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Emergy evaluation of benthic ecosystems influenced by upwelling in northern Chile: Contributions of the ecosystems to the regional economy
Citation:
Berrios, F., Dan Campbell, AND M. Ortiz. Emergy evaluation of benthic ecosystems influenced by upwelling in northern Chile: Contributions of the ecosystems to the regional economy. ECOLOGICAL MODELLING. Elsevier Science BV, Amsterdam, Netherlands, 359:146-164, (2017).
Impact/Purpose:
This paper examines the contributions to the regional economy made by the emergy inputs to the coastal benthic ecosystems of northern Chile. The coastal fishery system and its exchanges of real wealth (emergy) in the regional economy are examined in detail for 3 coastal bays in Northern Chile. A generalized estimate of the global ecosystem services provided by the emergy signatures of the 3 bays is also made. We show the emergy advantage to the sellers and buyers of resources for individual species and for the bays as complete systems. The results of the overall exchange differ for each bay, but with some similarities. Significant impact of this research is possible, since for the first time the trophic network of a benthic ecosystem has been evaluated and emdollar values assigned to both commercial and noncommercial species. Emergy is the only common denominator for evaluating environment, economy, and society is energy or more specifically available energy, which has the potential to do work. Furthermore, available energy alone is not sufficient to provide an accurate evaluation, because energies of different kinds have different potentials to do work. A simple example of quality differences in work can be seen in human labor, where a brain surgeon and a ditch digger expend the same joule of metabolic work with very different outcomes, that is the quality of the work done is different based on the knowledge and experience of the human performing the labor. This same principle applies to all actions performed in a system and can be generalized through accounting for actions in terms of the emergy required to perform them. For, business, government, and institutions, emergy accounting provides a new perspective on value that can be used in decision-making. It goes beyond economic value and its extension as ecosystems services, which are subjective in nature, to provide a comprehensive objective measure of worth for the comparison of alternatives. The emdollar uses the emergy to money ratio of an economy to express dollar flows as emergy.
Description:
Emergy evaluations of three benthic ecosystem networks found in Mejillones, Antofagasta and Tongoy Bays, located on the coast of northern Chile, were carried out with the intent of documenting the contributions of these coastal ecosystems to the economy. The productivity of these bays is strongly influenced by the Humboldt Current System, as well as by the loss of upwelled flows that occurs during El Nino events. The results of the emergy evaluations were expressed as emdollars (EM$), a combined emergy-money measure that can be used to examine the equity of the emergy exchanges between fishermen and the buyers of the harvested algae and shellfish. In addition, an estimate of the total ecosystem services provided by these coastal ecosystems was made. The emdollar (Em$ y−1) and the hypothetical monetary value (US$ y−1) of the nitrate nitrogen upwelled constituted the highest inflow of emergy to all three benthic ecosystems. The empower density expressed as Em$ m−2 y−1 was highest in Mejillones Bay; however, the natural capital (biomass) of the ecological components (EM$ m−2) was highest in Antofagasta Bay, where La Rinconada Marine Reserve is located. The relationship between the coastal zone system and the regional economic system was assessed using the emergy benefit after exchange, EBE, which showed that there were net gains to the overall welfare of the sellers in two regions, 3,280,000 Em$ to those in Mejillones Bay, and 34,000,000 Em$ to those in Tongoy Bay, but a net loss of 2,000,000 Em$ to the sellers of algae and shellfish harvested from Antofagasta Bay. By supplying a clearer picture of the equity of trade relationships for individual organisms, fisheries and bays, emergy evaluation can help develop and implement management strategies for the conservation and preservation of coastal ecosystems to ensure that they are sustainable in the future.
