The majority of solids in intensive culture systems are from uneaten feed and fecal solids. The settling velocity of feeds and fecal solids is needed for the design of settling basins and modeling of the impacts of netpens. The UFT column developed in Germany in the 1980s has become the dominant column type for wastewater settling testing. The primary advantage of this column compared to conventional columns is the preconcentration of the settleable solids, elimination of problems with time zero estimates, and reduced sampling requirements. The conventional settling velocity analysis presented in standard references, while theoretically correct, and is virtually impossible to apply to actual fecal waste because of uncertainty in numbers, mass, shape, density, and drag characteristics. In addition, this analysis is unneeded, as the removal efficiency is measured directly in the settling column tests. Because the UFT column uses only the settleable solid portion of the total suspended solids, the settling results will depend on the preconcentration process. If this process misses a significant portion of the settleable solids, the resulting settling tests will overestimate the removal efficiency. If the ratio of non-settleable solids/total suspended solids is known, the resulting removal efficiency can be presented in terms of either settleable solids or total suspended solids. Additional research is needed to develop standardized protocols for the collection of solids and handling prior to analysis.

Aquaponics, the integration of fish culture with plant production, has attracted widespread interest as a method to reduce the environmental impacts of food production and provide locally produced, healthy food. Recent surveys have found that most practitioners are hobbyists, producers, or educators. Many systems have evolved from small-scale experimental facilities devised by trial-and-error methods and implemented with locally available species. The expansion of aquaponics to commercial-scale systems is limited by the lack of standardized experimental design and performance metrics. This work documents the physical and chemical characteristics of aquaponic systems and reviews important performance parameters. This standardization will help in the design of aquaponic systems, streamline data collection and analysis, promote consistency among researchers, and aid in the economic evaluation of commercial systems.

Sablefish (Anoplopoma fimbria) is a Pacific marine species that adapts well to aquaculture, grows extremely fast, and command a high market price. Because of environmental and regulatory concerns, increased production of this species is likely to occur in land-based systems. Little is known about the waste production characteristics of sablefish, information that will have a critical impact on the design of aeration, solid removal, and biofilter design for this species. It was found that the concentration of total suspended solids (TSS) in the effluent was extremely low and the mean TSS ranged from 0.9 to 1.7 mg/L. Compared to other important culture fish, sablefish produce significantly less fecal solids (5.2-7.9 % based on feed inputs) and less of their solids settled out (57.3-65.8 % of total suspended solids). TSS production following feeding of a special feed for reuse systems was significantly higher (51.9 %) compared to fish fed a conventional diet. The reduced production of TSS by sablefish is due to higher apparent digestibility coefficients and possible production of wastes that are not retained on the standard filter used for TSS analysis. Additional rinsing of the filters to remove salt and the use of large sampling volumes can significantly improve the accuracy of TSS analysis for marine culture species.

To better document the potential impacts of aquaponics, performance metrics should be clearly defined and relevant to economic, environmental, and management objectives. An important performance parameter for fish is While much less common, it is also possible to determine a FCR for plants (FCRplant= amount of feed supplied/increase in weight of plants) in an aquaponics system. This parameter measures how well the nutrients from fish waste are converted into plant tissue. In contrast to the FCRfish, a theoretical value of FCRplant can be estimated from (a) the composition of feed and plants, and (b) the nutrient retention values. Only 50% of the experimental FCRplant values fell within this theoretical range. This analysis indicates significant room for improvement regarding nutrient retention among plant components of many aquaponic systems. Reduced retention efficiency may be due to (a) low nutrient and micronutrient concentrations, (b) suboptimal pH and temperatures, and (c) buildup of salts. It is strongly recommended that the FCRplant value be reported in future aquaponic research.

