An evaluation of a macroalgal bioassay tool for assessing the spatial extent of nutrient release from offshore fish farms

García-Sanz, T.; Ruiz-Fernández, J.M.; Ruíz, M.; García, Rubén Darío Álvarez; González, Mar; Pérez, Marta

doi:10.1016/j.marenvres.2010.05.001

Cited by 24 publications

(18 citation statements)

References 57 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In aquaculture studies, biomarkers such as stable isotopes, fatty acid profiles, and pigments are progressively being used to trace fish wastes in seaweeds (Garcia-Sanz et al 2010) and shellfish (Mazzola & Sara 2001, Both et al 2012, Graydon et al 2012, Handå et al 2012b, Jiang et al 2013. In order to identify a signal from biomarkers, the needed timeframe of applicability may be on the order of months to years.…”

Section: Statistical Considerationsmentioning

confidence: 99%

Discrete water quality sampling at open-water aquaculture sites: limitations and strategies

Jansen¹,

Reid²,

Bannister³

et al. 2016

Aquacult. Environ. Interact.

View full text Add to dashboard Cite

While environmental performance of cage-based aquaculture is most often monitored through benthic conditions, there may also be requirements that necessitate discrete, pelagic sampling. In the pelagic realm, adequately capturing the spatial and temporal dynamics of interest and attributing causality to aquaculture processes can be extremely challenging. Conditions are seldom ideal, and data adequacy concerns of discrete samples collected at open-water aquaculture sites are not uncommon. Further exploration of these challenges is needed. Herein, we aim to explore considerations for study design, analysis, and data interpretation of discrete pelagic sampling. As examples, we present 2 case studies where limited sampling occurred under conditions of complex pelagic dynamics. A Norwegian case study quantified particle abundance around salmon farms, and aimed to highlight the effects of spatial−temporal variation on sampling design, the need for inclusion of companion parameters, and the benefits of a priori and a posteriori data interpretation strategies. A Canadian case study collected discrete samples to measure ammonium concentrations with continuous current measurements at an Integrated Multi-Trophic Aquaculture (IMTA) farm, to explore issues of complex hydrodynamics, reference site suitability, sampling resolution, data pooling, and post hoc power tests. We further discuss lessons learned and the implications of study design, ambient conditions, physical processes, farm management, statistical analysis, companion parameters, and the potential for confounding effects. Pragmatic consideration of these aspects will ultimately serve to better frame the costs and benefits of discrete pelagic sampling at open-water aquaculture sites.

show abstract

Section: Statistical Considerationsmentioning

confidence: 99%

Discrete water quality sampling at open-water aquaculture sites: limitations and strategies

Jansen¹,

Reid²,

Bannister³

et al. 2016

Aquacult. Environ. Interact.

View full text Add to dashboard Cite

show abstract

“…Whereas phytoplanktonic δ 15 N is strongly affected by both the isotopic signature of DIN and isotopic fractionation due to changing nutrient conditions, the macroalgal δ Costanzo et al 2001, Rogers 2003, García-Sanz et al 2010. In cases of anthropogenic sewage input, microbial processes such as denitrification can become important (Savage & Elmgren 2004), because these processes alter the DIN isotopic composition substantially (Mariotti et al 1981).…”

Section: Nitrogen Sources and Availability For Primary Producersmentioning

confidence: 99%

Stable isotope variability in a Chilean fjord food web: implications for N- and C-cycles

Mayr

Försterra²,

Häussermann³

et al. 2011

Mar. Ecol. Prog. Ser.

