Upgrading the infrastructure of grouper grow-out mariculture systems
Aquaculture production in Israel has been stagnant over the last decade. Declining profits in currently produced fish, competition from exports, cutbacks in fresh water quotas and increased environmental restrictions – all emphasize the need to seek additional fish species for promoting Israeli aquaculture. In Israel , as in other countries, interest in fast-growing marine fish (such as groupers, amberjack, tuna and others) is on the rise. The white grouper Epinephelus aeneus has huge commercial potential as it already possesses a well-established Mediterranean market, demanding high prices, and in Israel , already enjoys an advanced stage of domestication. In addition to rearing in sea water systems the white grouper seems to grow well also in saline water, and is thus a suitable candidate for rearing in different inland regions in Israel (Negev, Arava, Beit Shean Valley ).
Grow-out and fattening of fast growing fish such as grouper will require in-depth modification of existing mariculture systems. Experience gained over the last years shows that the grouper tends to remain relatively inactive on the tank substructure and hereby lifts up far less settling matter from the bottom than does sea bream. As a result, it seems that different (stronger) water flow patterns will be required to clear the tank bottom. In addition, It is believed that water treatment systems will need to be modified in order to maintain adequate water quality required by this species. Other needs for groupers domestication would be increase in the tank depth and covering with opaque topping to facilitate photoperiod manipulations and artificially induced spawning season. These and additional changes, and improvements in the infrastructure of land-based mariculture systems, will advance the domestication of the grouper and the further development of necessary know-how for its intensive culture.
Upgrading and improving grow-out production systems as an infrastructure for conducting the R&D of scaling-up aspects for the grouper and later for other fast growing marine fish species.
Main Stages – Two types of systems are designed to be upgraded:
Type A – megaflow (MF) tanks – two tanks of this type implementing the recent MF technology improvements (developed in part by ICA ’s support), and incorporating structures and water flow patterns adjusted for the grouper. Type B- octagonal tanks – three 2m deep tanks will be built on an existing foundation (tanks of 1m depth), with adjusting circulated water flow pattern.