Subscribe to our free daily newsletters
. Earth Science News .




Subscribe to our free daily newsletters



WATER WORLD
A DNA analysis of ballast water detects invasive species
by Staff Writers
Madrid, Spain (SPX) Dec 11, 2015


This is photograph of the German research vessel Polarstern during its trip between Bremerhaven (Germany) and Cap Town (South Africa) in 2012. Image courtesy Anastasija Zaiko. For a larger version of this image please go here.

The German research vessel Polarstern covers thousands of kilometres between the northern and southern hemispheres in search of samples of biological material. This ship, however, has some other on board passengers: organisms that can adapt to extreme water temperatures and could potentially invade the new waters where this ice breaker takes them.

Upon analysing the DNA present in this vessel's ballast water, a team of scientists showed the first molecular evidence of the persistence of DNA belonging to a tiny sea snail which is capable of tolerating adverse conditions.

Maritime transport is considered one of the most important ways that native species are moved between marine regions. The trip can be especially successful if these species latch on to the vessel's anchors or chains, or even if they travel in the ship's ballast water tanks.

Each year, between 2.2 and 12 billion tons of water are transported around the oceans of the world in these ballast water tanks which also serve as a means of transport for about 7,000 species per day.

In a European report that analysed 15 samples of ballast water, live specimens of more than one thousand species were discovered in ship tanks that arrived to European ports. These taxa, however, must face very harsh conditions upon arrival: darkness, temperature changes, salinity, murky waters, turbulence and a lack of oxygen. Not all of the species will survive, and the ones that do become potential invasive species.

In order to identify which organisms are most capable of tolerating non-native waters and are thus the most invasive, a team of researchers led by the University of Oviedo (UO) analysed the environmental DNA present in the 70 m3 of ballast water in the tank - filled with water from the North Sea - of the scientific research vessel Polarstern. This ship travelled between Bremerhaven (Germany) and Cape Town (South Africa) between October and December of 2012.

"Seeing as this ballast water has travelled from the north to the south and has even crossed the tropics, it has thus been subjected to extreme temperature variations in addition to anoxic conditions [a total lack of oxygen]," explains Alba Ardura to SINC, the main author of the study published in the Journal of Molluscan Studies and a researcher at the University of Perpignan (France) at present.

Is this snail a potential invasive species?
While filling up the ballast water tank, the organisms that were alive upon entry into the tank in Bremenhaven could have been subjected to conditions of stress which could result in their death, thus meaning that "the number of DNA molecules would decrease over the course of the trip," points out Ardura.

Nonetheless, this is not what happened to the laver spire shell, also called the mudsnail (Peringia ulvae): "The number of one of the haplotypes (variations in DNA within the same species) increased during the trip," affirms the scientist.

Animals like this invertebrate leave behind traces of their presence in the waters where they live such as dead cells that have sloughed off or fluids. In this case, the mudsnail left behind traces in the ballast water.

It is possible to extract DNA from a sample of water in order to determine what species are living there. "We can thus have a wide range of information about the species which are present in the environment we are analysing without having to carry out individual sampling one by one," observes the expert.

Nonetheless, finding evidence of the mollusc does not confirm that it is alive, "but it does confirm the resistance of its DNA to adverse conditions," indicates Ardura. Up until now there has not been any evidence of the presence of this small snail outside of its natural habitat, although some studies have indeed described its ability to tolerate diverse ecological conditions.

For researchers, environmental DNA and its massive sequencing are a 'very promising' tool for rapid biodiversity analysis and the detection of potentially invasive species that are present in ships' ballast waters.

Though we should also point out that "the tool has its limitations which need to be remedied in order to develop an effective and robust method for applications in this field," concludes the scientist.

Ardura, Alba; Zaiko, Anastasija; Martinez, Jose L.; Samuiloviene, Aurelija; Borrell, Yaisel; Garcia-Vazquez, Eva. 'Environmental DNA evidence of transfer of North Sea molluscs across tropical waters through ballast water' Journal of Molluscan Studies 81: 495-501 Subdivision: Nov. 4, 2015. DOI: 10.1093/mollus/eyv022 November 2015


Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.

SpaceDaily Contributor
$5 Billed Once


credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly


paypal only

.


Related Links
FECYT - Spanish Foundation for Science and Technology
Water News - Science, Technology and Politics






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

Previous Report
WATER WORLD
Pacific tuna conservation meeting ends in deadlock
Kuta, Indonesia (AFP) Dec 9, 2015
Environmental groups expressed frustration Wednesday after a key Pacific fishing industry meeting failed to adopt measures to protect vulnerable tuna species from overfishing. The Pew Charitable Trusts said the bluefin and bigeye tuna species could become severely depleted due to inaction by the Western and Central Pacific Fisheries Commission. Critics said a commission meeting, which wr ... read more


WATER WORLD
Honduras to deploy security on gang-targeted buses

Climate-change foes winning public opinion war

Higher levels of Fukushima cesium detected offshore

US Supreme Court gives nod to assault weapons ban

WATER WORLD
Penn researchers make thinnest plates that can be picked up by hand

World's tiniest temperature sensor can track movement from inside cement

Researchers discover mother of pearl production process

In-Space Manufacturing Prototype

WATER WORLD
Microwaves improve green workings of materials used to clean wastewater

Quenching the water demands of today's megacities

Even thermally tolerant corals are in hot water when it comes to bleaching

Pacific tuna conservation meeting ends in deadlock

WATER WORLD
Greenland glaciers retreating at record pace

Warming opens famed Northwest Passage to navigation

Arsenic from Chilean mines found in Antarctica

Soil from deep under Oregon's Coast Range unveils frosty past climate

WATER WORLD
Peru's unpaid agrarian bonds: My family's quest

Global food system faces multiple threats from climate change

QUT scientists unlock secrets of Aussie 'resurrection' grass

First fossil peaches discovered in southwest China

WATER WORLD
31 dead, 20,000 families homeless in torrential rain in Kinshasa

At least two dead in earthquake in Tajikistan

Britain to review defences after floods

7.2-magnitude quake strikes Tajikistan, at least one dead

WATER WORLD
Lions made famous on television poisoned in Kenya

China, Africa call for homegrown solutions to solving African crises

Elephants: the forgotten giants at Africa-China summit

Cameroon army kills 100 Boko Haram fighters, frees 900 hostages: ministry

WATER WORLD
Research differentiates facial growth in Neanderthals and modern humans

East Asia Pacific ageing faster than anywhere else in history: World Bank

Engraved schist slab may depict paleolithic campsites

The accidental discovery of how to stay young for longer




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News






The content herein, unless otherwise known to be public domain, are Copyright 1995-2017 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement