Innovation and Technology

Dr Fang Kar-hei, James
Associate Professor, Department of Food Science and Nutrition
Marine Fellow, The Pew Charitable Trusts

Hong Kong boasts a rich history of pearl oyster reefs and a flourishing pearling industry dating back to the Imperial China era. However, these reefs were lost due to extensive overharvesting of wild pearls. Our research focuses on the restoration of pearl oyster reefs and the revival of their ecosystem functions in Hong Kong. Specifically, we have selected study sites in Tolo Channel, a former pearl harvesting area in Hong Kong where pearl oysters population have significantly declined. The pearl oysters used for the restoration effort will be sourced from our ongoing hatchery programme. By leveraging the technical expertise of PolyU, we are incorporating 3D printing technology to assist in the reconstruction of oyster reefs. This innovative approach is anticipated to create vital marine habitats and enhance local biodiversity, benefiting a wide range of seafood species. Ultimately, it aims to improve fishery resources in Hong Kong.

Another important objective is to rejuvenate the pearl production industry in Hong Kong through sustainable pearl oyster aquaculture. In this endeavour, we closely work with local fishermen and provide them with relevant training and technical support. For instance, we are developing an integrated aquaculture approach tailored to the specific conditions of local fish farms. This approach combines pearl oysters cultivation with other commercially valuable fish species. By harnessing the filter-feeding nature of pearl oysters, this integrated approach not only yields seafood but also improves water quality in the aquaculture areas. Importantly, the pearls harvested from these oysters offer an additional income stream for local fishermen.

Furthermore, the aquaculture of pearl oysters can contribute to carbon neutrality initiatives. Despite global efforts to reduce CO₂ emissions, the heavy reliance of civilisation on fossil fuels makes this task challenging. In addition to emission reduction strategies, an alternative approach to achieving carbon neutrality involves the removal of excess CO₂ from the environment, including the oceans, which absorb approximately a quarter of the human-emitted CO₂. In line with this goal, pearl oysters have the unique ability to extract carbon from seawater through the formation of calcareous shells and pearls. By incorporating pearl oysters into aquaculture practices, we can harness their natural carbon removal potential while also benefiting from them as a source of seafood and pearls. This integration offers a nature-based solution for carbon sequestration, making a significant contribution to a more sustainable future.

The concept of sustainability is paramount for ensuring the prosperity of future generations. In addition to our research activities, we recognise the pivotal role of education in fostering awareness about marine conservation. Thus, we are committed to translating our research findings on pearl oysters into educational materials with the potential to transform the mindset of our future society, promoting a sustainable approach for the betterment of our planet. For example, we develop STEM education packages centred around pearl oyster ecology and the application of advanced 3D technologies in ecological contexts. Beyond the confines of the classroom, we offer guided tours and internships for students to experience local pearl oyster farms firsthand. Through these initiatives, our goal is to raise students’ interest in marine ecology and conservation, while also encouraging them to explore career opportunities in the aquaculture and seafood industries.

We gratefully acknowledge the external support received for this pearl oyster restoration effort from The Pew Charitable Trusts and the Hong Kong Offshore Liquefied Natural Gas Terminal Project Fisheries Enhancement Fund, as well as the generous donation provided by Hang Seng Bank Limited.

(a) Cultured Akoya pearl oysters in the laboratory; (b) 3D models of a pearl oyster showcasing rotations at 0°, 90°, 180° and 270° using micro-computed tomography; (c) Cross-sectional views highlighting the placement of two pearls within the live oyster; (d) Computer simulation-based 3D reconstruction of the two pearls, illustrating the growth of nacre on the pearl nucleus.

恢復香港珍珠貝 造福環境社區

方家熙博士
食品科學及營養學系副教授
皮尤海洋保育學者

香港擁有豐富的珍珠貝礁和繁榮的採珠業，其歷史可追溯到中國帝王時代。然而，由於過度採挖野生珍珠，這些珊瑚礁的數量已大幅下降。我們的研究重點是恢復香港的珍珠貝礁及其生態系統功能，並已選定了吐露港部份地點進行研究。吐露港曾是香港的珍珠收穫區，但珍珠貝的數量已大幅減少。現時，我們正進行孵化計劃，將資源投放於珍珠貝的修復工作上，同時憑藉著理大的技術，利用三維打印技術重建蠔礁。這項創新方法預計將會創造重要的海洋棲息地，提高當地的生物多樣性，讓多種海洋生物受益，最終達至改善香港漁業資源的目的。

該項研究的另一重要目標，是透過可持續的方式進行珍珠貝養殖，振興香港珍珠生產業。為此，我們與本地漁民緊密合作，向他們提供相關的培訓和技術支援。舉例來說，我們依據本地養魚場的具體情況，發展綜合水產養殖方法，將珍珠貝與其他具商業價值的魚類結合養殖。透過利用珍珠貝的濾食性特性，這種綜合方法不僅能養殖出水產，還能改善養殖區的水質。此外，從這些蠔身上收穫的珍珠也為本地漁民提供額外的收入來源。

除此之外，珍珠貝的水產養殖亦有助實現碳中和倡議。儘管全球各地都在努力減少二氧化碳的排放，但人類生活仍然非常依賴化石燃料，令達成碳中和的目標極具挑戰性。除了減排策略之外，實現碳中和的另一種方法是清除環境中多餘的二氧化碳，包括吸收了人類排放的約四分之一的二氧化碳的海洋環境。當中，珍珠貝具有透過形成珍珠和鈣質外殼從海水中提取碳的獨特能力，有助減碳。將珍珠貝納入水產養殖項目後，不但可以利用其天然的除碳潛力，同時亦可增加海鮮和珍珠資源。這方案利用自然方法應對碳截存，為實現可持續未來作一分貢獻。

可持續發展是確保後代繁榮的關鍵。除了研究活動外，我們亦明白教育有助提高海洋保護意識。因此，我們致力將珍珠貝的研究成果轉化為教材，希望可以在未來改變社會的觀念，並推廣可持續發展的方法，改善我們的環境。例如，我們根據珍珠貝的生態環境，以及在生態學情景中應用先進的三維技術，開發了一系列STEM教學課程。另外，在課堂之外亦有提供導賞團和實習機會，讓學生親身體驗本地珍珠貝養殖場，提高學生對海洋生態和保育的興趣，同時鼓勵他們探索水產養殖和海鮮產業的工作機會。

最後，我們衷心感謝皮尤慈善信託基金（The Pew Charitable Trusts）和香港海上液化天然氣接收站項目漁業提升基金（Hong Kong Offshore Liquefied Natural Gas Terminal Project Fisheries Enhancement Fund），為珍珠貝修復工作提供額外支援，同時亦感激恆生銀行（Hang Seng Bank Limited）的慷慨捐贈。

(a) 實驗室中養殖的馬氏珍珠貝；(b) 利用微型電腦斷層掃描技術製作的珍珠貝三維模型，展示了0°、90°、180° 和270°的旋轉情況；(c) 截面圖，突顯兩顆珍珠在活蠔中的位置；(d) 利用電腦模擬製作出的兩顆珍珠三維重建圖，以展示珍珠核上珍珠質的生長情況。