The researchers studied the diversity and distribution of small sea creatures in the southeast Caspian Sea. They looked at factors like depth, temperature, and sediment type. They found over 4,000 individuals from different species, with worms being the most common. The creatures were most abundant in autumn and least in summer. The environment factors like salinity and sediment type played a big role in where the creatures were found. Some species preferred muddy areas, while others liked sandy ones. Overall, the study showed how different factors influence where these sea creatures live in the Caspian Sea.