Effects of the coastal sediment elutriates containing persistent organic pollutants (POPs) on early reproductive outputs of the Pacific oyster, Crassostrea gigas.

We previously found that embryonic development of the bivalve species was highly vulnerable to xenobiotic chemicals, damaging the coastal ecosystem integrity To further assess their potential damage to ecosystem, the xenobiotic composition of the sediment elutriates from two representative industrialized Korean coasts, Pohang and Ulsan, were determined with gas chromatography/mass spectrometry (GC/MS). The presumed critical dilution of the elutriate was then exposed to early life stages of the Pacific oyster (Crassostrea gigas), embryonic development and metamorphic stage to first spat, at which they were believably more vulnerable by the chemical exposure. The early life damage by the xenobiotic exposure was apparently significant by the significant degree of pollution. Here, we indicated their potential damages to the Pacific oyster

Comparison of the effectiveness of four organic chemoattractants towards zoospores of Ulva pertusa and macrofouling.

Algal spores respond to many environmental variables, especially to chemical "cues". This chemotactic response can be utilized to attract spores, thereby colonization of a new substrata is possible to be influenced. In this attempt, four chemoattractant candidates were screened against spores of Ulva pertusa to reveal their efficiencies. Attachment and subsequent germination of Ulva spores were effectively influenced by these chemoattractant candidates. In particular 100 microg cm2 of D-glucose coating was found to enhance spore attachment by > 150%. Furthermore, field investigations carried out with test panels, clearly indicate the chemoattractive properties of test coatings. In recent years, various anthropogenic activities and natural hazards cause detrimental impacts on the benthic algae and other fishery resources. Artificial reefs have been laid on many coastal regions to increase or restore marine resources. Chemoattractant coatings can be applied on artificial surfaces to increase the colonization of benthic forms. It also can be used in the mariculture devices. Influence of chemoattractants on Ulva spores and fouling biomass estimated on test panels are discussed.

Macrobenthic community at type and age-different artificial reefs located along the Korean coast of the East Sea.

Two types of artificial reefs, one for simple (S-AR), another for complex artificial reef (C-AR), were installed on a Korean coast of the East Sea (Sea of Japan) where a barren ground was progressive. Compared with macrobenthic organisms at NHB (natural hard bottom) control, AR (artificial reef) enhanced seaweed composition, reducing echinoderm composition, mostly sea urchins, the causative animal of the barren ground. Composition of the two mutually exclusive communities was AR type-specific, the C-AR exerting betterfunction over S-AR by enhancing higher seaweed composition. However this ecosystem-sound composition at C-AR was maintained only within 10 years. Another negative aspect of the AR was an unexpectedly higher composition of tunicates that canbe a sign of nutrient-rich environment in the Korean waters. Overall, CAR was more agreeable when simply based on its function excluding construction cost.