What’s in a name? It may not sound funny to you, but I find it amusing how American lawmakers could waste so much time and energy, not to mention taxpayers’ money, deliberating over what to call a fish. Last year, Senator Bill Hoffman of Minnesota was concerned that the name “Asian carp” was “hurtful” and “offensive” to some people so he sought to change the name to “invasive carp”. And guess what, the Minnesota Senate approved the bill.
Breathing space: Bundles of wood serve as a barrier to keep the weed at bay at the Sampran Riverside resort.
According to an account I read recently on Facebook, Asian carp were introduced in the US in the 1970s and the fish have since proliferated and spread to various states. The US Army Corps of Engineers have been fighting off the three most invasive species — the black carp (Mylopharyngodon piceus) and grass carp (Ctenopharyngodon idella) from China, and the silver carp (Hypophthalmichthys molitrix) from Vietnam — to prevent them from spreading into the Great Lakes, where they could do great damage to the region’s fishing industry. While arguing his case on the Senate floor, Senator Hoffman said that referring to the fish as “Asian” was hurtful to Asians in America.
The fish came from Asia, and they are carp, so what is so offensive and hurtful about calling them Asian carp? Asian carp are Asian carp, no matter what you call them. It is perplexing that instead of finding ways to fight the spreading terrorism in the US and the rest of the world, Minnesota’s lawmakers were more concerned about a fish’s name.
I would understand them more if their concern was about containing the invasive alien species or eradicating them once and for all. Eradicating invasive species, be they fish or plants, however, is a tall order. Take water hyacinth (Eichhornia crassipes, known in Thai as pak tob chawa), for example. With thick, glossy round leaves, which rise above the water surface on bulbous and spongy stalks, it makes a beautiful ornamental plant if placed in a glass bowl in the living room. Its flowers, which are purplish blue or lavender in colour, make it even more attractive.
Once it escapes into waterways, however, water hyacinth becomes an aggressive invasive species. In fact, it has been named one of the 10 worst weeds and the most widespread and damaging aquatic plant species in the world. Its proliferation can be attributed to the fact that it flowers all year round and releases thousands of seeds that are viable for up to 20 years. But even without seeds, its growth rate is among the highest in the plant world, as it reproduces vegetatively by short runner stems, or stolons, that branch out from the base of the plant.
A native of South America, the water hyacinth has made its presence felt not only in Thailand, but in more than 50 countries in Asia and Africa as well as some countries in Europe. While it has been found to be capable of absorbing heavy metals and toxic chemicals in wastewater, and its stems have been used in small cottage industries to make bags, baskets, slippers, etc, its disadvantages far outweigh its benefits.
During a trip to Nakhon Pathom recently, I saw the futility of the efforts to eradicate water hyacinth from Thailand’s waterways. Dense mats of the weed floating on the Ta Chin river had brought navigation to a standstill, affecting the livelihood of orchard growers who would normally paddle their small boats to sell their produce at the riverside Don Wai market. The market draws thousands of tourists every day, and a number of boat operators make their living by taking sightseers on cruises along the river, but the boats were inoperable during my visit due to the infestation of water hyacinth.
The floating mass affects the breeding, nursery and feeding grounds of some economically important fish species. Covering the water surface, it prevents phytoplankton and other aquatic life from getting sun, which provides energy. Without energy, no living organism could grow.
One of the river’s tourist attractions are the thousands upon thousands of striped catfish (Pangasianodon hypophthalmus, known in Thai as pla sawai) that converge behind Wat Rai Khing. The fish somehow find the temple’s perimeter a safe sanctuary, and tourists cruising the river like to feed them with bread bought from vendors in the market. The water hyacinth clogging the Ta Chin has not only affected the livelihood of people, but also that of fish.
The Sampran Riverside resort near Wat Rai Khing has found a novel way of preventing the weed from invading its side of the river. Bundles of wood and bamboo placed along the river serve as barriers to keep it at bay.
Actually, water hyacinth can be prevented from spreading by putting a bamboo frame around it. This, however, is possible only in bodies of water where the weed comes in small masses. An example can be seen at the Bhumirak Thammachart Centre in Nakhon Nayok, which showcases His Majesty the King’s por piang, or self sufficiency, scheme for farmers and other projects initiated by the King. By putting the weed in a bamboo enclosure, it is confined in one place, where it can then be harvested and eliminated.
Getting rid of an invasive alien species is no easy task. Therefore, before collectors bring in plants from abroad, they must first consider the consequences and make sure that these won’t pose a threat to the environment and a burden to future generations.
Email nthongtham@gmail.com.
Overrun: Water hyacinth covers the Ta Chin river in Nakhon Pathom’s Sam Phran district.
A solution: Bamboo frames keep the water hyacinth from spreading in the pond of the Bhumirak Thammachart Centre in Nakhon Nayok.
