Karnataka has a coastline of about 320 km starting from Talapadi in the south to Karwar in the north. Ecology of tidal pond in Mavinahole estuarine creek, Karwar was studied in 1979 by Bopaiah and Neelakantan (1982). Table 6 lists taluk-wise distribution of seaweed species in Uttara Kannada district, which are Â mostly confined to rocky shores. 43 species of marine algae in the littoral zone of the entire Karnataka coast was reported earlier (Agadi, 1985). NAAS (2003) reported 39 species of seaweeds from Karnataka coast, 39 species of seaweeds from Karnataka coast (Venkataraman and Wafar, 2005; Kaladharan, 2011) and Untawale et al. (1989) reported 65 species belonging to 42 genera from the northern Karnataka coast alone.

Table 6. Distribution of Seaweed species in Uttara Kannada district
SEAWEED SPECIES	KARWAR	ANKOLA	KUMTA	HONAWAR	*BHATKAL**
Amphiroa fragillissima (Linnaeus) Lamouroux	+			+	+
Bangia autopurpurea var.fuscopurpurea (Dillwyn) C.Agardh	+
Caulerpa peltata J.V. Lamouroux	+			+	+
Caulerpa racemosa (Forsskal) J. Agardh				+	+
Caulerpa scalpelliformis (R.Brown ex Turner) C. Agardh				+	+
Caulerpa sertularioides (S.G.Gmelin) M.A. Howe				+	+
Caulerpa taxifolia (Vahl) C.Agardh				+	+
Caulerpa verticillata J. Agardh				+	+
Chaetomorpha linum (Muller) Kutzing	+			+	+
Chaetomorpha media (C. Agardh) Kutzing	+		+	+	+
Dictyopteris australis (Sonder) Askenasy	+			+	+
Dictyota bartayresiana Lamouroux	+		+	+	+
Dictyota dichotoma (Hudson) Lamouroux	+			+	+
Enteromorpha clathrata (Roth) J.Ag	+	+	+
Enteromorpha flexuosa (Wulf) J.Ag.	+	+	+	+
Enteromorpha intestinalis (Linnaeus) Nees	+	+	+	+
Gelidium micropterum Kutzing	+	+	+	+	+
Gelidium pusillum (Stackhouse) Le Jollis	+	+	+
Grateloupia filicina (Wulf.) Ag.	+	+	+	+	+
Grateloupia indica Borgesen				+	+
Grateloupia lithophila Borgesen.			+		+
Gracilaria corticata J. Agardh	+	+	+	+	+
Hypnea valentiae (Turner) Montagne	+	+	+	+	+
Jania adherence Lamouroux	+		+
Laurencia cartilaginea Yamada	+			+	+
Laurencia obtusa (Hudson) Lamouroux	+
Laurencia papillosa (C. Agardh) Greville	+		+	+	+
Padina gymnospora (Kutzing ) Sonder	+	+	+	+
Padina tetrastromatica Hauck	+			+	+
Porphyra vietnamensis T.tanaka & Dham-Hoang Ho	+			+	+
Sphacelaria furcigera Kuetz	+			+	+
Spatoglossum asperum J. Agardh	+				+
Sargassum cinereum J. Agardh	+	+	+	+	+
Sargassum ilicifolium (Turner) C. Agardh	+		+	+	+
Sargassum polycystum C.Aga	+			+	+
Sargassum tenerrimum J. Agar	+			+	+
Sargassum wightii Greville	+				+
Stoechospermum marginatum (C. Agardh) Kutzing	+			+	+
Ulva fasciata Delile	+	+	+
Ulva lactuca Linnaeus	+	+	+	+
Ulva rigida C. Agardh					+
Source: Agadi, 1985; Untawale et al., 1989; NAAS 2003, Venkataraman and Wafar, 2005; Kaladharan, 2011; * http://www.niobioinformatics.in/seaweed/index.htm

Uttara Kannada district is endowed with four productive estuaries namely Kali estuary in Karwar, Gangawali estuary in Ankola, Aghanashini estuary in Kumta, Sharavathi estuary in Honnavar. Aghanashini estuary situated in Kumta taluk on the rive Aghanashini, this estuarine region extends from the river mouth to about 25 km upstream. The Aghanashini estuary has several mudflats and small islands and network of drainage canals called kodis. Farmers of this region traditionally cultivated a variety of salt tolerant rice- “kagga” in large expanses of the reclaimed backwaters, called gaznis, also known as Kharlands or Khajans. In these gazni land, farmers practice alternate rice cultivation and prawn filtration. There are few abandoned gazni in these estuarine region which could serve as a potential site for seaweed cultivation. (Suryanath ,1985). Table 7 lists the distribution of seaweeds along west Coast of India with the wide scope for biofuel production. There is a potential to develop large scale cultivation of seaweeds in west coast of India with optimization of existing labour intensive cultivation and harvesting technologies to reduce cost and energy demand. Extraction of value added products from macro algal biomass along with bioethanol production, further boosts the livelihood of local people while meeting the energy demand.