Aquaponics is the integration of aquaculture and hydroponics where nutrients released by growing fish are utilized by plants grown in a soilless culture, often in a controlled environment. Potential advantages of aquaponics include improved sustainability, reduced resource consumption, and fewer environmental impacts compared to conventional aquaculture. Based on a 2014 survey, it was found that most respondents were practicing aquaponics as a hobby. Other groups of respondents were educators, non-profit organizations that operate aquaponic systems, commercial operators, and consultants that sell goods, material, and services. Although many proponents cite the opportunity to create a commercially viable food production system few (if any) ventures have demonstrated sustainable financial outcomes. In general, much of the peer-reviewed aquaponic publications and popular literature, and despite the efforts of some investigators, lacks a methodical scientific basis for describing the essential mechanics, relationships, and culture methods within aquaponic systems. Many systems evolved from small-scale experimental facilities devised by trial and error methods and were implemented with locally limited appropriate species, limited finances, and distorted market situations. Many of the published aquaponic experiments are based on small systems, short growth trials, and weak experimental design. The predominant system design approach is based on a relatively small number of experiments. This review introduces notation and algorithms that are intended to standardize the numerous critical values essential in aquaponics for purposes of determining design criteria and operational parameters including flows, the concentration of water quality constituents, metabolite production, and productivity of plant and animal segments in an aquaponic systems. The objective of this systematic approach is to employ scientific methods that provide research results that can be replicated, challenged, and improved. This methodology is expected to facilitate more rapid development of scientific information, productive systems, and rational economic applications. This approach is crucial for commercial applications where production cost, product value, and investment returns are of critical importance for practitioners that envision investment in new ventures. For hobbyists and educators, economic issues may not be as important as the self-sufficiency and natural synergism aspects, personal satisfaction, and the learning experience that result from existing state-of-the-art of aquaponic practices. These outcomes remain for all and a clearer understanding of smaller personal systems is likely to be enhanced.

One potential advantage of aquaponic systems is reduced resource consumption compared to separate fish and plant rearing systems, but little has been published on the costs of providing nitrogen and phosphorus nutrients by fish in comparison to the purchase of inorganic fertilizers. The cost of providing nitrogen and phosphorus from six commercial fish feeds was compared to 9 commercial agricultural fertilizers. Waste production from fish was corrected for excretion of urea and the impact of feed wastage. For a typical aquaponic system without mineralization of fecal solids, the soluble nitrogen and phosphorus excretion ranged from 36.9 to 44.0 g/kg feed and 1.4-3.7 g/kg feed, respectively. The cost to provide 1 kg of nutrients from feeds ranged from $15-$29/kg for nitrogen and from $115 -$583/kg for phosphorus. Compared to the purchase of these elements from inorganic fertilizers, the feeds were 7-14 times more expensive for nitrogen and 17-88 times more expensive for phos-phorus. The feed/fertilizer cost ratio (FFCRfeed) required to replace the nitrogen and phosphorus in 1 kg of feed ranged from 2 to 4 times for monoammonium phosphate to 14-17 times for anhydrous ammonia and triple superphosphate. Based on the specific conditions and assumptions in this work, the economic value of nutrients provided by fish in aquaponic systems has been greatly over-stated.

Turkish Towel Chondracanthus exasperates and taurine were added to alternative plant-based feeds for juvenile sablefish Anoplopoma fimbria to evaluate the effect of these ingredients, alone or combined, on fish growth, feed intake and efficiency, whole body nutrient composition, and liver histomorphology. Fish growth was significantly increased with the addition of taurine, and to a lesser extent, Turkish Towel to the experimental feeds. Feed efficiency and protein retention were significantly improved with the addition of taurine, but were unaffected by Turkish Towel addition. As expected, whole body taurine content was significantly affected by taurine addition. Increases in whole body lipid were observed with both taurine and Turkish Towel addition, with a significant interaction between the two factors. Liver histomorphology was generally normal; however, histopathologic changes were observed in some fish at the end of the experiment. The occurrence of hepatocellular nuclear pleomorphism and clear cell foci was less among fish that had received the Turkish Towel feeds. The addition of taurine had no effect on the number of fish with a histopathologic change. Overall, results from this study reaffirm taurine supplementation is beneficial to sablefish receiving plant-based feeds and indicate Turkish Towel may be a promising feed ingredient for this species.

