Surimi is a Japanese delicacy made with ground fish meat. It is usually made with the Alaska polluck or Pacific whiting. Other fish used to make surimi include Atlantic cod, big-head pennah croaker, bigeyes, milkfish, shark, swordfish and black bass.
The FDA categorizes the Alaska polluck as a low mercury fish whereas swordfish and shark fall under the high mercury category.
Hence, surimi made with a low mercury fish is considered to be safe for consumption. But, if you opt for a store brought variant, then it might be difficult to track the type of fish used. Hence, it is recommended you consult your doctor before indulging in a surimi based product during pregnancy.