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...
Main Authors: | , , , , , , |
---|---|
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/ |
_version_ | 1828386124312084480 |
---|---|
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. |
first_indexed | 2024-12-10T05:31:51Z |
format | Article |
id | doaj.art-7b944cf468ce4e34bf370e5d933bcb0c |
institution | Directory Open Access Journal |
issn | 1869-215X 1869-7534 |
language | English |
last_indexed | 2024-12-10T05:31:51Z |
publishDate | 2018-07-01 |
publisher | Inter-Research |
record_format | Article |
series | Aquaculture Environment Interactions |
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/ |
work_keys_str_mv | AT sobarzom hydrodynamicsofachanneloccupiedbytheaquacultureindustryinsouthernchileimplicationsforconnectivitybetweenfarms AT bravol hydrodynamicsofachanneloccupiedbytheaquacultureindustryinsouthernchileimplicationsforconnectivitybetweenfarms AT iturrac hydrodynamicsofachanneloccupiedbytheaquacultureindustryinsouthernchileimplicationsforconnectivitybetweenfarms AT troncosoa hydrodynamicsofachanneloccupiedbytheaquacultureindustryinsouthernchileimplicationsforconnectivitybetweenfarms AT riquelmer hydrodynamicsofachanneloccupiedbytheaquacultureindustryinsouthernchileimplicationsforconnectivitybetweenfarms AT camposp hydrodynamicsofachanneloccupiedbytheaquacultureindustryinsouthernchileimplicationsforconnectivitybetweenfarms AT agurtoc hydrodynamicsofachanneloccupiedbytheaquacultureindustryinsouthernchileimplicationsforconnectivitybetweenfarms |