The competitiveness of the Chilean salmon aquaculture industry

Abstract

Commercial salmon and trout farming has emerged as a major industry in Chile during the 1990s. Salmon is not a native species to Chile, still excellent climatic conditions are provided for farming. Since 1992 Chile has been the second largest producer of farmed salmon and trout in the world after Norway. This report reviews the development of the Chilean salmonid industry from its early stages until today with respect to production patterns, legislation and main markets. A cost comparison between Chilean and Norwegian farmed salmon is also provided. Finally, the international competitiveness and future challenges of the Chilean salmonid farming industry are analysed.     

Salmon aquaculture in Chile

Abstract

Commercial salmon and trout farming has emerged as a major industry in Chile during the last two decades. Salmon is not a native species to Chile; however, excellent climatic conditions are provided for farming activities in the southern part of the country. After negligible production volumes during the early years, the harvest levels accelerated in the late 1980s, and since 1992 Chile has been the second largest producer of farmed salmon and trout in the world after Norway. This report reviews the development of the Chilean salmonid industry from its early stages until today with respect to production patterns, legislation and main markets. A cost comparison between Chilean and Norwegian farmed salmon is also provided. Finally, the international competitiveness and future challenges of the Chilean salmonid farming industry are analysed.     

The rise of fish oil: From feed to human nutritional supplement

ABSTRACT

This article tells the story of how fish oil has gone from an inferior to a premium oil product. With the growth of aquaculture, fish oil became a valuable feed component. Its value increased further as the belief in the health benefit of Omega-3 opened the market for direct human consumption through nutritional supplements. Strong demand, limited supply growth and weaker substitution between Omega-3 and Omega-6 has led to diverging trends between fish oil and vegetable oil prices, with fish oil now a premium oil product. We also investigated how the salmon aquaculture industry has responded to the challenge of rising fish oil prices. Concerted effort in nutrition and feed research is shown to have allowed a reduction in the share of fish oil in feed from around 25% in the early 2000s to around 12% today. This substitution effort has allowed salmon production to grow without using substantially more fish oil.     

Production of Spotless Allotriploids from Female Non-Spotted Rainbow Trout (Houraimasu), Oncorhynchus mykiss,and Male Amago Salmon,O. rhodurus

ABSTRACT

A new phenotype, spotless allotriploids, was introduced into the aquaculture industry. Spotless allotriploids were produced from female non-spotted rainbow trout, Oncorhynchus mykiss, and male ama-go salmon, landlocked type of O. rhodurus. These allotriploids combine the favorable characteristics of the good flavor of amago salmon, faster growth (compared to that of amago salmon), and absence of spots, preferred by the market. The relationship between the non-spot character (gene) and the external appearance of the allotriploids was traced by analyzing the erythrocyte major axis, the allozymes, and the progeny test in each maternal genotype. Results indicate that spotless allotriploids can be produced by using female dominant homozygotic (hh) non-spotted rainbow trout. When females are heterozygotic (hn) non-spotted rainbow trout, the offspring produced are both spotted and spotless allotriploids in approximately equal proportions.     

Aquacultural development,institution building and research and development policy: Norwegian salmon and Arctic char farming as cases

Abstract

During the past 20 years, Norwegian salmon fanning has grown to achieve export sales of 7 billion Norwegian kroner (NOK). In the same period, Arctic char has been promoted as a lucrative farmed species. Paradoxically, despite the well‐documented advantages of Arctic char farming, this commercial activity has not prospered. Here I study the interaction between research and development and fish farming, and how this interaction affects industrial development within salmon farming and Arctic char farming, respectively. Effective communication between these systems presumes organization by some superior structure that controls the flow of industrial information to the research system, and prepares research results for industrial utility. The focus here is on: the perceptions of industrial actors of tasks for the research community; how researchers interpret and respond to these tasks; how the results are imparted to the fish‐farmers; and how the research results function in practice. I contend that adequate conditions for interaction between research and industrial activity exists for salmon farming, but not for Arctic char farming.     

