40 SEPTEMBER 2017 • WORLD AQUACULTURE • WWW.WAS.ORG between 1969 and 2006, 63 percent was due to activities that were not related to aquaculture, mostly agriculture, cattle, logging for timber and charcoal, and housing development (Suman 1994). Thirty years ago, mangrove wood was used every day in barbeques as charcoal and disposable skewers, slum neighborhoods were being built in Guayaquil on top of mangrove forests at the shores of the Salado Estuary, flagship government projects like the “Perimetral” road and hydraulic filling were executed, even though they destroyed mangrove forest, and mangrove timber was a common building material. That was the Ecuador of the time, and the camaroneros were just another part of the country, neither better or worse. Ignorance or habit are lame excuses for making mistakes, however, and 20,000 ha of lost mangrove forest are not coming back simply by regretting their loss. Ecuador has had different laws that prohibited activities that affected mangrove ecosystems since at least 1974. However, enforcement of those laws was slow to come, although the situation has been improving since the turn of the millennium, and now it is very stern. Net mangrove area loss stopped in the mid1990s and has even started recovering since then (Fig. 1). The greatest effort made in reversing this loss has been the mangrove reforestation project that started in 2008 and the order for shrimp farms that had cut mangroves to conduct reforestation at their own expense. By 2012, 1,419 ha of mangroves had been reforested, with 3,447 ha planned. Based on a 2016 survey, 83 percent of farms that were required to do reforestation had fulfilled their reforestation plan, 11 percent were still in process, and the remaining 6 percent had not done anything or were having problems implementing reforestation. On the other side, many ancestral communities of mangrove dwellers, mostly crab and black clam fishermen, have been granted access and control of the mangrove forests where they make a living. They know that they must maintain the mangrove ecosystem’s integrity and function to secure their long-term source of income. In case of actions that affect mangrove ecosystems, they are the first to blow the whistle and inform authorities. Other beneficial effects of this measure have been better control of closure periods, increased environmental awareness, and better community organization. Although direct logging for pond construction is the main public concern, it does not seem to be a major problem for future sustainability. Indirect effects are a different story and the low public awareness of this threat makes it worse. One of the problems faced by Ecuadorian shrimp aquaculture is eutrophication. Several sites that had good water quality 30 or even 20 years ago now have problems related to low dissolved oxygen levels, low carrying capacity, high BOD, high bacterial counts, and off-flavor. This is a problem that was already reported in studies ten years ago at several places around Ecuador: El Recreo, Tenguel, Balao, Churute, Chone River Estuary, among others. Eutrophication is mostly associated with low water exchange in narrow estuaries, where many shrimp farms discharge water in the same place, or areas with agricultural or urban contamination. The 2016 survey showed the same patterns, with morning dissolved oxygen levels below 2 mg/L in many of these places. Although production levels per crop have risen from around 600 kg/ha to nearly 1,000 kg/ha in the past ten years, they are still significantly below production levels in zones with better water quality. There has been little research on the effects of nutrient discharge on the surrounding biota or on shrimp pond carrying capacity. Surely research on this topic is needed to shed light on the way the process works and its effects and on findings ways to mitigate possible effects. There have been some commercial trials using recirculation to address this problem, but this is not yet a mainstream practice. Seed Supply When shrimp farming first started, shrimp seed entered ponds naturally with intake water; it was not counted and was free. Many species of non-suitable shrimp for aquaculture, fish fry and other invertebrates came along as bycatch that eventually died. Gradually shrimp farmers began collecting their own seed, and later on buying it from specialized fishermen called larveros. Counting and identification methods were developed to access the amount of Penaeus vannamei post-larvae, generally called barba roja or redbeard shrimp. With the lack of commercial shrimp post-larvae production, Ecuador’s availability of wild P. vannamei post larvae became a competitive advantage for the development of this activity. After the 1982-1983 El Niño event, there was a shortage of wild postlarvae and in 1984 as much as 40 percent of pond area was either empty or understocked. This coincided with the beginning of hatchery production. Although the start was difficult, 30 percent of shrimp seed stocked were from hatcheries by 1986, and by the end of the decade, there were enough hatcheries to cover the cumulative demand from all farms. During the 1990s, there was sufficient installed capacity to produce maturation nauplii and hatchery post-larvae. Although the average price of wild seed was US$ 7.00 per thousand, and hatchery seed was US$ 3.50 per thousand, farmers almost always preferred wild post-larvae when available, rather than hatchery seed. Analyzing economic data from one of Ecuador’s main shrimp producers in that decade shows that, even if wild seed was twice as expensive, ponds stocked with wild seed produced on average double the gross margin per hectare per day as those stocked with hatchery seed. When deciding between hatchery post-larvae raised from maturation nauplii or from nauplii from wild-caught gravid females, farmers usually preferred the latter. This was a short-sighted strategy because it hindered earlier and more aggressive development of genetic improvement programs. By the end of the decade, most major shrimp corporations were working on genetic improvement of their broodstock lines. When White Spot Syndrome Virus (WSSV) hit the country in 1999, more emphasis was put into this effort. In 2000, the fishing, transportation, selling and stocking of wild shrimp post-larvae and gravid females was prohibited. This was done to protect bycatch and limit the spread of WSSV, supposedly more prevalent in wild shrimp, but the greatest effect was seen 10-15 years later with increased growth, survival, productivity, and lower feed conversion ratios. In the 2016 survey, 77 percent of interviewed farmers identified better seed or genetics as the main factor contributing to the increase in productivity. Feeds and Feeding Practices On the first farms, shrimp were not fed at all and natural productivity was the sole food source. After a couple of years, agricultural fertilizers were applied to increase productivity and later shrimp were fed with supplemental feed. Initially chicken feed was used and then formulated shrimp diets were produced. By the mid-1980s, formulated shrimp diets were used on nearly all shrimp
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