Nav: Home

How to prevent mosquitofish from spreading in water ecosystems

May 24, 2019

Preventing the introduction of the mosquitofish and removing its population are the most effective actions to control the dispersal of this exotic fish in ponds and lakes, according to a study published in the journal Science of the Total Environment. Neither the presence of predators nor the degradation of the quality of water and natural habitat are a threat to this invasive species -from the Atlantic coast in North America- which competes against and moves local species away.

The new study, carried out in water ecosystems close to urban environments of the Barcelona provincial area, is signed by the experts Oriol Cano Rocabayera, Adolfo de Sostoa, Lluís Coll and Alberto Maceda, from the Faculty of Biology and the Biodiversity Research Institute of the University of Barcelona (IRBio).

An exotic species threatening local fish

The mosquitofish (Gambusia holbrooki) is an edacious exotic fish regarded as one of the most dangerous invasive species at a global scale according to the International Union for the Conservation of Nature (UICN). It was brought to Spain in 1921 for the biological control of mosquitoes -carrying diseases such as malaria- and is now included in the catalogues of exotic invasive species of the Ministry of Agriculture, Fisheries and Food and the autonomous communities.

This species is especially present in the southern-western areas of the peninsula, the Mediterranean coast and the Ebro basin. In general, it is found in habitats with warm waters, with a low or no flow and shallow waters -in general, wetlands and the shallow waters in rivers- and areas with agricultural activity or peri-urban areas affected by pollution. In the peninsular area, it is a competitive predator that has forced local species to move -such as the Spanish toothcarp (Aphanius iberus), the Valencia toothcarp (Valencia hispanica), the Andalusian toothcarp (Aphanius baeticus) and the three-spined stickleback (Gasterosteus aceulatus), apart from other amphibians and invertebrates.

Exotic mosquitofish: strategies to survive under adverse conditions

Its high fecundity, sexual precocity, tolerance to environmental pollution and competitive superiority are "factors that make its monitoring more difficult if the only strategies to preserve biodiversity in the water ecosystem are based on the improvement of water or the natural habitat", notes researcher Oriol Cano Rocabayera, first author of the article and member of the Department of Evolutionary Biology, Ecology and Environmental Sciences of the UB and IRBio.

"If some mosquitofish enter a new habitat -or when there are a few of them after a control action to remove the population- this exotic species is able to increase its fecundity rate to balance the population imbalance. However, if the population of mosquitofish is stable and abundant, the fecundity lowers but new mosquitofish are bigger and have more chances of surviving", says Cano.

Changes in water regime -building of dams, canalizations, etc.- favour the presence of certain exotic species -like the mosquitofish- that prefer water with low flow. In general, the restoration of the hydrological regime has the best strategy to control invasive species.

"However, preventing the arrival of these and removing the populations of mosquitofish in the available ecosystems are the most effective actions for their control. Nevertheless, their small size, the wide range of tolerance, their diet and connectivity of water ecosystems makes this control and their removal very expensive and difficult".

The new study reveals that habitats with abundant water plants -for example, naturalized dams- and well-preserved environments improve the physical condition of mosquitofish. Therefore, the complexity of the habitat is a factor that brings more preys and shelter against the attack of the predators. "The mosquitofish's survival in high salinity waters is difficult, and these waters are now the natural habitat where the Spanish toothcarp is limited to", comments Cano Rocabayera.

The danger of releasing exotic animals in the environment

The global distribution of this invasive species -found in all continents but for the Antarctica- is related to the areas where it was introduced a century ago due the biological control of mosquitos that carried malaria. Therefore, the most recent outbreaks of tropical diseases transmitted via mosquitoes -Zika, Chikunguya and Pappataci fever- make it essential to extreme the surveillance on the effects of the introduction of these exotic fish in the local fauna, especially in tropical regions with a high biodiversity.

According to the authors of the study, "we need to apply more effective control measures on the small water masses, that is, in habitats where the complete removal of the population can be guaranteed. Also, we need to raise awareness among people on the danger of releasing exotic animals in the natural environment".
-end-


University of Barcelona

Related Invasive Species Articles:

'Trojan fish': Invasive rabbitfish spread invasive species
For some time, unicellular benthic organisms from the Indo-Pacific have been spreading in the Mediterranean.
New York schools help Cornell monitor local waterways for invasive species
With 7,600 lakes and 70,000 miles of creeks and rivers to monitor, Cornell researchers struggled to stay ahead of round goby and other invasive species -- until they tapped into New York's network of teachers looking to bring science alive for their students.
Documenting the risk of invasive species worldwide
In the first global analysis of environmental risk from invasive alien species, researchers say one sixth of the world's lands are 'highly vulnerable' to invasion, including 'substantial areas in developing countries and biodiversity hotspots.' The study by biogeographer Bethany Bradley at the University of Massachusetts Amherst and Regan Early at the University of Exeter, UK, with others, appears in the current issue of Nature Communications.
Invasive species could cause billions in damages to agriculture
Invasive insects and pathogens could be a multi-billion- dollar threat to global agriculture and developing countries may be the biggest target, according to a team of international researchers.
Entomological Society of America releases statement on the dangers of invasive species
The Entomological Society of America has issued a statement about the dangers of invasive species and the potential threats they pose to US national interests by undermining food security, trade agreements, forest health, ecosystem services, environmental quality, and public health and recreation.
Invasive species not best conservation tool: Study
Harnessing an invasive fish species sounded like a promising conservation tool to help reverse the destruction wreaked by zebra mussels on endangered native mollusks in the Great Lakes -- except that it won't work, says a University of Guelph ecologist.
Invasive water frogs too dominant for native species
In the past two decades, water frogs have spread rapidly in Central Europe.
Queen's University in new partnership to fight against invasive species
The rapid spread of invasive species across Europe, which currently threatens native plants and animals at a cost of €12 billion each year, is to face a major new barrier.
A DNA analysis of ballast water detects invasive species
The German research vessel Polarstern covers thousands of kilometers in search of samples of biological material.
Invasive freshwater species in Europe's lakes and rivers: How do they come in?
A JRC-led article has identified escape from aquaculture facilities, releases in the wild due to pet/aquarium trade and stocking activities as the main pathways of alien species introduction in European lakes and rivers.

Related Invasive Species Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Digital Manipulation
Technology has reshaped our lives in amazing ways. But at what cost? This hour, TED speakers reveal how what we see, read, believe — even how we vote — can be manipulated by the technology we use. Guests include journalist Carole Cadwalladr, consumer advocate Finn Myrstad, writer and marketing professor Scott Galloway, behavioral designer Nir Eyal, and computer graphics researcher Doug Roble.
Now Playing: Science for the People

#529 Do You Really Want to Find Out Who's Your Daddy?
At least some of you by now have probably spit into a tube and mailed it off to find out who your closest relatives are, where you might be from, and what terrible diseases might await you. But what exactly did you find out? And what did you give away? In this live panel at Awesome Con we bring in science writer Tina Saey to talk about all her DNA testing, and bioethicist Debra Mathews, to determine whether Tina should have done it at all. Related links: What FamilyTreeDNA sharing genetic data with police means for you Crime solvers embraced...