1

CULTIVATION OF GIGARTINA SKOTTSBERGII AND SARCOTHALIA

CRISPATA IN CHILE

MARCELA AVILA1 & HECTOR ROMO2 1 Division de Investigacion en Acuicultura, Instituto de Fomento Pesquero, Balmaceda 252, Puerto Montt, Chile 2 Departamento de Oceanografia, Universidad de Concepción, Casilla 160-C, Concepción, Chile. CONTENTS

1 Introduction 2 Species, morphology and distribution

a) Gigartina skottsbergii b) Sarcothalia crispata

3 Life history 4 Mass culture of spores 5 Maintenance of thallus from juvenile to adult 6 Carrageenan industry in Chile 7 References

Figure 1. Distribution of G. skottsbergii in southern Chile.

2

INTRODUCTION Marine macroalgae have gained an important place among Chilean fishery resources and today, the country is the largest producer in the western hemisphere. Around 21 species are commonly exploited, representing a total output volume of 44,038 dry tons in 2003. Furthermore, the growth achieved by the hydrocolloid and dry seaweed industries has been significant, representing US$ 87.5 million dollars in 2003. Today, Chile is at the same level of production as other leading producing countries namely Japan, Korea, China and Taiwan for seaweed products. Out of all the commercial seaweed species exploited yearly (Avila & Seguel, 1993), only “pelillo”, i.e. Gracilaria chilensis, is being produced under cultivation. This practice is now regulated, and goes back to the early 80’s, when the Gracilaria was cultivated by vegetative propagation. In the mid 90’s, the practice of nursery renewal and “pelillo” production from spores was introduced, using techniques developed by Alveal et al. (1994, 1995 and 1997). Since then some cultivation centers have gradually gone into mass production and improved their method (R. Rojas, pers. Comm.). Overall Gracilaria cultivation, both vegetative and through spores, represents over 80% of the total annual production; the remaining 20% corresponds to natural populations that are not subject to government regulation. Gigartina skottsbergii Setchell & Gardner is the is the most important Chilean seaweed for commercial exploitation currently recognized by experts (Hommmersand et al., 1993, 1999). The second group in importance includes the genera Sarcothalia and Mazzaella which also serve as raw material for carrageenan production. Since 1990, Gigartina has been the main raw material for hydrocolloid carrageenan production, a gel of multiple applications in the meat, dairy, pastry and cosmetics industries. Due to the product’s high demand from the local carrageenan industry and from other countries as raw material, there has been a drop in biomass of natural populations. Therefore extractive pressure in the harvesting areas has moved some 600 to 1000 kilometers towards the south, around the areas of Golfo de Penas in the XIth Region, and Puerto Natales and Punta Arenas in the XIIth Region (Fig. 1). In contrast with this extractive pressure, the biology of the species has only begun to be seriously investigated during the last decade including the phenology of its reproductive behaviour, and population management in the Islands of Chiloe (Zamorano & Westermeier, 1996; Avila et al., 1999a; Marin et al., 2002) and the biological bases for its cultivation and management (Buschmann et al., 1999a, 1999b, 2001a & 2001b; Avila et al., 2003a). In addition, Correa et al. (1999) suggested using vegetative propagation, especially the regeneration responses of G. skottsbergii thalli.

3

The topography of the coast, channels and archipelagos of the area between the Island of Chiloé and Cape Horn (Fig. 2) offer environments of unparalleled potential for aquaculture, including the cultivation of Gigartina (Romo et al., 2001b) and other algal species. Thus, Romo et al. (2001a), Avila et al., (1999b), and Avila et al., (2003b) report data on the technical and economic feasibility for cultivating Sarcothalia crispata. Therefore, diversification of seaweed production would include three possible species (including Gracilaria) for cultivation. This activity would contribute not only to maintain or increase the production of commercial algae; it may also serve as a restocking tool against over exploitation, or in the event of natural and anthropogenic disasters (Romo, 1988).

Figure 2. Collection sites from natural beds. SPECIES, MORPHOLOGY AND DISTRIBUTION a) Gigartina skottsbergii

Division: RHODOPHYTA Class: Rhodophyceae Subclass: Florideophycidae Order: Gigartinales Family: Gigartinaceae Genus: Gigartina Species: Gigartina skottsbergii Setchell & Gardner (1936) Common name: Luga roja, cuero de chancho, pork skin.

