When I was a high school every Saturday and Sunday I' always help my Lolo (Grandfa) in their fishponds. We catch Tilipia and sell them 35 pesos per Kilo and sometimes I clean the pond remove the water hyacinth (water hyacinth, were brought into the country purely to decorate fishponds). One day we catch fish using a net and were surprise that we have a turtle in our net.
The invasiveness of alien species lies in their adaptive behaviors, such as rapid growth, great dispersal characteristics, large reproductive capacity, broad environmental tolerance, and effective competition with local species.
Invasive alien species (IAS) are either plants, animals or microorganisms that have been introduced outside their natural distribution area, and which exhibit rapid growth, reproduction and dispersal to such an extent that they are highly competitive to native species, destructive and difficult to control, particularly if the new ecosystem lacks the predators or pathogens of their own native range. Their introduction to a new ecosystem threatens biodiversity, food security, human health, trade, transport and economic development. The cost of damage caused by IAS globally is estimated at USD1.4 trillion per annum.
In the ASEAN region, invasive alien species are becoming a threat to biodiversity and the economy. Over the recent years, the region witnessed how the introduction of certain species into ecosystems turned into virtual ecological and economic nightmares. The following examples clearly illustrate the impacts of IAS in the region:
- The janitor fish (Pterygoplichthys pardalis and P. disjunctivus) originally imported as aquarium cleaners, escaped and infested the Philippines’ Laguna Lake and Marikina River, disrupting balance in the lake’s and river’s ecosystem. It damaged fish cages and fishing nets, affecting fish production and the fish catch of locals. It also damaged important waterways, causing the collapse of riverbanks.Were originally introduced locally for aquariums but careless handling and weak controls allowed them to escape into the wild -- just like scores of other animals and plants.
- The golden apple snail cost Philippine rice farmers USD28 to 45 million annually. The snail wrought havoc to Viet Nam’s rice fields, where it was introduced in 1988 to the public for culturing in backyard ponds as an alternative high-protein food for duck and fish. Subsequently, two snail farms were established as a joint venture between Viet Namese and Taiwanese companies for large-scale culture and export to Taiwan. Some snails escaped and spread to nearby ponds, trenches and rice fields, where they quickly reached pest status. The government eventually banned snail farming, and spent vast sums of money on control programs and public awareness campaigns.(Perhaps the best -- or worst -- example was the Taiwanese golden apple snail, introduced by the government in the 1970s as a possible alternative food source for farmer)
- The water hyacinth (Water Lily)were brought into the country purely to decorate fishponds.
Now this floating water plant reproduces wildly, clogging water systems and preventing sunlight from reaching other aquatic vegetation.CALAUAN, LAGUNA— The worsening floods in the country is perhaps what led locals to discover a better use for water hyacinths.
Water hyacinths now provide a thriving economic industry for rural communities where these “pesky” plants float abundantly,makes household items like magazine, wine and plant holders and throw pillow covers, all handmade from water hyacinths.
- The knife fish look similar to “arowana,” making them a popular ornamental fish that grows up to 10 kilos and more.After the “ugly” janitor fish, another equally invasive predator – knife fish – has come to invade the already threatened Laguna Lake, the country’s biggest at 94,900 hectares.The knife fish multiplies better than the janitor fish, a type of African catfish that was introduced into the country by hobbyists who let their fish loose, swimming their way from ponds to creeks and the rivers before lodging in Laguna de Bay.
“The horrible-looking knife fish has low value in the market. Although there are buyers, they buy this fish for P5 to P15 per kilo. Not many people are keen to eat this fish because it is carnivorous, exotic and not part of the regular fish staple. The buyers use knife fish for fish ball, that is why it is also very cheap,”
For every 10 kilos of fish, 7 kilos are knife fish. The group said one of the fishpen operators told them that he bought 45,000 pieces of bangus fry that were supposed to deliver 90,000 kilos upon harvest season. He was completely shattered when harvest came as he only secured 3,250 small bangus.
