Jake Dytnerski
Ph.D. candidate
Research
Hong Kong has a seasonally dynamic marine environment. Summer sea surface temperatures can exceed 30°C whereas winter temperatures can drop below 15°C. This range in temperature allows for year-round coral communities, and abundant growth of macroalgae in the winter. For my PhD, I am researching the role of the long-spined sea urchin, Diadema setosum, in the ecosystem, here in Hong Kong. Much work has been done on Diadema antillarum in the Caribbean, and some work has been done on the D. setosum as a bioeroder of coral reefs in the tropics. However, little is known about which marcoalgae these urchins feed on; how they affect the seasonal patterns of macroalgae growth and distribution; if the urchins target living corals here in Hong Kong or just the turf algae that grows on the dead skeletons of the corals. Answering these questions will help understand the food sources of the urchins and how their energy stores vary with the seasonal change in food abundance. I am also interested in the connectivity of the populations of D. setosum across its range, as they can be found from the East coast of Africa to French Polynesia, from Honshu, Japan to NSW, Australia. I want to compare the physiological performance of the urchins from stable tropical environments and highly variable environments to determine if they show extensive physiological plasticity, or if populations have adapted to variable environments. This will allow me to predict how these important grazers will cope with future conditions across their range.
Education
2016: Bachelor of Science, Honours Marine Biology, University of British Columbia, Canada
2013: Arts and Science Diploma: Biology, Langara College, Canada
Awards
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2015: Dean of Science Scholarship – Biology research grant
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2013: Betty and Tony Pletcher Memorial Scholarship – For Achievement in Biology
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2012: Real Estate Foundation Biology Student Bursary – Bursary for Biology students
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The Search For Seaweed
Seaweeds are critical in supporting marine life and provide key ecosystem benefits. Hong Kong has a diverse population of seaweeds, with over 250 species recorded. However, climate change, poor water quality, overgrazing, harvesting, and infrastructure developments has likely impacted their abundance and survival.
The Search for Seaweed project is attempting to map Hong Kong’s seaweed species using citizen science. We would like to know where the seaweeds are and determine their health and abundance. It is important for us to identify this, so that we can monitor their populations and better manage them for the future.
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​But, we need your help.
On your next dive or visit to the coast, we are asking you to record the seaweed species you see, and their location and abundance. We would like you to record the presence / abundance of sea urchins, who feed on algae, and the water temperature, so that we can assess two of the main stress factors. By providing information on local seaweed species, you could help us to protect this important habitat.​ ​​​​​
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Why Seaweed?
​Seaweeds provide many important ecosystem benefits - they can absorb nutrients from the water and carbon from our atmosphere, and can even protect our coasts from storm damage. They also support commercial fisheries and have many commercial applications such as in food, medicine and cosmetics. As a large habitat-forming species, they also provide food and shelter for marine life.
Join the Survey
What do you need to do?
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You can take part in The Seaweed Search anywhere in Hong Kong at any time of the year. The Seaweed Survey Guide includes instructions on how to take part and an identification guide for the seaweeds and herbivores we are asking you to record.
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Download the following survey guide to learn about why we are studying seaweeds and how you can help to monitor the abundance and diversity.
Please share your findings on social media and encourage others to participate in the study.
