BlueTrend says: Establishing marine protected areas (MPAs) is widely recognized around the world as the simplest and most effective way to advance marine conservation, safeguard biodiversity, and restore fishery resources. At the same time, many experts and scholars have continually stressed that sound management and governance are the real keys to making a protected area work.
Taiwan currently has 46 marine protected areas. Among them, the Wanghaigou Bay Chaojing Resource Conservation Area (hereafter "Chaojing") and the Ruifang Aquatic Flora and Fauna Breeding Conservation Area (hereafter "Shen'ao") are both classified as Level 3 conservation zones — yet the two differ enormously in their management measures and enforcement intensity. In addition to a blanket ban on fishing throughout the entire area, Chaojing also has a patrol team and conservation volunteers involved in its upkeep, and enforcement is rigorous.
Underwater quantitative surveys follow strict protocols; before every dive, the methodology must be reviewed and explained again to minimize sampling error.
Shen'ao, by contrast, has no designated no-fishing zone and lacks both a patrol team and conservation volunteers, making effective enforcement impossible. To compare the ecological differences between the two sites, a research team conducted ecological surveys in 2022. The results showed that while the two areas share a highly similar species composition, Chaojing far outperforms Shen'ao in hard coral cover, fish diversity, individual abundance, and biomass — demonstrating that effective management is the true key to a successful marine protected area.
The research team prepares to carry out survey operations in the Wanghaigou Bay Chaojing Resource Conservation Area.
How Did the Research Team Do It?
To understand the differences in biological communities between the two protected areas, the Editor and the research team established two sampling stations at depths of 5 m and 10 m in each area. At each station, three 30 m × 2 m belt transects were laid out, and surveys were conducted covering three major categories: seafloor substrate, invertebrates, and fish.
To record the seafloor substrate in detail, the research team custom-fabricated 50 × 50 cm stainless steel frames. Underwater, the frames were placed along each transect at 5 m intervals to photograph the substrate; the frame was subdivided into 25 smaller cells to record substrate type and proportion. For the invertebrate and fish surveys, the team used underwater visual census and photographic documentation to record species, individual counts, and fish body lengths.
The custom-fabricated 50 × 50 cm stainless steel frames were placed along each transect at 5 m intervals to photograph the substrate.
In addition to daytime surveys (quantitative surveys), the team also arranged night diving surveys (qualitative surveys) to obtain a more complete picture of local biodiversity. From June to September 2022, the team conducted a total of 16 dives over 8 days — both day and night — at Chaojing and Shen'ao.
Night survey at the Chaojing conservation area — the twinkling lights across the water belong to the famous Jiufen Old Street.
What Did the Substrate Survey Find?
Following Reef Check standards, substrate types were classified into ten categories: hard coral, soft coral, dead coral, macroalgae, sponge, rubble, sand, rock, mud, and other.
After comparing the substrates at Chaojing and Shen'ao, the Editor found that the coral communities at both sites are very similar, dominated by Merulinidae and Lobophylliidae, followed by foliose and branching corals. The foliose corals are primarily Montipora sp., Astreopora sp., and Pachyseris sp., while the branching corals are mainly Acropora sp. and Stylophora sp. In addition, some rocky reefs in both areas are heavily encrusted with the zoanthid Palythoa tuberculosa, forming distinctive microhabitats.
A closer look at hard coral cover reveals that at Chaojing, coverage at 5 m depth ranges from 30–43%, while at 10 m depth it ranges from 27–29%, for an overall average of 32% — placing it in the "Fair" category by international coral health assessment standards. Compared with surveys conducted in 2018–2019, Chaojing's cover at 5 m showed little change, while hard coral cover at 10 m increased from 20% to 27–29%.
In contrast, Shen'ao showed hard coral cover of only 5–11% at 5 m depth and 12–16% at 10 m depth, with an overall average of 11% — rated "Poor."
Moreover, compared with the 2018–2019 surveys, hard coral cover at both depths in Shen'ao had declined (from 16% and 22%, respectively).
Beyond coral, the dominant algae at both sites are largely the same: Zonaria diesingiana, Pterocladiella capillacea, Eucheuma serra, and filamentous cyanobacteria.
