Liquid natural gas (LNG) exploration has started off the coast of northern Mozambique, in the Rovuma Basin, East Africa. In advance of gas production, we collected in 2018 over 100 samples of surface sediments from 40 locations in the pristine and exploration areas at water depths of 5–2000 m. We have determined the levels of hydrocarbons (total hydrocarbon contents (THC) and 49 individual PAHs), heavy metals, arsenic, grain size and total organic carbon. While sediment composition varied strongly from coarse sediment to high mud contents (<63 μm), background levels of hydrocarbons and metals were found in most samples. We found anthropogenic contamination at one site in Pemba harbor. We observed no petroleum-related contamination, including the Palma area with numerous exploration wells. Elevated concentrations of barium and THC at some locations in this area are attributed to drilling activities but are not considered to be of environmental concern.

液态天然气（LNG）勘探已经在东非Rovuma盆地的莫桑比克北部海岸开始。在天然气生产之前，我们于2018年从原始深度和勘探区域40个位置的5–2000 m水深处收集了100多个表面沉积物样本。我们已经确定了碳氢化合物（总碳氢化合物含量（THC）和49种单独的PAH），重金属，砷，晶粒度和总有机碳的含量。从较粗的泥沙到较高的泥浆含量（<63μm），泥沙组成变化很大，但大多数样品中发现了碳氢化合物和金属的背景水平。我们在奔巴港的一个地点发现了人为污染。我们没有观察到与石油有关的污染，包括帕尔马地区有许多勘探井。