漁電共生之堤岸型文蛤養殖評估:成長、水質及場域建模

Abstract

隨著全球能源轉型及土地利用衝突日益加劇，臺灣西部沿海地區逐漸成為太陽能光電發展的重點區域。為兼顧再生能源推廣與漁業生計需求，本研究提出「堤岸廊道型漁電共生」模式，透過將光電設施設置於魚塭岸邊，避免大面積遮蔽水體，降低對水質環境與養殖生物之干擾。此模式可確保約85%以上水域每日維持8小時以上直射日照，並藉適度遮蔭緩解夏季高溫壓力、降低水分蒸發及藻華風險，為土地資源有限地區提供一種兼顧能源生產與漁業經濟的可行策略。 本研究於2024年3月至11月在臺南市北門地區進行田間試驗，設置實驗組與對照組，並採用80萬及90萬顆 ha⁻¹兩種放養密度。透過SketchUp與SunHours模擬不同節氣的日照條件，並以Hydrolab設備監測水溫、pH、鹽度、溶氧與氧化還原電位等水質指標。養殖期間每兩個月隨機採樣，量測文蛤殼長、殼寬、殼高與全重，進而計算Fulton體況指數（K值）、緊實指數（CI）與延展指數（EI），以評估生長表現。最終根據收成數據計算存活率與產量，以綜合分析各處理組別之養殖成效。 結果顯示，實驗組於夏季降低水溫約0.8–1.4 °C，進而有效減緩季節性水質波動，並在乾季期間有效抑制鹽度上升。在文蛤成長方面，放養密度為90萬的實驗組於盛夏期間，K值達40.8，顯著優於對照組，顯示適度遮蔭可緩解熱緊迫所導致之生長壓力；CI表現則呈現季節性補償變化，EI則全期維持在0.83–0.88範圍，顯示殼型未受顯著影響。存活率和產量方面，放養密度為90萬顆ha⁻¹組別中，實驗組存活率為79%，總產量為10,800公斤；對照組存活率則為42%，總產量為12,600公斤，顯示遮蔭處理有助於提升文蛤之存活與生長表現。相較之下，在放養密度為80萬顆ha⁻¹的組別中，實驗組存活率為63%，總產量為4,200 公斤；對照組存活率則為83%，總產量為5,400公斤。 整體而言，「堤岸廊道型漁電共生」模式在不影響產量和成長的前提下，可同時提升土地資源利用效率與能源收益，對臺灣沿海地區之高密度文蛤養殖具有良好的應用潛力及示範價值。

With the growing demand for energy transition and increasing land-use conflicts, Taiwan's western coastal areas have become a major zone for solar power development. To balance renewable energy promotion with the needs of the aquaculture industry, this study proposes an “Embanked Solar PV Symbiosis for Clam” model. By installing solar panels along the pond banks, this design avoids large-scale shading of the water surface, thereby reducing potential impacts on water quality and aquatic organisms. The model ensures that over 85% of the water area receives more than 8 hours of direct sunlight daily, while the partial shading helps mitigate summer heat stress, reduce water evaporation, and lower algal bloom risk. This offers a feasible strategy for regions with limited land resources to achieve both energy production and aquaculture development. Field experiments were conducted in Beimen District, Tainan, from March to November 2024. The study included an experimental group and a control group, each tested under two stocking densities: 800,000 and 900,000 clams per hectare. Solar exposure simulations for seasonal solstices and equinoxes were conducted using SketchUp and SunHours. Water quality parameters including temperature, pH, salinity, dissolved oxygen (DO), and oxidation reduction potential (ORP) were monitored using Hydrolab equipment. Every two months, random samples were collected to measure shell length, width, height, and total weight. Fulton’s condition index (K), compactness index (CI), and elongation index (EI) were calculated to assess growth performance. At harvest, survival rate and yield were also calculated to evaluate the effectiveness of each treatment. Results showed that, in the summer, shading reduced water temperature by approximately 0.8–1.4 °C and stabilized seasonal water quality. During the dry season, salinity increase was effectively suppressed. Under 900,000 clams/ha stocking, the experimental group had a peak K-value of 40.8 during summer, significantly higher than the control, indicating reduced heat stress. CI showed seasonal compensation, while EI remained stable between 0.83 and 0.88, suggesting shell shape was not affected. In terms of survival rate and yield, in the group with a stocking density of 900,000 clams/ha, the experimental group had a survival rate of 79% and a total yield of 10,800 kg, while the control group had a survival rate of 42% and a total yield of 12,600 kg, indicating that shading treatment helps improve the survival and growth performance of clams. In contrast, in the group with a stocking density of 800,000 clams/ha, the experimental group had a survival rate of 63% and a total yield of 4,200 kg, while the control group had a survival rate of 83% and a total yield of 5,400 kg. Overall, the “Embanked Solar PV Symbiosis for Clam” model demonstrated its potential to enhance land-use efficiency and energy benefits without compromising aquaculture performance. It shows strong promise for application in Taiwan’s coastal high-density clam farming areas.