The thallus is laminar and ellipsoidal (Fig. 3 ), where the smaller axis corresponds to the height of the frond and the larger one to its width, in a height : width rate of approximately 2 : 3. In mature plants of harvestable size, the fronds reach up to 40 cm in height and 60 cm in breadth, but in very old plants from the archipelagos in the XIth and XIIth Regions, thalli of up to 1.60 m in breadth have been found. The laminae are

4

often lobulated, undulate and, occasionally chordate, always keeping the general ellipsoidal shape. They are of fleshy consistency, purple to deep red in color, and up to 1.5 mm thick in the case of larger plants. At the basal end, there are numerous haptera of up to 1 cm long and 1.5-2.5 mm in diameter, which attach the frond to the substrate by its inferior face. These haptera are usually restricted to the basal zone but they may also develop in any zone of the inferior face of the frond, generating secondary attachment points. Through this system of attachment the species adopts a horizontal dorsal-ventral position on the substrate. Despite such arrangement, no differentiation of the pseudoparenchyma of the upper cortex is observed with respect to the lower one, either in color nor in cell size, so that it is assumed that both faces function with the same efficiency during the photosynthetic process. Gigartina skottsbergii is a strictly sub-littoral species which grows on rocky substrates at between 5 and 15 m or more (30 m) depth depending on the turbidity of the water or on the availability of a stable substrate, such as rocky reefs, blocks, boulders, or mussel banks (Fig. 4), which are frequently found associated with the lower stratum of Macrocystis communities in the southernmost (53° S) part of Chile. Fronds and holdfasts are perennial. In the north (43° S) it is found in close

association with diverse species of crustose, calcareous Corallinaceae and with foliose Delesseriaceae or filamentous Ceramiaceae. Gigartina skottsbergii is endemic to the southernmost part of South America (Ramirez & Santelices, 1991), therefore it inhabits temperate to cold waters. Its thermal tolerance range fluctuates between 14°C in its northern limit to about 4°C in the extreme south. In Chile, it is found from Valdivia, Niebla (39° 52’ S; 73°26’ W), to Cape Horn. It has also been described in the Antarctic Peninsula. Its distribution extends toward the Falkland Islands (Malvinas) and ascends through the South American Atlantic coast to the southern coast of the province of Chubut in Argentina (Piriz, 1966). b) Sarcothalia crispata

Class: Rhodophyceae Subclass: Florideophycidae Order: Gigartinales Family: Gigartinaceae Genus: Sarcothalia Species: Sarcothalia crispata (Bory) Leister ex Iridaea ciliata

Figure 3. Habit of Gigartina skottsbergii.

Figure 4. Subtidal beds of Gigartina skottsbergii.

5

Common name: Luga negra, luga lija, luga luga, luga ancha y nama, sand paper, broad leaf..

The morphology of this alga is varied. Fronds are of a greenish brown color. Laminar and broadly lanceolate fronds originate from a narrow stipe with numerous short ciliary proliferations (Fig. 5). Fronds are longer than they are wide and may reach lengths of up to 2 m. Cystocarpic plants have branched external papillae giving the thalli a rugous texture. Cystocarps develop within the thallus and never in the external papilla processes. Tetrasporic plants also produce sori within the thallus which are distributed throughout the frond. Fronds of vegetative plants as well as male gametophytes are completely smooth. Plants are made up of one or two broad laminae that attach to the substrate by means of a small disc. The plant is commonly known in Chile as ‘luga negra’ (black luga), ‘luga luga’, ‘luga lija’, ‘luga ancha’ (Broad leaf) and ‘nama’. It is found from the inter-tidal to sub-tidal areas (Fig. 6). It is abundant in sheltered areas and can be found from 0 m to approximately 10 m depth growing on rocks, mollusc shells and other solid substrata. It is frequently found in association with Ulva spp. It grows at temperatures that fluctuate between 9°C and 14.5°C. Fronds are annual and

the holdfast discs are perennial. The species is endemic to the Chilean coastline and can be found from Valparaiso (33º02’S; 71°38’ W) to Tierra del Fuego (Santa Maria 54°28’S; 68°59’W).