Table 7: Distribution of potentialÂ Seaweeds along West Coast of India as a feedstock for Biofuel production
SEAWEED	GUJARAT	MAHARASHTRA	GOA	KAR	KER
Amphiroa fragillissima	+	+	+	+
Acanthophora specifera	+	+		+	+
Bangia fuscopurpurea		+	+	+	+
Bryopsis plumosa	+	+	+	+
Caulerpa peltata	+	+	+	+
Caulerpa racemosa		+		+
Caulerpa scalpelliformis	+	+		+
Caulerpa sertularioides		+		+
Caulerpa taxifolia		+		+
Caulerpa verticillata				+
Chaetomorpha linum	+	+	+	+
Chaetomorpha media	+	+	+	+
Cheilosporum spectabile	+	+	+	+	+
Cladophora fascicularis	+	+	+		+
Dictyopteris australis	+	+	+	+Â Â Â Â Â Â Â Â Â Â
Dictyota bartayresiana	+	+	+	+
Dictyota dichotoma	+	+	+	+
Enteromorpha clathrata	+	+	+	+
Enteromorpha flexuosa	+	+	+	+	+
Enteromorpha intestinalis		+	+	+	+
Gelidium micropterum	+	+	+	+
Gelidium pusillum	+	+		+
Grateloupia filicina		+	+	+
Grateloupia indica	+	+	+	+
Grateloupia lithophila		+	+	+
Gracilaria corticata	+	+	+	+
Gracilaria verrucosa	+	+	+
Hypnea musciformis	+	+	+	+
Hypnea pannosa	+	+		+
Hypnea valentiae		+	+	+
Jania adherence		+	+	+
Laurencia cartilaginea		+	+	+
Laurencia obtusa	+			+
Laurencia papillosa	+	+	+	+
Padina gymnospora	+	+	+	+
Padina tetrastromatica	+	+	+	+
Porphyra vietnamensis		+	+	+
Sphacelaria furcigera	+	+	+	+
Spatoglossum asperum	+	+	+	+
Sargassum cinereum		+	+	+
Sargassum ilicifolium	+	+	+	+
Sargassum polycystum	+	+	+	+	+
Sargassum tenerrimum	+	+	+	+
Sargassum wightii		+	+	+	+
Stoechospermum marginatum		+	+	+
Ulva fasciata	+	+	+	+	+
Ulva lactuca	+	+	+	+	+
Ulva reticulata	+	+	+	+	+
Ulva rigida	+			+
Source: http://www.niobioinformatics.in/seaweed/index.htm

Prospects of Bioethanol from Macroalgae

Considerable work has been carried out with respect to commercial production of agar and algin from macro algae in India. Different microorganisms are being employed for effective conversion of seaweed polysaccharides as well as of fermentation processes, in order to commercialize macroalgae based fuels, a priority needs to be put on identifying microorganisms that metabolizes macroalgal carbohydrates. Alginate and Ulvan are macroalgae specific carbohydrate which are not readily metabolized by commercially applied fermenting microorganisms such as saccharomyces cerevisiae (Wegeberg and Felby,2010). To overcome these constraints, macroalgae specific enzymes were developed to hydrolyze macroalgal carbohydrates (Erasmus et al., 1997; Jang et al., 2012). Â An attempt was made to cultivate red algae Kappaphycus alvarezii alongMandapam coast and demonstrated commercial scale production of bioethanol. Over the past twenty years, large scale cultivation of carrageenophytes (Khambhaty, 2012). Â In India, edible seaweeds such as Gracillaria edulis, Caulerpa spp., Poryphyra etc. can be cultivated along with biofuel feedstock seaweeds, in estuarine areas and coastal inundated waters. Appropriate technology for large scale seaweed cultivation is imperative to meet the growing energy demand. Implementing seaweed cultivation combined with post harvesting processing units could bring economic returns to seaweed cultivators.