AALSO 2018 Abstracts Tuesday
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Foam Fractionator Level Control for Variable Supply Flow Applications Steve Massar Vancouver Aquarium Watch Video (Login required) Full Abstract
Foam Fractionators work best when receiving consistent source water. Unfortunately many applications have variable flow rates by virtue of their operation. Many Foam Fractionators are supplied post solids filtration creating either a diminishing flow over time or pulse flow depending on the equipment. During a recent habitat renovation we were tasked with adding filtration to a raw seawater source. The filtration needed to fit inside the old sumps. In this application the water source is from a shared seawater intake. The flow rate varies based on demand of other uses and the tide. First stage filtration is through a rotating drum screen filter. The drum filter also creates a pulse flow which is inherent in normal operation. Considering these factors it was decided to control the level of the foam fractionator through modulating the discharge flow rather than the supply. To achieve this, a butterfly valve with ozone resistant components was installed low on the discharge stack. The valve was equipped with a pneumatic actuator with position control. A pipe was installed low on the fractionator body and extended above the collection cup to act as a stilling well. A sonic level sensor was used to measure water depth and provide input to the pneumatic valve. The positioner was programmed with a user defined slope to tune the flow control to the specific installation. The resulting system provides accurate level control to within 0.5” within 20 seconds of flow variation. |
Two Years Already? The Success and Challenge of the Detroit Zoological Society Polk Penguin Conservation Center
Paul Wilbert Detriot Zoo Watch Video (Login required) Full Abstract
The Polk Penguin Conservation Center opened at the Detroit Zoo in April 2016. The habitat pool has a volume of 326,000 gallons of filtered freshwater with a maximum depth of 22 feet. Perlite media filters, ozone and biological filtration provide excellent water quality for the penguins and clarity for our guests. Habitat pool and air temperature are maintained at 42F. Filtration is monitored continually and controlled at several points throughout the system. Establishing a life support system of this size and complexity can be very challenging, and a number of steps were taken to prepare the habitat for penguins. Since then, we have continued to make modifications and adjustments, to ensure that we continue to provide an ideal habitat for the penguins and an outstanding experience for our guests. |
Preventing Jelly Jams: A case study in flow modifications for Chrysaora pacifica at National Aquarium
Jennie Janssen National Aquarium Watch Video (Login required) Full Abstract
Gelatinous zooplankton are some of the most simplistic and mesmerizing animals commonly displayed in aquaria, yet the engineering required to house them is remarkably nuanced. With varying body types and modes of locomotion, flow requirements vary widely between species, as well as between developmental stages within the same species. Despite the simplicity of these animals, their behavior also plays an important role. To decrease the risk associated with the inherent dynamics of an existing stretch kreisel housing adult Chrysaora pacifica in the National Aquarium’s Jellies Invasion gallery, a 2nd Hartford loop and 2 topside spray bars were installed. These simple modifications have resulted in fewer jelly jams due to a decrease in the necessary flow rate, an even split of head pressure on each kreisel screen, and the animals naturally positioning themselves farther away from the screens and in the viewing window. The longevity and wellbeing of the animals has increased, as has the percentage of jellies viewable to the public, while aquarist anxiety has markedly decreased. Inventory and animal health notes allowed for analysis of longevity and wellbeing, while viewability was analyzed from photo documentation. Aquarists’ levels of concern were queried via an online survey. Similar LSS modifications have since been employed in 2 other kreisels, yielding similar results exhibiting Aurelia aurita, Chrysaora colorata or C. chesapeakei, thus demonstrating the plasticity in application for various Scyphozoans. |
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Lighting the Aquarium Experience - Exhibit Lighting Lessons Learned Steve File, Paul Boken, Alan McIntosh, Ripley's Aquarium of Canada Watch Video (Login required) Full Abstract
