Cultivation of Gracilaria on the sea-bottom in southern Chile: a review

This review contains information about the cultivation techniques, strategies, problems and new challenges faced as well as an economic analysis of the income-producing capacity of Gracilaria farming, considering the variability of environmental systems where this alga is cultivated in southern Chile. The development of Gracilaria farming in Chile was made possible by an increased market demand, as well as the existence of basic knowledge that permitted the management of wild stocks and the initiation of cultivation practices. Subtidal cultivation systems appear to be more productive than intertidal systems and are less susceptible to wave action than intertidal cultivation areas. In relation to farming practices, this difference implies that planting and harvesting methods and strategies vary between habitats where cultivation is being carried out on a commercial scale. Several problems such as the environmental impact of different cultivation methods adopted by the farmers, the management of contaminating organisms and strain selection appear to be important and new areas for future research. Finally, an analysis of the income-producing capacity indicates that environmental differences also have important consequences for the management strategies of Gracilaria cultivation.     

Effects of climate change on economic feasibility of future date palm production: An integrated assessment in Iran

This study set out to build a model identifying areas where a positive Net Present Value (NPV) could be obtained from date palm (Phoenix dactylifera) using CLIMEX and six parameters including (a) suitable soil taxonomy and physicochemical soil properties, (b) slopes of less than 10°, (c) land uses suitable for date palm cultivation, (d) availability of roads, (e) availability of water, and (f) low risk of the lethal disease caused by Fusarium oxysporum f. spp. in the years 2030, 2050, 2070, and 2100 in Iran. Here, we utilized the A2 scenario and two global climate models (GCMs): CSIRO-Mk3.0 (CS) and MIROC-H (MR). Economic feasibility was estimated based on the assumption that the decision to plant date palms by landholders is motivated by a desire to maximize their return to land. Our results indicate that only 5450 km² of southern Iran will be highly profitable for cultivation of date palm, with NPV > 10,000, while profitable (with NPV between 4200 and 10,000) and moderately profitable (with NPV between 0 and 4200) areas would cover only 500 and 50 km², respectively, in future. A comparison of mean outputs from the two chosen GCMs and those of the economic and CLIMEX output combination indicates that only about 0.01% of areas from both GCMs will be highly economically viable for cultivation of date palm. In this study we ensure that the predictions become robust, rather than producing hypothetical findings, limited purely to publication.     

Farming of the Giant Kelp Macrocystis Pyrifera in Southern Chile for Development of Novel Food Products

This study explores the potential cultivation of the giant kelp Macrocystis pyrifera (L.) C.A. Agardh in southern Chile, for the development of novel food products. The study demonstrates the importance of considering the collection site of the parent sporophytes for successful cultivation. This study also shows that the ropes must be seeded with 10,000 to 40,000 spores ml⁻¹, depending on the culture method used. We also demonstrated that under environmental conditions in southern Chile, the seeded ropes must be put at sea at the latest during autumn (April) in order to reach the harvesting season in December. However, several other management aspects must be considered to improve the quality of the product. Our final estimation indicates that over 14.4 kg m⁻¹of rope (fresh weight) can be produced and from this total production, over 70% can reach the quality to produce different food products that are already being introduced in oriental countries. The remaining 30% can be used for abalone feeding and is also available for the organic fertilizer industry located in Chile.     

Population dynamics and culture studies of the edible red alga Callophyllis variegata (Kallymeniaceae)

Callophyllis variegata is a red alga that has been exported to Japan as an edible seaweed over the past few years. Available data strongly suggest that after a few years of exploitation of the C. variegata stands in southern Chile, a decline of its abundance seems to be occurring. However, there is not sufficient knowledge available to sustain harvesting strategies or to develop cultivation techniques. This study describes the C. variegata landings in the south of Chile and also provides some basic data on the biology of this species. Experiments related to the cultivation of early developmental stages, frond cultivation under controlled conditions and the regeneration capacity of the holdfast of this red alga are also presented. Spore production occurs mainly in autumn and winter and survival of carpospores decreased as the temperature increased from 8 to 12°C. Survival of tetraspores increased significantly, from 50 to 60% to over 80%, when temperature was raised from 8 to 12°C. Carpospore survival was also significantly affected by the photon flux density. This effect was mainly at 8°C, whereas at 33 µmol m^?2 s^?1 the survival of the spores is always low. The cultivation of apical portions of C. variegata under laboratory conditions showed that lower temperatures (8°C) significantly increased growth. Salinity and photon flux density did not have an effect on specific growth rate. Laboratory experiments demonstrated that holdfasts can regenerate fronds and that these fronds can be excised and cultivated, and are far more tolerant to environmental factors than the apical portions.     

