Island Watch

posted in: April 1999 | 0

Will Bovine Growth Hormone Work On Shrimp? UH Study Seeks To Find Out

Gordon Grau, a scientist with the University of Hawai`i’s Hawai`i Institute of Marine Biology, has been administering recombinant bovine growth hormone to shrimp (Penaeus vannamei) and tilapia (Oreochromis mossambicus) to see if the hormone will stimulate growth in the two species.

The studies are a collaborative effort involving the Sea Grant programs of the University of Hawai`i and the University of California, as well as rBGH producer Monsanto Chemical Co. They began a few months ago after being reviewed last November b y the state Department of Agriculture and the University of Hawai`i’s Institutional Biosafety Committee. The IBC reviews all recombinant or genetic experiments undertaken by university staff.

Grau’s use of rBGH in aquaculture species stems from a field of studies seeking to improve production rates through the use of growth hormones. For example, in 1991, scientists were studying whether growth in coho salmon could be promoted with use of recombinant porcine growth hormone.

A project summary for Grau’s experiment notes that the United States imports some $9 billion worth of fish each year, with seafood constituting the largest component of the U.S. trade deficit among agricultural products.

“We import over 60 percent of our fish and shellfish, including 75 percent of the tilapia consumed in the U.S. United States producers must compete with foreign imports and reduce the environmental contamination from nitrogen (waste) excretion,” the report states.

“Growth hormone has high promise for addressing both issues. Studies on a wide range of vertebrates, including fish, show that GH stimulates growth, increases food utilization efficiency, and improves nitrogen balance, which in turn reduces the loss of nitrogen to the environment. Both natural and recombinant GH from several vertebrates including cattle promote growth in teleost fish, including tilapia. Growth hormone has also been shown to stimulate growth in decapod crustaceans.”

In addition to studying rBGH effects on growth, RNA and DNA production, and the regulation of salt and water balance in aquaculture species, Grau must also ensure that rBGH is not a threat to the environment. Both the state Department of Agriculture and the IBC have expressed concerns over the potential effect of rBGH-laced aquaculture effluent on the environment.

In a November 17, 1998 memo concerning the project, Hubert Olipares, the university’s biological safety officer, suggests that effluent from the project site be monitored for the presence of rBGH. “If the levels of rBGH are significant,” Olipares states, “the wastewater and effluent should be diverted into the sewer rather than to a settling pond and eventually the open water ways of Kane`ohe Bay.”

Environment Hawai`i
called Grau for an interview, but no appointment could be made by press time and he did not wish to respond to questions over the phone.

— Teresa Dawson

Volume 9, Number 10 April 1999