Hi, you can used to identified your population, used too tracability, identified migration flux and what ever!!!

Hello Subrata

DNA barcoding itself is a molecular Approach to biodiversity. Since it is a standardized, global approach it opens the field to a wide range of applications (being it biome studies, Food web studies, human Impact studies like anthropogenic transport etc. etc.).

Given a data base all life stages and even fragments of organisms can be determined.

Some advantages are nicely put together at

http://www.barcodeoflife.org/sites/default/files/materials/TenReasonsBarcoding.pdf

greetings

Nikola

it also can be used to assess "species evolutive uniqueness". This idea is super important facing the actual rate of extinction, conservation targets need to be clearly identified and evolutive uniqueness may be a tool to do it.

see Isaac et al. (2007): Mammals on the EDGE: conservation priorities based on threat and phylogeny

the basic uitilty is to identify the marine species,for that we cann't identify it though the phoenoty, and  I think we can using barcoding as a maker for researching the evolotuion,now it is very popular for using barcoding data with the phenotypic function introgression with the ecoysystem.

Our question was: is sushi really sushi or what is behind whitefish, eel on the menu. We got quite clear answers. Another question was: dow we eat endangered bluefin tuna or else and luckily we did not. Our sample area comprised german cities like Hamburg or Berlin, a small number sushi bars respectively. Sampling did not meet higher scientific standards as this was a school project linked to the GEOMAR.

The mainly utility is to identify species, however you can use to populations and phylogenetics studies. See http://www.barcodeoflife.org.

In the Marine realm, environmental conditions influence strongly the possible shapes of living organisms leading to both morphological convergence of phylogenetically unrelated organisms and phenotypic plasticity within closely related organisms... To make a long story short, it is very difficult to ID marine organisms (especially seaweeds which are my main interest) on the sole basis of morphological features.  Therefore, the use of molecular data is very useful to 1)  assess the phylogenetic distances among organisms and 2) ID organisms if a library of well ID specimens with sequences is available.

Interesting question! Basically there should be no fundamental difference in utility for terrestrial vs. marine systems. However, keep in mind the long - standing notion (assumption) that there *tends* to be more gene flow, fewer obvious physical barriers to gene flow in the three dimensional marine ecosystem, especially for vagile and/or broadcast spawning taxa. 

But recently, the role of mitochondrial DNA (mtDNA) sequences in taxonomy and phylogenetic inference has become quite contentious:  two extreme viewpoints have

emerged. One which criticizes the use of mtDNA because the marker suggests 'misleading patterns of variation'; specifically, phylogenies that

are inconsistent with those derived from nuclear gene

sequences in the context of species relationships among

closely related taxa (Ballard and Whitlock, 2004; Shaw,

2002). The other extreme, the DNA “barcode” movement,

espouses the sole use of small fragments of a single

mtDNA gene, cytochrome c oxidase I (COI), to identify

most of life (Hebert et al., 2003).

In a review paper my colleague Dan Rubinoff and i published a few years back we present the disadvantages of these two extreme

viewpoints and argue for an integrated role for

mtDNA, one that takes advantage of mtDNA’s strengths

but also accounts for its shortcomings by using it in concert

with other independent data sources (e.g., nuclear

DNA, cytosystematic, morphological, behavioral). We

are against the abolition of the use of mtDNA in phylogenetics

but also against its narrow use in barcoding as currently

defined. We try to show why neither viewpoint

is particularly productive and emphasize how analysis

of mtDNA can be an important tool in the context of both

taxonomic and phylogenetic studies, and I would say equally for marine versus terrestrial organism systematics.  (for our review on this debate in general see:

Rubinoff, D. & B.S. Holland. 2005.  Between the two extremes: Mitochondrial DNA is neither the panacea nor the nemesis of phylogenetic and taxonomic inference. Systematic Biology, 54(6): 952-961). 

For a couple of additional papers that used mtDNA markers to examine and evaluate  systematic boundaries in closely related marine taxa:

Bird, C.E., B.S. Holland, B.W. Bowen & R.J. Toonen. 2011.  Diversification in broadcast-spawning sympatric Hawaiian limpets (Cellana spp.). Molecular Ecology. 20: 2128-2141

Bird, C.E., B.S. Holland, B.W. Bowen & R.J. Toonen. 2007. Contrasting phylogeography in three endemic Hawaiian limpets (Cellana spp.) with similar life histories. Molecular Ecology, 16(15): 3173-3187

Conceptually, there's no difference from terrestrial barcoding!