Shrimp Frozen Solid: Red/Black Discoloration and Odor Concerns

We have observed the following situation: the freezing method used is water freezing, which has resulted in the entire box of goods being frozen into a single entity. All the shrimp are in a frozen state, and their bodies are hard. However, some shrimp heads and/or bodies have turned red or black, and some boxes of goods also have a strange odor.