Management of pests and diseases of castor (Ricinus communis L.) in India: current status and future perspective

Abstract

Castor (Ricinus communis L.) cultivation is generally cost-effective and profitable for small and marginal farmers in India. However, crop productivity is affected by the damage from pests and plant pathogens. From seedling till capsule harvesting, leaf sap-sucking insects and mites, defoliators, capsule feeding insects; bacterial and fungal diseases and root-knot nematodes attack the crop at various stages of growth and deteriorate plant health. Currently, synthetic pesticides are being applied extensively. Considering side effects of chemicals, other control measures are considered in this review. Findings of greenhouse and the field trials are discussed, and the efficient, economic and eco-friendly management has been elaborated.     

The profitability of smallholder rattan cultivation in Southern Borneo,Indonesia

Fieldwork in the village of Dadahup along the Lower Barito basin in Central Kalimantan (Southern Borneo, Indonesia) shows that smallholder rattan cultivation is financially profitable to smallholders and economically profitable to the nation. The financial net present value (NPV) for green and processed canes is Rp 828,000 and Rp 946,000;the economic rate of return is about 22% for both green and processed canes. The article contains a discussion of the methodology for evaluating the shadow price of a nontimber forest good.     

Austral Hepaticae,IV. Notes on Lophozia subgenus Protoloplzozia Schust., with diagnosis of a new South American species

Abstract

The distinguishing features of Lophozia subg. Protolophozia are enumerated. A key is provided for the eleven species of this primarily cool antipodal and subantarctic subgenus. Lophozia gymnocoleopsis Schust. & Engel from southern Chile is described as new. This species and L. crispata, also of southern South America, are the only representatives of subg. Protolophozia in South America. Protolophozia sect. Notolophozia and sect. Gymnocoleopsis Schust. are described as new.     

Opportunities and challenges for the development of an integrated seaweed-based aquaculture activity in Chile: determining the physiological capabilities of <Emphasis Type="Italic">Macrocystis</Emphasis> and <Emphasis Type="Italic">Gracilaria</Emphasis> as biofilters

Seaweed production is a reality in Chile. More than ten species are commercially used to produce phycocolloids, fertilizers, plant growth control products, human food or animal fodder and feed additives. These multiple uses of algae offer a number of possibilities for coupling this activity to salmon, abalone and filter-feeder farming. In this context, different experiments carried out in Chile have demonstrated that Gracilaria chilensis and Macrocystis pyrifera have great potential in the development of an integrated aquaculture strategy. The present Integrated Multi-Trophic Aquaculture (IMTA) approach study showed that Gracilaria can be cultured best at 1 m depth whereas Macrocystis has an especially good growth response at 3 m depth. Both species use available nitrogen efficiently. On the other hand, high intensities of solar radiation (UV and PAR) can be critical at low depths of cultivation, and our results indicate that both species show photosynthetic susceptibility mainly at noon during the summer. The demand of Macrocystis for abalone feeding is increasing, thus improving the opportunity for developing an integrated nutrient waste recycling activity in Chile. Although Gracilaria shows a higher nitrogen uptake capacity than Macrocystis, its market value does not yet allow a massive commercial scaling.     

Culture of Gigartina Skottsbergii (Rhodophyta) in Southern Chile. A Pilot Scale Approach

In the last 10 years studies on the management and exploitation of Chilean carrageenophytes have proliferated in response to the increasing development of the local processing industry. One of the most important sources of raw material for Chilean carrageenan, Gigartina skottsbergii Setchell et Gardner, was the subject of an intensive study to design a commercial cultivation technique which could be an alternative to wild harvest. In this context this pilot study reports the first successful attempt to culture G. skottsbergii from spores to harvestable plants. A three-step farming approach was developed: (i) seeding of spores onto scallop shells followed by a two-month nursery period in a greenhouse (until the development of initial upright thalli from the discoid crust occurred), (ii) outplanting juvenile plants on shells in the sea on a long-line system (until thalli attained 3–4 cm diameter) and (iii) detachment of fronds from the shells, fixing of individuals to vertical ropes and growth until commercial size was reached. Additional experiments to compare bottom and suspended growth, cultivation by fragmentation and whole fronds and meristematic activity of different zones of the fronds were performed. This study shows the technical feasibility of culturing G. skottsbergii from spores, complemented with growth of vegetative fragments, in order to optimize the management of the culture. In the future, therefore, it may be possible to replace the heavy exploitation of wild beds in southern Chile with farming activities.     

