以空間規劃模式分析台灣北部沿岸劃設海洋保護區之建議

Abstract

台灣北部海岸(含新北市及基隆市)總長約158公里，緊鄰人口密度最高的大台北都會區。近岸海域擁有豐富的資源，生態也承受極大的壓力，包括漁業、海岸開發、觀光遊憩、社區活動等。本論文首先綜合整理新北、基隆二市海岸的保育狀態、資源開發與利用現況，再針對其衍生的問題進行分析，規劃應優先劃設為海洋保護區的區域。 首先將北部海岸自高潮帶起向外延伸約3海浬的範圍，每一平方公里劃設為一網格，合計657格，其中含海岸類176格與水域類481格。海岸類網格依照沿岸生態與地理條件，蒐集其生物相資料（底棲生物歧異度、特殊珍貴棲地、珊瑚覆蓋率等）及社會經濟資料（觀光人數、人口密度、港口開發、人工海岸等），並使用海岸區域的各種棲地當作代理因子（surrogates），替代某些缺乏生物資料的區段。水域部分，以政府歷年來投放之人工漁礁做為基礎，參考文獻為各人工漁礁進行評分，並佐以該位置經濟魚類分布及各種漁業捕撈範圍進行分析。其次，利用電腦軟體（ArcGIS 10.0及MARXAN）以網格型式來描繪出北部海岸的保育地圖。依據訂定的保育目標及邊界長度修正項（Boundary Layer Modifier, BLM），即可從中挑選出優先區位。 海岸帶的176格，在BLM=0、0.02與1等情境下，分別劃設出20%面積做為保育目標的地圖，其中以BLM=0.02時可得到較符合實際需求的保育規劃。水域部分，在BLM=0、0.0002與1的情境下，劃設20%面積做為保育目標的地圖，也以BLM=0.002時可得到較符合實際需求的保育規劃。最後，我們將海岸帶與水域兩項規劃最佳的結果合併成一個總域地圖，首先是以 Scenario 2做為基準，向海域部分劃設保護區，再分別以BLM=0、0.002與1計算其所得結果，獲知後兩項的結果皆顯示鹽寮至三貂角沿岸，往北延伸至鼻頭角的水域，為最佳的海域保護區選址，此結果可供決策者規劃保育區時做為參考。

The coastline of Northern Taiwan is about 158 km (including 140 km in New Taipei City and 18 km in Keelung City) and the coastal area is intensively impacted by anthropogenic activities from metropolitan Taipei. This study is aimed to develop the most suitable design of marine protected areas by applying MARXAN to evaluate the biological, environmental, and socio-economic factors. The area from the high-tide zone to about 3 nautical miles offshore was divided into grid cells (each 1 km x 1 km) and a total of 657 cells including 176 cells of the Coast category and 481 cells of the Sea categories. In the Coast category, biological and ecological data (including benthic biodiversity, special habitats, coral coverage, etc.) and socio-economic data (tourists, local population, ports, artificial coast, etc.) of each cell was collected. For some cells lack of available data, a “surrogate” was applied as the conservation objectives of the category. In the Sea category, the results of evaluation studies of artificial reefs were used as the basis, together the data of commercial fisheries. Then, we used computer softwares (ArcGIS 10.0 and MARXAN) to evaluate the grid cells and to depict the coastal conservation map. Under MARXAN operation, each grid is given a relative cost of conservation and the plan is to achieve the maximum conservation objectives by minimum cost. Based on the conservation objectives and the length of the boundary correction term (Boundary Layer Modifier, BLM), the “priority sites” for conservation will be generated. The 176 grid cells of Coast category were evaluated with different scenarios (BLM = 0, 0.02, and 1) and 20% of the area as the conservation goal. The best result was reached under BLM=0.02. In the Sea category, three scenarios (BLM = 0, 0.0002, and 1) and 20% of the area as the conservation goals were applied for evaluation and the best result was reached when BLM=0.0002). Then, all the grid cells of the two categories were combined to generate conservation maps under different scenarios (BLM = 0, 0.0002, and 1). The results showed that the sea area from Bitoujiao（鼻頭角） to Yenliao（鹽寮） to Sandiaojiao（三貂角）, was the best site for marine conservation.