View full text Add to dashboard Cite

We analysed carbon (δ 13 C) and nitrogen (δ 15 N) isotope ratios of organisms and biogenic tissues from Comau Fjord (southern Chile) to characterise benthic food webs and spatial isotope variability in this ecosystem. These values were intended to serve as a baseline for detecting anthropogenic impacts on Patagonian marine fjord ecosystems in later studies. Benthic macroalgae and invertebrate suspension feeders were primarily considered, with some supplementary data from cyanobacteria, plankton, fish, and coastal vertebrates. Six depth transects typified the lateral salinity gradients from the innermost part of the fjord to its mouth, as well as the vertical density gradients caused by freshwater inflow. Carbon isotope signatures indicated predominant consumption of either CO 2 or HCO 3 -for benthic macroalgal. All CO 2 users belonged to rhodophytes. The δ 15N values of benthic macrophytes decreased with decreasing salinity, both vertically and along the fjord axis. This implies the influence of 15 N-poor terrestrial dissolved inorganic nitrogen (DIN) at these sites. Enhanced influence of freshwater influx also lowered N contents and increased C/N ratios in algal tissues. Exceptionally high macroalgae δ Mar Ecol Prog Ser 428: [89][90][91][92][93][94][95][96][97][98][99][100][101][102][103][104] 2011 2007, van Ofwegen et al. 2006, Esteves et al. 2007, Sinniger & Häussermann 2009). The driving forces behind these patterns are not yet fully understood (Fernandez et al. 2000, Escribano et al. 2003. Possible environmental factors affecting biodiversity are specific physical and chemical gradients or highly dynamic nutrient and organic matter fluxes. However, few oceanographic data are available (e.g. Pickard 1971, Silva et al. 1995, Strub et al. 1998). An understanding of the functioning of the Chilean fjord ecosystem is a prerequisite in order to assess the consequences of the intensified exploitation of marine resources and of rapidly expanding aquaculture, the latter adding additional nutrient sources to benthic ecosystems. In addition to species inventories, a deeper understanding of the biogeochemical cycles in Patagonian fjords is the basis for environmental monitoring.Stable isotope methods are frequently applied to characterise marine food webs (Minagawa & Wada 1984, Schoeninger & DeNiro 1984, Bergmann et al. 2009, Steinarsdóttir et al. 2009). The nitrogen and carbon isotopic compositions of natural samples are given as delta values (δ), representing the isotope ratio of the heavy to the light isotope (‰) relative to an international standard and is defined as: δ y X = (R sample / R standard -1) × 1000, with R being the ratio of the heavier to the lighter isotope ( The carbon isotope composition (δ 13 C) of an organism can be used to distinguish isotopically different sources in food webs (DeNiro & Epstein 1978). Minor δ 13 C differences of 0 to 1 ‰ are observed between animals and their food (Peterson & Fry 1987). Thus, the much larger carbon isotope discrepancies between certain groups of prim...

show abstract

“…Burford et al, 2003;. Nutrient availability is high in particular near fish farms, and is detectable in hundreds to thousands of meters distance as documented by using nitrogen stable isotopes and micro-and macroalgal bioassays to trace the nutrients (Dalsgaard and Krause-Jensen, 2006;Lin and Fong, 2008;García-Sanz et al, 2010. Accumulation and decomposition rates of OM are high in sediments near fish farms and decomposition is often dominated by anaerobic pathways such as sulphate reduction (Holmer and Kristensen, 1992;Holmer et al, 2003a;Holmer and Frederiksen, 2007).…”

Section: Introductionmentioning

confidence: 99%

Impact of pond aquaculture effluents on seagrass performance in NE Hainan, tropical China

Herbeck

Sollich

Unger

et al. 2014

Marine Pollution Bulletin

View full text Add to dashboard Cite

An evaluation of a macroalgal bioassay tool for assessing the spatial extent of nutrient release from offshore fish farms

Cited by 24 publications

References 57 publications

Discrete water quality sampling at open-water aquaculture sites: limitations and strategies

Discrete water quality sampling at open-water aquaculture sites: limitations and strategies

Stable isotope variability in a Chilean fjord food web: implications for N- and C-cycles

Impact of pond aquaculture effluents on seagrass performance in NE Hainan, tropical China

Contact Info

Product

Resources

About