Hong Kong Chironomidae Project

This webpage provides a semi-regular (roughly every 2 months) update on the, currently, ongoing ECF funded Hong Kong Chironomidae project

Project Summary: Chironomids are the most abundant insect species in freshwater ecosystems with a widespread diversity and functionality. Their importance as bioindicators for water quality, pollution control functionality and service as primary food source for fish, birds and mammals is we documented. Hong Kong Chironomidae biodiversity, life histories and distributions are unknown, however.

This study will provide the first survey of Hong Kong Chironomidae biodiversity, particularly for presently defined Ecologically Important Streams (EIS). Our aims are to 1) Initially characterize the Chironomidae biodiversity across Hong Kong 2) Assess the temporal and spatial variation of Chironomidae species found across Hong Kong 3) Test the feasibility of an environmental DNA (eDNA) assessment of Chironomidae biodiversity for Hong Kong EISs

Overall this project will fill a key knowledge gap on the most overlooked species group within Hong Kong. We anticipated the discovery of 500-800 species across Hong Kong, which would provide a valuable source of information related to the Hong Kong Biodiversity Action Plan (BSAP). Furthermore, this project will provide initial information regarding water quality links to species occurrence and abundances and allow for an initial assessment of molecular based biodiversity assessment, which is rapidly gaining traction for many government and private agencies across the globe. 

Meet the Team

Progress and Outcomes

July 2024 - 6 Month Progress Summary

After 6 months of progress on the Hong Kong Chironomidae biodiversity survey project, significant milestones have been achieved. Sampling activities began promptly, with 15 trapping locations across 5 ecologically important streams covered, resulting in the collection of approximately 105 malaise trap samples. Despite some setbacks, such as the loss of a few samples due to adverse weather and human or wildlife interference, the project has made substantial headway.

Dr. Han Wu was brought onboard in March 2024 to significantly enhance our research capabilities. Various sampling techniques, including Chironomidae larva　, exuviae, eDNA, and light trapping, have been conducted twice during the first 6 months. Preliminary findings from the survey were shared at the 3rd Annual Ecology and Biodiversity Research Symposium through a poster presentation by Ms. Chan Tsz Ying, a PhD Candidate from HKU. 

The establishment of the Hong Kong Chironomidae barcode project library has commenced and updated time to time. The project aims to generate over 1,000 barcodes from approximately 300 identified species, provide extra information for global researchers.,W with 60 barcodes from 27 unique species already deposited in a private BOLD database project folder. Another 100 barcodes are in the pipeline for upload in the upcoming period. The barcode library will be published as a research article for the public to use when it is ready. The project aims to generate over 1,000 barcodes from approximately 300 identified species.

Additionally, efforts are underway to develop a taxonomic key for Chironomidae identification in Hong Kong, create a photograph database linked to barcode sequences, and assess spatio-temporal and environmental factors influencing Chironomidae biodiversity dynamics. The project is also progressing towards evaluating the feasibility of using eDNA for Chironomidae assessment in Hong Kong, with 90 eDNA samples collected for future molecular analysis.

Despite challenges, including trap loss and weather disturbances, the project is on track to achieve its objectives. The ongoing research efforts aim to enhance public awareness and understanding of the diverse Chironomidae species in Hong Kong, contributing valuable insights to biodiversity conservation and environmental management.

2024年7月— 6個月進度總結

香港搖蚊生物多樣性調查項目在六個月已達到不少重要的里程碑。採樣活動於2023年10月及時展開，當中涵蓋了5條生態重要河流，共15個捕捉點，成功收集約108個馬氏網樣本。儘管採樣過程中遇到挫折，例如由於惡劣天氣和人為或野生動物的干擾導致一些樣本的損失，但該項目已獲得了重大進展。

韓武博士於2024年初加入團隊，顯著增強了我們的研究進度。在首六個月內，團隊已進行多項採樣，包括搖蚊幼蟲、蛹皮、環境DNA和燈誘採集（成蟲）。初步研究成果及發現已由香港大學博士候選人陳子盈女士在「香港大學第三屆生態與生物多樣性研究研討會」中以海報形式分享，吸引不少生物學家關注。

在分子技術方面，團隊建立了香港首個搖蚊科DNA條碼數據庫，並不時更新。此項目旨在從約300個已識別的物種中生成1000多個條碼，提供多個渠道協助研究人員辨別搖蚊物種。目前已將來自27個獨特物種的60個條碼存入私人BOLD數據庫項目文件夾，還有100個條碼亦正在計劃上傳。該條碼數據庫會在修輯完備後以論文形式發表，供公眾使用。

