Colonization of fiber-glass plates by benthic diatoms from subtidal sediment off the coast of Yucatan, Mexico

Abstract

Benthic diatoms thrive in many types of substrata, either natural or alternative such as the surfaces of large and small boats in which colonization by micro- and macro-organisms (fouling) represents an important economic and environmental problem. Addressing this issue is difficult given the scarce information on benthic diatoms one of the main micro-fouling settlers. Thus, this study aimss to describe the colonization process by diatoms on fiber-glass plates and construct a floristic list of the diatom taxa growing both on these surfaces and their likely source the subtidal bottom sediment. The study was conducted at a coastal site off Telchac, Yucatan (Mexico), where fiber-glass plates were laid over the bottom sediment at a depth of 10 m during four months. Sampling was carried out over successive spaced points in time (1st, 3rd, 4th, 8th, 12th and 16th weeks) after the initial immersion of the plates. At the end 88 taxa growing on the plates and sediment were identified, the most abundant ones being Cocconeis scutellum var. parva, Cymatosira lorenziana, Paralia sulcata, Delphineis surirella var. australis, Actinoptychus senarius, Grammatophora marina and Shionodiscus oestrupii. Included were two new records for the Mexican littorals: Cocconeis latestriata and Navicula uniseriata. Overall species composition differs from previous studies in the area, to which forty-seven taxa are added here, increasing their total number to 210. Our results show the changes in the species composition of the taxocenosis over time, during the initial colonization period, i.e., the period during which there is no intense competition for space. The high percentage of common species between the plates and sediment (similarity) support the hypothesis that subtidal sediment is the most likely source for diatoms colonizing the plates.