Hydrodynamics of a channel occupied by the aquaculture industry in southern Chile: implications for connectivity between farms

Residual circulation from nonlinear interaction of the tidal currents with topography in channels, fjords and bays can be important to represent the distance traveled by suspended materials in the water column (e.g. pathogens). Here the role of the semidiurnal tidal excursion was compared with resid...

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Main Authors: Sobarzo, M, Bravo, L, Iturra, C, Troncoso, A, Riquelme, R, Campos, P, Agurto, C
Format: Article
Language:English
Published: Inter-Research 2018-07-01
Series:Aquaculture Environment Interactions
Online Access:https://www.int-res.com/abstracts/aei/v10/p291-307/
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author Sobarzo, M
Bravo, L
Iturra, C
Troncoso, A
Riquelme, R
Campos, P
Agurto, C
author_facet Sobarzo, M
Bravo, L
Iturra, C
Troncoso, A
Riquelme, R
Campos, P
Agurto, C
author_sort Sobarzo, M
collection DOAJ
description Residual circulation from nonlinear interaction of the tidal currents with topography in channels, fjords and bays can be important to represent the distance traveled by suspended materials in the water column (e.g. pathogens). Here the role of the semidiurnal tidal excursion was compared with residual currents, during autumn 2011, to evaluate the connectivity among aquaculture production centers in Caucahue Channel (Chiloe Island, southern Chile), which has been widely occupied by the aquaculture industry. During 2015, around 30000 t of 3 different species of salmon were harvested in this channel, representing 3.7% of the national production. Along- and cross-channel tidal currents explained around 80 and 40-60% of the total variance, respectively. Thus, the major residual circulation came from the cross-channel component (40-60% of the total variance) caused by tidal asymmetry. We hypothesized that this asymmetry is related to the nonlinear interaction of the oscillatory flow with the Quemchi constriction. The residual advective distances (Ladv) were compared with tidal excursion (Lexc) and biological diffusivity (Ldiff) scales, considering the distances between centers (Lint), the size of the centers (Lcen) and the length of the south arm of the Cauchaue Channel (L = 11 km). For 3 d time scales, the Ladv/Lexc ratio fluctuated between 1.3 and 8, approximately, implying that, although the advective scale is greater, the tidal flow is still intense enough to favor the retention of pathogens. For larger time scales that consider longer-lived pathogens (e.g. greater than 15 d), this ratio grows 1 order of magnitude. In this scenario and in the event of an outbreak within the channel, pathogens could be exported.
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spelling doaj.art-7b944cf468ce4e34bf370e5d933bcb0c2022-12-22T02:00:31ZengInter-ResearchAquaculture Environment Interactions1869-215X1869-75342018-07-011029130710.3354/aei00268Hydrodynamics of a channel occupied by the aquaculture industry in southern Chile: implications for connectivity between farmsSobarzo, MBravo, LIturra, CTroncoso, ARiquelme, RCampos, PAgurto, CResidual circulation from nonlinear interaction of the tidal currents with topography in channels, fjords and bays can be important to represent the distance traveled by suspended materials in the water column (e.g. pathogens). Here the role of the semidiurnal tidal excursion was compared with residual currents, during autumn 2011, to evaluate the connectivity among aquaculture production centers in Caucahue Channel (Chiloe Island, southern Chile), which has been widely occupied by the aquaculture industry. During 2015, around 30000 t of 3 different species of salmon were harvested in this channel, representing 3.7% of the national production. Along- and cross-channel tidal currents explained around 80 and 40-60% of the total variance, respectively. Thus, the major residual circulation came from the cross-channel component (40-60% of the total variance) caused by tidal asymmetry. We hypothesized that this asymmetry is related to the nonlinear interaction of the oscillatory flow with the Quemchi constriction. The residual advective distances (Ladv) were compared with tidal excursion (Lexc) and biological diffusivity (Ldiff) scales, considering the distances between centers (Lint), the size of the centers (Lcen) and the length of the south arm of the Cauchaue Channel (L = 11 km). For 3 d time scales, the Ladv/Lexc ratio fluctuated between 1.3 and 8, approximately, implying that, although the advective scale is greater, the tidal flow is still intense enough to favor the retention of pathogens. For larger time scales that consider longer-lived pathogens (e.g. greater than 15 d), this ratio grows 1 order of magnitude. In this scenario and in the event of an outbreak within the channel, pathogens could be exported.https://www.int-res.com/abstracts/aei/v10/p291-307/
spellingShingle Sobarzo, M
Bravo, L
Iturra, C
Troncoso, A
Riquelme, R
Campos, P
Agurto, C
Hydrodynamics of a channel occupied by the aquaculture industry in southern Chile: implications for connectivity between farms
Aquaculture Environment Interactions
title Hydrodynamics of a channel occupied by the aquaculture industry in southern Chile: implications for connectivity between farms
title_full Hydrodynamics of a channel occupied by the aquaculture industry in southern Chile: implications for connectivity between farms
title_fullStr Hydrodynamics of a channel occupied by the aquaculture industry in southern Chile: implications for connectivity between farms
title_full_unstemmed Hydrodynamics of a channel occupied by the aquaculture industry in southern Chile: implications for connectivity between farms
title_short Hydrodynamics of a channel occupied by the aquaculture industry in southern Chile: implications for connectivity between farms
title_sort hydrodynamics of a channel occupied by the aquaculture industry in southern chile implications for connectivity between farms
url https://www.int-res.com/abstracts/aei/v10/p291-307/
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