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Ecology
The marine realm of possibility
Dr Claude Payri is coordinating a project to determine the origins and mechanisms behind
macroalgae proliferations in tropical and subtropical coastal ecosystems. We spoke with her and
her collaborators about their ongoing quest to uncover the what, how and where of marine species
Can you explain why the proliferation
of macroalgae has previously been
poorly studied?
CP: Macroalgae mostly live on the hard
substratum of coastal marine ecosystems, from
the surface down to a depth of 150 m. Therefore,
access to marine benthic populations is more
difficult than access to terrestrial communities
or oceanic plankton. Studying macroalgal
proliferations requires specific methods and
techniques of investigation that aren’t easy to
routinely use.
Dr Aschwin Engelen: Also, the scientific
community of phycologists is currently very
small worldwide and proliferating species
are just one tiny subset of the total seaweed
species of interest.
Dr Frederique Viard: There is a lack of existing
data which makes it difficult to establish
baselines for further study. Furthermore, the
fact that the general public and policy makers
have a poor perception of the issue leads to a
lack of interest in addressing it. However, this
problem isn’t specific to macroalgal studies
– almost all marine species (except marine
mammals or corals) suffer through a lack
of interest.
Dr Olivier Thomas: Because this is a highly
complex area of study, in terms of the number
of species and interactions, it’s difficult to find
an interdisciplinary team working on the same
group of organisms.
What drew the group to study Asparagopsis
taxiformis and Asparagopsis armata?
Dr Thierry Perez: It’s more a question of
who – Claude Payri! She was facing the
proliferation of an Asparagopsis on the outer
slope of the New Caledonian coral reef and
needed complementary skills to implement an
interdisciplinary research project. I duly obliged.
CP: People in New Caledonia pinpointed blooms
of Asparagopsis and recorded the impacts
on coral reefs. As the genus was known to
be one of the worst invasive species, we
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INTERNATIONAL INNOVATION
needed to establish its status (native versus
introduced), then characterise the proliferations
to determine whether impacts on cnidarians
building coral reefs could be found.
Is the approach you adopted
particularly unique?
CP: Our approach combined various disciplines,
including metabolomics, phylogeny and
molecular taxonomy implemented at different
biological scales. We applied this at different
geographical scales: seven different local
regions and globally.
AE: Knowledge of the marine realm is
rudimentary, especially in seaweeds; combining
16S amplicon sequencing and metagenomics on
seaweed ecology, proliferation and competition
is rare, particularly on the scale covered by the
Seaprolif project.
Could you briefly introduce the ERA-NET
NETBIOME programme and describe its
relationship to Seaprolif?
ALL: The EU Sixth Framework Programme
(FP6)-funded project is a consortium of 11
partners linking bodies related to the overseas
entities from five European member states.
The aim is to initiate and stimulate cooperation
and coordination of research programmes for
the sustainable and integrated management of
biodiversity. Specifically, in a way that addresses
the needs of the threatened ecosystems of
the European outmost regions and overseas
countries and territories.
Calls for transnational research projects are
one of the main goals of the ERA-NETs, as
a mechanism for validating the cooperative
effort between the various funding agencies.
Ultimately, this has led to the funding of several
research projects on biodiversity management
in support of sustainable development in
Europe’s tropical and subtropical outermost
regions and overseas countries and territories.
In November 2010, NETBIOME called for
proposals for transnational and transregional
research entitled ‘Towards Biodiversity
Management in support of Sustainable
Development in Tropical and Subtropical
EU’. This resulted in 80 manifestations of
interest and 35 project applications. Following
evaluations, seven projects were selected for
funding, one of which was Seaprolif.
What inspires you in your day-to-day work?
CP: As a phycologist, I am inspired by the
biodiversity of the marine flora associated with
coral reef, the question of species’ boundaries
and biogeographical distribution. In other words
– how many species, where are they and where
do they come from?
AE: Previous studies have suggested that
microbiomes might be maintained during
invasion or proliferation and form an important
part of the adaptive and stress-resistant
potential of the seaweed host. Therefore,
investigating the microbiomes of these
species is of great interest. Asparagopsis is
known to produce halogenated compounds
with strong antimicrobial activities, so it’s
extremely interesting to investigate what
kind of bacteria are associated with these
seaweeds, their function and if they are
involved in the production/ decomposition of
these compounds.
TP: I am driven to better understand
the mechanisms behind all biotic
interactions in the seas: prey-predator,
host-pathogen, competition for space and
resource relationships.
