Saturday, April 23, 2011

Playing God with Haiti’s freshwater ecosystems

In September of 2010, thousands of live fish of the species Gambusia holbrooki* were transported by air from a rural fish farm in the Mississippi Delta region of the southern United States to one on the outskirts of Port-au-Prince, Haiti, where they are to be raised in tanks and released into freshwater ecosystems all over the country. These fish, one of two Gambusia species commonly known as “mosquitofish” in English, are native to the southeastern United States, and no sightings of the fish have previously been reported in freshwater ecosystems in Haiti or elsewhere on the island of Hispaniola. The reason given for this mass introduction is to aide in malaria eradication efforts in Haiti: malaria is transmitted by mosquitoes, mosquitoes lay their eggs on the surface of standing bodies of freshwater, and the omnivorous mosquitofish, in addition to any other food source available, will certainly eat mosquito eggs and larvae as their name suggests. Intentional introductions of these fish as a biological method of mosquito control have been carried out all over the world since 1905, with many introductions resulting in long-term establishment of mosquitofish populations outside of their native range [1].




Successful invasions of alien species in island ecosystems often have severe ecological and socioeconomic impacts [2], and mosquitofish meet two important criteria which suggest that a successful invasion would likely result from their introduction into an area [3]: they can survive under a large range of environmental conditions, especially temperature [4] and salinity [5], allowing them to successfully establish populations wherever they are introduced, and they are highly mobile [6], allowing established populations to spread rapidly. Also, mosquitofish have a history of successful, and ecologically disruptive, invasions outside their native range. They often populate the ecosystems they invade at high densities, and since zooplankton constitute the overwhelming majority of their diet, their presence often results in elevated phytoplankton levels, and even algal blooms [7]. They attack native fish in the ecosystems they invade, compete with them for food, and eat their minnows [8] [9]. Amphibian species, some of which are also important mosquito predators [10], have been shown to be particularly threatened by mosquitofish introductions [11] [12] [13], as moquitofish eat their eggs and tadpoles. There are at least three related Gambusia species endemic to Hispaniola, and it appears that the proponents of this project have completely overlooked these fish both as a potential native species for use in biological mosquito control and also as species that would be potentially impacted by a mosquitofish invasion. Competition and hybridization with invading mosquitofish have threatened multiple rare species of Gambusia endemic to the southwestern United States, and the invasion of mosquitofish almost certainly contributed to the recent extinction of G. amistadensis in Texas [14] [15].

This, of course, is not to downplay the reality of the long history of human suffering caused by malaria in Hispaniola, a history that goes back to the first arrival of Europeans on the island in 1492. Malaria likely played a role in the decline and eventual extermination of the Taíno people who were living on the island when the first Europeans arrived, although probably not as significant of a role as smallpox or the cruel policy of genocide and forced assimilation practiced by the European conquerers. Malaria subsequently spread to much of the rest of the Americas, although contemporary Hispaniola is the only island left in the Caribbean where malaria has yet to be eradicated, with much of the effective disease reservoir being localized to the rural lowlands of Haiti [16]. In 2009, evidence for malaria resistance to chloroquine, an important drug for the treatment and prevention of malaria, was first reported on the island [17], and in 2010, a massive earthquake displaced over a million people, increasing their susceptibility to the disease [18]. Both events make the need for a campaign towards comprehensive malaria eradication even more timely [16].

The most essential tool for malaria eradication, however, would be the ability to effectively diagnose and treat malaria across the entire island, with the large scale distribution of mosquito netting to prevent transmission of the disease also being of prime importance [16]. Control of mosquito populations would certainly help these efforts, but the effectiveness of fish introductions is more or less limited to eliminating mosquitoes from fishless ponds. Tree holes, coconut shells, discarded tires, and peridomestic containers are also important breeding grounds for mosquitoes in rural tropical areas [19] [20] [21], making fish introductions only effective when integrated with environmental management, other biological methods, and possibly even chemical methods [22]. And fortunately, there are countless species of omnivorous freshwater fish around the world which will also consume mosquito larvae when they are available as a food source and which have just as much potential as do mosquitofish for biological mosquito control within their native range [23] [24] [25] [26] [27] [28] [29], making mosquitofish introductions completely unnecessary. There is, of course, one thing that all of these tools for successful malaria eradication all have in common: they all require a significant and prolonged engagement with and investment in rural communities across Haiti.

