Fish inbreeding may cause genetic erosion in aquaculture production

The existing unplanned fish inbreeding may cause a genetic deterioration into the aquaculture production and open water fisheries resources in terms of hatchery stock breed seeds in floodplain and other open waters.
“Unconscious negative selection of brood-stock, mating of female and male spawns from a finite population and unplanned hybridization in hatchery stocks especially carps has created the widespread concern,” Dr Golam Hossain, Director General of Bangladesh Fisheries Research Institute (BFRI), told BSS. Dr Hossain said fish seed production through artificial propagation or induced breeding is a common practice in the country. Around 1,000 hatcheries are engaged in the breeding purposes contributing more than 95 percent of the total spawn production at present. He, however, said genetic deterioration has frequently been reported in hatchery populations in a number of recent past research findings.
In this context, he defined that poor brood stock management and close mating of breeders possibly brother and sister or parent and offspring resulting in inbreeding causing adverse effect on the fisheries populations. Due to their ignorance, most commercial hatchery owners and employees use low quality brood fish for breeding purposes producing less health and weight offspring leading to an excessive death rate.
Many hatchery owners were also found unplanned and uncontrolled hybridization between carp, ruhi and mrigel, and carp and mirror carp frequently creating a horrible situation.
They do the malpractice only to catch the highly demanded markets of fish fry and fingerling as the government has been implementing fish releasing programme in the country’s floodplain during every monsoon in addition to large- scale promotion of fish farming for the last couple of years. “If the unplanned trend persists there will be an acute trouble in the gene introgression of the indigenous major carp species – ruhi, carp and mrigel,” Dr Hossain cautioned.
He said the BFRI has been providing necessary training for the hatchery owners and others concerned but unfortunately they do not follow the guidelines to earn more money through selling the low quality fish seed. Major demerit of the inbreeding problem is lethal gene action that causes production loss, breeding inequality, disability and disease infection.
Meanwhile, Divisional Deputy Director of the Department of Fisheries Abu Baker Siddiqui told BSS that there are 28 big and five small state level hatcheries, 233 private hatcheries and 2,065 nurseries in the northwest Bangladesh. To overcome the crisis, Dr Hossain put forward a number of recommendations.

Courtesy of BSS Via The BD Today