利用深層海水發展養殖產業規劃與策略之研究-以宜蘭縣大南澳深層海水園區為例

Abstract

深層海水（deep ocean water or deep sea water），一般學者的看法是水溫躍層 (thermocline，約海平面200公尺 ) 以下的海水，陽光照射不到，不受大氣與環境變動影響的海水。深層海水具有三大特性，分別是低溫性、潔淨性與富營養鹽，其應用範圍廣泛，可以創造極高的附加價值。台灣東部海域海底地形陡峭，極具發展深層海水產業之潛力，宜蘭縣政府為推動深層海水科技產業，於南澳地區設立深層海水園區，擬藉由資源利用商業化及引進民間投資開發方式，帶動地方發展及產業升級。本研究以大南澳深層海水園區為例，蒐集美國NELHA及日本深層海水之利用方式與取水量，以及深層海水售水價格，並針對園區深層海水利用於養殖產業之效益評估做初步試算，亦針對美、日兩國以及國內的深層海水取水管使用情形做簡介，相關研究成果摘述如下：(1)美國深層海水採較大管徑之管線設計，成本較為低廉。深層海水水價收費，每1,000加侖為0.074美元（每噸約0.66元新台幣）；(2)日本深層海水之開發規模較小，，管線內徑以小口徑設計方式為主，為提高取水管安全性，採用特殊設計之鋼線包覆HDPE管，以強化管線強度。深層海水原水收費部分，每噸售價從300～540日元不等，其中沖繩縣海洋深層水研究所對於原水利用做為原料加工方面，其售價為400日元/噸（約新台幣138元/噸），但利用於農業及水產養殖業方面，其售價只有6日元/噸（約新台幣2元/噸）；(3)深層海水利用於養殖產業之效益評估上，分成Ａ、Ｂ兩方案進行分析，Ａ方案以0.9公頃作為水產養殖多段利用規劃，魚類生產面積0.55公頃，推估其年產值約為6,650萬元，稅前效益約2,760萬元，日用水量約7,200噸。B方案以5.5公頃作為水產養殖多段利用規劃，魚類生產面積2.4公頃，推估其年產值約為4.11億元，稅前效益約1.85億元，日用水量約46,000噸。Ａ、Ｂ兩方案獲利的臨界水價各為10.5元/噸及11.0元/噸。若以美國NELHA之成本水價或日本提供給農漁產業的水價水準，利用深層海水發展養殖產業，可預期有極佳的獲利空間，值得政府大力推動。另從實際的市場需求、技術條件、生物特性等，並以結合深層海水之特性為思考觀點，研擬利用深層海水量產鮭魚之產業策略與短、中、長期發展目標，短期以國內市場需求每年3萬公噸為目標，以供應1~5公斤/尾之活魚或生鮮魚貨方式；中、長期則可以日本、中國大陸、東南亞各國為主要市場，每年需求以30萬～50萬公噸為生產目標。概估整個鮭魚產業內銷市場所能帶來的產業鍊經濟效益將達新台幣100億元，藉以提供政府輔導產業發展的一個思考方向，或有興趣之企業一個可能的投資參考。

Currently the utilization of deep ocean water (DOW or deep sea water/DSW) is receiving much attention due to its high added value with large quantity, high productivity and potential for recycling energy. Deep ocean water possesses three main characteristics: low temperature, cleanliness and nutrient richness. In eastern Taiwan, the steep coastal landforms make it a great potential to develop deep ocean water industry. In order to promote DOW related industry, Yilan County government in eastern Taiwan has established DOW Park in Nan'ao Township. Taking Danan’ao Deep Ocean Water Park as an example, this research has collected the utilization methods, draft, and the prices of deep ocean water of America’s NELHA and Japan, and had a preliminary calculation of benefit assessment for deep ocean water utilization in the Park. In addition, it has also briefly introduced the utilization conditions of deep ocean water extraction pipes of the United States, Japan, and Taiwan. Related contents have been summarized as below: (1) the pipe diameter of America’s deep ocean water extraction pipe is designed to be larger, whose costs are lower. The deep ocean water charges are 0.074 US dollars per 1,000 gallons (About 0.66 NT dollars per ton). (2) Japan’s deep ocean water exploitation scale is smaller. Due to the heavy weathers, the pipe diameter is mainly designed to be small caliber. In order to improve pipe safety, steel wires have been specially designed to cover the HDPE pipe to strengthen the intensity of the pipelines. Deep ocean raw water charges are 300-540 Yen per ton, in which Okinawa Prefecture Deep Ocean Water Research Institute charges 400 Yen per ton (about 138 NT dollars per ton) for raw material processing, but charges only 6 Yen per ton (about 2 NT dollars per ton) for agriculture and aquaculture. (3) The benefit assessment of deep ocean water utilization on aquaculture industry has been analyzed as Plan A and Plan B. Plan A has designed 0.9 hectare of the land for segmented utilization of aquaculture, the fish production area is 0.55 hectares, estimating the annual output value to be 66.5 million dollars, the benefit before tax to be 27.6 million dollars, and daily water consumption to be 7,200 tons. Plan B has designed 5.5 hectares of the land for segmented utilization of aquaculture, the fish production area is 2.4 hectares, estimating the annual output value to be 411 million dollars, the benefit before tax to be 185 million dollars, and daily water consumption to be 46,000 tons. The maximum water charges for making profits of Plan A and B are 10.5 dollars/ton and 11.0 dollars/ton respectively. If referring to the cost of water prices of America’s NELHA or the water price standards Japan provides for agriculture and fishery industry, abundant profits could be expected if utilizing deep ocean water on aquaculture industry, which is worth government’s vigorous promotion. Through commercializing the DOW resources and introducing non-governmental investment from the private sectors, the DOW Park aims to promote regional development and upgrade the related industries. In the present study, we investigated the potential market demands, technical conditions and its biological natures of developing salmon aquaculture at Nan'ao DOW Park. It aims to take advantage of the characteristics of DOW to propose industrial strategies on salmon aquaculture with DOW and establish the developmental goals at different times. Ingeneral, three stages i.e. short, medium and long-term stages will be analyzed respectively. In the short-term stage, the objective of harvested salmon is to achieve 30,000 mt yr-1 for the domestic market demands in the common size of 1 kg-5 kg fish-1. In the medium and long-term stages, the objectives are focusing on the markets in Japan, China and Southeast Asian countries, aiming to achieve the salmon harvest with 300,000 mt-500,000 mt year-1. The domestic market of the DOW salmon industry is estimated to reach approximately US$ 330 million (NT$ 10 billion) of linking industrial cluster and value chain. The study may also provide the government an innovative strategy and market orientation towards DOW industry guidance as well an investment consideration for enterprises having an interest in developing DOW related industry.