In vitro culture of Chloraea gavilu Lindl., an endemic terrestrial orchid from Chile

Orchids are the second most diverse plant family, recognized for their importance as ornamental species; this has driven research development in propagation. One of the most common culture methodologies is in vitro asymbiotic germination, in which the nutritional conditions that provide orchids with a fungal partner are emulated. Although Chile possesses more than 60 terrestrial orchid species, in vitro cultivation protocols have only been developed for Chloraea crispa. In Southern Chile, Chloraea gavilu stands out due to its floral characteristics. We evaluate different explants and cultivation conditions for C. gavilu. The best germination and development results were achieved in the MM medium +0.1% yeast extract +1% sucrose +0.454 µmol l^?1 TDZ, using immature seeds of 24–30 days after pollination, which we cultivated into seedlings in order to be acclimatized and mycorrhized. In addition, induction of protocorm-like bodies was achieved from germinated seeds, using the same culture media as in the germination and development of immature C. gavilu seeds. This resulted in the successful asymbiotic germination of immature seeds, along with the micropropagation of a terrestrial, temperate orchid. We hope to use our protocol in the commercial production of Chilean orchid species as well as to propagate threatened species.     

Assessing the impact of toothed whale depredation on socio-ecosystems and fishery management in wide-ranging subantarctic fisheries

Marine predators feeding on fisheries catches directly on the fishing gear, a behaviour termed “depredation”, has emerged as a major human-wildlife conflict globally, often resulting in substantial socio-economic and ecological impacts. This study investigated the extent of this conflict in commercial Patagonian toothfish (Dissostichus eleginoides) fisheries across subantarctic waters where both killer whales (Orcinus orca) and sperm whales (Physeter macrocephalus) feed on toothfish caught on longline hooks. Using long-term datasets from six major fishing areas, from southern Chile to the Indian Ocean sector of the Southern Ocean, statistical models were developed to quantify the catch removals due to whale depredation interactions. The results indicated that these removals were large, totalling more than 6600 t of toothfish between 2009 and 2016 with an annual mean of 837 t [95% CI 480–1195 t], comprised of 317 t [232–403 t] and 518 t [247–790 t] removed by killer whales and sperm whales, respectively. Catch removals greatly varied between areas, with the largest estimates found at Crozet, where on average 279 t [179–379 t] of toothfish per year, equivalent to 30% [21–37%] of the total catches. Together, these findings provide metrics to assess the impacts of depredation interactions on the fishing industry, whale populations, fish stocks and associated ecosystems. With an estimated $15 M USD worth of fish depredated every year, this study highlights the large geographic scale and economic significance of the depredation issue and its potential to compromise the viability of some toothfish fisheries which are the primary socio-economic activity in subantarctic regions.

     

New records of Salvin’s albatross (<Emphasis Type="Italic">Thalassarche salvini</Emphasis>) from fishing boats off southern Chile

The Salvin’s albatross, Thalassarche salvini, is a mollymawk that regularly visit the coasts of Chile and Peru along the Humboldt Current, occurring mainly as non-breeders. However, information on presence and distribution of this species in southern Chile (42°–57°S) is particularly scarce and limited to only a few observations, principally obtained in the inner fjords and channels, there is no information for areas more oceanic (continental shelf and slope). New records of Salvin’s albatross were obtained in the development of a project assessment of the interaction between commercial pelagic fisheries and marine mammals and seabirds. The observation effort (census during hauling operations) covered all seasons approximately 1 year. These records provide new information on the presence and abundance of this albatross for a wide latitudinal range offshore in the southern Chile that is also an area of operation of fishing fleets (e.g. Patagonian toothfish fishery). Our results suggest that probably this species flies around the southern cone of South America via Cape Horn–Drake Passage to get to the Patagonian Continental Shelf in the South Atlantic Ocean, which probably could be occurring during the austral spring and summer.     

