Shipping lines have different surcharges that they can use whenever they feel essential to implement them. One of them is, called the Emergency Bunker Surcharge, or EBS, which addresses the increasing fuel cost.
Please don't mix it with the EBS and its counterpart, the Bunker Adjustment Factor (BAF), which is used to compensate for the fluctuating fuel cost caused by market fluctuations. The BAF is usually beforehand. This is different from the EBS, which is applied as an emergency plan at any time and can result in sudden cost problems for shippers' budgets for logistics.
In the last couple of months, carriers have been implementing this Emergency Bunker Surcharge in response to what they say as unanticipated increases in fuel cost. This has triggered many protests from shippers who are not just irritated at being assessed for something they cannot control and also because of the alleged unfair methods. Many believe that the recent EBS is to compensate the operating expenses of shipping lines under the pretence of increasing the cost of fuel.