The effect of competition among three salmonids on dominance and growth during the juvenile life stage

Although non‐native species can sometimes threaten the value of ecosystem services, their presence can contribute to the benefits derived from the environment. In the Great Lakes, non‐native brown trout (Salmo trutta) and rainbow trout (Oncorhynchus mykiss) support substantial recreational fisheries. With current efforts underway to restore once‐native Atlantic salmon (Salmo salar) to Lake Ontario, there is some concern that Atlantic salmon will impede non‐native contributions to the recreational fishery because Atlantic salmon exhibit niche overlap with brown trout and rainbow trout, particularly during the juvenile life stage. We therefore examined competition and growth of juvenile Atlantic salmon, brown trout and rainbow trout in semi‐natural streams. We found that brown trout were the most dominant and had the greatest growth rate regardless of what other species were present. Rainbow trout were more dominant than Atlantic salmon and consumed the most food of the three species. However, in the presence of brown trout, rainbow trout fed less frequently and exhibited negative growth as compared to when the rainbow trout were present with only Atlantic salmon. These data suggest that, outside of density‐dependent effects, Atlantic salmon will not impact stream production of brown trout and rainbow trout.     

Comparison of population dynamics of Atlantic salmon (Salmo salar) and brown trout (Salmo trutta) in a small tributary of the River Scorff (Brittany, France)

The population dynamics of Atlantic salmon (Salmo salar L.) and brown trout (Salmo trutta L.) were compared in a small tributary of the River Scorff (Brittany, France) from spawning time to the beginning of the third growing season. The spawning and fry emergence of the two species took place at approximately the same time. In the first autumn, the densityof 0+ juveniles and settling rate from the egg stage were much higher in trout than in salmon. The emigration rate from 0+ population was much higher in trout than in salmon. The size of resident and migrating fish was always smaller in salmon than in trout, whatever the age. The low level of salmon production in the brook, compared with trout, was the result of low survival from egg to 0+ stage in autumn, combined with the small proportion of juveniles migrating after the first growing season. This was not compensated by a high number of migrants the next year. The role of physical habitat, inter-and intraspecific competition, predation and migration dependence on size and early sexual maturity is discussed. Indications are that small tributaries of the type studied are of great value for recruitment in trout but not very productive for juvenile salmon.     

Price volatility dynamics in aquaculture fish markets

Abstract

In this paper, a time-varying student-t copula is used to capture information on price volatility dependence in the short-, medium-, and long-run horizon in the US market for frozen and fresh salmon, trout, tilapia and catfish. Using monthly data from July 1992 to March 2017, the volatility dynamics for these aquaculture species are assessed. The analysis allows indicating significant differences in the volatility relationships, depending on time-frequency. While short-run volatility has limited dependency, there is significant dependency in both the medium- and long-run, indicating that market integration is stronger in the long-run. The information is particularly important to buyers and producers utilizing the futures markets, as contracts are typically traded using a set of frequencies, and may help them manage and reduce price risk.     

Lake trout growth is sensitive to spring temperature in southwest Alaska lakes

In high‐latitude lakes, air temperature is an important driver of ice cover thickness and duration, which in turn influence water temperature and primary production supporting lake consumers and predators. In lieu of multidecadal observational records necessary to assess the response of lakes to long‐term warming, we used otolith‐based growth records from a long‐lived resident lake fish, lake trout (Salvelinus namaycush), as a proxy for production. Lake trout were collected from seven deep, oligotrophic lakes in Lake Clark National Park and Preserve on in southwest Alaska that varied in the presence of marine‐derived nutrients (MDN) from anadromous sockeye salmon (Oncorhynchus nerka). Linear mixed‐effects models were used to partition variation in lake trout growth by age and calendar‐year and model comparisons tested for a mean increase in lake trout growth with sockeye salmon presence. Year effects from the best mixed‐effects model were subsequently compared to indices of temperature, lake ice, and regional indices of sockeye salmon escapement. A strong positive correlation between annual lake trout growth and temperature suggested that warmer springs, earlier lake ice break‐up, and a longer ice‐free growing season increase lake trout growth via previously identified bottom‐up increases in production with warming. Accounting for differences in the presence or annual escapement of sockeye salmon with available data did not improve model fit. Collectively with other studies, the results suggest that productivity of subarctic lakes has benefitted from warming spring temperatures and that temperature can synchronise otolith growth across lakes with and without sockeye salmon MDN.     

