Jinshan Three Islands Marine Ecological Nature Reserve

Jinshan Three Islands Marine Ecological Nature Reserve

The Shanghai Jinshan Three Islands Marine Ecological Nature Reserve (referred to as the Jinshan Three Islands) is the first nature reserve under the jurisdiction of Shanghai. It was established on June 5, 1993. The reserve is located on the northern shore of Hangzhou Bay, within Jinshan District, Shanghai, approximately 6.6 kilometers from Jinshanzui Coast. It consists of a core area (Da Jinshan Island) and a buffer zone (Xiao Jinshan Island, Fu Shan Island, and the adjacent 1 km of sea area). The reserve boasts an excellent natural environment, diverse biological species, and well-preserved natural vegetation. It is the area with the richest wild plant resources and the cleanest environmental quality in Shanghai, making it an important environmental reference point for the city and of high conservation value. The main conservation targets include typical mid-subtropical natural vegetation types, evergreen and deciduous broad-leaved mixed forests, insects and soil organisms, rare wild plant species, and near-shore oysters.

Da Jinshan Island is located at the northern entrance of Hangzhou Bay, 6.2 kilometers from the mainland’s Jinshanzui. The island has a roughly diamond-shaped planar form, wider in the middle and narrower in the west. It is 963 meters long at its longest, 437 meters wide at its broadest, with a coastline of 2,390 meters and an area of 0.229 square kilometers. Its main peak rises 103.4 meters above sea level, making it the highest and largest bedrock island in Shanghai. The island, along with Xiao Jinshan Island and Fu Shan Island, were once hilltops on land before becoming isolated due to rising sea levels and coastal erosion. Before the Five Dynasties period, it was called “Zhao Mountain,” and after the Jin Dynasty, it became known as “Jinshan.” The island’s rock composition is mainly acidic quartz porphyry, interbedded with rhyolite, volcanic breccia, and dacite. Wave erosion has created landforms such as sea cliffs, wave-cut platforms, and sea stacks. On the southwestern side of the island lies a gravel beach that is 750 meters long and 50–60 meters wide. There are two wells on the island, each about 10–20 square meters in area and 4.5 meters deep. Additionally, within mountain tunnels, there are two springs with relatively high sulfur and iron content, resulting in acidic water. Historically, the area between Da Jinshan and Xiao Jinshan Islands was known as “Jinshan Gate,” which leads to the Jinshan Gate Channel. This channel has a deep trough about 25 kilometers long, roughly 3 kilometers wide at its broadest, with a maximum depth of around 50 meters. The seabed around Da Jinshan Island is primarily composed of muddy silt, with patches of silt and fine sand in some areas, and exposed ancient marine clay in heavily eroded regions.

The soil type on Da Jinshan Island is brown mountainous yellow earth. The island’s vegetation belongs to the mid-subtropical zonal vegetation and remains minimally affected by humans, preserving its primitive state. The vegetation is lush, including deciduous broad-leaved forests such as Mallotus japonicus, Dalbergia hupeana, and Glochidion communities; evergreen broad-leaved forests such as Machilus thunbergii and Cyclobalanopsis glauca communities. There are also bamboo groves, such as Indosasa shibataeoides communities. The island hosts shrubs, herbaceous plants, and ferns. Owing to its distance from the mainland and minimal human impact, it largely retains its pristine condition and is the largest island in the “Jinshan Three Islands Marine Ecological Nature Reserve.” In the past, the island had military personnel stationed there, but currently, there are no permanent residents, although temporary caretakers may stay occasionally due to the presence of captive macaques.

Xiao Jinshan Island is located at the northern entrance of Hangzhou Bay, 4.1 kilometers from the mainland’s Jinshanzui. The island has a flat terrain, stretching from northwest to southeast, and is 450 meters long at its longest, 247 meters wide at its broadest, with a main peak of 32.5 meters, a coastline of 1,010 meters, and an area of 0.036 square kilometers. It is part of the “Jinshan Three Islands Marine Ecological Nature Reserve.”

Fu Shan Island is situated on the northern edge of Hangzhou Bay, 630 meters south of Da Jinshan Island. The island has an oval outline with a rounded, peak-less mountain body, resembling a turtle—hence its common name “Turtle Mountain.” In ancient times, it was also called “Wangpan Mountain.” Fu Shan Island is about 290 meters long, 183 meters wide at its broadest, with an area of 0.031 square kilometers and a coastline of 1,260 meters. Its main peak rises 30.8 meters. The island is a bedrock island composed of intermediate-acidic volcanic rocks and red clastic rocks, mainly quartz porphyry, volcanic breccia, and dacite. Due to strong erosion from waves and wind, the mountain is heavily weathered with bare rocks. There are no tall trees or shrubs on the island, only thorny acacia and weeds growing in rock crevices, along with a small number of low-level plants such as ferns, mosses, and lichens. Fu Shan Island is also part of the “Jinshan Three Islands Marine Ecological Nature Reserve.” The island has no water sources and no permanent inhabitants.