Mission

• Develop innovative chemical, biological and engineering technologies for monitoring the health of marine environments, pollution control, bioremediation and risk assessment.
• Conduct and foster high quality, multidisciplinary research relevant to the protection and conservation of the marine environment, especially in Hong Kong and the Asia-Pacific region.

Goals

Assume a leading role in marine environmental research relevant to the protection and management of the marine environment through multidisciplinary research, teaching, training, consultancy work and professional services.

Research Programs

Our research programs are summarized schematically in Figure 1

Figure 1. Relationships between different activities of the proposed AoE

Program 1: Development of Novel Technologies for Environmental Diagnosis

Program 1.1 Chemical Technologies

We will use Solid Phase Micro Extraction (SPME) & Molecular Imprinting techniques to identify algal toxins (Paralytic Shellfish Poisoning and Okadaic Acid) and xenobiotics, with an aim to develop highly selective in situ sensors for quantification of toxicants.

Molecular Imprinting Chemical Sensing: MIP-based biomimic chemical sensors, in which luminescent organic supramolecules and metal/organometallic complexes containing polar functionalities will be used as functional sensing monomers for the fabrication of MIP.

Biosensors: Novel immunosensors for direct detection of genotoxicants and algal toxins will be developed. The core technology of the proposed biosensor system is a piezoelectric quartz crystal device modified with red tide toxin antibodies. The sensing mechanism is based on the perturbation of acoustic wave signals transduced from the piezoelectric device, resulting from changes in interfacial properties when toxin molecules bind specifically to sensor-bound toxin antibodies. We will focus on the application of the immunosensors to detect toxins for PSP (paralytic shellfish poisoning) and DSP ( diarrhetic shellfish poisoning) as well as ciguatoxin.

Semi-Permeable Membrane Devices (SPMDs) and Artificial Mussels (AMs): Biomonitors such as bivalves and barnacles have been widely used to identify and quantify trace organic contaminants in marine waters over the last two decades. The major shortcoming of using mussels is that natural variability can affect uptake and sequestration of contaminants, and complicate data interpretation. Furthermore, in many environments, bivalves cannot survive because of adverse or unsuitable environmental conditions. SPMDs have been developed to overcome such problems. We will study and compare the uptake of xenobiotics by SPMDs with that of the bioindicator, the common green-lipped mussel Perna viridis, in laboratory and field deployments.

For monitoring trace metals in the marine environment, we have successfully developed a novel chemical device called "Artificial Mussel" (AM). The device consists of a polymer ligand suspended in artificial seawater within Perspex tubing and enclosed with semi-permeable gel at both ends. These devices can take up and release metals in a similar fashion to mussels under laboratory conditions. Research is being carried out to ensure that (a) the bioavailable fraction is being taken up from the aqueous phase; (b) uptake and release are not significantly confounded by salinity and temperature; and (c) laboratory results can be extrapolated to field conditions.

Program 1.2 Genomic Technologies

Quantification of Waterborne Pathogens: At present, Escherichia coli (or faecal coliforms) are used worldwide as an indicator of faecal contamination in routine water/seafood testing. Results of recent research, however, indicate that E. coli is not a reliable indicator for waterborne pathogens, and cost-effective technologies for regular monitoring of waterborne pathogens are urgently required to protect public health. We will develop real-time multiplex PCR methods and DNA microarray technologies for higher throughput and accurate detection of important bacterial and viral waterborne pathogens. The development of these pathogen detection technologies would represent a major breakthrough in public health and environmental monitoring.

Toxicogenomic Studies: We will develop DNA microarray to: (a) identify toxicant-specific patterns of gene expression; (b) elucidate molecular mechanisms of algal toxins and xenobiotics; and (c) develop gene expression-based biomarkers in fish and mussels.

Program 1.3 Biomarker Technologies

The key objective is to develop a suite of quantitative biomarkers for early detection and in vivo measurements of hypoxia, priority pollutants and algal toxins.

Molecular Markers: We will focus on developing molecular markers for endocrine disruptors and hypoxia. The H295R cell line developed in one of our external collaborators, Prof. John Giesy's laboratory, will be used to investigate the gene expression profile of steroidogenic enzymes as markers for endocrine disruptors. Both in vitro and in vivo studies will be conducted to develop and validate a set of molecular biomarkers for stressors such as exposure to xenobiotics and hypoxia in fish. The effects of hypoxia will be examined by use of gene expression profiles of various hypoxia-responsive genes, including: HIF-1α ; HIF-2α and HIF-4α , VEGF, EPO, GLUT, P4501A1, HSP70.

We will also develop an in vivo biomonitoring system for xenobiotics, using transgenic marine medaka which expresses Green Fluorescent Protein (GFP).

