Sprinkle the gelatin over the clam juice and allow to sit for 10 minutes to dissolve.
Add the gelatin, shrimp, mayonnaise, dill, Sriracha and salt to a blender and blend until smooth.
Whip the whipping cream until stiff peaks form.
Gently fold the shrimp mixture in to the whipping cream until thoroughly blended.
If piping, transfer the mixture to a piping bag. Stand the piping bag in tall cup and chill 1 hour until set. (Mixture can be refrigerated overnight before piping if desired).
If serving as a spread - coat a 2 cup container with cooking spray before filling with the mousse mixture and chilling. If you would like to unmold to serve, line a 2 cup mold with plastic wrap. Pour the mousse in and chill. To serve, turn the mousse out on to a serving plate and carefully remove the plastic wrap.
Garnish with fresh herbs, lemon or sweet piquillo peppers as desired.