26 MARCH 2023 • WORLD AQUACULTURE • WWW.WAS.ORG resemblance to those of humans and are able to crush small coconuts and other fruit. The pacu also has gill rakers that it uses for filter feeding of zooplankton, one of the characteristics that inspired its candidacy for aquaculture in Brazil the early 1980s. Both tambaqui and pacu have characteristics that make them ideal for pond culture in tropical regions. They are tolerant of pH variability in pond water (Val et al. 1998), have physiological and behavioral traits that increase their tolerance of low levels of dissolved oxygen (Val 1995), are resistant to diseases and pollutants (Kochhann et al. 2015), are very hardy in culture conditions (Campos-Baca and Kohler 2005) and are generally docile. The characteristics of these fish contribute to only a modest environmental impact from their cultivation. Being endemic to the region, escape and possible biological contamination of wild stock is not a prominent concern, although one that needs to be monitored as aquaculture grows and genetics of the fish are manipulated through breeding. Their feed also uses minimal levels or no fish meal, a common concern of aquaculture critics. Protein in feeds is primarily soy-based, complemented with cattle or chicken processing byproducts. The feed conversion ratio for tambaqui and pacu ranges from 1.0-1.5, indicating efficient feed use. Production. Tambaqui and pacu in central Bolivia are reared in earthen ponds that are primarily filled with rainwater and occasionally with water from nearby creeks. Few if any chemical inputs are used to grow fish. This mitigates contamination or alteration of waterways and watersheds. Most ponds are built on previously cleared land, usually pastures or other marginal lands. It also tends to displace or intensify other household farming livelihoods, rather than drive an overall expansion. As such, aquaculture has so far not been a contributor to deforestation, a key concern in the Amazonian region of Bolivia, but this is an area to monitor as aquaculture grows. The contribution of farms to carbon emissions is low as well due to the close proximity of producers and retailers, the limited use of machinery in production and processing and the short distance to markets. Pond production contributes methane emissions, primarily from decomposition in pond sediments. Fish manure is being increasingly upcycled as a fertilizer for fields, but the impact is small compared to other local agriculture activities, most notably cattle farming. Transportation and Marketing. The localized nature of the central Bolivian aquaculture system limits the environmental impact of transportation related to fish and input distribution. Most fish points-of-sale are less than 30 km from the ponds in which they are reared and very few are more than 250 km away. However, an area for improvement is moving away from small vehicle transport to something more efficient, thus reducing greenhouse gas production per unit of fish transported. A transport factor yet to be analyzed, and one to consider for any local agri-food development, is the added greenhouse gas emissions associated with increased tourist travel. The popularity of aquaculture in central Bolivia is leading some consumers to seek it out by visiting the region, thus increasing carbon emissions. It is likely, though, that these would pale in comparison to an export-oriented system. The environmental impact of marketing aquaculture fish in central Bolivia is currently unclear. Sales at markets likely generate impacts proportional to the overall impact of the market and its activities and aquaculture does not have any unique characteristics in this regard. Fish restaurants that draw on farmed fish are similarly typical to other restaurants, with no noticeably unique properties. The evidence overall points to aquaculture having no unusual contribution to environmental degradation from market or restaurant activity, other than its contribution to overall growth of those outlets. Guiding Aquaculture Growth and Development Perhaps the most important but elusive factor for any agri-food system development, and this is particularly relevant for aquaculture, is the approaches and best practices that are instituted to generate desirable outcomes. In central Bolivia, the history of aquaculture laid the groundwork of awareness and possibility, but rapid growth with development benefits and a small environmental footprint was particularly spurred and guided from two sources, one from below in the form of NGO work and international projects, and the other from above, in the form of governmental prioritization and investment. The Role of NGOs and The Peces Para la Vida Projects. NGOs and universities have played critical roles in central Bolivian aquaculture since the 1960s. Their work established early demonstration farms, experimented with different species and supported adoption by farmers. For example, the NGO HOYAM, University Mayor of San Simón2 and Gabriel René Moreno University3 were leaders in establishing pacu and tambaqui fingerling production. Those two universities, along with the indigenous university UNIBOL4 , have also been key educators of aquaculture specialists and extension workers in the country. However, despite the early efforts of these organizations, and a short boom around Trinidad of communal projects, aquaculture in central Bolivia remained in a state of relatively stalled development, with the number of farms and degree of popularity of fish relatively static. A key catalyst for aquaculture expansion came in the early 2010s with the start of the Peces Para La Vida (PPV) projects (Fig. 10). In 2011 the Canadian NGO World Fisheries Trust (WFT)5 and the Bolivian NGOs Faunagua6 and Agua Sustentable teamed up to investigate the opportunities for aquaculture and fisheries improvement in central and northern Bolivia, assisted by Brazilian partners from WFT’s past projects in that country and Canadian support through the Canadian International Development Agency (CIDA). Their focus was on propagation of tambaqui and pacu to improve rural livelihoods and FIGURE 9. Tambaqui.
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