Habitat niche separation of the nonnative rainbow trout and native masu salmon in the Atsuta River,Hokkaido, Japan

The mechanisms by which nonnative species establish populations can be classified into two broad categories: they usurp the niches of native species through interspecific competition, or they avoid this intense interspecific competition by making use of minimal niche overlap with the native species. In this study, we considered how a nonnative salmonid species, the rainbow trout Oncorhynchus mykiss, established a population in the presence of the native salmonid species, the masu salmon O. masou, in Hokkaido, Japan. Circumstantial field evidence shows that the masu salmon exceeds the rainbow trout in abundance and suggests that these species use different types of cover habitat (rainbow trout abundance increases with increasing abundance of large woody debris aggregates, whereas masu salmon abundance increases with increasing abundance of undercut banks). These results imply that the rainbow trout established a population due to minimal niche overlap with the masu salmon, and not by competitive exclusion of the native species.     

Diel migration pattern of Atlantic salmon (Salmo salar) and sea trout (Salmo trutta) smolts: an assessment of environmental cues

The timing of smolt migration is a key phenological trait with profound implications for individual survival during both river descent and the subsequent sea sojourn of anadromous fish. We studied relationships between the time of smolt migration, water temperature and light intensity for Atlantic salmon (Salmo salar) and sea trout (Salmo trutta). During 2006–2012, migrating smolts descending the southern Norway River Storelva were caught in a rotary screw trap located at the river mouth. The date of 50% cumulative smolt descent correlated significantly with the date when the river temperature exceeded 8°C for both Atlantic salmon and sea trout smolts. In 2010, smolts of both species were passive integrated transponder (PIT)‐tagged, and the diel timing of their migration was precisely documented. The degree of night migration decreased in both species as the river temperature rose, and at temperatures above 12–13°C, more smolts migrated during day than during night. A multinomial model was fitted for estimating temperature and species effects on probabilities of migration during night, daytime, dusk and dawn. Atlantic salmon smolts preferred migrating under lower light intensities than sea trout smolts during early, but not late spring when both species migrated during bright daylight. In accordance with the early‐season tendency to migrate at night, Atlantic salmon smolts migrated more during darker hours of the day than sea trout. In both species, smaller smolts migrated under dark conditions than during light conditions. Most of the findings on thermal, light and temporal effects on the observed smolt migration pattern can be explained as adaptations to predation avoidance.     

Linking habitat characteristics with juvenile density to quantify Salmo salar and Salmo trutta smolt production in the river Sävarån,Sweden

Abstract Habitat mapping along 85 km of river was related to juvenile (15 years of electric fishing) and smolt (3 years of screw‐trapping) abundance data to estimate salmon, Salmo salar L., and sea trout, Salmo trutta L., smolt production in the River Sävarån, northern Sweden. Spawning site selection by radio‐tagged salmon (n = 12) and sea trout (n = 4) was also assessed. Fifty‐one hectares of potential spawning and nursery habitat was found in the main stem river, representing 25% of the total river area. These areas were estimated to yield 1300–7580 salmon and 630–3540 sea trout smolts based on juvenile densities, equating with 3 years of screw‐trap data (2990–5080 salmon and 680–2520 trout smolts, respectively). A hypothetical maximum production of about 19 900 salmon smolts was predicted for the river at a density of 40, 0+ salmon 100 m^?2. Tracking adults during the spawning period identified optimal and potential reproductive areas.     

