"McVey et al. (2002) pointed out the importance of the balanced ecosystem management and suggested that polyculture (now referred to as Integrated Multi-Trophic Aquaculture , or IMTA) can help restore ecosystem function. The ecosystem service performed by seaweeds, extraction of inorganic nutrients, is now referred to as nutrient bioextraction (Galimany et al., 2013; Rose et al., 2012; Tedesco et al., 2014). IMTA and nutrient bioextraction have recently received much attention by federal/state governments and agencies , ENGOs, and the public (Rose et al., 2010; U.S. EPA, 2013). "
[Show abstract][Hide abstract] ABSTRACT: Nutrient bioextraction using Gracilaria tikvahiae McLachlan was tested at two sites: one off Fairfield, CT (LIS), and the other at the mouth of the Bronx River Estuary (BRE), during the summer and fall of 2011 and 2012. The estimates of nitrogen (N) removal by Gracilaria over a 90-day growing season were up to 28 and 94 kg N ha−1 at the LIS and BRE sites, respectively. In July 2012, Gracilaria grewup to 16.5% day−1 at BRE and 4.8% day−1 at the LIS site. Tissue N contents at the same periods were 3.7% (BRE) and 1.5% (LIS), respectively. These results demonstrate rapid assimilation of nutrients fueling the growth of new Gracilaria tissue at the BRE site, while nutrients appeared to limit growth at the LIS site during the summer months. The estimated C removal by Gracilaria at the BRE and LIS sites were up to 300 kg ha−1 (LIS) and 727 kg ha−1 (BRE), respectively. The potential economic values of N and C sequestration for the period examined in this study were as high as $311 (LIS) and $940 ha−1 (BRE) for N, and $5.51 (LIS) and $13.32 ha−1 (BRE) for C if seaweed aquaculture would be included in Connecticut's Nitrogen Trading Program. This represents a potential additional economic incentive for seaweed growers, beyond the direct value of seaweed products. The findings in this study showed that seaweed (Gracilaria) aquaculture can be a useful technique for nutrient bioextraction in urbanized coastal waters, such as the estuaries of New York City (BRE) and Long Island Sound.
"In contrast, extremely high rates of biodeposition in long-line mussel farms reduce oxygen availability and nitrification activity in the underlying sediments (Nizzoli et al., 2005, 2006b; Carlsson et al., 2010). Fixed nitrogen removal from aquatic ecosystems via natural bivalve reefs or mussel farming is also achieved by harvesting the biomass (Newell et al., 2005, Higgins et al., 2011; Stadmark and Conley, 2011; Rose et al., 2012; Carmichael et al., 2012; Kellogg et al., 2013) or through predation by waterfowl (Hamilton et al., 1994). "
[Show abstract][Hide abstract] ABSTRACT: Invertebrate animals that live at the bottom of
aquatic ecosystems (i.e., benthic macrofauna) are important
mediators between nutrients in the water column and
microbes in the benthos. The presence of benthic macrofauna
stimulates microbial nutrient dynamics through different
types of animal–microbe interactions, which potentially
affect the trophic status of aquatic ecosystems. This review
contrasts three types of animal–microbe interactions in the
benthos of aquatic ecosystems: (i) ecosystem engineering,
(ii) grazing, and (iii) symbiosis. Their specific contributions
to the turnover of fixed nitrogen (mainly nitrate and ammonium)
and the emission of the greenhouse gas nitrous oxide
Published data indicate that ecosystem engineering by
sediment-burrowing macrofauna stimulates benthic nitrification
and denitrification, which together allows fixed nitrogen
removal. However, the release of ammonium from sediments
is enhanced more strongly than the sedimentary uptake of
nitrate. Ecosystem engineering by reef-building macrofauna
increases nitrogen retention and ammonium concentrations
in shallow aquatic ecosystems, but allows organic nitrogen
removal through harvesting. Grazing by macrofauna on benthic
microbes apparently has small or neutral effects on nitrogen
cycling. Animal–microbe symbioses provide abundant
and distinct benthic compartments for a multitude of
nitrogen-cycle pathways. Recent studies reveal that ecosystem
engineering, grazing, and symbioses of benthic macrofauna
significantly enhance nitrous oxide emission from
shallow aquatic ecosystems.
The beneficial effect of benthic macrofauna on fixed nitrogen
removal through coupled nitrification–denitrification can
thus be offset by the concurrent release of (i) ammonium that
stimulates aquatic primary production and (ii) nitrous oxide
that contributes to global warming. Overall, benthic macrofauna
intensifies the coupling between benthos, pelagial, and
atmosphere through enhanced turnover and transport of nitrogen.
[Show abstract][Hide abstract] ABSTRACT: Non-point source eutrophication of coastal waters is a significant problem that may be exacerbated locally by effluent from aquaculture operations. Porphyra spp. grow and assimilate nutrients rapidly, making them good candidates for eutrophication abatement via systems of integrated aquaculture. I summarize our work examining the bioremediatory performance (growth rate, nutrient assimilation, tissue N and pigment content) of four U.S. and three Asian Porphyra species as functions of N concentration and source (nitrate vs. ammonium). The Northeast U.S. species P. amplissima is the best performing local bioremediator (maximum growth rate and tissue N=24% d-1, 5.2% DW, respectively), comparing well with P. yezoensis, an economically important species in Asia. When tissue remained non-reproductive, P. amplissima growing in 300 μM ammonium removed 99–100% of N but only about 50% of P (fed 10:1 molar N:P ratio). We have begun investigating the relationship between stocking density and yield, and will begin demonstration scale tests of the mesoscale system.
Note: This list is based on the publications in our database and might not be exhaustive.
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