Interacciones bioculturales del pueblo yagán con las macroalgas y moluscos: Una aproximación desde la filosofía ambiental de campo

Abstract

The coastal areas of the Magellan ecoregion host considerable diversity of macroalgae and mollusks. Indigenous peoples, such as the Yaghan, have developed biocultural interactions with austral coastal ecosystems. This study is an interdisciplinary ecological, ethnoecological and philosophical analysis. It applies the conceptual framework of biocultural ethics to characterize the intertidal habitat within the biocultural context of the Yaghan people. This is done through the composition of inhabitants, such as macroalgae and mollusks, linked to seasonal habits of abundance. Based on this account, we suggest methods and activities of biocultural conservations. We applied the Field Environmental Philosophy approach, which was carried out in Róbalo bay, Navarino island (55°S). Ecological results showed that biomass and macroalgae diversity increased in summer and decreased over the winter. Mollusks Mytilus edulis chilensis and Perumytilus purpuratus showed no seasonal variability abundance. Ethnographic results based on the literature and observant participation showed that low seasonal variability in mollusk abundance has been crucial to the subsistence of the Yaghan people. From the perspective of contemporary environmental ethics, we identified several values in the Yaghan worldview. For example, there are instrumental values in mollusks: they have been a source of food, aesthetic decoration, development of tools and building huts. We found references to the intrinsic values in mollusks, particularly in narratives and other ethnographic sources. These Yaghan values are rooted in a profound sense of empathy for biodiversity. As a result of the combined ecological, ethnographic, and philosophical issues, we suggest communication through metaphor (the submerged forest of Cape Horn) and field activities (open your eyes, dive with an open mind) for biocultural conservation.

Trophic ecology of two co-existing Sub-Antarctic limpets of the genus Nacella: spatio-temporal variation in food availability and diet composition of Nacella magellanica and N. deaurata

“…The multivariate analysis showed differences in the assemblage composition of micro and macroalgae between the two localities at each intertidal level and time. This dynamics of macroalgae assemblages in the channels and fjords of the Magellan Ecoregion was also observed by Ojeda (2013) , who observed that the macroalgae assemblages do not present a general spatial structuring pattern, and there may even be differences in the structure of macroalgae assemblages between sites for similar intertidal levels within a same Bay ( Ojeda 2013 ). This author also found that the macroalgae assemblages temporally presented a decrease in wet biomass in winter periods and a considerable increase in summer, showing the marked temporal dynamics of the macroalgae assemblages.…”

“…These results suggest indetectable general pattern in the vertical zonation of micro- and macroalgae assemblages in these two localities (this study). In the channels and fjords of the Magellan Ecoregion, it has been described that the local environmental heterogeneity likely plays a role in structuring ecological assemblages and communities in Sub-Antarctic marine channels ( Ríos et al 2007 , Aldea et al 2011 , Ojeda 2013 , Ojeda et al 2014 ). Finally, our data suggest an absence of a vertical pattern zonation between the two sites.…”

“…Among these factors, seasonality affects the coverage and biomass of micro- and macroalgae ( Cubit 1984 , Santelices 1987 , Iken 1999 , Jenkins et al 2001 ), and consequently the diet of intertidal herbivorous species ( Hill and Hawkin 1991 ). Seasonality itself may vary depending on the latitudinal range of rocky coasts, since, seasonal fluctuations in biomass of algae communities (micro and macroalgae) over the year increase with the latitude ( Hill and Hawkin 1991 , Thompson et al 2000 , Jenkins et al 2001 , Ojeda 2013 ), affecting the availability of food for different species of the food chain, including herbivores ( Hill and Hawkin 1991 ). At the same time, habitat structure and high environmental heterogeneity imply spatial variation in the richness, abundance and structure of algae communities ( Hill and Hawkin 1991 , Benedetti-Cecchi and Cinelli 1997 , Ojeda 2013 ), thus affecting the diet of herbivores ( Branch 1971 ).…”

“…The richness of patellogastropods in the Magellanic Province is represented by eleven species ( Linse 1999 ), among which the most represented genus is Nacella ( Valdovinos and Rüth 2005 , Aranzamendi et al 2009 , González-Wevar et al 2010 , González-Wevar et al 2011 ), a dominant group among the macro-benthic invertebrates, especially on rocky shores ( Guzmán 1978 , Ojeda et al 2014 ). Along the Strait of Magellan and the sub-Antarctic channels and fjords this group also has an important role in the feeding habits of local communities (indigenous people, fishermen; Ojeda 2013 ). According to lastest phylogenetic studies of the group, four valid taxonomic units are recognized in the Magellanic Province: Nacella magellanica (Gmelin, 1791), N. deaurata (Gmelin, 1791), N. flammea (Gmelin, 1791) and N. mytilina (Helbling, 1779).…”

Propiedades emergentes, valor intrínseco y ecología: Algunas perspectivas éticas sobre los habitantes de la isla navarino

“…Jaime Ojeda y colaboradores (Ojeda et al 2018) abordan la noción de valor intrínseco y su complementariedad con la noción de valor instrumental, proponiendo superar la dicotomía entre ambos valores, en el contexto del estudio sobre los moluscos de los canales del Cabo de Hornos y su importancia en la cosmovisión yagán. Estos autores afirman que las distintas especies de moluscos poseen para la cultura yagán tanto un valor instrumental como un valor intrínseco.…”