title: Spatial and temporal dynamics in macrobenthos during recovery from salmon farm induced organic enrichment: when is recovery complete?
abstract: This study documents eight years of benthic recovery at a highly impacted salmon farm. Substantial recovery occurred in the first 2 years, and was assessed to be complete after ∼5 years. However, minor differences were still evident, along with some on-going benthic instability, attributable to medium-scale spatial movements and successional patterns of macrobenthos. Quantifying the endpoint of 'recovery' proved challenging due to: lack of a widely accepted definition, inherent variability in recovering sediments, differing trajectories of impact and reference sites, and statistical challenges. More complex biotic indices and metrics incorporating multiple variables were the most robust indicators. Statistical tests for 'parallelism' in the trajectories of Cage and Reference sites proved useful, but results were contingent upon how the method was applied, and should therefore be used in conjunction with data-visualisation methods. The study highlights the importance of a predetermined recovery endpoint, and using multiple indicators and a weight-of-evidence assessment approach.
authors: Cawthron Institute, Nelson 7010, New Zealand; Tasmanian Aquaculture and Fisheries Institute, University of Tasmania, Taroona, Tasmania, Australia. Electronic address: nigel.keeley@cawthron.org.nz.
authors: Nigel B
authors: NB
authors: Keeley
authors: Tasmanian Aquaculture and Fisheries Institute, University of Tasmania, Taroona, Tasmania, Australia.
authors: Catriona K
authors: CK
authors: Macleod
authors: Cawthron Institute, Nelson 7010, New Zealand.
authors: Grant A
authors: GA
authors: Hopkins
authors: Cawthron Institute, Nelson 7010, New Zealand.
authors: Barrie M
authors: BM
authors: Forrest
mesh_terms: D000818:Animals; D017756:Aquaculture; D017753:Ecosystem; D004784:Environmental Monitoring; D052918:Environmental Restoration and Remediation; D019015:Geologic Sediments / Q000737:chemistry; D007448:Invertebrates / Q000145:classification / Q000254:growth & development; D012474:Salmon; D062211:Spatio-Temporal Analysis; D014873:Water Pollutants / Q000032:analysis; D014876:Water Pollution / Q000706:statistics & numerical data
chemical_list: D014873:Water Pollutants
keywords: Aquaculture; BACI; Benthic ecology; Fallowing; Parallelism; Remediation