METABARPARK at the XIX Iberian Marine Biology Symposium

From 5th to 9th September the XIX Iberian Marine Biology Symposium was held in Porto (Portugal). It was organized by the CIIMAR - Interdisciplinary Centre of Marine and Environmental Research -, and gathered together ca. 180 scientists from Spain, Portugal, and some latin-american countries.

The webpage of the symposium is available http://siebmxixciimar.wixsite.com/business-conferenc-1

The Iberian meetings have been organized since 1978, and are an excellent opportunity for researchers in the Iberian zone to meet, exchange ideas, and present ongoing projects and results.

Three members of Metabarpark (Owen Wangensteen, Creu Palacín, and Xavier Turon) attended the meeting. They presented the oral contribution "Wangensteen, Guardiola, Palacín, Turon: Molecular biodiversity assessment of marine hard-bottom communities from Spanish National Parks by metabarcoding of COI and 18S" where a summary of the main findings of the Metabarpark project was given. The presentation raised a lot of interest among the audience, as shown in the questions posed after the talk and the many interactions that followed during the meeting.

Xavier Turon also presented a plenary conference, entitled "Twenty-five years of genetic studies of the Iberian benthos: retrospect and prospect". Needless to say, metabarcoding was among the main techniques highlighted during this talk.

The nice logo of the XIX SIEBM

We had a good and fun time in Porto, we made interesting contacts for future metabarcoding studies. We are looking forward to the next Iberian Meeting, to be held in Faro in 2018!

Metabarcoding reveals significant differences in communities with and without invasive seaweeds

While the data corresponding to the 2015 collecting trips are being analysed, we would like to share the first results concerning the communities sampled with and without invasive algae. In the Cíes Island, we compared the photophilous community with Cystoseira nodicaulis (natural assemblage) with equivalent communities with the introduced Asparagopsis armata. In Cabrera, we sampled in the same walls photophilous natural assemblages as well as communities dominated by Lophocladia lallemandii, while at deeper waters we sampled the natural sciaphilous community and Caulerpa cylindracea-dominated patches.

We identified with the gene 18S 2937 MOTUs in these communities. Our statistical analyses showed clear qualitative and quantitative differences between assemblages with and without the invasive seaweeds. While this was expected for the bigger size fractions, even for the smallest fraction (i.e., organisms between 1 mm and 65 microns) the differences were significant. This rich component of the biodiversity cannot be efficiently assessed with conventional methods, while genetic techniques have allowed its quantification and analysis.

Thus, metabarcoding revealed community shifts affecting even the small-sized meio-organisms (animals, algae, and protists) at very reduced spatial scales (tens of meters). The presence of invasive algae has therefore profound effects in community structure at all levels. This is one of the several interesting outcomes we are finding with our data, more soon!

This spatial representation (Multidimensional Scaling) allows the visualization of the differences between the sampled communities linked to the presence of invasive seaweeds

The methods developed in METABARPARK explained in an international book chapter

Owen Wangensteen and Xavier Turon have been invited to write a chapter in the book "Marine Animal Forests. The Ecology of Benthic Biodiversity Hotspots", of the Springer International Publishing Company (ISBN: 978-3-319-17001-5), which is edited by Sergio Rossi, Lorenzo Bramanti, Andrea Gori and Covadonga Orejas.

In this chapter, entitled "Metabardoding techniques for assessing biodiversity of marine animal forests", Owen and Xavier explain the methods developed in METABARPARK to work with hard bottom communities using metabarcoding. We believe that it is crucial to setup standardized protocols, and that this book can be an excellent platform to share and disseminate our experience with the different steps of the metabarcoding process. 

This chapter has been sent out for editorial process, and we foresee that it will be published in the forthcoming months.

Techniques developed in METABARPARK, such as the size fractionation of the samples, can be adopted by other teams working on metabarcoding of marine benthos

METABARPARK at the workshop “Application of genomic tools for benthic monitoring”

The 4-5 April 2016, the Natural History Museum of Geneva (Switzerland) hosted the workshop “application of genomic tools for benthic monitoring of marine environment: from technology to legal and socio-economic aspects”, organised by Prof. Jan Pawlowski of the University of Geneva (http://goo.gl/forms/V9bLHtyJBk).