FV: My inspiration lies in the fact that the
project supports previous findings of mine
regarding the high level of unknown
biodiversity in the marine realm, including
in supposedly well-known habitats like
coastal marine habitats. It inspires
me daily to still question myself on
what a species or a population is,
and what processes (natural
or human-mediated
drivers) are responsible
for the patterns
observed in nature.
To the bottom of coastal ecosystems
The ERA-NET NETBIOME programme enabled the establishment of Seaprolif – an interdisciplinary
project involving six French and two Portuguese research teams. The project focuses on two red
seaweed species and their circumglobal proliferation
Biological diversity helps keep
ecosystems in a natural balance. The
permanent interactions between the
components of an ecosystem are more resilient
and adaptable to external stresses when
diversity is higher. Additionally, the potentially
damaging impacts to humans are notable. For
example, the wider the variety of species, the
better the scope for increasing available food
services. This is particularly important given the
expanding global population.
Alarmingly, the proliferation of macroalgae in
coastal ecosystems worldwide is perceived as
a possible serious threat to the biodiversity
of such ecosystems. The damaging effects
of macroalgae proliferation are among their
most alarming in coral reefs, where coral
and algal competition can modify the balance
and functioning of that particular ecosystem
in danger.
Expanding understanding
Until recently, studies on the origins and
mechanisms of these proliferations have been
relatively scarce for two main reasons. First,
the taxonomy of macroalgae is often highly
challenging and specialists of this domain –
phycologists – are rare, but these basic data
are a prerequisite for further studies of their
impact. Second, poor perception of the problem
from a public and policy maker point of view
reveals a need for scientists to adequately
address this issue and provide the public with
simple and clear communications.
Enter researchers from France and Portugal
who have established a vast network that has
afforded the opportunity to collect samples from
a great number of regions. This has enabled the
team to highlight the diversity of macroalgae
and unearth new discoveries concerning
new lineages and new cryptic species. The
International Union for Conservation of
Nature has identified the genus Asparagopsis
(Rhodophyta) as one of the 100 worst invasive
species in subtropical and temperate areas,
prompting the team to focus on Asparagopsis
taxiformis and Asparagopsis armata.
Controlling proliferation
The Seaprolif project coordinated by Dr Claude
Payri started in February 2012 and concluded
in August 2015. Thanks to the scope of the
consortium, the geographical areas studied are
spread around five regions belonging to four
French overseas countries and territories: New
Caledonia and French Polynesia for
the Pacific basin, La Réunion in the
Western Indian Ocean, Guadeloupe
in the French Antilles, as well as the
Portuguese outermost regions Azores
and Madeira in the Atlantic Ocean. In
addition, surveys were conducted and
observations made in the Mediterranean Sea
and Atlantic Portugal coast. The team aimed to
fulfil three specific objectives. First, to establish
the status of the algal proliferation and
monitor the interactions between Asparagopsis
individuals and native species like cnidarians,
mostly hard tropical corals and temperate
corals (a phylum of over 10,000 marine species),
across three oceans. Second, to identify
Asparagopsis lineages and populations using
three combined approaches: a phylogeography
analysis to determine whether clades
(organisms with a common ancestor) had been
introduced or were native; the relevance of
metabolomics fingerprinting to differentiate
between taxa and clades; and the assessment
of the microbial communities associated with
Asparagopsis samples using next-generation
sequencing technology.
www.internationalinnovation.com
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Seaprofil
OBJECTIVE
To shed light on the origin and mechanisms of
macroalgae proliferation.