Other Species is the Black Snake Head "DALAG" If you have this in ponds it will eat fingerlings or shrimps.
Other List Invasive Alien Species
- The Chinese softshell turtle, the scientific name of which is "pelodiscus sinensis" Snapping Turtle.These softshell turtles have reportedly invaded hundreds of fishponds in Pampanga, Bulacan, and nearby provinces in the region, prompting DENR authorities to create a task force to look into the animal's distribution, feeding habits, and reproductive characteristics."The Chinese softshell turtle has been classified as an invasive alien species (IAS) introduced in the country in the 90s," The DENR official also warned the public against propagating or raising the animal as a pet.
Today, the reptile is considered a threat to local biodiversity and a pest in the multi-million fish industry of Pampanga, Bulacan and Bataan, said Dichoso.
Fishermen and fishpond owners from the towns of Arayat, Candaba, San Luis, Minalin, Macabebe and Apalit in Pampanga likened the turtle menace to the "golden kuhol" that wreaked havoc in rice farms during the 80s, reported Arthur Salazar, deputy DENR director for protected areas, wildlife and coastal zone management service (PAWCZMS).
The Chinese softshell turtle is carnivorous and aggressive, preferring to forage at night to feed on fish, crustaceans, mollusks and insectsThe Chinese softshell turtle, according to the Food and Agriculture Organization (FAO) of the United Nations (UN), is found in several countries, including China, Taiwan, Vietnam, Japan and Russia where it is considered a native "delicacy" and made into turtle soup. In Japan, turtle meat is stewed
Other Species is the Black Snake Head "DALAG" If you have this in ponds it will eat fingerlings or shrimps.
Other List Invasive Alien Species
Alien species | Effects on the ecosystem |
| Tree species and insect pests | |
| Gmelina arborea | Host of Ozola minor, Attacus and Xyleutis spp. |
| Acacia mangium | Host of Anoplophora luciphor |
| Eucalyptus camaldulensis | Host of unidentified termite species |
| Swietenia microphylla | Host of Zeuzera coffeae |
| Leucaena leucocephala | Host of Heteropsylla cubana |
| Toona ciliata | Host of unidentified weevil |
| Invertebrates | |
| Big headed ant (Pheidole megacephalus) | Displaced most invertebrate faunas; pest to agriculture as it harbours phytophagous insects that reduce crop productivity |
| Fire ant (Solenopsis geminate) | Invaded native communities and affected many or all of the animals and plants in the community; has fiery and painful stings; nests in the soil |
| Jumping plant lice (Heterophylla cubana) | Introduced by the typhoon in 1980. Has affected almost all standing L. leucocephala plantations |
| Alien species | Effects on the ecosystem |
| Invertebrates | |
| Leafminer (Liriomyza sp.) | Accidentally introduced with the importation of chrysanthemum: major pest of potato and ornamentals |
| Spiraling whitefly (Aleurodicus dispeures) | Affected vegetables and ornamentals. Accidentally introduced with the importation of ornamental kalanchoe in the 1970s |
| Mealy bug (Pseudococcus sp.) | Affects coconut in Northern Palawan. Accidentally introduced in 1990 with the importation of hybrid coconut planting materials |
| Riceblack bug (Scontiniphora coarctata) | Major problem for rice in Mindanao and Leyte. Introduced through vessels plying the route between the province of Palawan and countries south of the Philippines |
| Potato cyst nematode | Accidentally introduced in the importation of potato planting materials. Heavily infesting potato farms in Benguet in Northern Philippines |
| American cockroach (Periplaneta americana) | Ubiquitous house pest |
IAS is an issue that is tied to major economic activities, and is thus a problem affecting both developed and developing countries. While some countries have addressed specific IAS issues in national programs like the National Biodiversity Strategies and Action Plans and specific IAS frameworks, the nature of the problem requires greater cooperation, particularly among regional partners.
0 comments:
Post a Comment