Predicting the expected number of jellyfish is very important for marine biologists and the approach is taken by photographing polyps at the bottom of the sea which later reproduce to jellyfish. Counting polyps by hand is a long and tedious task, therefore the second part of this web application will be implementation of automatic counting and marking system. As we know such systems are not perfect and human intervention is often required. This thesis introduces a modern web application that includes components and interfaces for solving multiple image uploads, previewing and processing of images, including reviewing (adding, deleting, confirming, denying) automatically detected polyp markings and appropriate interaction between client, ...