Peruvian marine ecosystems under metal contamination: First insights for marine species consumption and sustainable management.

Scientific research addressing environmental conditions of aquatic ecosystems has high priority in Peru. Nevertheless, there is a lack of knowledge on environmental contamination of Peruvian marine ecosystems. To address this knowledge gap, this review article summarizes the available information in order to estimate the environmental health status (EHS) of Peruvian marine ecosystems. In this study, none of the studied Peruvian marine ecosystems could be rated as EHS-good, and the southernmost locations showed the most degraded conditions and a low EHS. Freshwater and brackish ecosystems contribute to the overall metal concentrations in Peruvian marine ecosystems. Environmental contamination and stressors are also reaching the Peruvian Marine Protected Areas (MPAs). The management of coastal marine areas and MPAs in Peru should be urgently re-formulated. This study also identifies the optimal bio-monitoring approach in the current economic situation in Peru, and how marine research studies can support adjacent fields, e.g. nutrition and human health.

Marine species as safe source of LC-PUFA and micronutrients: Insights in new promising marine food in Peru.

Seafood could be a promising way to supplement healthy fatty acids and trace elements to the Peruvian diet. Seafood from northern Peru was characterized with the highest relative concentrations of long-chain polyunsaturated fatty acids (LC-PUFAs), while in the center region marine species had the lowest As and Pb contents. Peruvian marine species are rich in LC-PUFAs and micro-nutrients (Cu, Fe, Mn, Zn), including species considered as potentially edible (e.g. Cycloxanthops sexdecimdentatus), but also non-edible species (e.g. Caulerpa filiformis). Nevertheless, it is crucial to consider toxic metals, e.g. As and Cd, which could pose a risk for consumers. High levels of beneficial LC-PUFAs and micro-nutrients would be taken up (up to 80% of the recommended values) when the Peruvian population would consume the estimated safe amount of seafood. Scoring species for fatty acid and metal content resulted in gastropods (e.g. Bursa ventricosa) as being the least beneficial species.

Peruvian scallop Argopecten purpuratus: From a key aquaculture species to a promising biondicator species.

The present study analyzed the Peruvian scallop Argopecten purpuratus and its food sources for metal and fatty acid concentrations in order to determine spatial and temporal differences. Metals such as copper (Cu), manganese (Mn), and zinc (Zn) in gills and iron (Fe) and Zn in sediments were the most significant explaining factors for spatial differentiations (degree of contamination), while for fatty acids, it was C14:0, C15:0, C16:0 and C18:0 in A. purpuratus' muscle and in its food sources, which explained more temporal differences (El Niño-Southern Oscillation (ENSO) effect). Gills, digestive gland and intestine were the tissues where metal accumulation was the highest in A. purpuratus. Cd in digestive gland was always high, up to ∼250-fold higher than in other tissues, as previously reported in other bioindicator species for metal pollution. Fatty acids were good biomarkers when annual comparisons were performed, while metals when locations were compared. ENSO 2017 played an important role to disentangle A. purpuratus' biological conditions and food sources. A. purpuratus from Paracas locations mostly showed higher metal concentrations in gills and digestive glands, and lower fatty acid concentrations in muscle than those from Sechura and Illescas Reserved Zone.

Potential health risks via consumption of six edible shellfish species collected from Piura - Peru.

Scallops and their potential predators were collected in Sechura Bay and in front of the Illescas Reserved Zone (north Peru), during El Niño-Southern Oscillation (ENSO) 2016, and analyzed for the metals chromium (Cr), manganese (Mn), iron (Fe), nickel (Ni), copper (Cu), zinc (Zn), arsenic (As), cadmium (Cd) and lead (Pb). This study showed that ~20% of the molluscs exceeded the maximum residual levels (MRLs) for human consumption in inorganic As, while ~30% of the crustaceans did. For Cd, around 10% and 40% of the molluscs and the crustaceans were above the MRLs, respectively. The cephalopod Octopus mimus exhibited As concentrations, but not Cd concentrations, that exceeded the MRLs. Cr, Ni, Cu, Zn and Pb in muscle exhibited generally concentrations below the MRLs. Integrated risk indices were estimated to determine if there is a health risk for consumption. Target hazard quotients (THQs) and total hazard indices (HIs) were mostly < 1, implying no human health risk. Provisional tolerable weekly intake (PTWI) for Cd was exceeded in Bursa ventricosa at Illescas Reserved Zone. Target cancer risks (TRs) for inorganic As were always higher than the threshold (1 × 10-6), therefore an actual cancer risk is present.

A modified indirect mathematical model for evaluation of ethanol production efficiency in industrial-scale continuous fermentation processes.

AIMS: To calculate fermentation efficiency in a continuous ethanol production process, we aimed to develop a robust mathematical method based on the analysis of metabolic by-product formation. METHODS AND RESULTS: This method is in contrast to the traditional way of calculating ethanol fermentation efficiency, where the ratio between the ethanol produced and the sugar consumed is expressed as a percentage of the theoretical conversion yield. Comparison between the two methods, at industrial scale and in sensitivity studies, showed that the indirect method was more robust and gave slightly higher fermentation efficiency values, although fermentation efficiency of the industrial process was found to be low (~75%). CONCLUSIONS: The traditional calculation method is simpler than the indirect method as it only requires a few chemical determinations in samples collected. However, a minor error in any measured parameter will have an important impact on the calculated efficiency. In contrast, the indirect method of calculation requires a greater number of determinations but is much more robust since an error in any parameter will only have a minor effect on the fermentation efficiency value. SIGNIFICANCE AND IMPACT OF THE STUDY: The application of the indirect calculation methodology in order to evaluate the real situation of the process and to reach an optimum fermentation yield for an industrial-scale ethanol production is recommended. Once a high fermentation yield has been reached the traditional method should be used to maintain the control of the process. Upon detection of lower yields in an optimized process the indirect method should be employed as it permits a more accurate diagnosis of causes of yield losses in order to correct the problem rapidly. The low fermentation efficiency obtained in this study shows an urgent need for industrial process optimization where the indirect calculation methodology will be an important tool to determine process losses.