Figure 5. Habit of Sarcothalia crispata.

6

Figure 6. Subtidal bed of Sarcothalia crispata. Figure 7a. Habit of mature cystocarpic thallus of Gigartina skottsbergii.

Figure 7b. Mature tetrasporic thallus of Gigartina skottsbergii.

Figure 8a. Habit of mature cystocarpic thallus of Sarcothalia crispata.

Figure 8b. Mature tetrasporic thallus of Sarcothalia crispata.

7

Figure 9. Life cycle of Gigartina skottsbergii showing an isomorphic type.

Figure 10. Life cycle of Sarcothalia crispata showing an isomorphic type.

Figure 11. Tanks for the cultivation.

Figure 12. Mature fronds collected in the field and transported in boxes to the hatchery.

Figure 13. Seaweeds are partially dehydrated on the hatchery for one hour.

Figure 14. Suspension of spores ready to be spread on shells.

8

Figure 15. Scallop shells are spread across the bottom on tanks with filtered. seawater and fertilizer.

Figure 16. Released spores attached to the shells after 5 and 20 days.

Figure 17. Cultivation units (ten shells) ready to be transferred to the sea.

Figure 18. Long-line floating system.

Figure 19. Juvenile fronds after 7 months of cultivation in the sea.

Figure 20. Juvenile fronds after 11 to 16 months of cultivation in the sea.

9

Figure 21. Germlings of Sarcothalia after 5 days of cultivation.

Figure 22. Harvestable fronds of Sarcothalia cultivated in the sea for 8 months.

10

Figure 23. a) Rope with attached fronds, b) row of ten fronds attached to the ropes, c) detail of shell attachment to the ropes, and d) detail of frond attachment.

A B

A B

C

D

11

Figure 24.a) Young thalli of Gigartina in a pre-harvest stage, b) Adult thalli of harvestable Gigartina, c) Harvesting Gigartina, and d) Thirty-three month old cultivated Gigartina. The original size before drying was 1.5 m length (major diameter).

C

12

Figure 25. A case of extreme epiphytism. Heavy settlement of mytilids on a cystocarpic frond of Gigartina.

LIFE HISTORY The male thalli of Gigartina skottsbergii and Sarcothalia crispata are generally smooth fronds without papillae and proliferations, and produce spermatangia over most of the lamina. Spermatangia are superficial, formed over the most pigmented cortical cell layers and they develop pale spermatia in chains of 2 to 3 cells of 3-5 μm in diameter.

The female thalli form carpogonial branches of three cells. After fertilisation, a compact wrapping tissue forms around the auxiliary cell and the filaments of the gonimoblast are oriented towards the interior of the medulla . A compact group of nutritive filaments develops around the cystocarp (Kim, 1976). G. skottsbergii develop cystocarps in papillae that strongly project from the superior surface of the lamina (Fig. 7a ), while S. crispata cystocarps are immersed in the medulla (Fig 8a ). The tetrasporophytic thalli do not present papillae and develop tetrasporangial sori, either circular or ellipsoidal, over the whole frond. These sori are formed in the middle of the medulla (Figs 7b and 8b). The life cycle of G. skottsbergii (Fig. 9) and S. crispata (Fig. 10) correspond to the “Polysiphonia type” where tetrasporophytes and gametophytes have the same aspect; but the carposporophyte is different and develops its whole life inside the cystocarps of the female gamete. This carposporophyte is formed by the gonimoblast with its carposporangia and carpospores. Each cystocarp and/or tetrasporangial sorus can develop a few hundred carpospores or tetraspores, respectively. This species, like all those in the Rhodophyceae, presents a particular type of oogamic reproduction, in

