Effects of Formulated Feed on water Quality in Fingerling Waleye Production Ponds

Six 0.04-ha plastic-lined ponds were used at the Iowa Department of Natural Resources’ Rathbun Fish Culture and Research Facility to evaluate the use of supplemental fish food on walleye (Sander vitreus) fingerling growth and survival, and on the benthic invertebrate community. Walleye were stocked 3-4 days post hatch on 2 May 2003, and harvested 5-6 June 2003. Organic fertilizer (alfalfa pellets, 112kg/ha/week) was used to increase primary production and inorganic fertilizers were added periodically to maintain a target nutrient ratio of 7:1 nitratenitrogen to total phosphorus (NO3-N: TP). Additional nutrients in the form of Lansy CW fish feed were added to three of the six ponds. The objective of this project was to determine the effect of a commercial fish diet on water quality. At the end of the culture season, there were significant differences between water chemistry parameters in the ponds; the feed treatments had higher levels of nitrogenous compounds and total phosphorus

Benthic invertebrate management in plastic-lined fish culture ponds

The use of plastic-lined ponds in place of earthen ponds for fish culture is becoming common among agencies; however limited information is available on their management. Since plastic lining significantly reduces the amount of organic sediment typically found on the bottom of culture ponds there is also a limited amount of organic substrate available to potential benthic macroinvertebrates, which are important prey for larval fish. Previous studies on plastic-lined ponds have focused on fertilization and management of zooplankton populations. Zooplankton populations are an important prey for larval fish, but as fish grow, their diet switches from zooplankton to benthic invertebrates, most commonly Diptera. Therefore, this study looked at the effects of fertilization and supplemental formulated fish feed on benthic populations and fish production at the Iowa Department of Natural Resources\u27 Rathbun Fish Culture and Research Facility, Moravia, Iowa. In both years of the study, walleye (Sander vitreus) were stocked into six 0.04-ha ponds. In 2002, effects of organic fertilization on the benthic community and fish production were determined. It was found that benthic communities were not significantly (P\u3c0.10) affected by the fertilization regimes, inorganic vs a mix of inorganic plus organic fertilizers; however ponds in the mix treatment had more organisms. At harvest, walleye in ponds in the mixed treatment were significantly longer, heavier, and had greater biomass. These results suggest that organic fertilizer is important for the benthic food base as well as growth of fingerling walleye. In 2003, effects of supplemental fish food on fingerling growth and survival, as well as the benthic invertebrate community were investigated. It was found that supplemental feed did not significantly increase the benthic invertebrate community or fish growth and survival. Furthermore, only a small portion of the walleye had consumed formulated feed at harvest; this occurred when the natural food base of the larval walleye, zooplankton and benthic invertebrates, was depressed. Therefore, for the culture of walleye fingerling in plastic-lined ponds we recommend managing for zooplankton and benthic invertebrate food base with organic fertilizers. The application of supplemental commercial feed may be useful when the natural food base is depleted

Benthic invertebrate management in plastic-lined fish culture ponds

The use of plastic-lined ponds in place of earthen ponds for fish culture is becoming common among agencies; however limited information is available on their management. Since plastic lining significantly reduces the amount of organic sediment typically found on the bottom of culture ponds there is also a limited amount of organic substrate available to potential benthic macroinvertebrates, which are important prey for larval fish. Previous studies on plastic-lined ponds have focused on fertilization and management of zooplankton populations. Zooplankton populations are an important prey for larval fish, but as fish grow, their diet switches from zooplankton to benthic invertebrates, most commonly Diptera. Therefore, this study looked at the effects of fertilization and supplemental formulated fish feed on benthic populations and fish production at the Iowa Department of Natural Resources' Rathbun Fish Culture and Research Facility, Moravia, Iowa. In both years of the study, walleye (Sander vitreus) were stocked into six 0.04-ha ponds. In 2002, effects of organic fertilization on the benthic community and fish production were determined. It was found that benthic communities were not significantly (P<0.10) affected by the fertilization regimes, inorganic vs a mix of inorganic plus organic fertilizers; however ponds in the mix treatment had more organisms. At harvest, walleye in ponds in the mixed treatment were significantly longer, heavier, and had greater biomass. These results suggest that organic fertilizer is important for the benthic food base as well as growth of fingerling walleye. In 2003, effects of supplemental fish food on fingerling growth and survival, as well as the benthic invertebrate community were investigated. It was found that supplemental feed did not significantly increase the benthic invertebrate community or fish growth and survival. Furthermore, only a small portion of the walleye had consumed formulated feed at harvest; this occurred when the natural food base of the larval walleye, zooplankton and benthic invertebrates, was depressed. Therefore, for the culture of walleye fingerling in plastic-lined ponds we recommend managing for zooplankton and benthic invertebrate food base with organic fertilizers. The application of supplemental commercial feed may be useful when the natural food base is depleted.</p