Variation in semen production of farmed Atlantic salmon and rainbow trout

The variation in semen production among farmed Atlantic salmon (Salmo salar) and rainbow trout (Salmo gairdneri) has been studied. Both species were stripped at weekly intervals, the Atlantic salmon four times and the rainbow trout three times.The individual variation in volume of semen was very high, particularly in rainbow trout. The total volume of semen obtained was 137 ml (20 ml/kg body weight) in Atlantic salmon and 23 ml (5 ml/kg body weight) in rainbow trout. The intraclass correlation for volume of semen was estimated at 0.73 in Atlantic salmon and at 0.59 in rainbow trout. The correlations between volume of semen and body size (weight and length) were all positive. They were all significant and medium in Atlantic salmon whereas in rainbow trout they were all low and significant only for volume of semen at first stripping.The number of males needed to supply the Norwegian fish farming industry with semen is discussed. It is concluded that the possibility of disseminating genetic improvement throughout the whole population of farmed Atlantic salmon and rainbow trout by transport of semen from selected males is considerable.     

Polyphasic characterization of Aeromonas salmonicida isolates recovered from salmonid and non‐salmonid fish

Michigan's fisheries rely primarily upon the hatchery propagation of salmonid fish for release in public waters. One limitation on the success of these efforts is the presence of bacterial pathogens, including Aeromonas salmonicida, the causative agent of furunculosis. This study was undertaken to determine the prevalence of A. salmonicida in Michigan fish, as well as to determine whether biochemical or gene sequence variability exists among Michigan isolates. A total of 2202 wild, feral and hatchery‐propagated fish from Michigan were examined for the presence of A. salmonicida. The examined fish included Chinook salmon, Oncorhynchus tshawytscha (Walbaum), coho salmon, O. kisutcha (Walbaum), steelhead trout, O. mykiss (Walbaum), Atlantic salmon, Salmo salar L., brook trout, Salvelinus fontinalis (Mitchill), and yellow perch, Perca flavescens (Mitchill). Among these, 234 fish yielded a brown pigment‐producing bacterium that was presumptively identified as A. salmonicida. Further phenotypic and phylogenetic analyses identified representative isolates as Aeromonas salmonicida subsp. salmonicida and revealed some genetic and biochemical variability. Logistic regression analyses showed that infection prevalence varied according to fish species/strain, year and gender, whereby Chinook salmon and females had the highest infection prevalence. Moreover, this pathogen was found in six fish species from eight sites, demonstrating its widespread nature within Michigan.     

A survey of salmon gill poxvirus (SGPV) in wild salmonids in Norway

In 2016, the Norwegian health monitoring programme for wild salmonids conducted a real‐time PCR‐based screening for salmon gill poxvirus (SGPV) in anadromous Arctic char (Salvelinus alpinus L.), anadromous and non‐anadromous Atlantic salmon (Salmo salar L.) and trout (Salmo trutta L.). SGPV was widely distributed in wild Atlantic salmon returning from marine migration. In addition, characteristic gill lesions, including apoptosis, were detected in this species. A low amount of SGPV DNA, as indicated by high Ct‐values, was detected in anadromous trout, but only in fish cohabiting with SGPV‐positive salmon. SGPV was not detected in trout and salmon from non‐anadromous water courses, and thus seems to be primarily linked to the marine environment. This could indicate that trout are not a natural host for the virus. SGPV was not detected in Arctic char but, due to a low sample size, these results are inconclusive. The use of freshwater from anadromous water sources may constitute a risk of introducing SGPV to aquaculture facilities. Moreover, SGPV‐infected Atlantic salmon farms will hold considerable potential for virus propagation and spillback to wild populations. This interaction should therefore be further investigated.     

