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Most seaweed species that function as biofilters for finfish aquaculture have little market value, so produced biomass remains a by-product of biofiltration. This low value makes operation of these units economically difficult and is probably the key to today’s lack of industrial application of an otherwise highly feasible biofiltration method. 

The main goal of a seaweed biofilter design should be the production of marketable biomass, which would then turn aquaculture effluent from a nuisance into a resource, and its biofiltration into a positive side effect. 

Members of the marine plant ecology research group of the Center for Marine Sciences at the University of Algarve in Portugal have successfully established a commercially diverse seaweed biofilter using the tetrasporophyte of the red seaweed Asparagopsis armata. The plant is also referred to as Falkenbergia rufolanosa. 

F. rufolanosa produces high levels of biologically active secondary metabolites. Among these compounds are natural antibiotic, antifungal, and anti-viral substances that are marketable for a wide range of applications in the fields of antifouling, cosmetics, and medicine. 

Conventional biomass sources have been widely exploited for several end uses (mostly food, feed, fuel and chemicals). More unconventional sources are continually being sought for meeting the growing planetary demands for biomass materials. Biofuels are already commercially produced in many countries and are becoming mainstream. The role of biorefineries for production of chemicals is also on the rise. Plant biomass is the primary source of food for all multicellular living organisms. Primary production remains a key link in the chain of life support on planet Earth. Is there enough for all? What new strategies (or technologies) are available or promising for providing plant biomass in a safe and sustainable way? What are the potential impacts (footprints and efficiencies) of such strategies? What can be the limiting factors—land, water, energy and nutrients? What might be the limits for specific regions (OECD vs. non-OECD, advanced vs. developing, dry and warm vs. wet and cool, etc.). In this paper, we provided answers to these questions by critically reviewing the pros and cons associated with current and future production and use pathways for biomass. We conclude that in many cases, the jury is still out, and we cannot come to a solid verdict about the future of biomass production and use.

The importance of algivorous animals in the ecology of economic seaweeds has been recognised by many workers (Tilden, 1927; Leighton, 1960; Chapman, 1962; North, 1962, 1963; Boney. 1966). In recent years many studies have been made to ascertain the food and feeding habits of major algivores, the important among which are by Barkman ( 1955), van Dongen (1956), Bakker (1959), Satio and Nakamura (1961). Leighton and Boolootian (1963), Leighton (1966), Paine (1963) and Paine and Vadas (1969). In order to study the role of algivores in the ecology of cultivatable marine algae and to ascertain the nature of discri_ mination in the choice of algal food by them, a study was undertaken during 1968- '71 at tbe Marine Algal Researcb Station, Mandapam. This paper presents tbe findings pertaining to the cbief algivorous gastropods in tbe Gulf of Mannar and Palk Bay region.

Culture of agar yielding red alga Gracilaria edulis was canied out using fiberglass tanks in onshore condition under a shed with transparent roof and providing running seawater system and aeration. The seed material was pretreated for 12 hours at different concentrations of Urea, NPK, Superphosphate, Di-ammonium phosphate, Ammonium sulphate, Organic fertilizer, Organic mixture, Potash, Ammonium Chloride, Calcium nitrate, Magnesium sulphate and Ferrous sulphate. In general, the growth and biomass of cultured seaweed were found to be more in plants treated with low concentrations of these fertilizers than untreated and plants treated with higher concentrations. Data on the environmental and hydrological parameters from seaweed culture tanks were recorded.