A multivariable assessment of the spatio-temporal distribution of pyrethroids performance on the sea lice Caligus rogercresseyi in Chile

Arriagada, Gabriel; Sánchez, Javier; Stryhn, Henrik; Vanderstichel, Raphaël; Campistó, J.L.; Ibarra, R.; St‐Hilaire, Sophie

doi:10.1016/j.sste.2018.04.004

Cited by 5 publications

(9 citation statements)

References 37 publications

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“…Otherwise, our results are consistent with the spatiotemporal patterns observed for C. rogercresseyi resistance to chemical control. Limited effectiveness of pyrethroids against C. rogercresseyi has been reported in a retrospective study in two areas during 2012–2013, one located in northern Region X [Los Lagos] and the other in the central area of Region XI [Aysén] ( 25 ). However, even though we observe a heterogeneous C. rogercresseyi clustered pattern, there are unmeasured factors in the understanding of those processes behind the infestation patterns.…”

Section: Discussionmentioning

confidence: 99%

“…In the marine environment, different groups of farms cultivate a large number of susceptible fish hosts at the same time, becoming a source of infestation to neighboring farms and to themselves in a restricted spatial area ( 31 ). The spatial structure of C. rogercresseyi dynamics has been approached exclusively to evaluate the effect of chemical control, identifying a distance-dependent cluster response mediated by unknown factors ( 24 , 25 , 29 ). In addition, in most salmon-producing regions, local authorities encourage the adoption of Integrated Pest Management (IPM) and the exploration and use of other non-chemical measures to reduce sea lice occurrence levels ( 32 , 33 ).…”

Section: Introductionmentioning

confidence: 99%

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Epidemiological Factors Associated With Caligus rogercresseyi Infection, Abundance, and Spatial Distribution in Southern Chile

Lepe-López

Escobar-Dodero

Rubio³

et al. 2021

Front. Vet. Sci.

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Sea lice (Caligus rogercresseyi) are external parasites that affect farmed salmonids in Chile, and the scale of their sanitary and economic impact cannot be overstated. Even though space–time patterns suppose parasite aggregation, specific locations related to different infestation levels, as well as their associated factors across the geographic range involved, had not been investigated as of the writing of the present article. The understanding of the effects and factors entailed by the presence of C. rogercresseyi may be deemed a key element of Integrated Pest Management (IPM). In the present study, the multivariate spatial scan statistic was used to identify geographic areas and times of C. rogercresseyi infestation and to estimate the factors associated with such patterns. We used official C. rogercresseyi monitoring data at the farm level, with a set of 13 covariates, to provide adjustment within the analyses. The analyses were carried out for a period of 5 years (2012–2016), and they included three fish species (Salmo salar, Oncorhynchus mykiss, and Oncorhynchus kisutch) in order to assess the consistency of the identified clusters. A retrospective multinomial, spatial, and temporal scan test was implemented to identify farm clusters of either of the different categories of C. rogercresseyi infested farms: baseline, medium, and high, based on the control chemical threshold established by the health authority. The baseline represents adequate farm performance against C. rogercresseyi infestation. Then, production and environmental factors of the medium and high infestation farms were compared with the baseline using regression techniques. The results revealed a total of 26 clusters (p < 0.001), of which 12 correspond to baseline, 1 to medium, and the remaining 13 to high infestation clusters. In general, baseline clusters are detected in a latitudinal gradient on estuarine areas, with increasing relative risks to complex island water systems. There is a spatial structure in specific sites, north of Los Lagos Region and central Aysén Region, with high infestation clusters and epidemic peaks during 2013. In addition, average weight, salmon species, chemotherapeutants, latitude, temperature, salinity, and year category are factors associated with these C. rogercresseyi patterns. Recommendations for an IPM plan are provided, along with a discussion that considers the involvement of stock density thresholds by salmon species and the spatial structure of the efficacy of chemical control, both intended to avoid the advance of resistance and to minimize environmental residues.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Epidemiological Factors Associated With Caligus rogercresseyi Infection, Abundance, and Spatial Distribution in Southern Chile

Lepe-López

Escobar-Dodero

Rubio³

et al. 2021

Front. Vet. Sci.