Ripley Entertainment owns three world class aquariums; Ripley’s Aquarium in Myrtle Beach, SC which opened in 1997; Ripley’s Aquarium of the Smokies in Gatlinburg, TN which opened in 2000 and Ripley’s Aquarium of Canada in Toronto, ON which opened in 2013. Our biggest challenge in each has been exhibit lighting. With each aquarium we have tried different approaches, Myrtle Beach did not work out, and Gatlinburg did not work out. We tried something different at the Aquarium in Toronto. After all was said and done we won some battles but suffered some defeats many lessons were learned along the way, lets discuss both the wins and losses to improve exhibit lighting in aquariums. |
Total Gas Pressure Monitoring and Trends in Temperate and Tropical Seawater Systems at Monterey Bay Aquarium
John Negrey, Monterey Bay Aquarium Watch Video (Login required) Full Abstract
The Monterey Bay Aquarium (MBA) features marine animals ranging from the tropics, subtropics, and temperate ocean zone including local species from Monterey Bay, Ca. Incoming seawater (~55° F) is warmed in secondary systems or locally in aquaria (up to 80° F) which can lead to seawater becoming supersaturated with atmospheric gases. This is a concern for aquatic organisms as bubbles can form within vascular system and tissue, often referred to as gas bubble disease (GBD). In this study we monitored total dissolved gas pressure (TDGP) using a saturometer (Pentair Lumi4 TGP Optical O2/Temp) in select exhibits. Solutions to mitigating gas supersaturation in existing life support at MBA are examined as well as best practices for performing TDGP measurements and processing the data. Incoming seawater to the Aquarium first goes to the Kelp Forest Exhibit where monthly TDGP spot checks ranged from 102-105%. The Kelp Forest, in turn, supplies seawater to all other secondary systems and exhibits. Seawater is tempered and passes through de-aeration towers (DAT) prior to being distributed to the tropical exhibits. As such, tropical exhibit TDGPs were typically below 102%. However, subtropical exhibits do not have a main DAT downstream of the seawater supply line and TDGP measurements have been observed to fluctuate between 99 and 105% in monthly spot check measurements. Modifications to life support systems and methods for obtaining reliable TDGP measurements are discussed. |
Gas Supersaturation of a Shark Aquarium without Air Exchange Tower Ying Zhang, Ocean Park, Hong Kong Watch Video (Login required) Full Abstract
A newly renovated 2000 m3 shark aquarium (SM), due to lack of space, has a fractionator and a 63 m3 gas exchange tower. Immediately after sharks were introduced, dissolved oxygen [O2] dropped to as low as < 5 ppm. By using compressed air continuously, [O2] was kept to > 6 ppm. After one month, however, delta-P of total gas pressure (TGP) increased to 30 mmHg at 0.5m, as compared to 15 mmHg in a 5000 m3 aquarium (T20) which has with sufficient gas exchange towers. We then measured [O2], O2%, TG % and delta-P at different depths in SM and compared with those in T20. We found delta-P and TG% in SM are much higher than in T20; however, [O2] and O2% are lower than in T20. The increased delta-P and TGP are likely caused by the accumulation of nitrogen gas due to insufficient gas exchanges in SM. To reduce nitrogen accumulation, aeration with compressed air was replaced with compressed O2. After the replacement, the delta-P at 0.5m in SM decreased to 15mmHg on day 3rd; and within a month, other parameters at deeper depths reached the same level as in T20. In addition, due to insufficient gas exchange, [CO2] is accumulated to 2ppm in the deep part of SM as compared to undetectable level in T20. High [CO2] can decrease pH in aquarium. Laboratory experiments demonstrated that after stirring SM water for 6 minutes, pH of the SM water can increase to > 8. Moreover, mortality of sharks decreased significantly: there were 13 mortalities during aeration with compressed air, and only 2 mortalities after replaced with concentrated oxygen up till now. In conclusion, for a healthy fish environment, the gas balance between air and water should be among one of the critical components required by any aquarium. |
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The Nightmare Before Christmas: Losing Automation on a Holiday Weekend
Rebecca Keebler, Downtown Aquarium Denver Watch Video (Login required) Full Abstract
The Downtown Aquarium is a 1.25 million gallon aquarium that houses close to 700 species and 10,000 animals. There are 10 large exhibit systems, three salt water recovery systems, fresh water and salt water supply systems managed by the life support staff. On December 22nd, 2016 between 10:00 and 11:00 pm the programming on one of three PLC cabinets was deleted, and the automation and controls were lost for 8 of 10 of the exhibit systems. Four aquarium team members manually balanced the affected exhibits throughout the night until enough staff arrived the following morning to try resetting the PLC cabinet, and an integrator could be contacted to help get the automation back online. |