Novel microsatellite markers for an endangered freshwater snail,Heleobia atacamensis (Caenogastropoda: Cochliopidae), from the Atacama Saltpan

ABSTRACT

The minute freshwater gastropod Heleobia atacamensis is only known from its type locality Tilopozo, located at the southern end of the Atacama Saltpan, Antofagasta Region, Chile. It is classified as Critically Endangered by the national agency, Ministerio del Medio Ambiente de Chile, due to its restricted distribution. For the first time, we have isolated and evaluated 65 microsatellite markers in 42 specimens of H. atacamensis, successfully characterising 11 as polymorphic. Cross-amplification testing was successful in three other species of the genus. As a result, the development and characterisation of these markers could be useful in future genetic studies of H. atacamensis and its congeners, regarding population structuring, dispersal patterns and recent demographic history. Furthermore, this information will also be significant to undertake conservation efforts in this endangered species, since its environment is highly threatened by lithium mining activities and a global water crisis.     

Economically important seaweeds in Mar Piccolo,Taranto (southern Italy): a survey

A preliminary survey was carried out of the marine algae in the Mar Piccolo Basin, Taranto (southern Italy), in order to assess the degree of sewage pollution and to determine the presence of any economically important species that might be productively utilized. The following commercial species, belonging to a drift algal community, were found: Gracilaria bursapastoris, G. cf. verrucosa, Solieria sp. and S. filiformis. The species showed an aggregated distribution within the community and a clear cyclic annual pattern. Gracilaria bursa-pastoris exhibited the highest mean biomass values in May, whereas Solieria spp. were the most abundant in October. At the present time, only the harvesting of G. bursa-pastoris appears profitable. However, further detailed studies are required to more fully assess the standing crop of the Solieria spp. and G. cf. verrucosa. Considering the environmental situation in the basin, it might be more appropriate to cultivate, rather than harvest, these commercially important seaweeds. With the large number of sewage outlet plants available in the basin, the cultivation of seaweeds in a wastewater treatment-aquaculture system should be considered.     

Interaction mechanisms between Gracilaria chilensis (Rhodophyta) and epiphytes

Epiphytes can have a considerable effect on Gracilaria production, and Ulva is one of the commonest algal species identified as an epiphyte, reaching loads of 60% (g of epiphytes per g of Gracilaria) in the intertidal cultures of southern Chile. This study evaluates the relative importance of light reduction, addition of weight to the host thalli and nutrient depletion, as mechanisms determining the interaction effects of Ulva epiphytes on Gracilaria cultivation. Using field experiments undertaken during the main Gracilaria growth season (spring), we evaluate the mechanisms of epiphyte-host algae interaction by manipulating artificial epiphytes. The results indicate that Ulva can significantly depress Gracilaria biomass production and that the addition of weight to the host algae and the consequent dislodgement increase, appear to be the main mechanisms involved in the Ulva-Gracilaria interaction. However, the light reduction caused by the epiphytes can also partially explain the reduction in Gracilaria production. Nutrients depletion would not appear to fully account for the detrimental effects of Ulva over Gracilaria in intertidal farming areas of southern Chile.     

Cultivation of red seaweeds: a Latin American perspective

The Latin American seaweed industry plays an important role at a global scale as 17 % of all seaweeds and 37 % of red seaweeds for the phycocolloid industry comes from this region. Increased market demand for algal raw materials has stimulated research and development into new cultivation technologies, particularly in those countries with economically important seaweed industries such as Argentina, Brazil, Chile, México, and Peru. The marine area of Latin America includes almost 59,591 km² of coastline ranging in latitude from 30ºN to 55ºS and encompasses four different oceanic domains: Temperate Northern Pacific, Tropical Eastern Pacific, Temperate South America, and Tropical Atlantic. Commercial cultivation of red seaweed in Latin America has been basically centered in the production of Gracilaria chilensis in Chile. Attempts have been made to establish seaweed commercial cultivation in other countries, going from experimental research-oriented studies to pilot community/enterprise based cultivation trials. Some genera such as Kappaphycus and Eucheuma have been studied in Brazil and Mexico, Gracilaria species in Argentina and Brazil, Gracilariopsis in Peru and Venezuela, and Chondracanthus chamissoi in Peru and Chile. In this short review, we address the Latin America perspective on the status and future progress for the cultivation of red seaweeds and their sustainable commercial development, and discuss on the main common problems. Particular emphasis is given to the needs for comprehensive knowledge necessary for the management and cultivation of some of the most valuable red seaweed resources in Latin America.     