The potentially severe consequences of this attempt at using mosquitofish to control malaria in Haiti and the rather naive assumptions immanent in its rationale make it a rather curious project. The organization behind it is Operation Blessing International (OBI), a non-profit organization with an explicitly Christian mission and an annual revenue in excess of $400,000,000 founded by wealthy televangelist Pat Robertson in 1978. But there is an additional level of irony in that, even assuming that the intentions at all levels of the organization are genuine, OBI is, by engaging in such deliberate ecosystem engineering, effectively disregarding two important convictions that are nearly universal in Christian theology: that the Earth is God’s creation, and that God’s judgment should not be questioned. In the biblical creation narrative, the reason that Adam, the first man, is placed in God’s creation at all is merely “to tend and watch over it” (Gn 2:15), and Adam is never called upon to improve upon it as he sees fit, or to move things around. Adam’s descendants, at various points in the Old Testament, question God’s judgment and will. “Where were you when I laid the foundations of the earth?” (Jb 38:4) is what God says to Job after one such incident. The Book of Ecclesiastes, echoing its persistent theme of human vanity, asks in reference to the work of God “who can make straight what He has made crooked?” (Ec 7:13).

Pat Robertson has been well known for his large investments in mineral extraction interests in the countries where OBI operates, his use of OBI resources for his personal business ventures, and his close ties to right-wing dictators who violently expropriate land from and enforce crippling economic policies on the people they rule [30]. But whatever the organization’s larger plans for Haiti may be, the project to introduce mosquitofish to the country appears to be nothing more than a gimmick: a mythical “silver bullet” born in the heart of the rural U.S. South and about to be used against an exotic foe for once and for all, which when stripped of the reality of its certain ineffectiveness and its potentially severe consequences, is sure to win over the hearts of North American donors. The long-term consequences of this project for Haiti’s freshwater ecosystems are completely irrelevant to the project’s viability anyways, as it is not the people who live in Haiti and depend on its freshwater ecosystems for their livelihoods who control the means in which their collective suffering is exploited as the Christian tradition of charity is commodified. Equally irrelevant are the theological contradictions inherent in the project, as the project is not in any way an act of Christian charity, but a gimmick which is being sold to charitable Christians. Like the introduction of malaria itself to Hispaniola, the brutal extermination of the people who inhabited the island at the time, the clearing of the island’s forests for plantation agriculture, the damming of its rivers, and the reckless extraction of its mineral resources, the introduction of mosquitofish to Haiti amounts to simply another permanent alteration of Hispaniola’s landscape and ecology for short-term private profit, this time in the name of the empire of Pat Robertson.