Biochemical Markers: We will investigate responses of EROD, Phase II enzymes, DNA repair enzymes, DNA adducts, DNA strand breaks, 8-OHdG (8-hydroxy-2'deoxyguanosine) and micronucleus induction in response to exposure and body burden of xenobiotics in local species of fish and mussels.

Cytological Markers: Quantitative ultrastructural changes in gill, liver and intestine of fish (indicative of cell damage and functional impairment) in response to xenobiotics and red tide toxins will be studied, using morphometric analysis and stereology. We will be particularly interested to investigate the occurrence of apopotosis in vivo, as a cytological indicator for xenobiotic and hypoxic stresses.

Immunological Markers: We will investigate macrophage responses, lysosome levels, mitogenic responses and antibody response in fish and mussels with a view to developing rapid immunological markers. Immunocytochemical techniques.

Physiological Markers: We will focus on how hypoxia, xenobiotics and sublethal concentrations of red tides may affect growth and reproduction of fish and mussels. We will investigate scope for growth, RNA:DNA ratio, reproductive hormones (triiodothronine, growth hormones, gonadotropin-releasing hormone, gonadotropins, testosterone, progesterone and estradiol) in fish and mussels upon exposure to hypoxic stress and xenobiotics, with an aim to develop a suite of growth and reproductive markers. We will also explore the feasibility of using daily deposition on fish scales and mussel shells as a means of indicating daily growth and growth impairment.

Overall, we will attempt to relate the above biomarkers to Darwinian fitness traits, so that we can make quantitative predictions at the population level.

Program 2: Field Studies and Validation

Program 2.1 Validation of Novel Technologies

The various novel technologies for "environmental diagnosis" produced from Program 1 be tested and validated under local, field conditions before use, using field transplantation and field manipulative experiments.

Program 2.2 Ecological and Recovery Studies

Ecosystem Recovery: The Harbour Area Treatment Scheme (HATS), to be implemented by the Hong Kong SAR government, will remove >70% of the organic loading into Victoria Harbour and its vicinity. This AoE will capitalize on this unique opportunity and study recovery of bacterial, plankton and benthic communities after commencement of pollution abatement.

Program 3: Impact and Risk Assessments

Program 3.1 Modeling Fate and Carrying Capacity of Nutrients and Pollutants

Computer simulation models incorporating tidal flushing and mixing, biochemical cycles, sediment-water nutrient exchanges and algal dynamics will be developed, and used to (a) assess the dispersion and the concentration of nutrients and pollutants in coastal waters, (b) predict environmental impacts and the risks incurred, and most importantly, (c) estimate carrying capacity of specific water bodies to pollutants. We will model recovery of water quality parameters in Victoria Harbour after pollution abatement of the HATS project, and corroborate our modeling results with field study results. We will also develop data-assimilation methods and eutrophication models, integrating real time field data and modeling systems and using neural networks, genetic algorithms and adaptive parameter estimations.

Program 3.2 Modeling Biokinetics of Xenobiotics and Algal Toxins in Marine Biota

Both single and multi-compartment model will be used to predict uptake and transfer processes of xenobiotics and toxins in fish and mussels.

Program 3.3 System-Specific Ecological Risk Assessment Models

Ecological risk assessment models will be constructed to predict concentrations of pollutants in marine biota and their likely responses.

Program 4: Mitigation, Control and Bioremediation Technologies

Program 4.1 Cost-Effective Pollution Control Technologies

Microalgae systems will be developed for removal of xenobiotics in industrial effluents. Constructed mangrove wetland wastewater treatment systems will be set up to understand the mechanisms and efficiencies of how pollutants in sewage are removed by different species and sediment types, as well as the involvement of the associated microorganisms.

We will study the feasibility of using synthetic polymers to absorb nutrients in wastewater, with an aim to develop cost-effective, efficient and recyclable ion-exchange resins for removal of ammonia, nitrate, nitrite and phosphate.

Program 4.2 Development of Bioremediation Technologies

The objective of this program is to develop cost-effective bioremediation techniques to reduce risks caused by important contaminants. We will focus on: (1) remediation of mixed contamination by persistent organic pollutants using soil washing and biosorption techniques, immobilization and bioremediation; and (2) natural attenuation for sites contaminated by petroleum hydrocarbons, chlorinated solvents and pesticides.

Program 4.3 Control, Mitigation and Tracking of Harmful Algal Blooms (HABs)

We will conduct experiments to identify suitable types of domestic clay and assess their cost-effectiveness in the control of common red tide causative species in Hong Kong and southern China . We will also investigate the possibility of enhancing the removal efficiency of Hong Kong's domestic clays using PAC and other flocculants.

A 3-D hydrodynamic model will be developed to predict the circulation patterns in Hong Kong waters for the dry (winter) and wet (summer) seasons and hence the likely transport patterns of HABs during outbreaks. The model will be validated against historical field data of red tides.

Figure 2. Governance structure of the proposed AoE
(convener in each sub-task is shown in bold)