Effects of poly(L-lactic acid) (PLLA), as a purportedly environmentally benign antifoulant, on the adhesion behavior of the marine mussel Mytilus galloprovincialis were studied. PLLA-casting sheet samples having different molecular weights, which were prepared by treatment with super-heated steam, were subjected to a mussel adhesion test. The numbers of attached mussels and byssus threads produced by them on the sheet decreased with a decrease in the molecular weight of PLLA, while no vital effect was observed on the mussels. These results indicate that the lower the molecular weight of PLLA, the more significant the effect on mussel adhesion behavior, without any toxic effect.

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Coral reefs, seagrass beds, and mangrove forests possess abundant fauna and form the coastal landscape in tropical and subtropical zones. These ecosystems have also been subjected to anthropogenic disturbances. Population genetics using genetic markers are useful to estimate genetic differentiation. If populations are genetically diverged by geographic and oceanographic factors, the differentiation will accumulate and form the genetic structure. Biological features such as reproductive mode also influence genetic differentiation among populations. In reef-building corals, compared to brooding species, broadcast-spawning species indicates lower genetic differentiation among populations. Furthermore, other historical factors might influence the genetic differentiation. Here, we review the genetic differentiation pattern for understanding the maintenance system of reef-building coral, seagrass, and mangrove species and is helpful for the conservation of these coastal ecosystems.

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