不止如此，團隊正在努力編撰 「香港搖蚊分類手冊」和一個與條碼序列相關聯的照片數據庫，以用於評估時空和環境因素如何影響香港搖蚊科生物多樣性變化。該項目向利用環境DNA在香港評估搖蚊多樣性方向前進，目前已收集90個環境DNA樣本以供未來分子分析。

儘管計劃或繼續面臨天氣及人為干擾等潛在挑戰，本項目仍在按計劃達成目標的軌道上。我們會持續研究，旨在提升公眾對香港搖蚊多樣性的認識，望為生物多樣性保育和環境管理提供重要資訊及意見。

January 2025 - 12 Month Progress Summary

After 12 months of progress on the Hong Kong Chironomidae biodiversity survey project, significant advancements have been made. Sampling activities were carried out as planned, with monthly sampling at 15 trapping locations across the 5 ecologically important streams. The first year of surveying has been completed, resulting in 180 malaise trap samples, which have been sorted and identified to the species level. Additionally, 180 exuviae samples have been sorted for preparation for metabarcoding.

Chironomidae larva, eDNA, and light trapping were conducted once during the last six months, with plans for the 4th sampling event in February 2025. Currently, 165 eDNA samples, 45 kick Chironomidae larva samples, and 15 light trap samples have been collected and processed according to the grant proposal plan. The Chironomidae larva samples have been identified, and the eDNA samples have undergone DNA extraction and cleanup for metabarcoding. A trial run of the metabarcoding library protocol has been successfully completed, with preparations underway for the remaining samples.

The Hong Kong Chironomidae barcode project library has been updated, with 393 specimens uploaded and 107 species records verified. An additional 300 barcode sequences will be generated and added to the library database in the next few months. The identification manual is near completion, with adjustments being made for accuracy.

The project has identified 240 species from 61 genera, with over 25 new records to Hong Kong. The ongoing research efforts aim to enhance public awareness and understanding of the diverse Chironomidae species in Hong Kong, with anticipated identification of around 300 species across all sites and time points.

Efforts continue on the barcode sequence database, photograph database, taxonomic key development, and assessment of spatio-temporal and environmental factors influencing Chironomidae biodiversity dynamics. Overall, the project is progressing well and meeting expectations thanks to the amazing group of researchers involved.

2025年1月— 12個月進度總結

一年過去，香港搖蚊生物多樣性調查項目繼續取得了重大進展。採樣活動按計劃進行和完成，在5條生態重要河流的15個捕捉點定期採樣，一共收集了180個馬氏網樣本。團隊已對所有馬氏網樣本分類和識別物種，更額外對180個搖蚊蛹皮樣本分類，預備DNA條碼分析。 

在過去的六個月內，搖蚊幼蟲、環境DNA和燈誘採樣活動各進行了兩次，並計劃在2025年2月進行第四次採樣活動。目前已經收集並按照計劃書處理了165個環境DNA樣本、45個搖蚊科幼蟲樣本和30個燈誘樣本。搖蚊科幼蟲樣本已經被識別，環境DNA樣本亦已提取DNA提取及提純，以進行高通量分子條碼（eDNA metabarcoding）分析。初步測序平台文庫構建已試運成功，正在為剩餘樣本做準備。 

香港搖蚊科條碼數據庫亦繼續更新，目前已上傳393個標本並驗證了107個物種記錄。未來幾個月將生成另外300個條碼序列並添加到條碼數據庫中。至於「香港搖蚊分類手冊」即將完成，正在進行準確性調整。 

本項目從61個屬中識別出240個物種，其中有超過25個是對香港的新記錄。相比現有紀錄，本項目所得到得數據是現有的紀錄十倍以上。此反映香港具有豐富生物多樣性尚待發現，需要更多科研人員在政府支持下共同努力，繼續了解本港生物多樣性。預期隨時間及項目推進會識別出共約300個搖蚊物種。 

團隊持續努力完善以上提及的條碼序列數據庫、照片數據庫、分類手冊以及繼續評估時間及環境因素如何影響香港搖蚊科生物多樣性變化。整體而言，參與其中的出色研究人員使本項目進展順利，達到了預期目標 。