Date of Award

5-2009

Document Type

Thesis

Degree Name

Master of Engineering (ME)

Legacy Department

Biosystems Engineering

Committee Chair/Advisor

Brune, David E

Committee Member

Schwedler , Thomas E

Committee Member

Kirk , Kendall R

Committee Member

Privette , Charles V

Abstract

The objective of this 4-year research project was to evaluate the performance of channel catfish (Ictalurus punctatus) fingerling production in the Partitioned Aquaculture System (PAS). The goal was to demonstrate production of 80-gram minimum sized fingerlings in a single growing season, allowing for 100% market-size fish production after one additional season in the grow-out PAS.
A series of 2-inch airlift pumps fed by a single 3-hp low-head blower was found to be capable of supplying sufficient water flow-rate (in 2005, 2006, and 2007) of gpm per container to 9 cohorts. A series of 0.75-hp axial flow pumps (in 2005, 2006, and 2007) were required for each 1/4th inch net-pens providing an average flow of gpm/cohort. In 2008 it was found that sufficient water flow to both fry/fingering containers and cells could be maintained using the paddlewheel generated flow (passive flow) yielding an average flow rate of gpm/cell but produced as lower cell cross-sectional flow- rate of 0.34 ft/sec as compared to 1.82 ft/sec. Passive flow reduced overall power consumption by 58% to 7,409 kw-hr/acre-yr. Under passive flow conditions a flow deflector of 12' by 12' positioned at an angle of 45 degrees in the water path was found to be necessary to generate a flow vortex within the container to provide feed retention within the containers and prevent fry disorientation. Over the four year culture period, average morning water temperatures ranged from 25.6-27.7 ¡C. Average morning dissolved oxygen concentrations ranged from 4.3-5.3 mg/L with an average dissolved oxygen drop across the fingering containers ranging from 0.20-0.84 mg/L. Average total ammonia-N concentration ranged from 0.6-1.2 mg/L.
Over the four year period, optimal stocking into fry and fingerling containers was determined as: initial stocking (3-5 days after hatching) into 1/16th inch mesh container at average weight of g/fry for a growth period of days, after which the fingerlings were moved into 1/8th inch mesh containers at average weight of g/fish for a growth period of days, followed by transfer to 1/4th inch net-pens at average weight of g/fish where the fingerlings remained for the remainder of the growing season.
Optimal feed application rates required to grow catfish from a 0.05 g fry to a 115 g fingerling was observed to be (from combined observations during the 2005 and 2006 seasons) with %Fd = percent of catfish wet body weight to be fed per day (as dry feed), and AvWt = average individual fingerling wet weight. The optimum catfish-fry stocking rate was determined (in 2005 and 2006) to be 5,000 fry per 162 ft3 cell. In 2005, stocking at a rate of 10,000 fry/162 ft3 was observed to reduce fingerling growth by 47%. In 2006, stocking at a rate of 3,000 fry/162 ft3 was observed to reduce final cohort density by 26% with no increase in fingerling growth. Maximum total system carrying capacity of 4,695 lb/acre was observed during 2007, with fry stocked at 5,000 fry/162 ft3 cell, and fed at previously determined optimal feeding rate, yielding an average catfish fingerling size of 113.9 g/fish, with overall fry survival rate of 91%.
Market-size catfish yields from conventional pond fingerling production combined with conventional pond grow-out was projected at an overall fish yield of 3,279 lb/acre of 1.63 lb fish, as opposed to 10,137 lb/acre of fish projected from conventional fingerling production coupled to PAS fish grow-out, and 11,280 lb/acre of market-sized fish yield projected from PAS fingerling production coupled to PAS grow-out. Additional advantages offered by PAS fingerlings grow-out include the potential to stage more harvests throughout the growing season due to a larger stocked fingerling, which would increase yearly harvest for a given carrying capacity; the elimination of the need to over-winter fish in the grow-out PAS; high survival rate; ease of disease treatment; ease of harvest; and no discharge into the environment, with the disadvantages including higher energy inputs and more intensive management of algal culture.

Share

COinS
 
 

To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.