評估我國近年之遠洋漁業生產力

Abstract

我國的漁業以遠洋漁業為主，主要捕撈魚種為鮪類、旗魚類、魷魚以及秋刀魚，年產量居全球前三位，年產值約400億元。若以漁法別來看則以鮪延繩釣為主，產業規模全球排名第一，魷魚產量世界排名第二，2013年秋刀魚年產量首度超過日本成為世界上產量最多的國家，作業漁場更是遍佈世界三大洋區。農林漁牧業等第一級產業對臺灣來說屬於弱勢產業，易受國際協議或規範衝擊，也常常拿來作為國際貿易談判犧牲的籌碼，而現有關於台灣漁業之文獻大多以加入國際組織或區域協議對漁業之影響評估等，鮮少文獻以漁業為研究對象評估生產力，但漁業生產力是許多因素所造成的結果，包括內生和外生因素，例如管理措施和資源存量，了解生產力的變化和影響這種變化的因素對於管理和可永續發展漁業來說非常重要。 本研究以Tornqvist總要素生產力成長率指數為衡量方法，以10種產出、3種投入來評估，而因漁業屬自然資源產業，資源量的多寡亦會影響生產力，且考慮到資源耗竭之衝擊，故本研究將資源量予以加入衡量，以處於過漁狀態之大目鮪與黃鰭鮪所組成之資源量，評估我國遠洋漁業近年之總要素生產力成長率之變動。實證結果發現，我國遠洋漁業亦受國際管制與氣候因素所影響，未包含資源量之總要素生產力成長率平均為2.29%，包含資源量之總要素生產力成長率平均為4.84%，資源量的減少表示人類對於海洋資源的捕撈效率提升、使用更高產能的生產技術或漁具，資源量的減少反映生產力的提升；而相較於大目鮪，黃鰭鮪之總要素生產力成長率波動程度較低，MSY之變化也表示其過漁情況較大目鮪輕微。研究也發現大目鮪與黃鰭鮪之總要素生產力成長率產生數次的交錯，推測兩種魚種存在替代關係，而該現象於太平洋尤其明顯。

Deep sea fishery is the primary fishery type in Taiwan. The main catches include tunas, marlins, squids and saury. The average annual output ranks top three in the world, with an annual output value of about 40 billion NT dollars. From the point of view of fishing methods, longline fishing is the main fishing method. In 2013, the annual output of squid in Taiwan surpassed that in Japan, making Taiwan the most productive country of squid in the world. Furthermore, the operating area spreads across the world's three major ocean regions. The first-tier industries such as agriculture, forestry and fishery are weak industries in Taiwan, vulnerable to international agreements, and often used as a bargaining chip for international trade negotiations. Most of the existing literature on Taiwan's fishery is based on the assessment of the impact of international organizations or regional agreements on fisheries. Little literature uses fishery as a research object to assess productivity, but fishery productivity is the result of many factors, including endogenous and exogenous factors, such as management measures and resource stocks, and understanding the changes in productivity and the factors that influence this change are important for managing and sustainably developing fishery. This study uses the Tornqvist total factor productivity growth rate index as a measure of 10 outputs and 3 inputs. Since fishery is a natural resource industry, the amount of resources will affect productivity and its impact should be considered. Therefore, this study adds the amount of resources to the measurement, and uses the resources of bigeye tuna and yellowfin tuna in the state of overfishing to assess the changes in the growth rate of the total factor productivity in recent years. The empirical results show that deep sea fishery in Taiwan is affected by international regulation and climate factors. The growth rate of the total factor productivity is 2.29% while resources are not included, and is 4.84% if resource-included. It indicates that human beings have improved fishing efficiency of marine resources with higher-capacity production techniques or fishing gear, and the reduction of resources reflects the improvement of productivity. In comparison with the bigeye tuna, the fluctuation of the growth rate of the total factor productivity of yellowfin tuna is low, changes in MSY also indicates that the overfishing problem is rather minor. This study also finds that the growth rate of the total factor productivity of bigeye tuna and yellowfin tuna was several times interlaced, and it is speculated that there is a substitute relationship between these two species, and is especially evident in the Pacific ocean.