Colonization dynamics of periphytic ciliates at different water depths in coastal waters of the Yellow Sea, northern China

Abstract

The colonization features of ciliate communities have proved to be a useful tool for indicating water quality status in aquatic ecosystems. To determine an optimal water depth for bioassessment using these ecological bioindicators, the colonization process of periphytic ciliates was studied at four depths of 1, 2, 3.5 and 5 m in Chinese coastal waters. Samples were collected at time intervals of 3, 7, 10, 14, 21 and 28 days using glass slides. The periphytic ciliate communities represented similar colonization dynamics from a depth of 1 to 3.5 m: (1) the temporal variability was well fitted to the MacArthur-Wilson and logistic models; (2) the species composition reached an equilibrium during the exposure time periods of 10–14 days; and (3) the maximum abundances were definitely higher at a depth of 1 m than those at 3.5 m. PERMANOVA test revealed that the colonization pattern at 1 m depth was significantly different from those at the other three depths. Results suggest that the colonization dynamics of periphytic ciliates may be influenced by water depth in coastal waters. These findings provide an important reference for establishing an optimal sampling strategy for bioassessment on large spatial/temporal scales in marine ecosystems.

Colonization features of marine biofilm-dwelling protozoa in Chinese coastal waters of the Yellow Sea

“…This suggests that colonization by periphytic ciliate communities is influenced by variations in food supply that, in turn, is correlated with physical-chemical conditions, e.g., sunlight, nutrients, etc., at different depths in the water column. Using distance-based redundancy analysis ordinations, Sikder et al (2019a) demonstrated that the colonization process at 1 m depth occurs in three separate stages ( Fig. 6) which is consistent with earlier reports such as Bamforth (1982), Mieczan (2010), Xu et al (2009a, b), and Zhang et al (2012Zhang et al ( , 2013.…”

“…Furthermore, the colonization curves and the increase in abundance of biofilm-dwelling ciliates and other protozoa closely fitted the MacArthur-Wilson model, and a logistic equation showed differences in functional parameters, i.e., S eq , G and T 90%, representing equilibrium species numbers, colonization rates and the time to 90% S eq , respectively, among different depths in the water column ( Fig. 1a-h; Sikder et al 2019a).…”

“…6). Sikder et al (2019a) also observed that the colonization rate (G), equilibrium species number (S eq ,) and carrying capacity (N max ) showed vertical variability from depths of 1-5 m in the water column. The highest values of each were measured at 1 m depth; while, lower values were found at 2 m, 3.5 m and 5 m ( Fig.…”

“…To use colonization dynamics of periphytic ciliates as pollution bioindicators, it is necessary to determine the optimal depth in the water column for community and ecological research. Sikder et al (2019a) reported that patterns of colonization dynamics by marine periphytic ciliates differed among four water depths. The colonization dynamics of the ciliates fitted the MacArthur-Wilson and logistic equation models at different depths (i.e., 1 m, 2 m and 3.5 m) and the projected maximum values of abundances denoted a declining tendency from a depth of 1 m-5 m (Fig.…”

“…1a-c) suggesting that lower light intensity in deeper water depths might influence the availability of food supply and, therefore, the periphytic ciliate colonization process. Sikder et al (2019a), thus, represents an important reference for adopting an ideal sampling plan for bioassessment using marine periphytic ciliates. In the case of Chinese coastal waters of the Yellow Sea, 1 m appears to be the optimal depth for sampling periphytic ciliate communities.…”