Photo Credit: Paparazzo Presents


References

  1. L.A. Krumholz, "Reproduction in the Western Mosquitofish, Gambusia affinis affinis (Baird & Girard), and Its Use in Mosquito Control", Ecological Monographs, vol. 18, 1948, pp. 1-. DOI.
  2. J.K. REASER, L.A. MEYERSON, Q. CRONK, M. DE POORTER, L. ELDREGE, E. GREEN, M. KAIRO, P. LATASI, R.N. MACK, J. MAUREMOOTOO, D. O'DOWD, W. ORAPA, S. SASTROUTOMO, A. SAUNDERS, C. SHINE, S. THRAINSSON, and L. VAIUTU, "Ecological and socioeconomic impacts of invasive alien species in island ecosystems", Environmental Conservation, vol. 34, 2007, pp. 98-. DOI.
  3. C.S. Kolar, "Ecological Predictions and Risk Assessment for Alien Fishes in North America", Science, vol. 298, pp. 1233-1236. DOI.
  4. R.G. Otto, "Temperature tolerance of the mosquitofish, Gambmia affinis (Baird and Girard)", Journal of Fish Biology, vol. 5, 1973, pp. 575-585. DOI.
  5. J. Chervinski, "Salinity tolerance of the mosquito fish, Gambusia affinis (Baird and Girard)", Journal of Fish Biology, vol. 22, 1983, pp. 9-11. DOI.
  6. J.S. Rehage, and A. Sih, "Dispersal Behavior, Boldness, and the Link to Invasiveness: A Comparison of Four Gambusia Species", Biological Invasions, vol. 6, 2004, pp. 379-391. DOI.
  7. S.H. Hurlbert, and M.S. Mulla, "Impacts of mosquitofish (Gambusia affinis) predation on plankton communities", Hydrobiologia, vol. 83, 1981, pp. 125-151. DOI.
  8. N. Caiola, and A. Sostoa, "Possible reasons for the decline of two native toothcarps in the Iberian Peninsula: evidence of competition with the introduced Eastern mosquitofish", Journal of Applied Ichthyology, vol. 21, 2005, pp. 358-363. DOI.
  9. D.K. Rowe, J.P. Smith, and C. Baker, "Agonistic interactions between Gambusia affinis and Galaxias maculatus: implications for whitebait fisheries in New Zealand rivers", Journal of Applied Ichthyology, vol. 23, 2007, pp. 668-674. DOI.
  10. S.E. DuRant, and W.A. Hopkins, "Amphibian predation on larval mosquitoes", Canadian Journal of Zoology, vol. 86, 2008, pp. 1159-1164. DOI.
  11. S. Komak, and M.R. Crossland, , Wildlife Research, vol. 27, pp. 185-. DOI.
  12. H. A., L. S., and M. M., "The role of introduced mosquitofish ( Gambusia holbrooki ) in excluding the native green and golden bell frog ( Litoria aurea ) from original habitats in south-eastern Australia", Oecologia, vol. 132, 2002, pp. 445-452. DOI.
  13. S.C. Gamradt, and L.B. Kats, "Effect of Introduced Crayfish and Mosquitofish on California Newts", Conservation Biology, vol. 10, 1996, pp. 1155-1162. DOI.
  14. G. Huxel, "Rapid displacement of native species by invasive species: effects of hybridization", Biological Conservation, vol. 89, pp. 143-152. DOI.
  15. K.T. Scribner, K.S. Page, and M.L. Bartron, , Reviews in Fish Biology and Fisheries, vol. 10, pp. 293-323. DOI.
  16. J. Keating, D.J. Krogstad, and T.P. Eisele, "Malaria elimination on Hispaniola", The Lancet Infectious Diseases, vol. 10, 2010, pp. 291-293. DOI.
  17. B.L. Londono, "Chloroquine-Resistant Haplotype Plasmodium falciparum Parasites, Haiti", Emerging Infectious Diseases, vol. 15, 2009, pp. 735-740. DOI.
  18. P. Adams, "Rainy season could hamper Haiti's recovery", The Lancet, vol. 375, 2010, pp. 1067-1069. DOI.
  19. S.M. Kulkarni, and P.S. Naik, "Breeding habitats of mosquitoes in Goa.", Indian journal of malariology, vol. 26.
  20. J.C. Anosike, B.E.B. Nwoke, A.N. Okere, E.E. Oku, J.E. Asor, I.O. Emmy-Egbe, and D.A. Adimike, "Epidemiology of tree-hole breeding mosquitoes in the tropical rainforest of Imo State, south-east Nigeria.", Annals of agricultural and environmental medicine : AAEM, vol. 14.
  21. D.A. Yee, "Tires as habitats for mosquitoes: a review of studies within the eastern United States.", Journal of medical entomology, vol. 45.
  22. L.A. Lacey, and B.K. Orr, "The role of biological control of mosquitoes in integrated vector control.", The American journal of tropical medicine and hygiene, vol. 50.
  23. S.M. Nelson, and L.C. Keenan, "Use of an indigenous fish species, Fundulus zebrinus, in a mosquito abatement program: a field comparison with the mosquitofish, Gambusia affinis.", Journal of the American Mosquito Control Association, vol. 8.
  24. D.K. Lee, "Predation efficacy of the fish muddy loach, Misgurnus mizolepis, against Aedes and Culex mosquitoes in laboratory and small rice plots.", Journal of the American Mosquito Control Association, vol. 16.
  25. T.P. Hurst, M.D. Brown, and B.H. Kay, "Laboratory evaluation of the predation efficacy of native Australian fish on Culex annulirostris (Diptera: Culicidae).", Journal of the American Mosquito Control Association, vol. 20.
  26. A.R. Van Dam, and W.E. Walton, "Comparison of mosquito control provided by the arroyo chub (Gila orcutti) and the mosquitofish (Gambusia affinis).", Journal of the American Mosquito Control Association, vol. 23.
  27. P. Irwin, and S. Paskewitz, "Investigation of fathead minnows (Pimephales promelas) as a biological control agent of Culex mosquitoes under laboratory and field conditions.", Journal of the American Mosquito Control Association, vol. 25.
  28. V. Louca, M.C. Lucas, C. Green, S. Majambere, U. Fillinger, and S.W. Lindsay, "Role of fish as predators of mosquito larvae on the floodplain of the Gambia River.", Journal of medical entomology, vol. 46.
  29. G. Chandra, I. Bhattacharjee, S.N. Chatterjee, and A. Ghosh, "Mosquito control by larvivorous fish.", The Indian journal of medical research, vol. 127.



* UPDATE April 27,2011:
Operation Blessing International has said they did not import Gambusia Holbrooki Fish Into Haiti, they introduced Gambusia Affinis. In response, the author of this piece states:
The difference between G. holbrooki and G. affinis is minor. They are both known as "mosquitofish" in American English and though they are two separate species, they are often treated as one in the scientific literature because their biology is very similar. Some of literature that I cited, especially those by Australian scientists, actually deal with G. affinis, since that was the species introduced there (G. holbrooki was introduced in Europe, Asia, and Africa).

