Keelung's Chaojing Fan Zai Ao: Where Marine Protection and Citizen Science Meet

The Fan Zai Ao Chaojing Bay Marine Resource Conservation Area sits on the boundary between Keelung City and New Taipei City, along the eastern side of the Badouzi Peninsula. Facing the sea is a rocky-reef bay teeming with fishery resources, while the inland area was once an important coal-mining hub during the Qing dynasty. Today, the National Museum of Marine Science and Technology occupies the central portion of Badouzi, and Chaojing has been designated a fishery resource conservation area (no-fishing zone), making it a model marine protected area (MPA) for northern Taiwan.

Chaojing is located on the Badouzi Peninsula. The origin of the name "Badouzi" remains a matter of debate, but according to the prevailing account, the area was once the settlement "Pataw" of the Basay people, an indigenous Ping-pu group. In the Basay language, "Pataw" means witch or hot spring — a metaphor for the hazy, fog-laden days brought by the winter northeast monsoon — which was later transliterated into Taiwanese Hokkien as "Badouzi."

As the name "Chaojing" (潮境, "tidal boundary") suggests, the North Coast straddling Keelung and New Taipei is also a zone where warm and cold water masses converge. Shaped by the monsoon climate and ocean currents, the composition of marine life and the underwater environment of the bay change dramatically with the seasons.

Chaojing is one of the few well-functioning marine protected areas (MPAs) in Taiwan. The Keelung City Government has established a local community enforcement mechanism, and hopes that the community will maintain its efforts over the long term. Combined with marine conservation education and outreach from the nearby National Museum of Marine Science and Technology, future generations of students can come to appreciate the beauty of Chaojing and understand the importance of designating MPAs. The site also supports marine biological surveys, long-term monitoring, and database development. Moreover, well-structured standard survey protocols — such as reef check assessments — now include the participation of citizen scientists. These efforts not only help sustain local fishery resources but also protect tourism assets (snorkeling, scuba diving, and more).

The Ecological Diversity of Chaojing

The Fan Zai Ao Chaojing Bay Marine Resource Conservation Area is one of Taiwan's classic rocky-reef environments, dotted with extraordinary rock formations sculpted by marine erosion. Within the rocky-reef ecosystem, distinct biological zones can be identified, including the supralittoral zone, the high, mid, and low intertidal zones, and the subtidal zone.

The supralittoral zone at Chaojing consists of rocky shores above the high-tide line and stands in stark contrast to the intertidal zone — this area is generally a harsh, dry environment. Nevertheless, the zone features depressions carved by sea wind and burrowing organisms, along with scattered pools formed by breaking waves that give animals a place to cool down and drink. When water is scarce for cooling, most creatures seek shelter in shaded spots.

The intertidal zone is the area influenced by tidal fluctuation. The most distinctive feature of the rocky-reef intertidal zone at places like Chaojing — compared with other ecosystem types — is its near-vertical zonation: on a single rock face, you can read off the positions of the high, mid, and low intertidal bands simply by observing which organisms live there. The high intertidal zone, reached only by spring tides, is home to desiccation-tolerant species such as sea slaters and periwinkles. The mid intertidal zone hosts barnacles, oysters, and other organisms that can survive out of water as long as they remain moist. Species of the low intertidal zone — such as nudibranchs — require more prolonged submersion than those of the upper two bands.

Chaojing's Secret Garden: A Thriving Ecosystem That Draws Divers from Across Taiwan

Below the subtidal zone lies the deeper subtidal realm, accessible only with scuba gear and the primary draw for visiting divers. Currents here are somewhat less intense than in the intertidal zone, yet surges and swells still make their presence felt. Combined with turbid water and low temperatures — generally below 20°C in winter — conditions make it difficult for reef-building hard corals to develop significant structures. Every cloud has a silver lining, however: the very same challenging environment, enriched with nutrients, actually benefits soft coral growth. Soft corals, with their flexible body structures, can adapt to strong currents, and they thrive here, forming distinctive soft coral communities.

Divers are consistently treated to breathtaking sights, and word has spread: Chaojing Park has earned the reputation of the "Northern Taiwan Underwater Secret Garden." Beyond its exceptional soft coral forests, the predominant substrate in the subtidal zone consists mainly of rock and hard coral, with smaller patches of sponge and sand. The maximum depth of the Chaojing Bay subtidal zone is approximately 25 metres.

Although Chaojing is a straightforward rocky-reef environment, the unique combination of weather and oceanographic conditions has created distinctive habitats that support a wide range of organisms — and those organisms, in turn, shape the very microhabitats they inhabit.

An Underwater Photography Paradise

Chaojing is a playground for underwater photographers. When conditions allow, the Northeast Coast offers the visibility needed for wide-angle compositions that capture the grand sweep of the seascape. Based on experience, the best diving season — marked by good visibility — runs from May each year through until the first typhoon makes landfall in Taiwan. Master the day's tidal currents and you can come away with stunning wide-angle shots. Subjects to target include tiger-patterned cuttlefish mating in March, glassfish storms in summer, and the apex predators drawn in by those baitballs — including greater amberjack and barracuda tornadoes.

Poor visibility? No problem. At Chaojing you can reach for a macro lens and search the reef for the diverse small creatures hiding within. Here you have the chance to photograph rare species such as the pineconefish, Kuda seahorse, and "Pikachu" nudibranch. These tiny residents require a patient and careful eye to find — consider hiring a professional macro eco-dive guide to help track them down.

How Marine Protected Areas Can Integrate Ocean Citizen Science and Ecotourism: A Crucial Question for Taiwan's Marine Future

Chaojing is one of the few well-functioning marine protected areas (MPAs) in Taiwan. Since the protected area was designated, the Keelung City Government has enforced regulations strictly and works together with the Keelung City Fishermen's Association, the Coast Guard Administration, and the National Museum of Marine Science and Technology to shoulder responsibilities across different dimensions of MPA management. The site also supports marine biological surveys, long-term monitoring, and database development to deepen understanding of this bay. Well-structured standard survey protocols — such as reef check assessments — now include the participation of citizen scientists. These efforts not only help sustain local fishery resources but also protect tourism assets (snorkeling, scuba diving, and more), thereby driving local industry transformation.

Chaojing may well have become a guiding light for the establishment of marine protected areas in Taiwan — particularly for no-fishing zones along the main island and surrounding outlying islands, all of which can look to Chaojing as a reference model.

Cover image source: Nick Zhan

Further reading:

• Fan Zai Ao Chaojing Bay Marine Resource Conservation Area – Ocean Conservation Administration Introduction
• 『潛進台灣』The Cradle of Taiwan Marine Conservation – Fan Zai Ao Bay Conservation Area
• 【Taiwan Dive Sites】Chaojing Fan Zai Ao Bay – Hai Jian Hao