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“…Recently, based on the prevalence of anti‐parasite treatment results, the resistance of C. rogercresseyi to pyrethroids is suspected in neighbourhoods located in the central Aysén Region and northern zone of the Los Lagos Region (Arriagada et al . ). A previous study detected a severe reduction of sensitivity to pyrethroids in areas with high parasite abundance located in the Los Lagos Region (Marín et al .…”

Section: Salmon Farming Environmental Impacts During the Marine Fattementioning

confidence: 97%

“…These pesticides have low solubility in water, a high octanol-water partitioning coefficient and high capacity for absorption by suspended matter, thereby reaching bottom sediments (Tucca et al 2017). Recently, based on the prevalence of anti-parasite treatment results, the resistance of C. rogercresseyi to pyrethroids is suspected in neighbourhoods located in the central Ays en Region and northern zone of the Los Lagos Region (Arriagada et al 2018). A previous study detected a severe reduction of sensitivity to pyrethroids in areas with high parasite abundance located in the Los Lagos Region (Mar ın et al 2015).…”

Section: Pesticidesmentioning

confidence: 99%

Environmental issues in Chilean salmon farming: a review

Quiñones

Fuentes

Montes

et al. 2019

Reviews in Aquaculture

206

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The growth of Chilean salmon production has not been free of important sanitary and environmental shortcomings. To ensure sustainability, it is necessary to understand the environmental impacts of salmon production on the Patagonian ecosystems. Currently, there is limited regulation or monitoring of impacts in the freshwater phase compared to the marine fattening stage, and there is some evidence of local eutrophication impact and diversity changes downstream the farms. Eutrophication of Patagonian channels and fjords from marine farms has been recognized as crucial environmental risk, although most scientific evidence comes from local effects below and around farms. So far, there are no regulations based on carrying capacity estimates to limit maximum fish biomass per area or water body. There is controversy regarding the potential role of nutrients derived from farming in triggering harmful algal blooms, yet current environmental monitoring and available information does not allow establishing or rejecting a cause–effect relationship. Pesticides used to control sea lice infestation have been shown to be deleterious to some non‐target species. There is evidence that the use of high quantities of antibiotics has allowed the development of antibiotic‐resistant bacteria in sediments and there is concern that salmon aquaculture has the potential to increase the proportion of antimicrobial‐resistant bacteria to antibiotics that are used in human medicine. There is an urgent need for more comprehensive ecosystem (beyond farm) studies on the impacts of antibiotics. Escapes of salmon (exotic species) from farms are a relevant environmental risk, although the most farmed species, Salmo salar, has shown little success in establishing wild populations. The review identifies critical knowledge gaps whose fulfilment is essential to advance towards an ecosystem approach to aquaculture and to protect Patagonian ecosystems.

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“…However, there are many hypotheses in practical application, especially that it is difficult to obtain accurate mathematical model of the controlled plant [11][12]. The multivariate statistical process monitoring methods are very popular nowadays, particularly principal component analysis (PCA) [13][14] and partial least squares (PLS) [15][16]. With the rapid development of science and especially the information technology, chemical, power and other enterprises changed significantly.…”

Section: Introductionmentioning

confidence: 99%

Performance Analysis of Multi-Variable Control System Based on Data Driven

Shi-zhe¹,

Wang²

2018

IJIMSE

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With the development of science and technology, the control system has become an indispensable means to ensure the safe, stable and efficient operation of the process with the improvement of system capability and modernization level. As time goes on, the characteristics of industrial production process will change, resulting in the degradation of control performance, product quality decline, directly affecting economic benefits. Therefore, performance evaluation of control system is of great significance to improve control performance and economic benefits of enterprises. Combustion control system is an important and typical multivariable control system in thermal power plant. Its performance evaluation is very important for power production process. So a method and detail steps of performance analysis based on data driven for multivariable control systems are presented. Using multivariate statistical analysis, the overall performance of the system and the performance index of the individual variable are defined respectively by the generalized eigenvalue of the covariance matrix. Through the supervisory information system, the data of the combustion control system of a certain thermal power unit is obtained and the operating data for one day is analyzed using the proposed method. The results show that this method can realize the relative accuracy evaluation of the overall performance and the individual performance for each controlled variable of the control system.

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A multivariable assessment of the spatio-temporal distribution of pyrethroids performance on the sea lice Caligus rogercresseyi in Chile

Cited by 5 publications

References 37 publications

Epidemiological Factors Associated With Caligus rogercresseyi Infection, Abundance, and Spatial Distribution in Southern Chile

Epidemiological Factors Associated With Caligus rogercresseyi Infection, Abundance, and Spatial Distribution in Southern Chile

Environmental issues in Chilean salmon farming: a review

Performance Analysis of Multi-Variable Control System Based on Data Driven

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