Energy and nutrient utilization of Atlantic cod, Atlantic salmon and rainbow trout fed diets differing in energy content

The growth and feed utilization of Atlantic cod (Gadus morhua) (437 g), Atlantic salmon (Salmo salar) (485 g) and rainbow trout (Oncorhynchus mykiss) (413 g) fed a diet (170 g kg⁻¹ fat, 600 g kg⁻¹ crude protein; LE) similar to that used in commercial cod production or one that was top dressed with additional fat (280 g kg⁻¹ fat, 530 g kg⁻¹ crude protein; HE), were compared in an 11‐week trial. In the cod, relative feed intake was 41–58% and thermal growth coefficient 63% of that in the salmonids, but the feed efficiency ratio (FER) was 38% better (P ≤ 0.05). In contrast to the cod where there was no effect of diet on feed intake, growth or FER, both the salmon and trout fed the HE diet had greater feed intake than those fed the LE diet, but the effect of this was only positive for growth in the salmon. The cod retained more of the digested nitrogen (44.9 ± 2.7%) than the salmon (39.4 ± 0.8%), and both of these species retained more than the trout (33.6 ± 1.1%) (P ≤ 0.05). The retention of digested energy was significantly higher in the salmon (52.2 ± 0.9%) than in the trout (44.8 ± 1.1%), with the cod (44.9 ± 4.9%) not different from either of the other species. There were no differences between the species in the retention of absorbed phosphorus (65.9 ± 3.6%). There were very few dietary effects on nutrient utilization in this trial and, for the cod, this indicates that higher energy diets may be feasible for use in production.     

Ecology and movement of juvenile salmonids in beaver-influenced and beaver-free tributaries in the Trøndelag province of Norway

There is concern that expanding beaver (Castor fiber) populations will negatively impact the important economic, recreational and ecological resources of Atlantic salmon (Salmo salar) and sea trout (Salmo trutta) populations in Europe. We studied how beaver dams influenced habitat, food resources, growth and movement of juvenile Atlantic salmon and trout on three paired beaver-dammed and beaver-free (control) tributaries of important salmon rivers in central Norway. Lotic reaches of beaver-dammed and control sites were similar in habitat and benthic prey abundance, and ponds were small (<3,000 m²). Though few juvenile salmonids were detected in ponds, trout and salmon were present in habitats below and above ponds (comprising 9%–31% and 0%–57% of the fish collected respectively). Trout dominated control sites (79%–99%), but the greatest proportion of Atlantic salmon were upstream of beaver ponds (0%–57%). Growth rates were highly variable, with no differences in growth between lotic reaches of beaver-dammed and control sites. The condition and densities of juvenile salmon and trout were similar in lotic reaches of beaver-dammed and control sites, though one beaver-dammed site with fine sediment had very few juvenile salmonids. Beaver dams did not block the movement of juvenile salmonids or their ability to use upstream habitats. However, the degree of repeated movements and the overall proportion of fish moving varied between beaver-dammed and control sites. The small scale of habitat alteration and the fact that fish were able to move past dams makes it unlikely that beaver dams negatively impact the juvenile stage of salmon or trout populations.     

