Hammour than meets the eye: NYU Abu Dhabi study reveals secret

Hammour, as it is known locally, is actually three different species of grouper.

The orange-spotted grouper, or hammour. Courtesy NYUAD
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ABU DHABI // Hammour, the grouper that has long been the UAE’s most popular eating fish, has been hiding a secret – it is three species masquerading as one.

Researchers at New York University Abu Dhabi analysed DNA from 140 tissue samples collected in four fish markets.

Remi Ketchum, a graduate from NYUAD, says the genetic study showed up three separate species.

Ms Ketchum said that, in hindsight, there was always something fishy about the hammour.

“When I started the project I couldn’t tell the difference, but after repeatedly looking at them you can,” she said.

The orange-spotted grouper has zigzag lines down its body. The second species, bleekeri, has a very dark tail and the third, areolatus, is a light fish, but they are all very subtle differences, Ms Ketchum said.

She revealed the findings in a recent edition of the Marine Pollution Bulletin, in the hope that it would lead to better management of the three species.

But if you think the news justifies the number of times you have handed back the plate to the chef insisting it is not hammour, you could still be wrong.

“They are very similar fish and I’d say they’d probably taste the same,” Ms Ketchum said. ​

“We were able to tell that these three species have levels of genetic diversity that are similar to other critically endangered grouper species and that there are two species that remain under-reported in the UAE.”

Thought to be overfished in the region at six times the sustainable level, the fish are managed and sold as one species, Epinephelus coioides, in local markets.

“They use hammour to indicate all the groupers here, but technically fishermen will refer to hammour as only the orange-spotted grouper, but the other ones look so similar that most people can’t tell them apart, so they say hammour for all the grouper fish they sell,” Ms Ketchum said.

“The fishermen that I have spoken to actually know the difference and they aren’t in charge of management. I have spoken to some where I have told them that I need the real hammour and they know what I am talking about.”

Ms Ketchum said there has been some indication of crossbreeding of the grouper species worldwide, but more research would have to be done on the grouper fish found in the Arabian Gulf.

“The reason the population is dwindling is that they catch them as one species and they are treating them as one species,” she said.

John Burt, an associate pro­fessor of biology at New York University Abu Dhabi, said the study was a good start to better management of fisheries.

“This has important implications for fisheries management, as earlier management efforts, which had assumed there was just one species, need to be broadened to account for possible differences in the biology of these three species,” he said.

​Mohammed Ali, a fisherman in Ras Al Khaimah, said he did not know about the different species.

“I catch hammour and mostly the varieties differ not at all. The kind you find in the sea and the kind they serve is all the same,” he said. “There is a different fish but it doesn’t look exactly like the hammour.

“If you are talking about the hammour that is popular to eat, then no, it is one kind.”