Spanning an area of around 3.8 million square kilometers, the South China Sea (SCS) is bordered by 12 countries and territories – the area is home to two billion people and has some of the fastest developing economies of the world.
The SCS is biologically diverse, but knowledge of its marine fauna is relatively incomplete. The most comprehensive catalogue of its marine fishes lists nearly 3,400 species in over 260 families. It is one of the top five most productive fishing zones in the world – in terms of total annual marine catch – with marine aquaculture contributing significantly to seafood production capacity in the region. Its fishery resources are crucial for supporting coastal livelihoods, food security, and export trade in its bordering countries. Small-scale fisheries are prevalent in SCS countries, and inshore waters are subject to intense fishing pressure from heavily populated coastal areas.
Our group at the University of British Columbia Fisheries Economic Research Unit, set out to outline the threats to the SCS, and determine what its marine ecosystems, fisheries, and seafood supply may look like in the next 30 years under several differing climate change and management scenarios.
In studying the SCS, a key obstacle we faced was that national fisheries statistics of SCS countries do not fully capture all fishing sectors. Small-scale fisheries and the level of illegal, unreported, and unregulated (IUU) fishing in the region are poorly known and documented.
As a result, fish catch statistics are likely largely underestimated. To deal with this problem we supplemented national statistics with data from the Sea Around Us, which reveals significant amount of unreported catches.
Key findings from this research show that if business continues as usual, (status quo scenario), by 2045 (compared to now) the following would likely occur:
- All fish groups studied will experience a population decline ranging from 9-59 per cent, with groupers and sharks the worst affected;
- About 63 per cent of the fish and invertebrate groups studied will generate less catch, with serious food security implications;
- About 55 per cent of the fish and invertebrate groups studied will generate less landed value or revenues, causing significant economic consequences.
On the other hand, under a sustainable management scenario, by 2045 there will be a significantly positive impact on biodiversity relative to business as usual. In order to achieve this, catch of about 63 per cent of the animal groups will have to decrease initially.
We also reported that the SCS’s marine ecosystem has changed dramatically from the past, as illustrated by the following examples:
- Overfishing and habitat destruction has directly contributed to biodiversity loss. Marine megafauna such as dugongs used to be abundant as along the coast of Thailand, Malaysia, and the southern provinces of China in the SCS, but are rarely found in the present time;
- Its coral reefs face substantial anthropogenic threats and are estimated to be declining at a rate of 16 per cent per decade;
- The fisheries on the coral reefs are also in bad shape; even in remote islands, catch rates appear to have declined three to four times over the past two decades;
- In some areas, monthly catches of valuable reef fish species such as Napolean wrasse and coral groupers decreased by almost 100 per cent over eight years, while relative abundance declined by almost 80 per cent over the same period.
Our study highlights that to implement an effective sustainable management framework for the SCS, a significant cut back on the trawl effort is needed. Sustainable management of the SCS would bring more seafood, provided political leaders and policy-makers are brave enough to put aside their political differences and put in place sustainable and cooperative management of the fisheries – for the sake of their citizens, both current and future generations.
As far-fetched as this may seem, because of the ongoing territorial disputes, putting aside political differences to sustain fisheries is not without precedent – the former Soviet Union and Norway put aside the cold war to work together cooperatively to ensure the sustainable use and management of Barents Sea cod, which is, still today, one of the best managed cod stocks in the world.
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