Interactions between organisms and their fluid environment
Impacts of ocean change on early life stages
We are also conducting plankton diversity surveys in Hong Kong waters
1. INTERACTIONS BETWEEN ORGANISMS AND THEIR FLUID ENVIRONMENT
2. IMPACTS OF OCEAN CHANGE ON EARLY LIFE STAGES
Climate change is considered one of the greatest threats to marine ecosystems in the 21st century. Our research focuses on the sub-lethal effects of climate change-related stressors, e.g., temperature, salinity, oxygen, and pH.
In Hong Kong, we are starting to investigate the impact of multiple stressors on local species and quantifying the variability in environmental factors in Hong Kong waters. Ultimately, we are interested in the question: Are species exposed to anthropogenic stresses pre-adapted to climate change?
Together with Dr. Chan’s collaborator Dr. Sam Dupont, we are addressing these questions:
How does elevated pCO2 level affect sperm and egg physiologies? Thus far, most studies focus on the reduction in sperm motility but not changes in the biochemistry of the eggs, which could affect ease of fertilization and target size.
Do the responses differ between populations? Individuals?
What are the population-level implications of these changes?
B. Functional morphology of planktonic larvae
Morphology of plankton are diverse and our lab is interested in the biomechanical constraints morphology imposes and the implications for the larval form. To address this question, Dr. Chan collaborates with her dissertation advisor, Dr. Daniel Grunbaum at University of Washington, Seattle, to develop a small-scale hydrodynamic model that reflects realistic morphology using confocal micrographs.
We are currently working on the following questions:
Morphology often varies under different environmental conditions, what are the functional implications of this phenotypic plasticity?
How do changes in morphology affect larval movement in realistic flow fields and what are the implications for transport?
B. Functional morphology of planktonic larvae Morphology of plankton are diverse and I am interested in the biomechanical constraints morphology impose and the implications for larval form. To address this question, I collaborate with my disseration advisor Dr. Daniel Grunbaum at University of Washington, Seattle, to develop small-scale hydrodynamic model that reflect realistic morphology using confocal micrographs. We are currently working on the following questions?
Morphology often vary under different environmental conditions, what are the functional implications of these phenotypic plasticity?
How changes in morphology affect larval movement in realistic flow fields and what are the implications for transport?
A. Quantification of fluid disturbance of marine invertebrate larvae and their ecological implications
Swimming plays an important role in the survival and dispersal of marine invertebrates during the planktonic larval stage. Applying the micro-PIV technique pioneered at Dr. Houshuo Jiang's lab, we are studying larval performance and behavior in still and in flowing water.
Some of the questions we are asking include:
How does swimming speed, ciliary motion change with ontongey?
What kind of fluid signal do the organisms create?
What is the tradeoff between filtering water to capture food and minimizing hydrodynamic signal to reduce predation risk?
Do organisms from different taxonomic groups follow the same optimization rule if a-trait basted model is applied?
There are also other on-going projects to quantify larval swimming in shear and turbulence, spanning the scale of microns to meters.
We are conducting plankton surveys in Hong Kong, one in the Tolo Harbor area and another in Port Shelter. Our goals are to building a plankton diversity inventory and to develop a best practice guide for plankton sample collection and identification in shallow bays in Hong Kong. This information is essential for understanding community dynamics and guiding conservation and management strategy.
Recently, we completed a plankton survey in the eastern waters (Port Shelter) of Hong Kong from May 2016 to July 2017. The principal objective of this project was to investigate the distribution and seasonality of marine decapod crustacean larvae and stomatopod larvae. What we discovered was a wealth of zooplankton diversity in our coastal waters including larvae of commercially important species all well as some very unique and surprising planktonic organisms.
Very little information is available on local plankton diversity, so we made it our goal to share our findings with the community via a website to increase awareness and appreciation of plankton, a critical component of the marine ecosystem. You can visit the website by clicking HERE.
PLANKTON DIVERSITY SURVEYS IN HONG KONG WATERS
LIFS, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
Division of Life Science
Hong Kong University of Science and Technology
Photos by Dr. Karen Chan. Last updated on Jul 4, 2018