Effects of Formulated Feed on water Quality in Fingerling Waleye Production Ponds

Six 0.04-ha plastic-lined ponds were used at the Iowa Department of Natural Resources’ Rathbun Fish Culture and Research Facility to evaluate the use of supplemental fish food on walleye (Sander vitreus) fingerling growth and survival, and on the benthic invertebrate community. Walleye were stocked 3-4 days post hatch on 2 May 2003, and harvested 5-6 June 2003. Organic fertilizer (alfalfa pellets, 112kg/ha/week) was used to increase primary production and inorganic fertilizers were added periodically to maintain a target nutrient ratio of 7:1 nitratenitrogen to total phosphorus (NO3-N: TP). Additional nutrients in the form of Lansy CW fish feed were added to three of the six ponds. The objective of this project was to determine the effect of a commercial fish diet on water quality. At the end of the culture season, there were significant differences between water chemistry parameters in the ponds; the feed treatments had higher levels of nitrogenous compounds and total phosphorus.This article was published as Kaatz, S. E. and J. E. Morris. 2007. Effects of formulated feed on water quality in fingerling walleye production ponds. Scientific Papers Animal Science and Biotechnologies 40:29-36. Posted with permission.</p

To bleed or to clot: Stroke prevention strategies in patients with atrial fibrillation or flutter after bleeding

Background Patients with atrial fibrillation or atrial flutter (AF) on anticoagulation (AC) for stroke prevention are at an increased risk of bleeding events. A common dilemma is deciding when to safely restart AC after bleeding. Studies have shown better outcomes with reinitiation of AC 7 days after stabilization of gastrointestinal bleeds and 4 weeks after intracranial hemorrhage. Our aim was to assess stroke prevention strategies upon discharge in patients with AF hospitalized with a bleeding event. Methods We retrospectively identified patients with AF on AC who were admitted with a bleeding event. The type of AC, form of bleeding, and CHADS2VASC were collected. Stroke prevention strategies on discharge were noted. Results Between January 2016 and August 2019, 174 patient with AF were hospitalized with a bleeding event. Nearly 10% of patients died, emphasizing the severity of this clinical situation. AC was restarted in 40% of patients upon discharge, 8.6% of patients were referred for LAA closure, and the remaining 40% were discharged without a stroke prevention strategy. CHADS2VASC did not differ among the groups. Of patients discharged on AC, 16% had a repeat bleeding episode requiring hospitalization within 30 days. Conclusion A significant portion of patients with AF hospitalized with a bleed were discharged with no definitive stroke prevention strategy. Barriers to restarting oral anticoagulation should lead to consideration of LAA closure as an alternative

New Clean Energy Communities in a Changing European Energy System (NEWCOMERS) : Deliverable D3.1 Description of polycentric settings in the partner countries

This deliverable maps the prevailing polycentric settings of six studied countries. The studied countries are the partner countries for the NEWCOMERS project, i.e. Germany, Italy, the Netherlands, Slovenia, Sweden and the United Kingdom. In this report, the countries' polycentric settings will be described in relation to the polycentric framework developed in WP 2, with specific focus on the technical system and actors. The factors in focus for the country descriptions are socio-economic conditions, technical system (electricity and heat), institutional arrangements as well as actors. Additionally, a description of energy communities in each country is presented, showing different developments in this area.The research was conducted through a desktop research. Existing literature, reports as well as statistical information were gathered and then organised according to the factors chosen.The aim in this delivery is to describe and understand the national polycentric settings as a first step to understand the emergence of new forms of energy communities. This deliverable is the basis for delivery 3.2, which will compare different polycentric national settings and delivery 3.3, which will evaluate what forms of energy communities work best in different polycentric setting and what are the potentials for learning between different polycentric settings