What Did the Invertebrate Survey Find?
Invertebrate diversity is vast, so the research team selected several indicator species with specific ecological functions known to maintain the stability of coral reef ecosystems.
Survey results showed that indicator invertebrate counts were low at both sites, largely because many invertebrates are nocturnal and therefore difficult to detect during the daytime surveys specified by the project plan. Future surveys could adjust methodology to capture more precise records. Overall, Shen'ao had a higher number of indicator invertebrate individuals per unit area; however, in terms of species richness, Chaojing recorded more invertebrate species than Shen'ao at the 10 m depth during the summer season.
What Did the Fish Survey Find?
The research team recorded a total of 150 fish species across both sites — 139 at Chaojing and 66 at Shen'ao. The dominant species shared by both areas are the Neon damselfish (Pomacentrus coelestis), the Stegastes obreptus, the Pearl-spot chromis (Chromis notata), and the Pinkeared wrasse (Halichoeres melanochir). The top six dominant fish species at 5 m depth in both areas are the Neon damselfish, Stegastes obreptus, Pinkeared wrasse, Stethojulis terina, Pearl-spot chromis, and Moon wrasse (Thalassoma lunare). At 10 m depth, the top six are the Neon damselfish, Pearl-spot chromis, Smoky chromis (Chromis fumea), Pinkeared wrasse, Moon wrasse, and Grey chromis (Chromis cinerascens). Although the dominant species show similarities between the two sites, after analyzing fish species composition and abundance, the research team found clear differences between the two areas across both locations and depths.
In terms of species richness, each transect at Chaojing recorded 30–42 fish species, while Shen'ao recorded only 9–17.
In terms of abundance, Chaojing had 6–21 fish per unit area, while Shen'ao had only 5–7; fish density in some sections of Chaojing was more than twice that of Shen'ao.
In terms of biomass, Chaojing also recorded significantly more large fish with body lengths exceeding 30 cm — such as Grouper, sweetlips (Haemulidae), and moray eel (Gymnothorax spp.) — with biomass at Chaojing reaching as high as 5–9 times that of Shen'ao (Figure 38). In short, Chaojing has more fish species, more individual fish, and more large fish.
Sunlight streaming down through a dense school of fish — like a living painting. Photo credit: Jian Chenyu
A further comparison of the ecological functions of fish species reveals that Chaojing hosts more herbivorous fish capable of removing algae — such as surgeonfish and parrotfish — which help clear algae from coral reef surfaces. Chaojing also harbors more large predators, including snappers, sweetlips, Grouper, and moray eels; large individuals with body lengths exceeding 30 cm are frequently recorded at 10 m depth, indicating a resource-rich and ecologically stable environment. Butterflyfish, which are good indicators of coral reef health, were most abundant at Chaojing's 10 m depth, with 9 species recorded there — and in greater numbers than in the Shen'ao area.
The Research Team's Conclusions
The survey results show that although Chaojing and Shen'ao are geographically adjacent and share highly similar species compositions and dominant fish species, Chaojing significantly outperforms Shen'ao in every measured parameter — coral growth, fish diversity, abundance, and biomass. This clearly demonstrates that effective management is one of the most critical factors in determining the success of a marine protected area.
Gymnura japonica, the Japanese butterfly ray, was recorded at Chaojing for the first time through a citizen science program. Photo credit: Jian Chenyu
The Wanghaigou Bay Chaojing Resource Conservation Area was established in 2016. The remarkable underwater ecosystem it has restored and the success it has achieved as a marine protected area in just six years are the result of the participation and hard work of various agencies, local residents, and visitors. As its reputation grows, however, so do the recreational pressures and challenges it faces. For the sake of Chaojing's sustainable future, we recommend implementing a comprehensive zoning management system within the protected area to guide visitors to appropriate zones for different ocean-related activities. This would not only reduce damage to the marine environment but also better fulfill the purpose for which the protected area was established.
References:
- Marine "quasi-protected areas" can be more effective than marine protected areas with poor management!
- Marine Protected Area Management Effectiveness Assessment and Guidance Program
- Taiwan Marine Protected Areas
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