Niche modelling of the Chilean recluse spider Loxosceles laeta and araneophagic spitting spider Scytodes globula and risk for loxoscelism in Chile

In Chile, all necrotic arachnidism is attributed to the Chilean recluse spider Loxosceles laeta (Nicolet) (Araneae: Sicariidae). It is predated by the spitting spider Scytodes globula (Nicolet) (Araneae: Scytodidae). The biology of each of these species is not well known and it is important to clarify their distributions. The aims of this study are to elucidate the variables involved in the niches of both species based on environmental and human footprint variables, and to construct geographic maps that will be useful in estimating potential distributions and in defining a map of estimated risk for loxoscelism in Chile. Loxosceles laeta was found to be associated with high temperatures and low rates of precipitation, whereas although S. globula was also associated with high temperatures, its distribution was associated with a higher level of precipitation. The main variable associated with the distribution of L. laeta was the human footprint (48.6%), which suggests that this is a highly invasive species. Similarly to other species, the distribution of L. laeta reaches its southern limit at the Los Lagos region in Chile, which coincides with high levels of precipitation and low temperatures. The potential distribution of L. laeta in Chile corresponds to the distribution of cases of loxoscelism.     

Recent trends of seaweed production in Chile

In the last fourteen years the production of seaweeds in Chile has ranged from 74 000 to 229 000 wet metric tons per year and has included about twenty species belonging to Phaeophyta and Rhodophyta. The only source of this production has been the exploitation of natural beds, except for Gracilaria, which is the only case of commercial cultivation and contributes significant quantities to total production. Initially most of the raw material was exported but currently important quantities of Gracilaria and several carrageenophytes are being processed by local industry. Changes in production of the main resources are analyzed with consideration of potential demand, level of knowledge about natural beds, and the situation of total Gracilaria farming, in order to attempt predictions for the supply. Current possibilities of applying new technologies to cultivate other economically important Chilean seaweeds are also analyzed and discussed.     

Effects of amphibian phylogeny,climate and human impact on the occurrence of the amphibian‐killing chytrid fungus

Chytridiomycosis, due to the fungus Batrachochytrium dendrobatidis (Bd), has been associated with the alarming decline and extinction crisis of amphibians worldwide. Because conservation programs are implemented locally, it is essential to understand how the complex interactions among host species, climate and human activities contribute to Bd occurrence at regional scales. Using weighted phylogenetic regressions and model selection, we investigated geographic patterns of Bd occurrence along a latitudinal gradient of 1500 km within a biodiversity hot spot in Chile (1845 individuals sampled from 253 sites and representing 24 species), and its association with climatic, socio‐demographic and economic variables. Analyses show that Bd prevalence decreases with latitude although it has increased by almost 10% between 2008 and 2013, possibly reflecting an ongoing spread of Bd following the introduction of Xenopus laevis. Occurrence of Bd was higher in regions with high gross domestic product (particularly near developed centers) and with a high variability in rainfall regimes, whereas models including other bioclimatic or geographic variables, including temperature, exhibited substantially lower fit and virtually no support based on Akaike weights. In addition, Bd prevalence exhibited a strong phylogenetic signal, with five species having high numbers of infected individuals and higher prevalence than the average of 13.3% across all species. Taken together, our results highlight that Bd in Chile might still be spreading south, facilitated by a subset of species that seem to play an important epidemiological role maintaining this pathogen in the communities, in combination with climatic and human factors affecting the availability and quality of amphibian breeding sites. This information may be employed to design conservation strategies and mitigate the impacts of Bd in the biodiversity hot spot of southern Chile, and similar studies may prove useful to disentangle the role of different factors contributing to the emergence and spread of this catastrophic disease.     

In vitro recruitment of Ulva sp. and Enteromorpha sp. on gametophytic and tetrasporophytic thalli of four populations of Chondracanthuschamissoi from Chile

Chondracanthus chamissoi is a red alga which is acquiring an increasing economic importance in Chile and becoming a target species for cultivation. Because epiphytism is a major problem in the mariculture of seaweeds, the recruitment of Ulva sp. and Enteromorpha sp. on gametophytic (cystocarpic) and tetrasporophytic thalli of C. chamissoi was tested in vitro on four populations from different locations in Chile. For Ulva sp., the density, cover and length of the recruits varied between the reproductive phases of the host and among the studied populations of C. chamissoi. In most experiments, a larger number of epiphytic thalli was observed on gametophytic plants of C. chamissoi; populations from Calderilla and Lechagua had a higher resistance to epiphytism. For Enteromorpha sp., its ability to grow epiphytically on both phases of the host showed a greater variability, but was inferior to that of Ulva sp. The differential resistance to epiphytism in both reproductive phases and in plant origin indicates the possibility of obtaining selected strains of C. chamissoi with lower susceptibility to epiphytism that could be utilized in planning maricultural programs.