We often hear only part of the story. Sometimes because we want to, other times because the truth has never been told.
GM Salmon have made a big splash, But what about GM Grouper…
Never heard about it!
Why we should be worried about ‘Frankenfish’ in south-east Asia
Unlike GM salmon, hybrid grouper gets little attention but they potentially pose a greater threat to marine ecosystems
The fast-growing super salmon produced by American biotech company Aquabounty Technologies are poised to become the first genetically modified animals to hit food markets in the US, with approval from authorities widely expected later this year. But AquAdvantage® salmon has made headlines because of the potential risks to wild stocks in the Atlantic should they escape and breed.
Hybrid grouper, on the other hand, gets almost no media attention, yet they potentially pose a greater threat to marine ecosystems because they’re farmed at sea, not inland like salmon. Hybridisation through in-vitro fertilisation is big in south east Asia, where aquaculture businesses are interbreeding valuable grouper species in a bid to create a fast-growing super fish.
Live grouper and other reef predators are highly-prized food in Hong Kong, Mainland China, Taiwan and other parts of south-east Asia. They crowd tanks in seafood restaurants and are ubiquitous at Chinese wedding banquets and other formal occasions, where tradition demands they are served. Grouper can sell for well over US$100 (£59) a kilo, with very large or rare specimens selling for much more.
The market is huge. In Hong Kong alone, an estimated 3.6 million grouper are consumed each year. Demand has led to rampant overfishing across South East Asia’s Coral Triangle, a million square kilometre bioregion that’s home to more marine species than anywhere else on earth. Fishermen often use cyanide to stun grouper, destroying coral reefs in the process. According to a recent University of Hong Kong study, one in ten grouper species face extinction if current trends aren’t arrested.
In theory, advanced aquaculture techniques offer a way of fulfilling demand while reducing the pressure on wild populations. In reality, aquaculture has simply added a new market, with additional sealife being taken from the ocean to feed farmed fish in Malaysia, China and Taiwan.
Grouper are nurtured first in hatcheries from cultivated eggs and then in coastal cages or factories. Hybridisation aims to achieve the holy trinity of rapid growth rates, resilience and superior taste.
“Hybridisation of grouper isn’t new,” says Dr. Geoffrey Muldoon, a fisheries economist with the World Wildlife Fund (WWF). “As far back as 1996 the University of Malaysia produced a giant grouper/tiger grouper hybrid, dubbed the Sabah Grouper specifically for live reef fish food markets in Hong Kong,” he explains. The hybrid was popular with consumers and a boom followed. “Two decades on and the science of grouper hybridisation has exploded,” says Muldoon.
In the early days, scientists only experimented with cross breeding natural grouper species. But then researchers in Taiwan began breeding hybrids with naturals and then different hybrids with each other. According to Irwin Wong, a live fish trader in Sabah, at last count, there were at least 12 new hybrid grouper variants and research is continuing in what has become a race to create a super grouper. But what if they escape?
“The fact is, hybrids have already escaped,” says Wong. “If there’s a storm, fish often get free from coastal cages.”
His fear is that two hybrids will breed in the wild. “If that happened, the effects on the ecosystem could be severe.” Because captive hybrids are fed a mix of protein rich pellets and fish, they need to consume less than their wild counterparts to add weight, according to Muldoon. If they escaped and proliferated, there could be a dramatic knock on effect in terms of demand for prey species.
Grouper are hermaphrodites – or monandric protogynous hermaphrodites to give them their full title. Early in their growth cycle they are females, but in adulthood they can change into males. No one knows the precise trigger for this transformation, though size, age and environmental factors all play a part. Hybrid groupers in captivity are all female – but in the wild they could easily change sex, according to Wong. Which brings up the possibility of a sort of “X-Grouper” wreaking havoc with the food chain.
Source: The Guardian Read more
Once again man is meddling with nature, and we don’t have any idea what we are doing.