Comparative Growth and Survival of Juvenile Atlantic Cod (Gadus morhua)Cultured in Copper and Nylon Net Pens
- *Corresponding Author:
- Michael Chambers
Jere A Chase Ocean Engineering Lab
University of New Hampshire, USA
Tel: +1 603-862-3394
Fax: +1 603-862-0241
Email: [email protected]
Received Date: March 21, 2012; Accepted Date: June 25, 2012; Published Date: June 30, 2012
Citation: Chambers M, Bunker J, Watson III W, Howell WH (2012) Comparative Growth and Survival of Juvenile Atlantic Cod (Gadus morhua) Cultured in Copper and Nylon Net Pens. J Aquacult Res Dev 3:137 doi:10.4172/2155-9546.1000137
Copyright: © 2012 Chambers, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Bio-fouling on net pens has been a major concern for the marine aquaculture industry. As cage systems increase in size, so does the surface area for the attachment of colonial organisms that create drag on the net, reduce water flow important to fish health, and increase operational expenses due to net cleaning. To solve this problem, the International Copper Association (ICA) has been developing copper alloy netting for sea cages. Copper netting has unique properties that minimize bio-fouling, reduce the risk of fish escapement, prevent predators from entering the net pen, and is recyclable. To test the alloy netting, an experiment was conducted to compare juvenile cod cultured in traditional nylon nets with cod grown in Seawire copper netting ([email protected]). Six, 0.78 m3 cages were each stocked with 200 Atlantic cod (Gadus morhua) averaging 29 ± 2.2 g and grown for 4 months in coastal waters of New Hampshire, USA. Results of the study indicated no significant differences in cod growth, survival, feed
conversion ratio (FCR), specific growth rate (SGR), or Fulton’s condition factor (K) between the fish grown in the copper alloy and nylon nets. A chemical analysis was conducted on the cod and indicated no differences in copper levels in muscle, liver and gill tissues taken from the net treatments. Nylon nets with antifouling paint accumulated significantly more bio-fouling than the copper nets. Materials that were in direct contact with the copper netting (plastic cable ties) fouled heavily with hydroids indicating minimal leaching to the environment. This study describes some of the beneficial attributes of copper netting, however future studies need to be conducted over a longer period of time, on a larger scale, and in a more energetic environment to definitively test the utility of this new product.