13

which the egg cell or carpogonium which matures in the female gametophyte is fertilized by an non-motile spermatium. Furthermore, the elements of propagation, carpospores or tetraspores, lack flagella and are non-motile, pertaining to the category of aplanospores or spores lacking movement. Mature reproductive structures are observed year round, but the most cystocarpic plants occur in spring and part of the summer, while tetrasporangial thalli are particularly numerous in winter. Both kinds of reproductive structures sporulate more frequently in winter and early spring (Avila et al. , 1997, 1999a). MASS CULTURE OF SPORES G. skottsbergii is a sub-tidal alga, hence cystocarpic or tetrasporic reproductive material must be harvested by hooka divers from previously selected natural kelps beds preferably in the fall, winter and spring months (May – September) when there is greater abundance of reproductive biomass. Spores are more viable during fall and winter. Seeding can take place until the end of spring. Sarcothalia crispata forms large beds which run from intertidal to subtidal areas. Mature reproductive plants are best harvested from sub-tidal plots where they have fewer epiphytes. Cystocarpic and tetrasporic fronds are found from May to October (fall, winter and spring). Substratum preparation Before seeding, the substratum must be prepared for the attachment of germlings. Scallop shells are used as substrate. The shells are washed and brushed in fresh as well as in seawater. A 3mm drill is used to perforate a hole near the hinge of the shell through which a rope will be later threaded for cultivation at sea. The shells are placed at the bottom of each tank, with the convex side up (external side of the shell). The tank is filled with filtered and sterilized seawater and commercial liquid fertilizers at a rate of 0.1 ml fertilizer per liter of seawater (Fig. 11). Mature reproductive algae collected from natural kelp beds are separated according to their cystocarpic and tetrasporic reproductive phase at harvest so as to avoid any cross- contamination of spores. Whole fronds are selected and epiphytes that could later contaminate the crop are removed by hand. The algae are transported to the greenhouse in thermally insulated containers capable of keeping low temperatures (Fig. 12). Spore release Mature reproductive fronds that will be used to obtain the spores must be transferred to the greenhouse in isolated containers, under low temperature conditions to avoid sporulation. In the greenhouse, the fronds previously separated into cystocarpic and tetrasporic phases, undergo the same procedures described below. Reproductive phases must be seeded apart, since tetrasporic plants produce lambda carrageenan while cystocarpic and gametophytic fronds produce kappa carrageenan. The haptera of the fronds are discarded because they might have other seaweeds or spores that could contaminate the future cultures. The fronds are then thoroughly and repetitively rinsed

14

with running filtered seawater at least 3 times and brushed with soft brittle brushes, eliminating all possible vestiges of spores that could have been spontaneously released after collection and other seaweeds. Generally the stress suffered by the plants overnight, after being stored at low temperature in the dark, is sufficient to activate the sporulation mechanisms. To complete the preparation of the fronds, they are submitted to partial dehydration (Fig. 13), the fronds are spread out over a work bench (previously washed, and disinfected with 60° alcohol) and totally covered with absorbing drying paper in several layers, to better use the space available. They are left to dehydrate at least for one hour, at the end of which fronds will be ready for seeding. If the reproductive material is mature enough, this process will ensure good sporulation. Only mature reproductive material should be used. Simple training allows recognition by eye (or with the help of a magnifying glass) when the cystocarps or tetrasporangial sori are in an acceptably mature state. The partially dehydrated material is then hydrated, putting it in a plastic bucket at a ratio of 3 kg seaweed/20 L filtered seawater at 1 m, keeping it still and in darkness for 1 hour. During this period of time, carpospores and tetraspores (depending on the phase chosen) are released by the thousands from the reproductive structures into the seawater. It is important to mix the suspension occasionally to allow homogeneity of the spores in the seawater (Fig. 14 ). Once a pale to deep pink color is obtained, fronds are discarded from the bucket and the spore suspension is sieved through a 35 m phytoplankton net in order to remove any tissue residue and impurities that could be passed into the culture. Occasionally, the reproductive material may be used for a second sporulation, following the previous steps. Seeding Three aliquots are obtained from the suspension and transferred to a Sedgewick-Rafter cell count chamber where the average density is determined, the optimum range being from 6,000 to 10,000 spores/ml. If it is optimum they are spread out homogeneously at 3 l spore suspension per substrate stratum in the tanks (2 x 1 x 0.5 m), approximately 270 l (Fig. 15). If, on the contrary the suspension exceeds the optimum concentration it must be diluted or less than 3L must be added to each stratum. If the density falls below the optimum range higher volumes of spore suspension must be added to each substratum strata. After seeding, the tank must not be handled for approximately 5 days to allow good spore attachment on the substratum (scallop shells), germination, development and growth of the fixation discs on the substrate (Fig. 16a). Each tank seeded with spores is filled with filtered seawater and is fertilized with nutrients (nitrate and phosphorus).

15

MAINTENANCE OF THALLUS FROM JUVENILE TO ADULT Nursery stage Juveniles are kept in the greenhouse for 2 months with a regular exchange of water and nutrients every week. Excessive handling of substrates is to be avoided to encourage the spore settlement and disc formation on the scallop shells. Shade netting is used during this semi-controlled growth stage to reduce light intensity by 50% to 80% depending on the mesh, specially during the spring and summer months when light intensity can be higher than 20 moles.m- .s- . This is done both to avoid excess radiation that could affect germination and thallus growth in Gigartina and to inhibit microalgal contaminants. In case of any contamination occurring the scallop valves must be cleaned with small brushes and large amounts of seawater (Fig. 16b). After two months in the greenhouse shells with G. skottsbergii juveniles are removed from the tanks and attached to 30 mm rafia ropes in order to form the cultivation unit (Fig. 17). A cultivation unit is made up of 10 scallop valves threaded on a 1-m long rope. Each shell is attached to the cord with knots above and below the valve at a fist distance apart (±10 cm). When cultivation units are placed in the sea they should weigh 1 kg so

as to hang vertically in the water column. S. crispata juveniles are ready to be transferred to the sea after 45 days of cultivation. Pre-growth stage This stage has been called “pre-growth” because it includes care of the individual from the disc stage, through the formation of the primary laminae of the microthalli attached to the substrate at one sole point to a juvenile that looks like an adult plant with the initial formation of haptera for attachment. The best cultivation system for the pre-growth stage is the long-line system (Fig. 18). The ease with which the lines can be handled is one of the advantages when compared to a bottom cultivation system since the lines can be placed at different depths if needed (independently from variation in tidal level) no diving is needed for cleaning them and sporadic maintenance of the crop is possible. The double long-line,( 100-m long, 10mm diameter) is used for the cultivation of G. skottsbergii and S. crispata semi-sheltered bays. The system includes two 10-mm mother lines in parallel, 0.8m apart with 13 medium size floats at 8m intervals. The mother lines are attached to a 12-mm rope by means of a removable clamp connected to a 1000-kg weight (Fig 18). At this stage, cleanliness and control are very important since, during the spring and summer months, there are more epiphytes and fouling of the lines. A weekly cleaning is recommended. This is done directly from the boat, lifting the line and applying a gentle jet of seawater with a hydrowasher installed on board. In the pre-growth of G. skottsbergii, sporelings (seen by the naked eye), develop after 7 months (Fig. 19). Juveniles (1-3 cm) are obtained from 11 to 16 months, depending on at what time of year the cohort was seeded (Fig. 20).

16

Only one growth stage has been identified in the case of S. crispata since, once transferred to sea, discs with newly formed thalli after 45 days in the greenhouse begin their growth stage at sea (Fig. 21). After 6 to 8 months on the line commercial size fronds, over 40 cm long, can be harvested (Fig. 22). They must be harvested carefully, trying not to detach the discs from the shells since they can form new fronds. These can be harvested again within 30 to 45 days, thus increasing the yield. FARMING FROM JUVENILE STAGE TO HARVEST Growth and cultivation maintenance In the case of Gigartina, once young thalli attain 2-3 cm diameter, it is useful to remove the fronds from the shells and reattach them to a rope. This is necessary because when they have successfully seeded and survived, one shell can at times support 10 or more little fronds forming a canopy that covers it almost entirely. Also, even more important is that the canopy usually covers many dormant germlings and frond removal stimulates triggering their growth (Fig. 23). Frond reattachment to ropes is done by drilling a hole through each blade (2mm diameter) with a cork borer, threading 10 fronds on to each rope and attaching them with knots on and below each frond (see Fig. 23), similar to the way in which the shells were attached to the ropes. A cross-section of a young G. skottsbergii frond (3 cm diameter) has a thickness of about 400 m and up to 500 m in older specimens. Their very rigid and leathery texture allows the reattachment of the fronds to ropes so as to allow them to grow separately from the shells. A cross section of S. crispata on the other hand, measures only 150 μm, being considerably thinner and more fragile than Gigartina. Therefore, Sarcothalia necessarily must grow on shells until harvest. Once G. skottsbergii reaches 10-15 cm, the fronds are too heavy to be sustained by the attachment knots; they are ripening and subsequently drop off the ropes. To prevent detachment due to this a couple of plastic tie-cables can be fastened on and under each frond, replacing in this form the knots until harvest. The tie-cables retain the heavy fronds, avoiding their detachment (see Fig. 23). A frond can reach a diameter of 10-15 cm about 6-7 months after its detachment from the shell. During this period, and until fronds measure 30-40 cm and are ready for harvest, the tie-cables offer secure attachment to the ropes from the floating system. A frond is considered an adult when its reproductive structures reach maturity for the first time. In the case of S. crispata this occurs about the seventh to ninth month after spore attachment coinciding with when thalli are ready to be harvested. In the case of Gigartina, frond maturity occurs approximately during the second year when, for instance a gametophyte frond reaches a 30-cm diameter and a rope with ten fronds weighs approximately 1500 g. However, in order to optimize the capacity of a floating system, an additional set of four ropes (five ropes if the main vertical rope is also considered) with fronds can be tied to the main vertical rope and placed at the selected depth. Thus, each main vertical rope can sustain five units with at least 50 fronds at 6 m depth. If considering 2 meter length units, then each vertical rope could sustain 100

17

fronds at the selected depths (e.g. placed at approximately 6 to 7 m depth in the case of Gigartina). Fouling and epiphyte control As in the pre-growth stage, once fronds detached from shells are growing on ropes, a heavy and continuous invasion by diatoms, other algae, invertebrates such as mussels, sponges and hydrozoans attack the ropes interfering with frond growth. A program to keep ropes and floating structures clean must be maintained. One of the most difficult fouling events is caused by the Giant Kelp, Macrocystis pyrifera on floating systems. This brown alga can invade farming structures in two ways: firstly kelp, detached from the bottom, is carried by tidal current until it drifts into the floating system. The kelp then overlaps the mother lines and entangles the ropes, causing severe detachment of the growing Gigartina fronds. Secondly, gametophytes of M. pyrifera colonize ropes leading to subsequent and rapid growth of new sporophytes. The microscopic gametophytes settle on mother lines on ropes in late winter and rapidly develop into sporophytes. If uncontrolled they can grow to at least 10m. These events can partially or completely destroy a long-line. A continuous monthly programme must be maintained in order to keep clean both ropes and floating structures. Another important factor in the case of Chiloe’s cultivation sites is the damage produced by epiphytes on fronds. Cultured G. skottsbergii has been found heavily loaded with juvenile commercial mussels, such as Mytilus chilensis, Aulacomya ater and Choromytilus chorus, from late spring to fall (Fig. 25). If epiphytes are uncontrolled the molluscs would completely cover cystocarpic fronds. The strong papillae in mature female fronds seem to be an excellent surface for larval settlement. On sporophytes as well as on male thalli this fouling is only found on haptera. So a convenient procedure to avoid an aggressive epiphyte attack is to harvest cystocarpic fronds once they reach the first stages of maturation. A second measure is to eliminate the hapteral basal zone from fronds. In G. skottsbergii, epiphytism by algae is mainly carried out by certain members the Ceramiaceae, such as Polysiphonia abscissa, and Anthithamnionella sp. which can be harmful when the target fronds are young. Heavy epiphytism by Ceramium pacificum on S. crispata has been reported in central Chile but the problem has been particularly restricted to older fronds. Sarcothalia, Ulva nematoidea, Ectocarpus siliculosus, Giffordia mitchellae and two species of hydrozoans have fouled ropes seeded with S. crispata. Many species of colonial benthic diatoms were especially aggressive. They compete for substratum as well as for light. Berkeleya rutilans, whose individuals grow in the inner part of the mucilaginous thread secreted by themselves, is the most important species. Fouling was found to be specially dense above 3.5 m depth during summer months, therefore S. crispata cultivation lines should be placed at or a little below this depth (Romo et al., 2001b). A strict maintenance program must be started in order to keep maximum cleanliness on both shells and supporting ropes (Figs 24a and b). Regular hosing down of shells and ropes carrying fronds with seawater has been shown to be an effective treatment against fouling. Hosing could be done with a gasoline-powered pump on board a boat. In case of excessive fouling, additional scrubbing with a soft shoe brush can be effective

