[論文レビュー] Modeling the Senegalese artisanal fisheries migrations

Alassane Bah, Timothée Brochier|arXiv (Cornell University)|Mar 9, 2026

Climate Change, Adaptation, Migration被引用数 0

ひとこと要約

論文は気候変動、漁業努力、および社会経済的要因がセネガルの漁村の artisanal 漁業の移動をどのように形成するかを多-agent モデルで研究し、持続可能性と地域計画のシナリオを評価する。

ABSTRACT

The North-West African coast is enriched by the Canary current, which sustain a very produc- tive marine ecosystem. The Senegalese artisanal fishing fleet, the largest in West Africa, ben- efit from this particularly productive ecosystem. It has survived the ages with remarkable adaptability, and has great flexibility allowing it to react quickly to changes, in particular by changing fishing gear and performing migrations. However, since the 1980s, the increasing fishing effort led to a progressive fish depletion, increasing fisher's migration distances to access new fishing grounds. Since 2007 many fishers even started to navigate to Canary archi- pelago in order to find a more lucrative job in Europe, carrying candidate to emigration in their canoes. This phenomenon further increased since 2022 due to a new drop in fishery yields, consecutive to the development of fishmeal factories along the coast that amplified overfishing. Climate change may also impact fish habitat, and by consequence the distribution of fishing grounds. The question addressed in this research was how climate change, fishing effort and socio-economic parameters interact and determine the artisanal fishery dynamics. An interdisciplinary approach allowed us to collect data and qualitative information on cli- mate, fishing effort and socio-economic parameters. This served as a basis to build a multi- agent model of the mobility of Senegalese artisanal fishing. We implemented a first version of the model and presented some preliminary simulations with contrasted fishing effort and climate scenario. The results suggested that first, climate change should have only a slight impact on artisanal fishing, even in the most extreme climate scenario considered. Second, if fishing effort was maintained at current levels, we found a collapse of the fishery with massive fishers migrations whatever the climate scenario. Third, with reduced fishing effort, a sustain- able fishery equilibrium emerges in which Senegal's artisanal fishery catches ~250,000 tons of fish a year mostly in Senegal, approaching the 2000s catches records. This sustainable equi- librium maintained with the two-climate change scenario tested. Fishers migrations provide clues of the fish populations state and have implications for the sustainable exploitation of fishing resources. Senegalese artisanal fishers' migrations impact the regional distribution of the fishing effort, therefore must be taken into account in regional development and planning policies for this sector, particularly in a context of increasing infrastructure and spatial man- agement measures (e.g. marine protected areas). This work lays the foundations of a computer simulation tool for decision support.

研究の動機と目的

• 気候変動、漁業努力、社会経済パラメータが漁業ダイナミクスの形成にどのように影響するかを理解する動機づけ。
• セネガルの artisanal 漁師の多-agent 移動モデルを開発する。
• 異なる漁業努力と気候シナリオの下での予備的シミュレーションを提供し、政策と地域計画を支援する。

提案手法

• モデル設計を informing する気候、漁業努力、社会経済パラメータに関する定性的および定量的データを収集する。
• 漁師の多-agent 移動モデルの第一バージョンを実装する。
• 異なる漁業努力と気候シナリオの下で予備的なシミュレーションを実行し、結果を探索する。

実験結果

リサーチクエスチョン

• RQ1 気候変動はセネガルの artisanal 漁師の分布と移動にどのような影響を与えるか？
• RQ2 現在の漁業努力と低減された場合の影響が漁業の持続可能性と移動パターンに与える影響は？
• RQ3 漁業努力を減らすことでセネガルで重大な漁獲を伴う持続可能な均衡を生み出せるか？
• RQ4 漁師の移動は地域の漁業努力の分布と政策（例：保護区域）への影響にどうつながるか？

主な発見

• 気候変動は、検討されたシナリオでは artisanal 漁業に対してわずかな影響しか与えないと予測される。
• 現在の漁業努力を維持すると、気候シナリオに関係なく大規模な移動とともに漁業が崩壊する。
• 漁業努力を減らすと、セネガルを主体に年間約25万トンの漁獲を伴う持続可能な均衡が得られ、2000年代初頭の記録に近づく。
• 二つの気候変動シナリオでも、漁業努力を減らせば持続可能な均衡を維持できる。
• 漁師の移動は魚類の個体群状態に関する情報を提供し、資源管理に資する。