It is probably advisable that you give consideration to watermarking and fingerprinting the digital material you produce as a safety mechanism if your resources are of value. If your project aims to make your resources available for non-profit, educational use, your online images will be of comparatively low quality and you have a copyright statement on your site then watermarking will probably not be necessary for your images. If you feel that your money could be used more constructively in another way then you are free to do this.