Chaojing Marine Reserve Ecological Survey Released! Biomass 5–27x Greater Inside the Reserve Than Outside

For the full results video, see below:

An unidentified deep-sea crab spotted at Chaojing — what other new discoveries did the reserve's ecological survey turn up? The Keelung City Government's Bureau of Industrial Development hosted a results exhibition on the 3rd floor of the East Side Mall, giving the public a closer look at the Chaojing Marine Reserve. The event not only shared key findings from this year's ecological survey, but also showcased the achievements of the marine citizen science training programme.

Chaojing Marine Reserve Survey Results

The Keelung City Wanghaihang Chaojing Bay Marine Resource Conservation Area (hereafter "Chaojing Marine Reserve") has been in operation for over seven years — and the survey confirms that conservation efforts are paying off. The number of fish species has grown compared to last year (2022), and a comparison of biodiversity inside and outside the reserve shows that the area within the reserve supports more species, with biomass 5–27 times greater than outside.

Keelung City Bureau of Industrial Development Director Lin Ding-Chao noted that the Keelung City Government has supported the "Marine Citizen Science Programme" for two consecutive years. This year (2023), 95 marine citizen scientists were trained, successfully contributing over 1,200 valuable photographs of the Chaojing Marine Reserve. The city government also hopes to establish systematic ecological survey data through regular annual surveys, providing a basis for marine conservation policy. In addition, Keelung City plans to replicate this research model across other waters around Keelung, gradually uncovering the ecological profile of the surrounding sea.

Rigorous quantitative surveys of the Chaojing Marine Reserve have been carried out for two consecutive years with the assistance of the BlueTrend team, accumulating systematic data. This year, a total of 165 fish species across 42 families were recorded inside and outside the reserve combined. Within the reserve alone, 151 species were documented — up from 139 last year — reflecting rich biodiversity.

The survey found that individual biomass within the Chaojing Marine Reserve has increased, with many large fish exceeding 40 cm in body length recorded, including Grouper, parrotfish, ringtail surgeonfish, moray eel, and sweetlips. Biomass per unit area within the reserve is 5–27 times greater than outside.

Additionally, algal coverage within the Chaojing Marine Reserve is lower while coral coverage is better. This is likely due to a greater abundance of herbivorous fish — such as parrotfish and surgeonfish — inside the reserve, which helps suppress excessive algal growth and creates space for coral and other reef-building organisms to thrive.

The survey also found that, both inside and outside the reserve, the number of individual fish per unit area has decreased compared to last year. Referencing biological database records, summer water temperatures this year were 0.5–1°C lower than in previous years, suggesting that cooler water may have suppressed fish growth and reproduction, leading to a decline in individual numbers. The team will continue to monitor whether other factors — such as excessive human activity — are affecting population levels, and will make rolling adjustments as needed.

These findings demonstrate that the database not only provides biological information, but that the accumulating volume of photographic data also helps objectively document environmental change. Long-term monitoring of various marine environmental indicators — including continuous updates to baseline environmental data and the biodiversity database — serves as a critical basis for evaluating the effectiveness of marine conservation measures and adjusting conservation strategies.

A Previously Unstudied "Deep-Sea Crab" Discovered at Chaojing

Through the lenses of marine citizen scientists, a previously unstudied "deep-sea crab" was recorded inside the Chaojing Marine Reserve this year. The crab clips pieces of coral onto its body as camouflage. Scholars and experts are still searching for related information to assist with identification. The discovery not only adds a layer of mystery to the Chaojing Marine Reserve, but also highlights the limitless potential of marine citizen scientists.

Keelung Chaojing Marine Citizen Scientist Training Programme

This year's programme was expanded, extending from foundational courses to advanced courses and an intertidal zone course, continuing to deepen and broaden the scope of public participation.

Advanced course participant Jin Ying-Yue shared that transect surveys are rarely accessible to the general public. "Having learned all this, I'm not just a recreational diver anymore — I now have the chance to contribute something to science. I think that's wonderful, and I hope the programme keeps running." Participant Xia Feng-Jun noted that she had often heard people say "the ecosystem here is great," but it wasn't until taking the course that she understood which "indicator species" to look for and why they serve as indicators.

The Chaojing Marine Reserve has been praised as a model marine protected area (MPA). In addition to strictly enforcing zonal management and ecological surveys, it continues to expand public participation. This year's "Marine Citizen Science Programme" also received support from internationally renowned brand GARMIN, which provided dive computers for participants to use. The devices allow divers to instantly monitor depth changes and no-decompression limit (NDL) alerts even while focused on sampling and photography, making every survey dive and training session safer.

Witness the Keelung Chaojing Results Exhibition — Ocean Market

Further reading:

• Exploring the Marine Beauty of Keelung: Unveiling the Chaojing Marine Reserve Ecological Survey and Marine Citizen Scientist Results

• A Hawksbill Turtle Stranded at Badouzi, Keelung Recovers After 3 Months and Is Successfully Released with the Help of Citizen Scientists

• What Do Keelung Chaojing Marine Citizen Scientists Learn in the 2023 Advanced Underwater Training Course?

• A Major Marine Protected Area Survey: Chaojing Outperforms Shen'ao! Revealing the Differences in Management Measures and Intensity

• 2023 Biological Classification Workshop — Building a Marine Life Database, Together

• Keelung Chaojing Wanghaihang: The Perfect Combination of Marine Protected Area and Citizen Science

• Keelung City Government Harnesses the Power of Marine Citizen Scientists to Give the Ocean a Voice Through Photography

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