|  |
Program |
 |
| |
 |
General Session 4: Marine environment, ecosystem & sustainability |
| |
|
|
The future of integrated multi-trophic aquaculture in the South China Sea, starting with the noble scallop, Chlamys nobilis (Reeve, 1852)
Monday 9th @ 1545-1605
Room 1
Reece Wartenberg* , State Key Laboratory of Marine Pollution, City University of Hong Kong, Hong Kong SAR
Paul Lam, State Key Laboratory of Marine Pollution, City University of Hong Kong, Hong Kong SAR
Trevor Telfer, Institute of Aquaculture, University of Stirling, Scotland
Presenter Email: rwartenbe2-c@my.cityu.edu.hk
|
| China has a population of 1.3 billion people that consumes, on average, more than 20 kg of seafood per person annually. One opportunity to help meet China’s seafood demand, without encroaching on terrestrial industries, is open water (inshore and offshore) aquaculture. But open water aquaculture is criticised globally for its substantial environmental impacts. In this study a systematic, quantitative review was conducted to assess the current open water aquaculture industry in China and to investigate the future potential of integrated multi-trophic aquaculture (IMTA), an aquaculture technique that integrates species from multiple trophic levels to mitigate waste from fed aquaculture. Commercial open water aquaculture of fed finfish and shellfish started in Guangdong in 1981. Now China’s coastlines accommodate over 1 million finfish cages. The literature review showed that open water aquaculture in China can cause substantial, ecosystem-wide environmental impacts including eutrophication; algal blooms; hypoxia; hydrodynamic alterations; sediment impacts; metal, organic and inorganic compound accumulation; food web disruptions; introductions of diseases, parasites and invasive species; antibiotic release; poor product quality and economic loss from fish kills. Nearly all papers recommended the use of IMTA as one path towards sustainability. Studies that investigated IMTA in China showed that it can be implemented for bioremediation; biomitigation; reducing stock mortality; and improving productivity, product quality, public opinion and financial returns. The consensus from the literature was that the implementation of IMTA in China is recommended. In the tropical south China Sea, the use of IMTA is under-researched and the list of species that can be incorporated into balanced ecosystem designs remains under-studied. As an experimental case study, the filter feeding scallop Chlamys nobilis was integrated with popular fed finfish in a sea cage system in Hong Kong. Phase 1 of the experiment showed that scallop growth rates were 0.21 mm per day from May to October 2016, with no significant difference between depths; 1 m, 3.5 m and 6 m. Mortality in this study was high, particularly in the 6 m treatment that had 70 % mortality by October, probably due to predatory invertebrates associated with fouling communities or seasonal monsoon rains that substantially lowered salinities throughout the water column. Phase 2 of the experiment will run until mid-December 2016. This study suggests that the integration of C. nobilis with fed finfish is recommended but the high mortality must be studied further so that it can be effectively managed. |
|
|
|
|