18

to maintain most of the shells clean of persistent fouling without greatly damaging the germlings. Harvest Although at present cold water carrageenophytes are not being farmed commercially in Chile or elsewhere, there have been a couple of pilot studies on both S. crispata and G. skottsbergii, and a private company is testing a commercial program for Sarcothalia cultivation in southern Chile. These programs have been implemented to offer alternatives to exploitation of natural populations specially considering 2003’ shortage of G. skottsbergii under natural production. After field experiments with S. crispata in central Chile, Romo et al. (2001a) report harvestable biomass of about 1,500 g fresh weight per lineal meter nine months after placement on ropes at 3.5 m depth. The same species growing on experimental floating cultures in southern Chile showed reduced growth, yielding about 700 g wet wt. per lineal meter. In the first case, in central Chile, ropes were hung vertically from the mother lines of a floating system. In the Island of Chiloe in southern Chile, the ropes were placed horizontally in a floating system at 2 m depth and a heavy load of epiphytes was reported (Avila et al., 1999b). In the case of Gigartina, a double 100-m long-line can support 4,000 one-meter long ropes (Fig. 24c; see present chapter) and each rope can produce 1.5 kg wet weight. Therefore the total yield per double long-line, assuming 1.5 kg per 1m rope with fronds, is about 6,000 kg wet weight. An exceptional cultivated 4-year old frond reached 1.5 m in diameter, but it is possible to harvest 30-40 cm wide fronds which are commercially acceptable (Fig. 24d). CARRAGENAN INDUSTRY IN CHILE The carrageenan industry in Chile began in 1989 with only two processing plants. Later, in the 90’s there were four working plants. However, today only two companies are producing carrageenan, namely: Danisco Chile and Extracts Naturales Gelymar. The initial production of 26 t, since then have increased greatly with time. The industry has shown constant growth during the last few years. In 2003 Chile exported 3,438 t of carrageenan representing approximately US$25 million. Chile’s carrageenan production is based on raw material from local species (Sarcothalia crispata and Gigartina skottsbergii) and tropical species (Kappaphycus alvarezii). Acknowledgements This research was supported by FONDEF (Grants: D00I1064, D01I1109, D00T2053) and FDI (Corfo). The authors want to thank M. Nuñez, R. Perez, G. Aroca, and R. Sepulveda for field work.

19

References Alveal K, H Romo, C Werlinger & M Núñez 1994. Uso de esporas como alternativa de

propagación masiva de macroalgas. Revista de Investigaciones Científicas y Tecnológicas. Ser. Ciencias del Mar 3:77-87.

Alveal K, H Romo & C Werlinger 1995. Cultivo de Gracilaria a partir de esporas. In: Alveal K, ME Ferrario, E Oliveira & E Sar (Eds), Manual de Métodos Ficológicos. Pub. Universidad de Concepción, Concepción, pp. 599-610.

Alveal K, H Romo, C Werlinger & EC Oliveira 1997. Mass cultivation of the agar producing alga Gracilaria chilensis from spores. Aquaculture 148: 77-83.

Avila M & M Seguel 1993. An overview of seaweed resources in Chile. Journal of Applied Phycology 5: 133-139.

Avila M, M Núñez, A Candia & R Norambuena 1997. Reproductive phenological patterns of a population of Gigartina skottsbergii (Gigartinaceae, Rhodophyta) from Ancud, Chile. Gayana Oceanologia 5: 21-32.

Avila M, A Candia, M Nuñez & H Romo 1999a. Reproductive biology of Gigartina skottsbergii (Gigartinaceae, Rhodophyta) from Chile. Hydrobiologia 398/399: 149-157.

Avila M, EI Ask, B Rudolph, M Nuñez & R Norambuena 1999b. Economic feasibility of Sarcothalia (Gigartinales, Rhodophyta) cultivation. Hydrobiologia 398/399:435-442.