The workshop was intended as a forum for the exchange of ideas about the potential of environmental DNA (eDNA)-related techniques for assessing biodiversity and the impact of human activities on it. It was attended by environmental professionals, members of regulating bodies, and scientists.

The presentations and discussion were very lively, and the overarching idea is that DNA-derived indicators may be effectively used in the field of environmental monitoring (as they are in other applied sciences). However, more development and standardization is necessary before they can be integrated with- or substitute altogether- current techniques using morphology-based indicators, which are slow, time-consuming, and reliant on a worlwide dwindling taxonomic expertise.

Xavier Turon and Owen Wangensteen contributed to the workshop with the talk “Issues in metabarcoding of marine benthos”, where they pinpointed some conflicting issues, such as the use of DNA vs RNA, the choice between 18S rDNA or COI markers, or the use of a fixed vs a variable threshold for clustering sequences into MOTUs. The talk was illustrated with results obtained in the project METABARPARK.

Xavier Turon and Tom Wilding, of the Scottish Association for Marine Science, at the entrance of the Natural History Museum, with a lovely pet!

Working with the data

We processed the samples, extracted the DNA and amplified the barcoding genes for the second sampling (2015) performed at each site. We received the sequences in November (for the COI gene) and December (for the 18S gene). So we have now all genetic data of the samplings done in 2014 and 2015 in Cíes Islands and the Cabrera Archipelago.

In the last months we have been busy working with the bioinformatic analyses of such a huge amount of data. We had to adapt and improve existing pipelines, write code ourselves, and check different approaches at each step of the process.

Now we are drafting our first manuscript for publication with the results of the first samplings with biodiversity assessment and community comparisons within and between the Parks. We have also assembled a large dataset with all sequences obtained in 2014 and 2015 that is currently being analysed to assess temporal changes in the community structure in both Parks. We hope to come up with interesting results soon!

Master Thesis with Metabarpark results

In November, 2015, Manuel Orobitg, student of the Master of Oceanography and Management of the Marine Environment at the University of Barcelona, presented his MSc Thesis “Morphology vs metabarcoding. A comparison of techniques for biodiversity assessment in Maërl beds”, supervised by Xavier Turon, Creu Palacin and Owen Wangensteen.

Image of the sampling of the Maërl community in Islas Cíes

In this study, Manuel analysed morphologically samples collected at the same time as the ones for the genetic studies in the detritic bottoms of Islas Cies and Cabrera Archipelago. He focused his analyses on three major groups: polychaetes, arthropods, and molluscs. He identified at the lowest level possible, with the help of taxonomists (a big thanks goes to Daniel Martin and Lídia Delgado), the species present in the 10 and 1 mm filtrates, and obtained biomass values by weight. The morphological analyses found 77, 45, and 44 morphospecies of polychaetes, crustaceans, and molluscs, respectively, while the genetic technique yielded 182, 245, and 70 MOTUs, respectively, for the same size fractions. Thus, metabarcoding allowed the determination of a higher diversity, but the taxonomic precision attained was higher with morphology. On the other hand, all structural parameters (biomass dominance curves, alpha- and beta-diversity patterns) were markedly different between the metabarcoding and the morphology datasets, indicating that both methods capture different aspects of the biodiversity structure present. The morphological datasets tended to be quantitatively dominated by a few species, while metabarcoding detected a more even distribution of biomass of the dominant MOTUs.

Assortment of arthropods from the 1 mm fraction

Project Metabarpark in IRBio Seminars

Project Metabarpark will be present in the talk session hosted by IRBio (Institute for Research in Biodiversity) at the School of Biology of the University of Barcelona, this Thursday 26th of November.

Xavier Turon will talk about "Biodiversity crisis and the taxonomic impediment: what the metabarcoding of communities has to offer" and Owen Wangensteen will follow with a talk about "Metabarcoding of marine hard-bottom communities, the unseen biodiversity".

The entrance is free and you are all invited!