Ancient Coast and Wetlands National Nature Reserve

　　The Tianjin Ancient Coast and Wetlands National Nature Reserve, approved by the State Council in October 1992, is China’s only national marine nature reserve mainly focused on the protection and management of rare ancient coastal relics such as shell ridges, oyster reefs, wetland natural environments, and their ecosystems. Within the reserve, three different types of geological formations coexist within a single administrative region—an extremely rare phenomenon both domestically and internationally.

　　The reserve is located on the western coast of the Bohai Bay, in the eastern part of the Tianjin area. It is a discontinuous, open-type reserve characterized by the coexistence of various geological formations. Its coverage spans parts of six districts and counties in Tianjin: Dagang, Jinnan, Dongli, Tanggu, Hangu, and Ninghe, with a total area of approximately 99,000 hectares (990 square kilometers), about one-tenth of Tianjin’s total land area.

　　At the eastern end of the reserve, there are four shell ridges. Together with the shell ridges of Louisiana in the United States and Suriname in South America, they are renowned in the geological community as the world’s three most famous shell ridges. These four shell ridges were formed by the transportation, accumulation, and wave-built deposition of shells from the nearby seabed by tides and sea waves. Their orientation generally parallels the current coastline. The total span of the four shell ridges is approximately 36 kilometers, with a maximum distance of about 18 kilometers between adjacent ridges, extending over a north-south distance of around 60 kilometers. From west to east (i.e., from inland to sea), they are named the Ⅳth, Ⅲrd, Ⅱnd, and Ⅰst shell ridges, respectively. The higher the sequence number, the earlier the formation period. The Ⅰst shell ridge starts from Chengtougou in Hangu District, Tianjin, passes through the Tianjin Development Zone, Lüjühe, Gaoshaling, Baishuitou, and extends to Mapengkou in Dagang District, dating back approximately 700–500 years. The Ⅱnd shell ridge begins at Baishaling in Dongli District, extends southward through Dengcenzi and the Third Branch Farm of Banqiao Farm in Jinnan District, reaching Shanggulin in Dagang District, and is about 2,500 years old. The Ⅲrd shell ridge starts from Huangcaotuo in Dongli District, runs southward via Cuijiamatou, Juguezhuang, Zhongtang, and up to Xueweitai, dating back around 4,000 years. The Ⅳth shell ridge extends from north to south across Tianjinzhenjing, Dasuzhuang, Shuyuanzi in Dagang District, and reaches into Hebei Province, approximately 5,000 years old. The ages of these shell ridges mark the approximate locations of the ancient coastline on the western shore of Bohai Bay and serve as important evidence and precious relics of ancient coastal and sea-land changes—a true record of the shifting landscape.

　　Oyster reefs are another geological relic in the reserve, formed in the area north of the Haihe River in the Tianjin coastal plain, particularly in the lower reaches of the Chaobai River and Ji Canal within Ninghe County and Baodi County. Their distribution is concentrated in the southern part of Baodi, central and eastern Ninghe, with the most typical section being the core oyster reef area in Kalukou Village, Ninghe County. Oyster reefs are natural accumulations of dead and live oysters, mostly forming in subtidal, brackish lagoon and estuarine environments, dating back 7,000–3,000 years. The reefs consist of Crassostrea gigas and Crassostrea rivularis, with distinct stratified profiles. The thickest layers can reach up to 5 meters, an extremely rare occurrence in the marginal coastal plains of the Western Pacific. The scale of Tianjin’s oyster reefs is comparable only to those in the Pathumtani area north of Bangkok, Thailand, and the Atchafalaya Bay and Point Au Fer Island oyster reefs in Louisiana, USA. However, no other oyster reef layers as thick as the 5-meter deposits in Tianjin have been discovered to date. The burial process of the oyster reef sediments also reflects the region’s history of sea-land transformation. Like the shell ridges, the oyster reefs are unique ancient coastal relics of Tianjin’s nature reserve.

　　Qilihai Wetland is a treasured part of Tianjin’s nature reserves. Located in the western part of Ninghe County, about 15 kilometers from the Bohai Sea, it evolved gradually from an ancient bay about 7,000 years ago, forming an ancient lagoon-type wetland covering approximately 890 square kilometers. Qilihai Wetland is distinctive—it is the largest wetland with ancient coastal features in northern China. It boasts extremely high levels of negative oxygen ions, dozens to hundreds of times greater than those in urban city centers, earning it the reputation of being the “green lung” of Beijing and Tianjin. It has been listed in the National Key Wetlands Directory. With vast waters, fresh air, and abundant flora and fauna, the wetland provides an ideal habitat and breeding ground for many rare and endangered wildlife species. Especially in summer, when vegetation thrives and landscapes are lush, various birds inhabit and breed here. Some rare migratory birds also favor this spot for resting during their journeys. Qilihai Wetland is not only a prime example of biodiversity and harmonious coexistence between humans and nature, but it also serves multiple ecological functions such as flood discharge, flood detention, drought and waterlogging resistance, microclimate regulation, sedimentation and detoxification, water retention, nutrient preservation, biomass output, and water storage—all contributing to the improvement of Tianjin’s natural and ecological environment and that of its surrounding areas.

　　Thanks to the regulatory role of the wetland, the natural environment within the reserve has improved, providing favorable living conditions for the flora and fauna. According to incomplete statistics, the reserve is home to more than 180 bird species, including over 10 classified as national first-class protected species, 6 listed as endangered in the IUCN Red List, and 5 included in the Asia-Pacific Migratory Waterbird Conservation Strategy. Other wildlife includes 6 reptile species, 4 amphibian species, 8 crustacean species, 2 annelid species, 13 mammal species across 5 orders and 6 families, 28 mollusk species in 2 classes and 19 families, 50 fish species across 7 orders and 9 families, and 164 insect species in 155 genera under 56 families across 10 orders. Additionally, there are 165 plant species from 114 genera across 44 families.

　　The protected objects of the reserve—the rare ancient coastal relics such as shell ridges and oyster reefs, the natural environment of the wetlands, and their ecosystems—form an extraordinarily precious "natural museum." They represent key products and relics from the Holocene epoch around 10,000 years ago, when the western line of Bohai Bay evolved from sea to land. They reflect the process of sea-land transformation in the Tianjin coastal plain due to climate change over the past ten thousand years. The Tianjin Ancient Coast and Wetlands National Nature Reserve holds significant scientific value not only for the study of ancient geography, paleoclimate, marine ecology, and sea-land changes, serving as a base for research, teaching, and scientific studies, but also as an irreplaceable, non-renewable treasure.

　　Filming location for "Red Flag Chronicles." Features 8 courtyards and 40 rooms. Earthen kang beds, courtyards, and paths authentically showcase the rural charm of the past.

　　Best travel time: March to November each year