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Background: Natural polyphenols have potential therapeutic effects on colon-based diseases and gut microbial dysbiosis. However, the delivery of pure polyphenols to the colon has to overcome chemical instability, de- gradation, and metabolism in the upper gastrointestinal tract after oral ingestion. Dietary fibers have been exploited as microbiota-triggered release systems to protect polyphenols in the upper gut and specifically deliver them to the colon. 

Scope and approach: This review focuses on the recent development of colon-targeted polyphenol delivery systems using encapsulation technologies based on dietary fibers for both food and pharmaceutical applications. The detailed characteristics and advantages of commonly used dietary fibers and the main mechanisms of en- capsulation preparation are discussed. The challenges of targeting the colon and the colonic health benefits of polyphenols are elaborated. In addition, the scope for specific modulation of gut microbiota by the selective combination of polyphenol and dietary fiber is highlighted. 

Key findings and conclusions: The microbial-triggered release mechanisms of dietary fiber-based delivery systems maintain the structural integrity and protect the polyphenols during passage through the harsh environment of the upper gastrointestinal tract to maximize their concentration in the colonic region. In addition, dietary fibers offer several advantages over other materials for polyphenol encapsulation and delivery, including strong dietary fiber-polyphenol binding interactions, high colonic mucoadhesion, and synergistic prebiotic effects from dietary fiber and polyphenol that result in health benefits for the colon and the body. 

Background: Feed additives which can ease the negative effects of infection by the Aleutian mink disease virus (AMDV) are of interest to mink farmers. The effects of kelp meal (Ascophylum nodosum) supplementation on immune response, virus replication and blood parameters of mink inoculated with AMDV were assessed. AMDV-free black mink (n = 75) were intranasally inoculated with a local strain of AMDV and fed a commercial pellet supplemented with kelp meal at the rates of 1.5% or 0.75% of the feed or were kept as controls (no kelp) for 451 days. Blood was collected on days 0 (pre-inoculation), 31, 56, 99, 155, 366 and 451 post-inoculation (dpi). 

Results: No significant difference was observed among the treatments for the proportion of animals positive for antibodies against the virus measured by the counter-immunoelectrophoresis (CIEP), viremia measured by PCR, antibody titer measured by quantitative ELISA, total serum protein measured by a refractometer or elevated levels of gamma globulin measured by iodine agglutination test at the sampling occasions. At the termination of the experiment on 451 dpi, there were no differences among treatments for antibody titer measured by CIEP, total serum protein, albumin, globulins, albumin:globulin ratio, alkaline phosphatase, gamma-glutamyl transferase, and proportions of PCR positive spleen, lymph node or bone marrow samples, but blood urea nitrogen and creatine levels were significantly lower in the 1.5% kelp supplemented group than in the controls. 

Conclusion: Kelp supplementation improved kidney function of mink infected with AMDV with no effect on liver function, immune response to infection by AMDV or virus replication. 

Since it was introduced to Zanzibar (Tanzania), seaweed farming has significantly contributed to local, socio-economic development. However, several investigations have shown impacts on the coastal environment near where the farms are located. As many seaweed farms are located on seagrass beds, there is a risk that seaweed farming could affect seagrass beds, and thereby disturb important ecosystem functions and the flow of ecological goods and services. This study compares characteristics of macrophytes (focusing on seagrasses), benthic macrofauna and sediment in seagrass beds, with and without seaweed farms, and a sand bank without vegetation in Chwaka Bay, Zanzibar. The results showed that seagrass beds underneath seaweed farms generally had less seagrass and macroalgae, finer sediment, lower sediment organic matter content and a reduced abundance and biomass of macrofauna, than seagrass beds without seaweed farms. Further, the macrofaunal community structure in seaweed farms showed more similarities to that on the sand bank than in the unfarmed seagrass beds. Most of the dissimilarity was attributable to Lucinidae (suspension-feeding bivalves), which were almost absent in the seaweed farms, resulting in the large difference in biomass between the seaweed farms and the unfarmed seagrass beds. When interpreted together with information from farmers, the observed pattern is believed to be caused by the seaweed farming activities. This indicates that more research is needed to establish the effects of seaweed farming on seagrass beds, and that more attention should be given to the location of farms and the choice of farming methods.

Resources survey of algae and seagrasses in 63 estuaries and backwaters existing from Madras to Athankarai in Tamil Nadu and Pondichery was made during 1988-89. Among these water bodies, only 44 supported vegetation. Totally 36 species of algae belonging to 23 genera under the groups Chlorophyta, Phaeoph~ta,R. hodophyta and Cyanophyta, and 5 species of seagrasses belonging to 3genera were recorded from these estuaries. The agar yielding seaweeds Gracilaria arcuata and G. verrucosa and carrageenan yielding seaweed Hypnea valentiae occurred in harvestable quantities in some estuaries.