Oxygen consumption and other metabolic rates for commercial systems are typically measured under flow-through conditions and therefore are biased because of hydraulic lag. To evaluate potential correction approaches, three representative (SINE, STEP, MULTI-STEP) daily metabolic responses (R-i(a)) were developed. Using the values of R-i(a), the resulting concentration of dissolved oxygen (C-i(i)) on a minutely basis over the day was estimated from either a hydraulic mixing model or mass balance equations. Six approaches (STEADY, FRY, NORTHBY, NIIMI, SPLINE, and POLY) were used to estimate the metabolic oxygen consumption rate (R-i) for the 20-, 40-, and 60-minute periods. Three analytical approaches were tested (MEAN, POINT, and DETAILED). Based on all three test metabolic rates, the combination of the DETAILED analytical approach and the SPLINE correction was the most accurate. The DETAILED approach is based on estimation of the minutely oxygen consumption and computation of the average rate over a specific time period. The combination of DETAILED and NIIMI was more accurate for STEP and MULTI-STEP but was very inaccurate for the SINE response. It is not surprising that NIIMI is an excellent correction for STEP and MULTI-STEP as the derivation of this equation was based on a step change in metabolic rate. STEADY was the least accuracy for all metabolic response. For SINE, all of the equations can be used to estimate the daily average value ((R) over bar (daily)). For STEP and MULTI-STEP, STEADY is less accurate. STEADY under-estimated the upper and lower peaking factors, but the other correction equations were very accurate. This same lag response can also bias other metabolic rates (carbon dioxide, ammonia, solids) and the computation of performance and efficiencies of unit processes such as biofilters and solids removal processes. The correction of unit process performance metrics may be further complicated by rapid changes in influent concentrations that were not considered in these correction approaches and the kinetic response of the process to changes in substrate concentrations.

An understanding of the dynamics of oxygen consumption by the culture animal is needed to properly design and operate an aeration system. In commercial production systems, oxygen consumption rates are typically determined under flowing water conditions. A simple mass balance on a flow-through system results in the following equation in terms of mg oxygen/(kg fish h): Oxygen Consumption =-{ [flow/mass of fish](C-t(in)- C-t} + {[rearing volume/mass of fish][dC/dt]} The formula commonly used to estimate oxygen consumption is biased because it only considers the first term. The error in the oxygen consumption rate depends primarily on the rate of change of oxygen within the rearing unit (dC/dt) and is larger when the oxygen consumption rate has a significant variation with time. This same lag response can also bias other metabolic rates (carbon dioxide, ammonia, solids) and the computation of performance and efficiencies of unit processes such as biofilters and solids removal processes. While a number of approaches have been developed to correct oxygen consumption rates for the impact of this hydraulic lag, their accuracy has never been evaluated in any comprehensive manner and in many cases, their derivation is entirely lacking. To better understand their assumptions and limitations, the derivation of these correction approaches (and several new methods) have been clearly and comprehensively developed in this article. Without this background information, it is difficult to understand the differences between the approaches and their potential limitations. In companion paper, the accuracy of the correction equations and analysis assumptions will be evaluated.

The impact of the addition of a wide variety of commercial, experimental, and larval feeds as well as fish oils, specific lipid products, amino acids, and surfactants on airlift pumping rates were documented. At 250 min after addition, the airlift flow rate varied from 12% to 102% of baseflow for diffuser injection but only 77 to 85% of base flow for direct injection. As a group, the fish and algal-based oils had the greatest impact on airlift flow rate. It is hypothesized that the impact of feed addition is due to lipids and surface-active compounds leaching out of the feed and increasing bubble size. There was a significant correlation between gas holdup and airlift pumping rate. Higher gas holdup was positively correlated with higher water flows. There was also a wide range in speed and range of flow rate recovery; flow recovery may depend on adsorption of lipids on the tank walls or chemical reactions. There was a positive correlation between lipid content and flow reduction, but the physical characteristics of the feed and specific fatty acid profiles of the feed may be important. The use of performance information based on clean water tests may significantly over-estimate pumping rates of airlift pumps. For critical applications, on-site evaluation using actual airlift pumps and feeds may be needed. While feed addition had much more impact on the performance of airlift pumps using diffuser injection compared to direct injection, the significantly higher efficiency of diffuser injection makes this injector type a better choice for many applications.

