While many countries do not even protect marine mammals by law, which is one of the most widespread subcategories of aquatic animals being noticed, some countries extended legal protections to decapods. There are some countries recognizing the protection of decapods under their animal welfare legislation, yet it is not certain if those regulations are actually enforced.
With that being said, Canada includes cephalopods and “some other higher invertebrates” in its Canadian Council on Animal Care.
New Zealand protects such decapods as crabs, lobsters, and crayfish in its Animal Welfare Act of 1999. Section 2 of the Act provides:
In this Act, unless the context otherwise requires,—
accredited reviewer means a person accredited under section 109 to carry out independent reviews under section 105
aircraft has the meaning given to it by section 2 of the Civil Aviation Act 1990
(a) means any live member of the animal kingdom that is—
(i) a mammal; or
(ii) a bird; or
(iii) a reptile; or
(iv) an amphibian; or
(v) a fish (bony or cartilaginous); or
(vi) any octopus, squid, crab, lobster, or crayfish (including freshwater crayfish); or
(vii) any other member of the animal kingdom which is declared from time to time by the Governor-General, by Order in Council, to be an animal for the purposes of this Act;” [...]
In Norway, Section 2 of the Animal Welfare Act of 2009 says:
“The Act applies to conditions which affect the welfare of or respect for mammals, birds, reptiles, amphibians, fish, decapods, squid, octopi, and honey bees. The Act applies equally to the development stages of the animals referred to in cases where the sensory apparatus is equivalent to the developmental level in living animals.”
Only a very few countries list decapods in their legislative acts, but whether those regulations are actually enforced is another issue. The high demand for seafood all over the globe is raising more and more concerns for animal advocates and environmental law activists due to the objective to free animals from abuse/cruelty and to save the planet. Keeping our oceans full and healthy is a possible goal to achieve by understanding a very simple and logical thing - all inhabitants depend on one another, and if some aquatic animals begin to disappear, it causes other aquatic animals who are fed with them to disappear too due to the lack of food. A great example can be made with sharks who are at the top of the food chain in the oceans, and many species of sharks feed on small size fish and invertebrates. Sharks are able to regulate the species abundance, distribution, and diversity, which can afterward impact the health of marine habitats.
Decapods are the source of food for other aquatic animals too, and, besides so many other existing threats, natural or man-made, there is a need to protect lobsters, crabs, prawns, and others by simply decreasing the demand for seafood and/or exotic food. Pain in invertebrates is a complex question that has always required and still requires a lot of debates and studies from a scientific point of view. Definitions of pain and suffering vary, but because of the complexity of determination of pain, it is not sufficient to just observe the animals. Rather, the reasoning of whether a certain animal is capable of feeling pain/suffering derives from their physical and behavioral reactions. If decapods have demonstrated their suffering, fear, and pain reaction according to the studies, these animals are sentient and shall be recognized by the legal system.