Marine collagen peptides are made in the same way that other collagen is, it’s just different animal bi-products that are used.
Fish scales, bones, crustacean shells and other sea creatures are boiled down to make gelatin which is then put through a process called hydrolysis.
The general consensus is that Marine collagen is superior to other collagens and the claims include: Marine collagen is more effective for joint health and skin health; Marine collagen is more sustainable and Marine collagen is more humane.
However, research shows that Marine collagen is not clinically better and in fact, may actually be inferior. Why? Because Marine collagen is only made up of Type 1 collagen - this means it only supports skin, hair and bones; whereas, Bovine is made up of both Type 1 and Type 3 collagen, meaning it not only supports your skin, hair and bones, but your muscles, arteries and organs too.
Marine collagen isn’t necessarily an animal bi-product, which means the animal is being used for one thing and one thing only. Bovine collagen is produced from cowhides, which are also used to produce the leather for the car industry, making it more financially effective and sustainable, unlike fish scales which are rarely used for anything else.
(Source: WillPowders UK)