Inclusion of soybean meal into summer flounder (Paralichthys dentatus) feeds: An environmentally-friendly protein alternative to fish meal and a potential immunostimulant

Inclusion of soybean meal into summer flounder (Paralichthys dentatus) feeds: An environmentally-friendly protein alternative to fish meal and a potential immunostimulant

Summary

The graduate researcher has contacted all participants in the study, starting with both commercial aquaculture facilities; Local Ocean (Hudson, NY), and GreatBay Aquaculture (GBA; Portsmouth, NH). Local Oceans did not have the appropriate permits to transfer live fish to the study site at the Marine Biological Laboratory (MBL; Woods Hole, MA), therefore fish will be transferred from GBA once they are the appropriate size. GreatBay Aquaculture spawned summer flounder in early October (2010), and was weaning them to pelleted feeds as of early November. The fish will be a minimum of 15-20g in late January, at which point the fish will be transferred from the hatchery in NH to the study site at the MBL. The graduate researcher has also been in contact with Dr. Chong Lee at the Food Science and Nutrition Center, at the University of Rhode Island, in order to formulate the soy-based feeds. He has also filled out the necessary animal care and safety forms (IACUC, IRB, and seawater facilities forms) for both the MBL and URI, and is awaiting approval of final IACUC revisions for both the MBL and URI, so that the study can start as soon as the fish are the correct size from NH.

Objectives/Performance Targets

Objective 1: Create feeds with fish meal replaced by SBM or SPC to various levels, with balanced amino acid profiles, including additions of taurine and phytase.

Daniel Ward (the graduate researcher) has started work on objective 1, in collaboration with Dr. Chong Lee at the Food Science and Nutrition Center, at the University of Rhode Island. Dr. Lee has started to help Daniel formulate the feeds, and together form a plan for which methods will be used for proximate analysis.

Objective 2. Feed the diets with SBM or SPC inclusion to summer flounder. Evaluate growth, feed conversion, hematological profiles, immune function, and histological changes to the intestines.

The feed trial has not started yet. The necessary paperwork has been submitted, and all preliminary tank setup at both the MBL and URI has been completed. Fish will be delivered from GreatBay Aquaculture as early as mid-Janurary, with feed trials starting in early February.

Objective 3. Evaluate effect of SBM on mortality when challenged with Vibrio harveryi.

Objective 4. Disseminate results to commercial partners, and present findings at sustainable aquaculture venues in the Northeast.

Objectives 3 and 4 have not been started yet.

Accomplishments/Milestones

Since the project only officially started August 1st, there has been minimal, though significant progress thus far. Initially the fish for this trial were going to come from Local Oceans this fall, in order to be able to start the feed trial sooner than February. Unfortunately, Local Oceans does not have the necessary permits to transfer live fish out of NY, even if only for research purposes. While this seemed like a set back at the time, it now seems like it was a positive development. If the fish had been delivered this fall, the whole project would have been very rushed, and there would have been room for mistakes. The correct paperwork wasn’t submitted yet, the feeds had not been formulated and tested, the correct tanks and biofilters weren’t ready, etc. Now that the fish are coming later, the correct steps are being taken, and therefore the trials should go much smoother. Also, there has been more time available to more completely develop the experimental design as far as which immune parameters to look at, as well as which protocols make the most sense for the size of the fish and time constraints. This allows the researchers to pick more appropriate protocols, as well as leaving more time to practice this fall before performing the assays on the actual fish in the trial this winter.

Impacts and Contributions/Outcomes

One of the main disease issues facing summer flounder culture is infectious necrotizing enteritis (FINE), which has been determined to be caused by the pathogenic bacteria Vibrio harveyi (Gauger et al. 2006). A preliminary study at the University of Rhode Island showed reduced mortality in summer flounder fed SBM when challenged with Vibrio harveyi (Gomez-Chiarri, per. comm.). Both reduction of disease, and sustainable feed production are two of the main obstacles facing aquaculture expansion in the northeast, and the proposed experiment will advance current knowledge in this area, and will positively affect future farm practices. If successful, it will also open a new market to soybean farmers. Thus far the project has not had any outreach or publications; though publications, presentations as well as outreach are expected at the conclusion of the feed trial and bacterial challenges. If a soy-based feed can be shown to have equal if not better growth, as well as immunostimulatory benefits, this could make carnivorous finfish aquaculture much more environmentally sustainable as well as economically viable in the Northeast.

Collaborators: