Katherine Martínez, Veterinary Doctor.

"In many countries around the world, fish are considered sentient beings"

Veterinarian Katherine Martínez asserts that there is evidence that salmon can experience pain, learn, remember, and modify behaviors.

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Great controversy was recently caused by a proposal from deputy Jorge Brito, in the context of modifying the Fishing Law, which sought to establish fish as sentient beings. In this regard, taking the issue to the technical area, Katherine Martínez, Veterinary Doctor and expert advisor in the field of Animal Welfare, gives her view in an interview with Salmonexpert, a media associated with LandbasedAQ.

Although the provision in the law about sentient aquatic animals was withdrawn, do you think it is something scientifically proven, in salmon for example?

Until the year 2002, the scientific community denied the presence of nociceptors in fish, however, it is now known that fish have peripheral nociceptors that detect harmful and painful stimuli (Sneddon, 2003). In response to such stimuli, a modification of brain activity and a change in behavior is generated, where fish avoid experiencing the same negative experience again. Another argument that seeks to deny fish sentience indicates that they lack a neocortex similar to the human one and, therefore, do not respond to pain in a meaningful conscious sense (Rose, 2002). However, there are studies that show that it is not only this part of the brain that is involved in consciousness in humans and that fish possess structures that are homologous to the neocortex, performing the same function as it (Brown, 2015).

Therefore, empirical evidence shows that fish can experience pain. It is also demonstrated that fish have the ability to learn, remember, and modify their behaviors in response to already known situations (Brown, 2015). A concrete example of this can be seen in sea centers, where newly planted smolt move away from the presence of divers and ROVs. However, over the days, they learn that both elements are not a threat and, after a few weeks, we can already see them very close and calm.

Although this indication was extreme, where it was said that fish even played soccer, among other things, how should the new Aquaculture Law go further in animal welfare?

In several countries around the world, fish are considered sentient beings and there are specific regulations aimed at safeguarding their welfare during productive practices.

For example, the welfare of fish is considered in the New Zealand Animal Welfare Act (1999), the Australian Capital Territory Animal Welfare Act (1992), the Norwegian Animal Protection Act (1974), and the Norwegian Animal Welfare Act (2009). In the latter country, the legislation grants fish a level of protection similar to that of other vertebrates. Additionally, in 2005, the Council of Europe welcomed a recommendation on the welfare of farmed fish and in 2008, the OMSA adopted guidelines for fish welfare. Other standards and certification schemes for sustainable aquaculture that include fish welfare are ASC, the GlobalGAP aquaculture standard, BAP, RSPCA, and the recently launched Certified Humane.

Currently in our country we have the General Law of Fisheries and Aquaculture (LGPA), in which in its 5th Paragraph; Article 13 F it is stipulated: "Aquaculture must include norms that safeguard animal welfare and procedures that prevent unnecessary suffering".

On the other hand, in law 20.380 which is applicable to hydrobiological species, it is indicated in Article 1: "This law establishes norms aimed at knowing, protecting, and respecting animals, as living beings and part of nature, in order to give them proper treatment and prevent unnecessary suffering"

However, there is still no specific regulation that indicates the norms to protect and care for the welfare of these species in their different stages and productive processes, as is the case with livestock animals, for example.

Most salmon-producing companies in our country have procedures to safeguard the welfare of the fish, but due to the absence of regulation in this area, each company defines how it addresses this concept internally.

Is it important to take care of the physical and mental well-being of salmon? How do we avoid going to any extreme, technically speaking?

The way to objectively assess the welfare of animals, including their physical and mental state, is through indicators, which must be valid, reliable, and practical. We must consider environmental parameters, infrastructure, and management, which are called indirect or environment-based indicators. But, above all, we must observe the salmon, their swimming behavior, feeding, scaling, injuries, signs of diseases, etc. These are called direct or animal-based indicators. We know that salmon cannot communicate with words how they feel, but they do so through their behavior.

Do you currently believe that salmon are respected as sentient beings?

In my experience, I have observed that people who are in daily contact with fish care about their welfare through continuous monitoring, feeding, careful handling, behavior observation, tracking signs of illness, etc. However, they do not associate these usual practices with the concept of animal welfare, so initially, and despite practicing animal welfare, they may consider this concept distant and often associated with ideologies close to animalism and veganism.

On the other hand, we must consider that, as fish are phylogenetically distant from humans compared to mammals, it is very difficult for us to empathize with them. We cannot hear them vocalize and they lack recognizable facial expressions, which are main signals of human empathy. Therefore, it is essential to conduct training for staff from a sensitization perspective, in order to make them understand that fish are indeed capable of feeling pain, just not expressing it in the same way as humans.