Download A New Approach to Measuring Marine Biodiversity

08 June, 2006
A New Approach to Measuring Marine Biodiversity
American scientists have recently applied a genetically-based method to identify and
catalogue marine biodiversity in its larval phase. The results suggest that marine
biodiversity may be underestimated in some parts of the world such as the Coral Triangle
in the Indo Pacific region and the Red Sea. In spite of certain limitations, this new
approach provides a mechanism to quantify the unknown marine biodiversity.
The rapid loss of marine and terrestrial species has promoted efforts to catalogue the biodiversity of the
globe within the next 25 years. Nevertheless, the magnitude of this work is not yet well known.
Documenting biodiversity in the vast and often inaccessible marine ecosystems presents a major
challenge. Traditionally, surveys of species diversity in the world's oceans have focused on adult
organisms.
American researchers have recently used a genetically-based method, called DNA barcoding, to
identify and catalogue marine biodiversity. This method, not traditionally used in aquatic ecosystems,
consists in using DNA sequence data to identify organisms of different species. The goal of barcoding
is to assign unknown individuals to species and enhance discovery of new species by using large scale
screening of one or a few reference genes. In spite of certain controversies regarding this method, DNA
barcoding is gaining acceptance among many in the scientific community. The current study, which
focuses on coral reef-dwelling mantis shrimp (stomatopods), is the first to compare larval stage
organisms to adults. Through DNA barcoding, scientists compared the DNA sequences of a random
sampling of stomatopod larvae to a sequence database of the most wel known mature species of
mantis shrimp. They applied this method in both the Coral Triangle (coral reef in the Indo-West Pacific)
and the Red Sea.
According to the authors, examining marine life in the larval stage offers a new and highly effective way
of estimating biodiversity, since most organisms have a developmental phase where minute larvae
disperse on ocean currents.
The comparisons revealed numerous new varieties of shrimp that are completely unknown in their adult
forms. In particular, the results showed that biodiversity in mantis shrimp in these regions is estimated
to be at least 50 to 150 percent higher than previously believed. Given that few groups of marine
organisms are as well studied as mantis shrimp, the biodiversity in other groups is likely to be even
more poorly known. These results suggest that biodiversity is greatly underestimated in the region of
the Pacific known as the "Coral Triangle" and in the Red Sea.
Nevertheless, the authors also argued that, although the DNA barcoding methodology was effective, its
overall success was restricted by the limitations of the reference DNA sequence database available,
thus highlighting the importance of more research.
Areas with particularly high rates of biodiversity are often targeted for conservation, and this new
method could therefore help to highlight potential regions for protection. Furthermore, it could be a
useful tool for documenting the species of the entire world, both in aquatic and terrestrial settings.
Source:. Paul Barber and Sarah L. Boyce (2006) "Estimating diversity of Indo-Pacific coral reef stomatopods through DNA barcoding of
stomatopod larvae", Proceedings of the Royal Society B: Biological Sciences, doi: 10.1098/rspb.2006.3540. Published online
Contact: [email protected]
Theme(s): Marine ecosystems
Opinions expressed in this News Alert do not necessarily reflect those of the European Commission
European Commission DG ENV
News Alert issue 25
June, 2006
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