Turkish towel (Chondracanthus exasperatus), Pacific dulse (Palmaria mollis, also known as Red ribbon seaweed), and sea lettuce (Ulva spp.) were cultivated in a land-based intensive culture system at the Manchester Research Station, USA from August 2013 to September 2014. Macroalgae were grown in tumble-aerated tanks, harvested bimonthly for seasonal growth calculations, and analyzed for protein, lipid, ash, and amino acid content. Growth rate of all three species exhibited a similar pattern, with the highest specific growth rates occurring during the summer months (Turkish towel: 7.8%, Pacific dulse: 8.2%, and sea lettuce: 6.2%). Growth of all three species was lowest around winter solstice; with negative growth only observed in sea lettuce. On a dry weight basis significant differences in protein content existed between the three species with highest values for sea lettuce (29.5 +/- 1.4%). Lipid content varied between species (0.95-2.78%) with significantly higher lipid observed in sea lettuce (0.58-4.82%). No significant differences were detected on a seasonal basis among each species. Essential amino acids accounted for 43 +/- 0.9 to 47 +/- 1.2% of total amino acids with Turkish towel having the highest value. Turkish towel had a significantly higher taurine level (0.82 +/- 0.27) than the other macroalgae. The levels of persistent organic pollutants and heavy metals were low. The estimated annual product of the three species ranged from 50-to 70-mt dry weight ha(-1) y(-1), significantly higher than conventional crops. Land-based culture of these species can produce year-round harvest, consistent product quality, and low contaminant levels.

Mechanical chillers can be used to slow the development of salmon eggs and fry. Chiller failure can result in a rapid temperature increases that may adversely impact salmon development. In this study, three types of chiller failure were simulated: (1) CF - failure of chiller, (2) PF - failure of recirculation pump, and (3) NR - chiller failure for a chiller system without a coldwater reservoir. Temperatures were monitored at 38 locations at the Burley Creek Hatchery using 4-channel loggers (Onset, Model U12-008) and Hobo pendant loggers (Onset, UA-001-64). The maximum temperature responses for 30-, 60-, and 90-min intervals were determined for both failure and restart. For the 30-min period, the maximum Delta Ts were equal to 3.37 degrees C for NR, 2.62 degrees C for PF, and 1.79 degrees C for CF. The magnitude of the Delta Ts were larger for restart compared to failure. The response of the Hobo loggers were very close to the 4-channel loggers even though their time response was significantly slower. The PF and CF failure modes were modeled as two unequal sized CFSTR (coldwater reservoir and incubator) in series and NR mode was modeled as a single CFSTR (incubator). Theoretical and measured mean hydraulic resident times were used to estimate the both deviation between the actual temperature and the modeled temperatures as well as the maximum temperature increases at 30-, 60-, and 90-min intervals. The PF-failure and NR-restart were quite good CFSTRs (stagnant regions of about 9%), while the remaining failure modes had poorer performance (stagnant regions ranging from 25 to 35%). If the theoretical mean hydraulic residence times are used for design, these values must be multiplied by the appropriate reactor correction factors to estimate the size of physical coldwater and glycol reservoirs needed. (C) Published by Elsevier B.V.

Airlift pumps are commonly used in aquaculture systems to circulate water and maintain critical gas levels. In production marine reuse systems, a significant decrease in airlift pump flowrate was visually observed immediately after feeding. In experimental systems without fish, it was found that feed additions of less than 10 mg/L decreased water flow by as much as 78% for diffuser injectors but only 10% for pumps with direct air injection. For both injector types, feed impact diminished over several hours but persisted longer in seawater than in freshwater. Video footage revealed increasing bubble coalescence with the addition of feed. The decrease in pump flow is likely attributed to water property changes due to compounds leaching out of the feed. This decrease in pumping rate has the potential to negatively impact water quality, system performance, and fish health.

