I completely agree with Reevolver's critique. I can guess at the main point of what you are trying to communicate, but it's not completely clear. I assume that the shark wants to eat the bird, but the bird is in love with the shark. It's an original idea for sure, it just might need to be more clear.
The character design has appeal, and as Reevolver has given you a good critique of the form and shape I will focus on the color and lighting. Right now the image is completely flat and there's no sense of light direction. Maybe this was intentional as this is a comic, but I could imagine the scene having more appeal and impact if there was a stronger sense of lighting. Try to remember when you paint that local object color (blue water, grey shark, pink gums, white teeth) should be strongly affected by the light in the scene. I suggest trying to start with showing a single light source (the sun), coming from a single direction and have shadowed areas and lit areas. Right now the light is coming from every direction.
Overall, it's a good start. I suggest working on your story telling element first. Make sure the message is communicated well with the character posing. Then you can try more with the light and color.