I'm not sure if I believe their claim that G. affinis already exists in Haiti, though. When I wrote the article, I searched pretty hard for any evidence that either species had been introduced to the island, but found none. If it was already there, why did they have to fly fish in from Mississippi? And why aren't they using native fish? Perhaps I could contact Dr. Abe personally to clarify this.

They claim that they are not going to release G. affinis into open water, which is good. This doesn't mean that G. affinis won't successfully invade freshwater ecosystems though, especially in the event of a flood.

So, although I will certainly edit my article to reflect their claim that it was G. affinis that they introduced, I certainly will not change my analysis. I'm working on drafting an open letter Bill Horan, which I will post on my website. I plan to address the fact that the press release seems to imply that they didn't just introduce a species of fish into Haiti, which they did. It also does not accept that what they are doing will have ecological consequences, which it will.

un.chemyst

An open letter to Bill Horan


5 comments:

Operation Blessing said...

Good Day! Rachel from Operation Blessing International here. Would like to share our latest press release with you: http://bit.ly/fxrn8j It asserts the truth that we have never imported gambusia holbrooki into the Haitian environment, and outlines our approval from the Haiti Ministry of Agriculture and Ministry of Environment to import gambusia affinis. I hope you find it an enjoyable and interesting read. Thanks!

thezenhaitian said...

Both gambusia holbrooki and gambusia affinis are mosquitofish, which are invasive, predatory fish that are regulated in the U.S. As stated in the petition Haiti has little regulation.

"These fish are native to the watershed of the Gulf of Mexico, where they feed readily on the aquatic larval and pupal stages of mosquitoes. They are remarkably hardy, surviving in waters of very low oxygen saturations, high salinities (including twice that of seawater), and high temperatures; they can even survive in waters up to 42 °C (108 °F) for short periods. For these reasons, this species may now be the most widespread freshwater fish in the world, having been introduced as a biocontrol to tropical and temperate countries in both hemispheres, and then spreading further both naturally and through even further introductions. The majority of these introductions were ill-advised; in most countries where mosquitofish have been introduced it has been proven that endemic fish species were already providing maximal mosquito control, and that the introduction of mosquitofish has been both unnecessary and highly damaging to endemic fish and other endemic aquatic life."

Source: http://en.wikipedia.org/wiki/Gambusia_affinis

thezenhaitian said...

Also from the post:

"There are at least three related Gambusia species endemic to Hispaniola, and it appears that the proponents of this project have completely overlooked these fish both as a potential native species for use in biological mosquito control and also as species that would be potentially impacted by a mosquitofish invasion."

thezenhaitian said...

How does OBI respond to the observation that the fish kill at Lake Azeui back in December 2010 was due to the introduction of tilapia by OBI:

"The first phase of TEACH A NATION TO FISH, already underway, is a microenterprise project run by Dr. Abe and funded by OBI that provides a source of food and income for many families. The program takes place at Lake Azuei, where OBI funds a $1,000 starter kit for each family participating in the project."
http://reliefweb.int/node/356613

thezenhaitian said...

The following is the response of the writer of this post (un.chemyst) to the OBI statement (http://bit.ly/fxrn8j):

________________

Chantal,

The difference between G. holbrooki and G. affinis is minor. They are both known as "mosquitofish" in American English and though they are two separate species, they are often treated as one in the scientific literature because their biology is very similar. Some of literature that I cited, especially those by Australian scientists, actually deal with G. affinis, since that was the species introduced there (G. holbrooki was introduced in Europe, Asia, and Africa).

I'm not sure if I believe their claim that G. affinis already exists in Haiti, though. When I wrote the article, I searched pretty hard for any evidence that either species had been introduced to the island, but found none. If it was already there, why did they have to fly fish in from Mississippi? And why aren't they using native fish? Perhaps I could contact Dr. Abe personally to clarify this.

They claim that they are not going to release G. affinis into open water, which is good. This doesn't mean that G. affinis won't successfully invade freshwater ecosystems though, especially in the event of a flood.

So, although I will certainly edit my article to reflect their claim that it was G. affinis that they introduced, I certainly will not change my analysis. I'm working on drafting an open letter Bill Horan, which I will post on my website. I plan to address the fact that the press release seems to imply that they didn't just introduce a species of fish into Haiti, which they did. It also does not accept that what they are doing will have ecological consequences, which it will.

un.chemyst

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