A study was done in Jiaozhou Bay to look at the different types of small animals living in the mud at 10 different spots. Some areas had fewer types of animals and less variety than others. The places with more pollution or rough sand had less diversity. The mud areas had more types of animals. Over two years, the diversity was lower in spring and autumn compared to winter and summer. The evenness of the animals was highest in summer and lowest in spring. The number of different species was a bit higher in winter and lower in autumn. The researchers think that human activities might be affecting the diversity of these small animals in the bay.