Jim Duston

Bio: Jim Duston is an academic researcher from Dalhousie University. The author has contributed to research in topics: Chondrus crispus & Palmaria palmata. The author has an hindex of 7, co-authored 12 publications receiving 158 citations.

Bioremediation potential of Palmaria palmata and Chondrus crispus (Basin Head): effect of nitrate and ammonium ratio as nitrogen source on nutrient removal

Abstract: Palmaria palmata and Chondrus crispus were grown for 4 weeks in 1-L flasks at 10 °C to evaluate nutrient uptake and their potential application as nutrient biofilters in effluent from finfish culture. For greatest bioremediation benefit within an integrated system, we conclude that a seaweed biofilter using these species should be placed prior to bacterial biofiltration for exposure to greater proportions of ammonium than nitrate, though it is apparent that the productivity of both species is not influenced by the nitrogen source. Five combinations of ammonium– and nitrate–nitrogen were compared, each with a total N concentration of 300 μM (300:0, 270:30, 150:150, 30:270, 0:300). Molar nitrogen/phosphorus ratio was 10:1. The maximum growth rates were 8.9 and 6.0 % per day for P. palmata and C. crispus, respectively. For both species, the total nitrogen uptake was highest at 300 μM ammonium, 4.46 mgN gDW−1 day−1 for P. palmata and 3.40 mg N g DW−1 day−1 for C. crispus. Over a 24-h period, 23–37 % of the available nitrate and 91–100 % of the available ammonium were taken up by P. palmata. In the same period, C. crispus took up 55–87 % of available nitrate and 89–100 % of ammonium. Tissue N in P. palmata was highest (4.1 %) at 270 and 300 μM ammonium, while the nitrogen source did not have a significant effect on the tissue N of C. crispus (mean of 4.6 %).

Growth and nutrient uptake by Palmaria palmata integrated with Atlantic halibut in a land-based aquaculture system

Abstract: Many aquaculture businesses are intent not only on maximizing productivity and profitability, but also ac-complishing this using environmentally responsible practices. Efficient use of energy (e.g., pumping of water) and natural resources (surrounding environment, ambi-ent water supply, and waste streams) are key elements in this approach. Land-based recirculating aquaculture systems facilitate greater control over culture water and waste discharge than flow-through systems (Blancheton et al. 2009). Though the surrounding environment may be enhanced by moderate volumes of aquaculture discharge (White et al. 2011), the trend toward larger land-based fa -cilities (e.g., 1,000 metric tons finfish production per year) and the associated effluent waste may pose a risk of local eutrophication. Alternatively, integration of seaweed and land-based marine finfish culture can convert these nu-trients to a usable product. Previous investigations into land-based seaweed integration have included

Intermittent aeration affects the bioremediation potential of two red algae cultured in finfish effluent

Abstract: The high cost of aeration needed to tumble culture macroalgae is a limiting factor for integration with land-based finfish culture. Toward reducing this electricity cost, we compared intermittent aeration (16 h on:8 h off) with continuous aeration (24 h on) on the productivity of two strains of Chondrus crispus (Basin Head and Charlesville) and Palmaria palmata from Atlantic Canada between May and June 2011. Algal fronds were cultured under a 16:8-h light/dark photoperiod in 50-L tanks supplied with finfish effluent (49 μmol L−1 of ammonium and 11 μmol L−1 of phosphate) at a mean water flow rate of 0.4 L min−1. Nitrogen (N) influx was 1.8 gN m−2 day−1, and phosphorus (P) influx was 0.9 gP m−2 day−1, with uptake rates ranging from 0.02 to 2.4 gN m−2 day−1 and −0.2 to 0.4 gP m−2 day−1. On average, the macroalgae culture system (algae and biofilms) removed 1.0 gN m−2 day−1 (51.9 %). The growth of macroalgae (pooled across treatment and strain) ranged from 0.5 to 1.6 % day−1, which accounted for a yield of 2.2 to 5.4 g DW m−2 day−1. Switching off aeration at night improved the growth rate of Basin Head Chondrus by 146 % and had no effect on growth rate or nitrogen and carbon removal by P. palmata and Charlesville Chondrus. Growth and yield of Basin Head Chondrus under intermittent aeration were over two times greater than both Charlesville Chondrus treatments.

