There is a diverse range of nervous systems that can be found across different aquatic species, likely resulting in an equally diverse range of mental/cognitive capabilities that can be found amongst these different animals. In helping to distinguish between these different mental capacities, it is vital that working definitions for the following terms are clearly outlined.

Cognition: 

Refers to the broader mental action of acquiring, processing, and transforming sensory data from its surrounding environment into information that the animal can then understand, learn from, and remember (i.e., its ability to form a mental framework of its surrounding environment).

Awareness:

The ability to sense events, objects, or sensory patterns and respond appropriately to them. This does not necessarily imply an understanding of the events themselves, nor does it imply a capacity to feel, perceive, or experience on a subjective level.

Consciousness:

An all-encompassing term used to describe the varying degrees of awareness that can be found within organisms. Consciousness can be seen as a spectrum, ranging from basic awareness of the surrounding environment to a higher-order of awareness that involves reflective thoughts.

Sentience:

A specific, higher level of consciousness that involves more complex, private, and subjective experiences/thoughts. Rather than simply being ‘aware’ of one’s surroundings, a sentient individual is also aware of itself within the context of those surroundings. This ‘self-awareness’ allows an understanding behind the surrounding environment AND what those surroundings mean to the individual themselves. This, consequently, also includes the capacity for a sentient individual to feel, perceive, or experience on this subjective level (i.e., to experience suffering or pleasure).

There is an ongoing debate that animals must have certain levels of consciousness, even to the point of sentience, as a prerequisite before their well-being/welfare should be considered. If it can be concluded that farmed aquatic species are sentient, and therefore capable of perceiving pleasure and suffering, then their welfare is of our concern.

The following video gives a simple explanation of the difference between sentience and cognition.

NB: This third-party video is linked for illustration only and copyright and control belong entirely to the originating organisation