ARTICLE | doi:10.20944/preprints202104.0115.v1
Subject: Biology, Anatomy & Morphology Keywords: sustainability; hatchery; SDG; lambari; conservation unit; rural farm; Deuterodon iguape
Online: 5 April 2021 (12:19:46 CEST)
Protected areas have been used worldwide to conserve natural resources. Nevertheless, economic activities to provide income for communities living inside and surrounding conservation areas remain an issue. This study aimed to assess the sustainability of a Deuterodon iguape hatchery, placed inside an Atlantic Rainforest Park, to leverage this small native fish's grow-out farming, affording income and food security for local families. We have used a set of indicators of economic, social, and environmental sustainability. The initial investment is about US$ 40,000, which returned in ~2 years. The internal rate of return is close to 50%, including the externality costs, which is attractive for public and private investments. The hatchery generated few direct jobs, but the workforce can be recruited in the community, and hatchery can enable the establishment of several small grow-out farms, leveraging the development of indirect jobs and self-employments. The system had a low environmental impact, showing minor release of pollutants, low risk for biodiversity, and absorption of 18 g of CO2 equivalent per thousand post-larvae produced, contributing to the struggle against climate change. Therefore, D. iguape hatchery demonstrates the potential of combining biodiversity conservation and income generation, meeting the Sustainable Development Goals of Agenda 2030.
ARTICLE | doi:10.20944/preprints202112.0130.v1
Subject: Biology, Agricultural Sciences & Agronomy Keywords: rural aquaculture; water use; emergy; fish production
Online: 8 December 2021 (14:21:43 CET)
Freshwater pond aquaculture is the prevailing fish culture system worldwide, especially in developing countries. Climate change outcomes and inadequate environmental practices challenge its sustainability. This study applies emergy synthesis to assess the environmental performance of freshwater pond aquaculture in Brazil, aiming to identify and propose practices towards sustainability. As a study model, nine semi-intensive lambari farms operating at three levels of management were evaluated: low (LC), moderate (MC) and high (HC) control. Results showed that the main inputs for LC were services (27-46%), feed (7-39%), and water (15-21%), while for the MC and HC farms, they were feed (35-49% and 17-48%, respectively) and services (33-39% and 26-36%, respectively). All farms required more than 60% of their emergy from purchased inputs, resulting in low emergy sustainability index (ESI = 0.1-0.5). Replacing animal protein and oil on diet composition by vegetal sources, using superficial water instead of springwater, increasing juvenile productivity, and controlling pond fertilization can lead all systems to higher efficiency and resilience, increasing sustainability.
ARTICLE | doi:10.20944/preprints202108.0110.v2
Subject: Life Sciences, Biotechnology Keywords: Astyanax; Macrobrachium; Prochilodus; IMTA; resources optimization; integrated aquaculture
Online: 23 August 2021 (12:56:04 CEST)
A single farmed fish species assimilates about 20% of the nutrients in the supplied diet. This study evaluated if the culture of complementary ecological-function species can recover nutrients dispersed into the water and transform them into high-valued biomass. A completely randomized experiment was designed with three treatments and four replications of each production system: monoculture of lambari (Astyanax lacustris); integrated aquaculture of lambari and Amazon river prawn (Macrobrachium amazonicum); and integrated aquaculture of lambari, Amazon river prawn, and curimbatá (Prochilodus lineatus). Fingerlings of lambari (0.8 ± 0.8 g) were stocked in twelve earthen-ponds (0.015 ha) at the density of 50 fish m-2. Eight ponds, were stocked with juveniles of Amazon river prawn (1.1 ± 0.2 g) at the density of 25 prawn m−2. Four of these eight ponds were stocked with curimbatá fingerlings (0.2 ± 0.1 g) at a density of 13 fish m-². Only lambari was fed twice a day with an extruded commercial diet. The experiment lasted 60 days when lambari attained commercial size. The inclusion of prawn increased the total species yield from 1.8 to 2.4 t ha-1 cycle-1 and reduced the feed conversion ratio (FCR) from 2.5 to 1.8. The inclusion of prawn and curimbatá increased the total yield to 3.2 t ha-1 cycle-1 and reduced the FCR to 1.4. Therefore, the integrated culture of lambari, prawn, and curimbatá improves the use of space, water, feed, and benthic species can recover the large quantity of nutrients accumulated in the bottom of lambari pond production, converting them into high-nutritional and monetary-valued biomass.