Superficial neuromasts facilitate non-visual feeding by larval striped bass (Morone saxatilis)

Abstract: To investigate whether mechanoreception is used in non-visual feeding in larval striped bass (Morone saxatilis), the ontogeny of superficial neuromasts along the lateral line was described using the vital stain FM1-43FX and fluorescent microscopy. The number of neuromasts visible along one flank increased from 11 at first feeding [5 to 7 days post-hatch (dph)] to >150 by the juvenile stage (27 dph). A neomycin dose response (0, 1, 2 and 5 mmol l(-1)) was evaluated for neuromast ablation of bass aged 10, 13, 17 and 20 dph. Using these same age groups, the ability of bass to catch Artemia salina prey in both dark and light tank-based feeding trials was compared between larvae with neuromasts ablated using neomycin (5 mmol l(-1)) and controls. Neomycin significantly reduced the incidence of feeding in the light and dark. Among larvae that fed, those in the dark treated with neomycin caught fewer Artemia (~5 prey h(-1); P<0.05) than controls (16 prey h(-1) at 10 dph; 72 prey h(-1) at 20 dph). In the light, by contrast, neomycin treatment had no significant effect on prey capture by larvae age 13 to 20 dph, but did inhibit feeding of 10 dph larvae. Verification that neomycin was specifically ablating the hair cells of superficial neuromasts and not affecting either neuromast innervation, olfactory pits, or taste cells was achieved by a combination of staining with FM1-43FX and immunocytochemistry for tubulin and the calcium binding proteins, S100 and calretinin.

Seaweed aquaculture: cultivation technologies, challenges and its ecosystem services

Abstract: Copyright © 2017 The Korean Society of Phycology 1 http://e-algae.org pISSN: 1226-2617 eISSN: 2093-0860 Seaweed aquaculture: cultivation technologies, challenges and its ecosystem services Jang K. Kim, Charles Yarish*, Eun Kyoung Hwang, Miseon Park and Youngdae Kim Department of Marine Science, School of Natural Sciences, Incheon National University, Incheon 22012, Korea Department of Marine Sciences, University of Connecticut, 1 University Place, Stamford, CT 06901, USA Department of Ecology & Evolutionary Biology, University of Connecticut, 1 University Place, Stamford, CT 06901, USA Seaweed Research Center, National Institute of Fisheries Science, Mokpo 58746, Korea Southeast Sea Fisheries Research Institute, National Institute of Fisheries Science, Tongyeong 46083, Korea

Correction for Feeding aquaculture in an era of finite resources

Abstract: Aquaculture's pressure on forage fisheries remains hotly contested. This article reviews trends in fishmeal and fish oil use in industrial aquafeeds, showing reduced inclusion rates but greater total use associated with increased aquaculture production and demand for fish high in long-chain omega-3 oils. The ratio of wild fisheries inputs to farmed fish output has fallen to 0.63 for the aquaculture sector as a whole but remains as high as 5.0 for Atlantic salmon. Various plant- and animal-based alternatives are now used or available for industrial aquafeeds, depending on relative prices and consumer acceptance, and the outlook for single-cell organisms to replace fish oil is promising. With appropriate economic and regulatory incentives, the transition toward alternative feedstuffs could accelerate, paving the way for a consensus that aquaculture is aiding the ocean, not depleting it.

Seaweed nutrient physiology: application of concepts to aquaculture and bioremediation

Abstract: Inorganic carbon, nitrogen and phosphorus are the main elements required by seaweeds for photosynthesis and growth. This review focusses mainly on nitrogen, but the roles of carbon and phosphorus, ...

The Potential of Seaweeds as a Source of Functional Ingredients of Prebiotic and Antioxidant Value.

Abstract: Two thirds of the world is covered by oceans, whose upper layer is inhabited by algae. This means that there is a large extension to obtain these photoautotrophic organisms. Algae have undergone a boom in recent years, with consequent discoveries and advances in this field. Algae are not only of high ecological value but also of great economic importance. Possible applications of algae are very diverse and include anti-biofilm activity, production of biofuels, bioremediation, as fertilizer, as fish feed, as food or food ingredients, in pharmacology (since they show antioxidant or contraceptive activities), in cosmeceutical formulation, and in such other applications as filters or for obtaining minerals. In this context, algae as food can be of help to maintain or even improve human health, and there is a growing interest in new products called functional foods, which can promote such a healthy state. Therefore, in this search, one of the main areas of research is the extraction and characterization of new natural ingredients with biological activity (e.g., prebiotic and antioxidant) that can contribute to consumers’ well-being. The present review shows the results of a bibliographic survey on the chemical composition of macroalgae, together with a critical discussion about their potential as natural sources of new functional ingredients.