategies influencing economic and impact performance of the fishery for several stocks and ecosystem components and in different areas (e.g. here for carbon footprints, or here for impacts on seafloor). By regulating catch quotas, the deployed effort and potential fishing grounds, both fisheries management and marine spatial plans can result in unintended consequences and incentives affecting the overall economic and energy performance of the fisheries at stake, which may further undermine the ecosystem approach to fisheries.

We intend to support the fishery sector and the policy makers with a benchmark tool for efficiently evaluating alternative scenarios in individual decision making, by designing decision trees to model when, where, how, and for how long they go fishing.

This allows sensitivity experimentation of several factors determining fisheries including the vessel´s internal states and various external constraints such as spatial and seasonal resource conditions, fish and fuel price, weather conditions and spatial plans. User-made decision trees are embedded within the broader DISPLACE individual vessel-based spatial modelling approach (2014, 71: 366-386 in Can. J. Fish. Aqu. Sci.; Screenshot version 0.7.15) screenshot_Displace_v0715 which offers an evaluation of the consequences of alternative dynamics in vessel movements using information about fishing ground preferences and vessel-specific experienced catch rates.

In order to support a quantitative analysis for the generalization of impacts at the macro-scale from all the micro-decisions taken by the vessels aggregated, a spectrum of decision trees and trigger events are attached to the vessels.

have a look here for a quick overview of the model architecture

Impact assessment of spatial planning on the fishery economy and ecosystems

In the competition for marine space, the fishing sector needs to prepare for management impacts from other directives than the EU Common Fishery Policy. Our purpose is to support the sector specific stakeholders and policy makers and provide them with a tool for evaluating the spatial planning and management scenarios and spatial explicit fishery dynamics. This tool is informed by the different types of fishing activities and other activities occupying marine space. The tool is designed to assist optimal decision making in reaction to stock fluctuations, changes in available space for fishing, and management actions, at the finest scale available. The model offers a detailed level of understanding on how stable profits and more energy efficient fisheries are screenshot_displace_0_5_3_smallpossible, even if a zonation  reduces the fishing opportunities and the number of fishing grounds. The model further contributes to the coordination and integration of different spatial activities in certain sea areas and reduces potential inefficient management and use of space according to the aims of the EU MSP directive.


screenshot_displace_078_2 Source: Bastardie, F., Nielsen, J. R., Eigaard, O. R., Fock, H. O., Jonsson, P., and Bartolino, V. Competition for marine space: modelling the Baltic Sea fisheries and effort displacement under spatial restrictions. – ICES Journal of Marine Science, doi: 10.1093/icesjms/fsu215. (here or here)

Have your say on how spatial restrictions affect your fishing

COLOURBOX4013895_smallIn relation to present simulations performed under the Baltic case study of the SOCIOEC project, the stakeholder feed-back is expected to provide information on (and contribute to) what the stakeholders consider to be the most important risk factors in such spatial management. Furthermore, they are expected to contribute with information on how they plan to react to the spatial management measures in their short-term decision making (on a daily basis or at the trip level). For example, how they will react to increased fuel prices? Or how increase price is changing the choices of fishing grounds? Or how do fishermen react to some stocks with altered productivity? Or do they switch to another ground, fisheries, occupation, etc.? Or do they on a longer term basis change their investment dynamics, exit from fishery, etc.?.) . Answers to such type of questions are very relevant because the model is designed to handle the answers and potentially add some new type of reactions based on the answers without too much additional modelling work. The methodology is already to a high extent based on questionnaires and answers to those, i.e. the model has been developed and structured to build on decision trees established from stakeholder feed-back (here). As a better understanding of the fishermen reactions to changed spatial management measures and fishing conditions it is important to know and understand the risks better, which can greatly refine the model perception.

How spatial planning constrains cross-border fisheries: the bio-economic DISPLACE evaluation on the Baltic Sea

DISPLACE_striking_plotOur approach is aiming at modelling the interaction between fisheries and stock spatial dynamics and assessing the interlinked consequences on both the vessel economy and the viability and sustainability of the harvesting (including the issue of energy efficiency for greener fisheries) under alternative effort allocation scenarios and management options. As such, we design a benchmark tool for management strategy evaluations which is able to capture short-term economic behavioral reactions from individual tactical decision-making.