A native of Michigan, Bouck served in the U.S. Air Force as a survival instructor from 1953 to 1957. Following his military service, Bouck enrolled in Central Michigan University, graduating in 1960 with a major in biology and minor in chemistry. He then attended Michigan State University and received an M.S. in fisheries ecology and physiology (1963) and a Ph.D. in physiological ecology and biochemistry (1966). In 1976, Bouck was hired by the U.S. Fish and Wildlife Service's Western Fisheries Research Center, Seattle, to develop a new research program in physiological ecology. Working with key staff at the lab, Bouck initiated innovative new research at the center's Marrowstone Island Marine Field Station to identify environmental conditions during freshwater rearing that were adversely affecting the parr-smolt transformation and thus the early marine survival of anadromous salmonids released from federal and state mitigation hatcheries. Bouck also continued and expanded his previous innovative research to solve nitrogen supersaturation problems limiting the health, quality, and survival of juvenile salmonids in freshwater ecosystems. Under Bouck's leadership, the Marrowstone seawater pumping and ultraviolet treatment systems were enlarged and improved to allow larger-scale studies to be conducted in partnership with other federal and state fisheries research groups including research with scientists at the University of Idaho. In 1983, Bouck was hired by Bonneville Power Administration (BPA) where he remained until his retirement in 1994. He began as a lead to provide funding for increasing the health and productivity of regional salmon hatcheries. In 1984, he became chief of the Biological Research Section and finally a senior scientist as advisor for the administrator on a range of projects, including habitat restoration, hatchery operations, genetics of Endangered Species Act–listed species, and improving fish health. He represented BPA on interactions with the National Academy of Sciences and continued in an advisory role for studies to mitigate gas supersaturation with spill. Under his leadership, BPA provided important funding to develop a wet lab for fish health research at Oregon State University (now the John L. Fryer Aquatic Animal Health Laboratory). Bouck was a life member of the American Fisheries Society (AFS) and served as president of the Western Division (1977), helped to found the Portland Chapter, and served as president of the Bioengineering Section (1987). Through his activities in the Bioengineering Section, Bouck was a leader in application of biological and engineering principles to improve the understanding of hatchery production, habitat restoration, and fish passage. Bouck was awarded a Distinguished Service Award by the Bioengineering Section for his contributions and was instrumental in the coordination of 12 state and federal agencies that resulted in a hugely successful Fisheries Bioengineering Symposium in Portland in 1988. Bouck helped to organize the first World Fisheries Congress in 1993, which now is part of the World Council of Fisheries Societies. In 1994, he was instrumental in developing the program for the Gas Supersaturation Conference to assist managers with mitigation and understanding the implications of supersaturation. Bouck was inducted as an AFS Fellow in Portland in 2015. In addition to service in AFS, Bouck was a member of Sigma XI, Pacific Fisheries Biologists, the Association for the Sciences for Limnology and Oceanography, the Ecology Society of America, and the Pacific Northwest Chapter of the Society of Environmental Toxicology and Chemistry. The Oregon Chapter has established a college scholarship fund to assist future students in pursuing a career in fisheries research throughout the Northwest. Donations may be made online: http://orafs.or/contribute-to-orafs/ or mailed to Gerald R. Bouck Memorial Scholarship Fund Oregon Chapter of the American Fisheries Society Katie Pearson, Chapter Treasurer PO Box 8062, Portland, OR 97207-8062 Questions? Call Steve Bouck (480) 767-7660 Christine M. Moffitt, University of Idaho Gary Wedemeyer, U.S. Geological Survey, retired John Colt, National Oceanic and Atmospheric Administration, National Marine Fisheries Service Ron Garton and Chris West, U.S. Environmental Protection Administration, retired Steve Bouck, Solution Synergy, LLC