Avila M, A Candia, H Romo, H Pavez & C Torrijos 2003a. Exploitation and cultivation of G. skottsbergii in southern Chile. In: Chapman ARO, RJ Anderson, VJ Vreeland & IR Davison (Eds), Proceedings International Seaweed Symposium 17: 137-143.

Avila M, H Pavez, A Candia, R San Martín & J Cáceres 2003b. Effects of temperature and irradiance on the germination and growth of Sarcothalia crispata in southern Chile. In: Chapman ARO, RJ Anderson, VJ Vreeland & IR Davison (Eds), Proceedings International Seaweed Symposium 17:27-33.

Buschmann AH, JA Correa & R Westermeier 1999a. Recent advances in the understanding of the biological basis for Gigartina skottsbergii (Rhodophyta) cultivation in Chile. Hydrobiologia 398/399: 427-434.

Buschmann AH, J Correa, R Westermeier, MC Hernández-Gonzalez, R Norambuena. 1999b. Mariculture of red algae in Chile. World Aquaculture 30:41-45.

Bushmann AH, JA Correa, R Westermeier, MA Paredes, D Aedo, P Potin, G Aroca, J Beltrán & MC Hernández-González 2001a. Cultivation of Gigartina skottsbergii (Gigartinales, Rhodophyta): Recent advances and challenges for the future. Journal of Applied Phycology 13: 255-266.

Buschmann AH, JA Correa, R Westermeier, MC Hernández-González & R Norambuena 2001b. Red algal farming: a review. Aquaculture 194: 203-220.

Correa JA, AH Bushman, R Westermeier & J Beltrán 1999. Healing and regeneration responses in Gigartina skottsbergii (Rhodophyta, Gigartinales): optimization of vegetative propagation for cultivation. Journal of Applied Phycology 11: 315-327.

Hommersand MH, MD Guiry, S Fredericq & GL Leister 1993. New perspectives in the taxonomy of the Gigartinaceae (Gigartinales, Rhodophyta). Hydrobiologia 260/261: 105-120.

Hommersand MH, S Fredericq & DW Freshwater & J Hughey 1999. Recent developments in the systematics of the Gigartinaceae (Gigartinales, Rhodophyta) based on rbcl sequence analysis and morphological evidence. Phycological Research 47:139-151.

20

Kim DH 1976. A study on the development of cystocarps and tetrasporangial sori in Gigartinaceae (Rhodophyta, Gigartinales). Nova Hedwigia 27: 1-146.

Marín, SL, R Westermeier & J Melipillán 2002. Simulation of alternative management strategies for red algae, luga roja, (G. skottsbergii Setchell and Gardner) in southern Chile. Ecological Modelling 154: 121-133.

Piriz ML 1966. Phenology of a Gigartina skottsbergii Setchell et Gardner population in Chubut Province (Argentina). Botanica Marina 30: 311-316.

Ramírez ME & B Santelices 1991. Catálogo de algas marinas bentónicas de la costa templada del Pacífico de Sudamérica. Monografías Biológicas 5. Pontificia Universidad Católica, Santiago, 437 pp.

Romo H 1988. Cultivo de algas mediante esporas. Investigación Pesquera (Chile) 35: 89-98.

Romo H, K Alveal & C Werlinger 2001a. Growth of the commercial carrageenophyte Sarcothalia crispata (Rhodophyta, Gigartinales) on suspended culture in central Chile. Journal of Applied Phycology 13: 229-234.

Romo H, M Avila & A Candia 2001b. Manual de Técnicas de Cultivo y Repoblación de “luga roja” (Gigartina skottsbergii). Documento Técnico, Proyecto FONDEF D97 I1064. IFOP-Universidad de Concepción, Chile, 30 pp.

Westermeier R, A Aguilar, J Sigel, J Quintanilla & J Morales 1999. Biological basis for the management of G. skottsbergii (Gigartinaceae, Rhodophyta) in southern Chile. Hydrobiologia 398/399: 137-147.

Zamorano J & R Westermeier 1996. Phenology of Gigartina skottsbergii (Gigartinales, Rhodophyta) in southern Chile. Hydrobiologia 326/327: 253-259.