There are many kinds of art that the subject is animals that includes the marine species. One of the art that is created is making of an animal silhouette. It is now a widespread trade as many people make their own kind of silhouette whether professionally as an artist or one that sells the crafts of animal silhouette personally made. There are artists or people who love animals especially their pet who makes the silhouette of their own pet and displays it in their home.
You can see a jewelry in the image that was made from the silhouette of a dog. There are many that could be found online that you can buy or in many physical stores around the world that sells them. They are treasured and other animals are available like dolphins, cats, owl, rabbits and many more.
Other people make the silhouette of their own pets in a paper or other art materials and preserved them and use it as decorations. It is a nice sight to see anytime.
Others use photography to produce an art with their pets. They can also put the silhouette in other art perspective and this is the result.
In the image is a dog and its owner or trainer took in a very nice background that captures their silhouettes and makes the phot more interesting and relaxing to see that the just plain picture of an owner and a dog.
Whatever style of art you like it all depends on you as it has no limitations.