This research examines the gate-to-grave life cycle of salmon processing wastes (offal) management options in Sitka, Alaska using Life Cycle Assessment. The bases for comparison are the management of 1 kg of offal and the management of similar to 33,000 metric tons of offal generated intermittently throughout the 2010 fishing season in Southeast Alaska. Management options are (a) grind and discharge disposal, (b) two types of fresh processing, and (c) stabilized/ensiled offal processing. It is found that the contributions to eutrophication, acidification, and climate change are consistently reduced by assuming product displacements of meal, oil, and gelatin coproducts as compared to grind and discharge disposal. Further, increasing the allowable storage time by stabilizing the offal feedstock provides additional benefit by reducing the amount of offal ground and discharged. (C) 2013 Published by Elsevier B.V.

The impact of stirring on the response of the field YSI ProODO luminescence dissolved oxygen sensor was measured in a 300-mL biological oxygen demand (BOD) test bottle with a magnetic stirrer either on or off. With a water sample from a fish transport experiment, the dissolved oxygen dropped by 2-3 mg/L when the magnetic stirrer was turned off for 11 min. The initial rate of dissolved oxygen decline ranged from -0.39 to -1.04 mg/L per min for this water. The dissolved oxygen returned to a value projected from the oxygen uptake rate when the stirrer was turned on. A much smaller impact was observed for 18.2 M Omega high-purity water (mean: -0.11 mg/L). Acid-washing the BOD bottle/stir bar and cleaning the sensor cap reduced the decrease to -0.08 mg/L. Based on t-tests between pairs of stirring-on and stirring-off results, the lack of stirring had a significant effect on measured dissolved oxygen. The source of this effect and its potential impact on the accuracy of the optical probe under typical operating conditions remain to be determined.

The effects of aeration and alkalinity on water quality and product quality of Nile tilapia (Oreochrmis niloticus) were determined for simulated commercial hauling conditions. Three types of aeration were tested: pure oxygen aeration with a fine bubble diffuser (Oxygen), air aeration with medium bubble diffusers (Air), and a combination of both pure oxygen aeration with a fine bubble diffuser and air aeration with a medium bubble diffuser (Mixed). Simulated transport hauls were conducted at two initial alkalinities: 1.74 +/- 0.11 meq/L (Low) and 8.84 +/- 0.55 meq/L (High).The Air treatments resulted in the lowest carbon dioxide concentration, and the highest pH and un-ionized ammonia concentrations. At high alkalinities, the Air treatments were unable to maintain adequate dissolved oxygen levels. The Mixed treatment resulted in reduced carbon dioxide and dissolved oxygen concentrations. The Oxygen treatment resulted the highest dissolved oxygen, highest carbon dioxide, and lowest pH and un-ionized ammonia. Un-ionized ammonia concentrations were higher with the High Alkalinity treatments because of higher pH. Significant mortality was observed in the Air treatments in both the Low- and High-Alkalinity treatments. Mortality in the Oxygen and Mixed treatments for both low and high alkalinities were comparable to that observed in commercial tilapia transport using fine bubble diffusers and pure oxygen.These results indicate that mortality due directly to hauling water quality will not be increased at high alkalinity, if pure oxygen aeration is used. The potential effects of water quality during hauling on survival and product quality may be less than the impact from (a) physical damage from loading and un-loading and (b) physiological problems resulting from pH and temperature shock during the transfer from the hauling tanks to retail holding systems, especially for fish of reduced fitness. Published by Elsevier B.V.

The removal of carbon dioxide gas in aquacultural systems is much more complex than for oxygen or nitrogen gas because of liquid reactions of carbon dioxide and their kinetics. Almost all published carbon dioxide removal information for aquaculture is based on the apparent removal value after the CO2(aq)+ HOH double left right arrow H2CO3 reaction has reached equilibrium. The true carbon dioxide removal is larger than the apparent value, especially for high alkalinities and seawater. For low alkalinity freshwaters (< 2000 mu eq/kg), the difference between the true and apparent removal is small and can be ignored for many applications. Analytical and reporting standards are recommended to improve our understanding of carbon dioxide removal. Published by Elsevier B.V.