In recent years the South China Sea has become a fiercely contested region.  China's rise as a regional and global superpower has emboldened an aggressive strategy to claim a larger share of the sea than would otherwise be allowed under the United Nations Convention on the Law of the Sea (UNCLOS).  While UNCLOS permits countries to exercise exclusive economic jurisdiction over a 200 mile extension from shore, China has claimed an ambiguously explained "9-dash line" that seemingly cuts into the maritime jurisdictions of Vietnam, Malaysia, and the Philippines (see map below the jump).  A 2002 agreeement between Association for Southeast Asian Nations (ASEAN) called for self-restraint in the area, but recently all countries have participated in an island development arms race to justify maritime and territorial claims.  China, in particular, has been the most aggressive:

In 2011 Chinese patrol boats harassed Vietnamese and Philippine oil-exploration vessels near the Spratlys. In 2012 China occupied Scarborough Shoal after a stand-off with the Philippines, which also has a claim. Last year a Chinese state-owned company sent an offshore oil rig into waters claimed by Vietnam, leading to violent anti-Chinese protests in Vietnamese cities. The rig withdrew months later. China has responded angrily to a case challenging the basis of its claims in the South China Sea which was filed in 2013 by the Philippines at a UN-backed arbitration panel. It has refused to co-operate with the hearings.

The refusal to acknowledge the jurisdiction of the Permanent Court of Arbitration under the auspices of UNCLOS is problematic for several reasons.  First, because it erodes the legitimacy and persuasiveness of a treaty if a major nation does not participate.  Second, because without a meaningful legal response the international community has less information with which to understand China's concerns and facilitate dispute resolution.  And finally, because uncertainty over the impending decision of the court is escalating island development ahead of the decision, destroying coral reef habitats.  

The South China Sea has now become a conflict of global concern.  Relations between China and its neighbors (including Japan) have deteriorated; much of the island development appears to be militarized; and the integrity of UNCLOS is being undermined.  The United States is deeply involved, with an interest in countering China's rising maritime influence by pivoting toward warmer relations with Japan, Vietnam, and the Philippines (although the US position that China's 9-dash line is invalid is somewhat undermined by the fact that the US is not a ratified party to UNCLOS).  

Less attention has been paid to the South China Sea environment itself.  In order to stake territorial claims (and the 200 mile exclusive economic zones that may go with them), countries are "reclaiming" shallow coral reef areas by dredging the seafloor in order to build artificial islands.  Shipping channels are cut and infrastructure is built over the reef.  One recently discovered artificial island has grown to accommodate an 82,000 square yard facility.  The land reclamation race only adds to the already fragile condition most reefs in the area find themselves in.  And given that legal jurisdiction is in dispute in the region, it probably goes without saying that fish stocks are plummeting due to overfishing.  Indonesia has resorted to sinking illegal fishing vessels, a move that has been criticized for antagonizing neighbors.  

But while many see the environment as a casualty of the South China Sea dispute, it also represents an opportunity for reconciliation.