In the growing marine spatial planning (MSP) legislative context, concurrent uses of the sea are further constraining the possibilities of displacing each vessel´s fishing activities. These new constraints require empowering the fishing industry with the right tools and knowledge to engage in MSP dialogues. The impact assessment and scenario evaluation of wider marine cross-sector use, exploitation of the marine environment and competition for space should be considered in a spatial explicit evaluation tool and our ongoing evaluation  is dedicated to investigate this aspect.

This application considers the case of the international western Baltic Sea area and the ongoing spatial marine plans including offshore windmill farms and Natura2000 conservation areas. Almost for the first time some cross-national VMS data have been processed in the same  framework and the movement of around 300 fishing vessels (Danish, German and Swedish vessels) are informed and simulated individually,  each vessel displacing and harvesting on a hourly time step over a projection period of 5 years. Fine scale fishing pressure in space and time are then deduced and the effect of redirection towards some benthic habitats evaluated.

Interesting results are emerging from the work and for example interlinked dynamic of vessels and stocks does show higher revenues from catches which could offset the additional costs from effort displacement, with release of the pressure on the stocks and habitats. At the individual scale, some vessels are strongly stressed, sometimes offering new opportunities for a part of the participants. These results are valuable for engaging a dialogue with stakeholders and managers while a support tool for facilitating the understanding of the dynamics, reproducing the observed patterns and evaluating alternative scenarios, is described and applied to the Baltic Sea area.

This study is conducted in association with a number of EU research projects and the development of a spatial explicit bio-economic model that covers both many stocks and fisheries. We are convinced that the development of such an approach and its current application has the potential to form near future developments in EU from the perspective of the fisheries within the context of maritime spatial planning.

Spatial planning constraining cross-border international Baltic fisheries

 We have just submitted an abstract to the next IIFET conference (International Institute of Fisheries Economics and Trade) about an impact assessment we are conducting on the large-scale western Baltic Sea fisheries:

“Supporting bio-economic evaluation of spatial planning constraining fishing activities: be quantitative, spatially-explicit, vessel-oriented, dynamic stochastic, and coupled to fish populations”

Maritime spatial planning and fishery management are likely to generate extra costs for the fisheries by constraining fishermen activity with conservation areas and new utilization of the sea such as offshore windmill parks. Growing concerns for greener and energy efficient fisheries are also likely to alter existing fishing patterns already varying from fishery to fishery and from vessel to vessel.

In this context, impact assessment of new spatial plans should support quantitative analyses that take into account individual vessel behaviour, local practices and tradeoffs in conflict resolutions. We used a vessel-oriented decision-support tool (the DISPLACE model) for combining stochastic spatial fishing activities to harvested resource dynamics over time in scenario projections.

The impact assessment computes time series of economic and stock status indicators by considering the activity of Danish, Swedish and German vessels (>12m) in the international western Baltic Sea, together with the underlying size-based distribution dynamics of sprat, herring and cod. The outcomes of alternative solutions in spatial effort allocation and displacement are exemplified by evaluating the fishermen capacity to adapt to spatial plans under various constraints.

The DISPLACE model serves as a benchmark tool for management strategy evaluations which are able to capture short-term economic behavioral reactions from individual tactical decision-making. This study is conducted in association with a number of EU research projects and the development of a spatial explicit bio-economic model that covers both many stocks and fisheries has the potential to form near future developments in ICES and EU within the context of maritime spatial planning.

Participatory modeling of fisheries for supporting maritime spatial planning

No HorizonModelling the interactions between fishery and stock dynamics as well as the economic fishery importance on a highly spatial disaggregated scale like in DISPLACE, is useful in context of broader spatial planning, marine management, and stakeholder involvement.

It is important to develop supporting tools for impact evaluations that can inform all parties (scientists, stakeholders, and managers) on the overall fishing sector dynamics on a highly disaggregated scale to develop a collective understanding and common discussion platform based on quantitative predictions of impacts and beneficial/detrimental effects of any new spatial marine planning project . As such, the DISPLACE model can be used to obtain further information on fishermen behaviour with direct input from stakeholders (e.g., here).

windmillsSuch an approach should foster management choices to be based on a more objective and transparent basis and on actual feedback from the stakeholders when they react to spatial planning. More participatory management requires quantitative support and a common platform for input that will likely promote good fishing practices and achieve better compliance with the regulations and where stakeholders can feel more engaged in the ecosystem-based fisheries management decision process (also advocated here).