大西洋鲑、三倍体虹鳟和金鳟的肌肉营养成分与品质特性

为了解大西洋鲑(Salmo salar)、三倍体虹鳟(Oncorhynchus mykiss)、金鳟(Oncorhynchus mykiss)3种鱼肌肉营养成分和品质特性,利用生化分析、物性分析方法分析3种鱼肌肉的营养成分、氨基酸和脂肪酸组成、肉色、系水力和质构特性。结果表明,大西洋鲑、三倍体虹鳟、金鳟肌肉的水分质量分数分别为62.91%、67.15%、73.02%,粗蛋白质量分数分别为22.39%、21.03%、22.11%,粗脂肪质量分数分别为14.64%、17.16%、5.11%。3种鱼肌肉的滴水损失、黄色值(b~*)、羟脯氨酸含量、内聚性均显著不差异(P0.05)。3种鱼肌肉的硬度和咀嚼性由低到高依次为大西洋鲑、三倍体虹鳟、金鳟,而pH值的结果则与之相反(P0.05)。大西洋鲑和三倍体虹鳟肌肉的灰分、解冻损失、蒸煮损失、回复性、弹性和红色值(a~*)差异不显著(P0.05),但灰分、蒸煮损失、回复性均小于金鳟肌肉的对应指标(P0.05),弹性和红色值(a~*)则均大于金鳟肌肉的对应指标(P0.05)。大西洋鲑、三倍体虹鳟、金鳟肌肉中必需氨基酸含量占氨基酸总量分别为42.28%、41.84%、41.63%(质量分数),必需氨基酸/非必需氨基酸(EAA/NEAA)比值分别为73.25%、71.94%、71.32%,均符合联合国粮农组织/世界卫生组织(FAO/WHO)对优质蛋白质的评价标准;3种鱼肌肉中均检测到22种脂肪酸,组成丰富,其中不饱和脂肪酸含量较高。综上所述,3种鱼的肌肉都是符合人体营养需求的优质水产品,其中大西洋鲑和三倍体虹鳟肉质接近,且都优于金鳟的肉质。     

The effects of ration size on migration by hatchery‐raised Atlantic salmon (Salmo salar) and brown trout (Salmo trutta)

Abstract – The possibility to increase the proportion of migrating hatchery‐reared smolts by reducing their food ration was studied. Lake‐migrating, hatchery‐reared salmon (Salmo salar) and trout (Salmo trutta) smolts were either fed normal rations, based on recommendations from the fish‐farming industry, or reduced (15–20%) rations. They were released into the River Klarälven, western Sweden, and followed as they swam downstream to Lake Vänern, a distance of around 25 km. For both Atlantic salmon and brown trout, smolts fed a reduced ration migrated faster than fish fed a normal ration. Furthermore, a higher proportion of salmon smolts fed reduced rations migrated to the lake than fish fed normal rations in 2007 but not in 2006. This difference between years corresponded to greater treatment differences in size and smolt status in 2007 than in 2006. For trout, the proportion of migrating individuals and smolt development did not differ with ration size. Trout migrants fed a normal ration had a higher standard metabolic rate (SMR) than nonmigrants, whereas there was no difference in SMR between migrating and nonmigrating salmon. These results show that it is possible to use a reduced food ration to increase the migration speed of both Atlantic salmon and brown trout and to increase the proportion of migrating Atlantic salmon.     

Inclusion of camelina meal as a protein source in diets for farmed salmonids

Camelina meal (Camelina sativa) (CM) is a potential protein source for aquaculture feeds, on account of its crude protein level (380 g kg^?1) and inclusion of most indispensable amino acids. Two experiments were conducted with rainbow trout (Oncorhynchus mykiss) and Atlantic salmon (Salmo salar). Rainbow trout (44.9 g fish^?1) were fed diets with CM at 0 g kg^?1 (0% CM), 70 g kg^?1 (7% CM), 140 g kg^?1 (14% CM) or 210 g kg^?1 (21% CM) for 12 weeks at 14 °C in freshwater, and salmon (241.8 g fish^?1) were fed diets with CM at 0 g kg^?1 (0% CM), 80 g kg^?1 (8% CM), 160 g kg^?1 (16% CM) or 240 g kg^?1 (24% CM) for 16 weeks at 14 °C in sea water. Growth, lipid and amino acid tissue compositions were compared between species. Trout could tolerate up to 14% CM diets without affecting the growth compared to the control, while salmon fed ≥8% CM gained less weight than the control (P = 0.008). The feed conversion ratio in trout fed 21% CM was higher than the control (P = 0.002), and feed intake in salmon fed ≥8% CM was lower than the control (P = 0.006). Trout fatty acid and amino acid composition showed minimal differences between CM‐fed and control‐fed fish, while salmon showed significant alterations after feeding CM diets. Multivariate analyses emphasized differences in tissue composition between species fed CM diets.