A股港口航运板块盘初大跌，招商南油、兴通股份跌停，国航远洋跌超12%，中远海能、招商轮船等跟跌。

Group 1 - The A-share port and shipping sector experienced a significant decline at the beginning of trading, with major companies like China Merchants Energy and Xingtong Co. hitting the daily limit down [1] - China National Aviation's ocean shipping segment fell over 12%, indicating a broader downturn in the industry [1] - Other companies such as COSCO Shipping Energy and China Merchants Shipping also followed the downward trend, reflecting a negative sentiment in the market [1]