The goal is to also inform managers with quantitative supports about the potential gain of spatial regulations against the cost for displacement when fishermen loose access to valuable fishing grounds and/or have to travel more to go fishing from their home harbour to make a living out of the catches.

High-resolution mapping of fishing activities: toward well-informed marine spatial planning

Multi-sectoral and multi-disciplinary marine spatial planning methods are prevailing in the EU Marine Strategy Framework Directive. Such integrated marine management needs to consider the commercial fishery and all other sector uses of the sea, such as transport, energy exploitation and recreational use.

Consequently, each of these pressures on the marine ecosystem needs to be mapped.


Mapping of the 2005 Danish landing value (left: Cod; right: Nephrops, click on images to see animations per year-quarter) over the North Sea and the Baltic Sea for VMS-equipped fishing vessels. (Source: here)

Simultaneously, the EU Common Fisheries Policy recently recognized the importance of accounting for heterogeneity in fishing practices from different fleets for managing
commercial fisheries. It was acknowledged that a shift should take place from managing individual fish stocks towards managing fleets, mixed fisheries, and economic issues.

Fine-grained VMS data enable obvious improvements to describe used areas and spatial fishing pressure with higher resolution than the ICES rectangles. Hence, the linkage of VMS with logbooks constitutes very valuable information for mapping the spatio-temporal heterogeneity of landings and economically important fishing grounds to act as the basis for management decisions and designation of priorities areas.

COLOURBOX527799_fishing_net_small_sizeThese maps can be used directly for conditioning the DISPLACE model and inform area-based management performing strategy evaluation and scenario modelling of different management options associated with, for example, the establishment of spatial regulated areas and displacement of fishing effort in relation to ecosystem conditions (sensitive habitats), variability in fish stock occurrence and other uses of the sea.

Impact assessment of windmill parks on fisheries

DONG Wind Farm 1An on-going work is to apply and downscale the DISPLACE model to the commercially important and busy Western Baltic marine area where several utilisations of the sea currently coexist. In line with this it is evaluated to which extent the international plans for offshore windmill parks in the Baltic area are affecting the fishing opportunities per activity and fishing communities in the vicinity of the planned windmill sites.

Hence, preliminary data mining shows that the planned offshore windmill parks in the area do not really interfere with important fishing grounds for the Danish fisheries. A notable exception is the large ‘Kriegers Flak’ site (where turbines will be shared between Denmark, Germany and ultimately, Sweden). A windmill farm here will impact important existing fishing grounds.map_spatial_dependency_and_planned_windmillfarms_sitesTwo indices of spatial use by the Danish vessels (>12m) visiting the Kattegat and the Baltic Sea in 2012, (a) revenue of the vessel visiting the cells over the total revenue, and (b) revenue realized on the cells by the visiting vessels over the total revenue of the same vessels. The gradient colour shows low (blue) up to high (red) index values. The planned (from 2013) windmill parks given in purple polygons (Source: compiled by DTU-Aqua)

Indices of activity (margin figure) reveal that this area is not really an important area in terms of total revenue at the scale of the entire Danish fisheries because not visited by “big players”. By contrast the area is important for a large portion of vessels (likely conducting small scale fisheries) which realise a significant portion of their total 2012 revenue in the designated area. Accordingly, it will impact many fishing businesses and the local societies. If this impact leads to major disruption of the fishing activities and/or major consequences on the population dynamics should be further investigated by modelling applying the DISPLACE model.

The evaluation intends to cover the implications in terms of individual profitability, and also in terms of the sustainability of the exploitation of the main commercial stocks in the area (i.e. sprat, herring, cod and flatfish) and possibly the likely effect on the benthic communities from redirected bottom-disturbing activities. Integration of the Swedish and German vessels (also operating in the area) on top of the Danish ones is also planned to expand the impact evaluation.