Seagrass (Posidonia oceanica) vertical growth as an early indicator of fish-farm-derived stress.

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dc.contributor.author Marbà, N.
dc.contributor.author Santiago, R.
dc.contributor.author Díaz-Almela, E.
dc.contributor.author Álvarez, E.
dc.contributor.author Duarte, C.M.
dc.date.accessioned 2019-12-11T08:54:14Z
dc.identifier.uri http://hdl.handle.net/11201/150423
dc.description.abstract [eng] The usefulness of vertical rhizome growth as an early indicator of fish farm impacts to Posidonia oceanica meadows was tested by comparing annual estimates of vertical rhizome growth, quantified retrospectively, at distances ranging between 5 and 1200 m from fish cages at four Mediterranean locations (Cyprus, Greece, Italy and Spain). The studied fish farms had been operating since, at least, 1997, producing between 150 and 1150 tons yr−1 of sea bream (Sparus aurata) and sea bass (Dicentrachus labrax), and, at Italy, also sharpsnout sea bream (Diplodus puntazzo). The reconstructed vertical rhizome growth spanned from 19 to 25 years of growth, depending on sites, and the average vertical rhizome growth before the onset of fish farm operations ranged between 4.48 and 8.79 mm yr−1. The vertical rhizome growth after the onset of farming activities declined significantly (t-test, P < 0.05) from the control station (at >800 m from the farm; vertical growth rate averaged 6.79, 5.52, 3.89 and 3.70 mm yr−1 at Cyprus, Greece, Italy and Spain control stations, respectively) to the impacted one (at 5-300 m from the farm; vertical growth rate was 4.82, 3.52, 2.77 and 1.92 mm yr−1 at Cyprus, Greece, Italy and Spain impacted stations, respectively) at each farm. Moreover, vertical growth significantly (t-test, P < 0.05) declined by about twofold following the onset of fish farm operations for the extant meadow nearest to the cages, as well as those supporting intermediate impacts at distances 35-400 m from the cages. Vertical rhizome growth was not significantly affected after the onset of fish farm operations for the meadows located more than 800 m from the farm, except in those from the Italian site, the largest farm. Examination of the time course of vertical growth for individual rhizomes in the areas of the meadow nearest to the farms, except for those at Cyprus, showed that the decline in vertical growth was initiated within the year of the onset of farming activities, suggesting a negligible resistance of seagrass meadows to fish farm impacts. The results obtained confirm that fish farm activities strongly affect seagrass health on the surrounding meadows, and clearly demonstrate the value of reductions in vertical rhizome growth as an early warning symptom of stress and impacts to P. oceanica meadows.
dc.format application/pdf
dc.relation.isformatof Versió postprint del document publicat a: https://doi.org/10.1016/j.ecss.2005.11.034
dc.relation.ispartof Estuarine Coastal and Shelf Science, 2006, vol. 67, num. 3, p. 475-483
dc.subject.classification 57 - Biologia
dc.subject.classification Medi ambient
dc.subject.other 57 - Biological sciences in general
dc.subject.other Environment
dc.title Seagrass (Posidonia oceanica) vertical growth as an early indicator of fish-farm-derived stress.
dc.type info:eu-repo/semantics/article
dc.type info:eu-repo/semantics/acceptedVersion
dc.date.updated 2019-12-11T08:54:14Z
dc.date.embargoEndDate info:eu-repo/date/embargoEnd/2026-12-31
dc.embargo 2026-12-31
dc.rights.accessRights info:eu-repo/semantics/embargoedAccess
dc.identifier.doi https://doi.org/10.1016/j.ecss.2005.11.034


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