Fisheries are characterized by variations in space and time. This study investigates the characteristics of seasonality in cod trawl fisheries in two distinct areas: the coast along the northern Norway and the high sea area of the Barents Sea. Catch per unit effort (CPUE) is used to proxy variation in stock abundance. A CPUE function has been estimated in the frequency‐domain framework, to detect the presence of seasonality. Our analysis reveals that seasonality in stock abundance is only present in the northern coast of Norway. We conclude that as a consequence of seasonality in stock aggregation during the first quarter of the fishing year, possible economic losses caused by reduced prices—stemming from a large supply of cod—are larger than the economic benefits from cost reduction per unit of harvest. We speculate that declined price and consequently potential economic losses encourage trawlers to substitute cod by other high‐value fisheries during the winter months. As the price of cod starts to rise after the first quarter, trawlers begin to target cod in the high sea areas, a region with less seasonality.

中文翻译：

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挪威鳕鱼渔业的时空分布

渔业的特点是时空变化。这项研究调查了两个不同区域的鳕鱼拖网渔业的季节性特征：挪威北部沿海地区和巴伦支海公海地区。每单位工作量的捕获量（CPUE）用于替代库存量的变化。已经在频域框架中估计了CPUE功能，以检测季节性的存在。我们的分析表明，仅在挪威北部沿海地区存在存量丰富的季节性。我们得出的结论是，由于捕捞年度第一季度种群总量的季节性变化，价格下降（源于大量鳕鱼的供应）造成的经济损失可能大于单位收获成本降低所带来的经济利益。我们推测，在冬季，价格下降以及潜在的经济损失促使拖网渔船用其他高价值渔业替代鳕鱼。随着鳕鱼价格在第一季度之后开始上涨，拖网渔船开始将鳕鱼瞄准季节性季节较少的公海地区。