What is a workplace hazard that is unique to shellfish aquaculture?

In the context of shellfish aquaculture, scuba-diving related injuries represent a workplace hazard that is distinctive to this specific field. In shellfish farming, divers are often required to harvest shellfish from underwater cultivation sites, which introduces risks associated with underwater operations. These risks include but are not limited to decompression sickness (commonly known as "the bends"), barotrauma, and drowning incidents.

The unique nature of these hazards stems from the underwater environment where divers work, which can involve varying depths, limited visibility, and potential encounters with marine life. Proper training in diving procedures, safety protocols, and emergency response measures are essential in mitigating these risks for workers involved in shellfish aquaculture.

The other options indicate hazards that can occur in various types of work environments rather than being specific to shellfish aquaculture. Electrical-related injuries can happen in any setting where electrical equipment is used. Tractor overturns pertain to agricultural machinery hazards and are not unique to shellfish farming. Respiratory issues due to chemical exposure can arise in multiple industries that utilize chemicals, making them a broader concern rather than one specifically tied to shellfish aquaculture.