KEY COLLABORATORS
Dr Claude Payri; Ms Sylvie Fiat, Institute of Research
for Development, UMR ENTROPIE, New Caledonia
• Dr Mehdi Adjeroud, Institute of Research for
Development, UMR ENTROPIE, Perpignan, France
• Dr Mayalen Zubia-arreta, UFP, UMR EIO, French
Polynesia • Monsieur Jean-Pascal Quod, ARVAM, La
Réunion • Dr Claude Bouchon; Dr Yolande Bouchon,
Université des Antilles, Guadeloupe • Dr Frédérique
Viard, CNRS, Station Biologique Roscoff, France •
Dr Thierry Perez, CNRS, IMBE, Marseille, France •
Dr Olivier Thomas, UNS, Nice, France • Dr Aschwin
Engelen, CCMAR, Faro, Portugal • Dr Joao Monteiro;
Ms Paola Paretti, IMAR, Horta, Azores
PhD students: Dr Laury Dijoux, IRD, UMR ENTROPIE,
New Caledonia (co-supervised by Payri and Viard)
• Stéphane Greff, IMBE, Marseille, France (cosupervised by Perez and Thomas)
PARTNERS
Institut de Recherche pour le Développement,
New Caledonia • Centre National de Recherche
Scientifique, Roscoff, France • Centre National de
Recherche Scientifique, IMBE, Marseille, France •
Université Nice Sophia Antipolis, France • Agence
Pour la Recherche et la Valorisation Marine (ARVAM),
La Réunion • Université des Antilles, UMR BOREA,
Guadeloupe • Center of Marine Sciences (CCMAR),
Portugal • Instituto do Mar (IMAR), Azores
FUNDING
EU Sixth Framework Programme (FP6) • French
National Research Agency (ANR) • Agence de
Développement de la Calédonie (ADECAL) • Fundação
para a Ciência e a Tecnologia (FCT) • Région Réunion
•Région Guadeloupe • Pôle Mer Méditerranée
CONTACT
Dr Claude Payri
Project Coordinator
Institute of Research for Development
UMR ENTROPIE
101, Promenade Roger Laroque
BP A5
98848 Noumea
New Caledonia
T +687 26 07 50
E [email protected]
http://bit.ly/agencenationalerecherche
@UMREntropie
DR CLAUDE PAYRI works as
research Director at the Institute
of Research for Development
(IRD) in Noumea, New Caledonia.
Her research is focused on the
biodiversity of marine flora associated to coral reef
ecosystems, particularly integrative taxonomy and
biogeography at the Indo-pacific scale. Within the
Seaprolif project she contributes to the sampling and
investigates the taxonomy, phylogeny and ecology
aspects of Asparagopsis.
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INTERNATIONAL INNOVATION
The third and final objective was to test the
proliferation of Asparagopsis – both in situ and
in aquaria – and the ecological harm it may
inflict upon cnidarians. More specifically, the
researchers examined the natural toxicity
of algal species on the health of coral.
Ultimately, in achieving these three objectives,
the team was able to fill knowledge gaps
to provide a better understanding of the
mechanisms behind algal proliferation –
essential when determining effective means
of controlling and managing the abundance
of Asparagopsis.
New clades, new species
Over the course of the project, the team made
several important discoveries. A new cryptic
species was found in the ‘species’ A. armata,
demonstrating that there are actually two
different species under this name. Importantly,
the researchers ascertained that while this
could not be recognised morphologically,
it could be seen using molecular, DNAbased tools.
The researchers also unearthed several key
findings regarding the native or introduced
status of each species in each location. “We
discovered a new lineage of A. taxiformis that
was restricted to the South Pacific, including
New Caledonia and French Polynesia,” explains
Payri. The introduced origin of other A.
taxiformis lineages was confirmed in both the
Mediterranean and Atlantic.
Further findings included the discovery of a
new clade in A. taxiformis which, so far, has
been found to be endemic from a single region
surrounding New Caledonia, New Zealand and
one part of Australia. Interestingly, the team
has determined that this clade is unlikely to
have been transported by human activities and
probably evolved in the South Pacific.
Asparagopsis
Although Asparagopsis is widely known for its
antimicrobial properties, it turns out to harbour
a rich associated bacterial community that
shows distinguished differentiation among
higher taxonomic levels of the host, but that is
also strongly dependent on the environment
in which the Asparagopsis host occurs.
Metabolomics analyses highlighted a high and
untapped chemical diversity. The researchers
isolated and properly characterised two
new brominated compounds with original
antibacterial, antifungal, and cytotoxic
activities. The comparative analyses of a proxy
of the algae bioactivity showed that temperate
individuals are overall more toxic than tropical
ones. However, all ecological assessment,
performed both in natural conditions and in
aquaria, did not allow the team to demonstrate
a negative effect on native corals.
Spread the news
The team is now embarking on a mission
to disseminate its findings to the scientific
community and general public. The goal is to
foster further research and inform policies
designed to protect tropical and subtropical
coastal ecosystems around the world, eg.
as part of the French coral reef initiative –
IFRECOR – action plan. Ironically, one of the
papers they have published acknowledges
how little is known about marine biodiversity
for, although the group’s endeavours have
gone some way to filling in knowledge gaps,
spaces remain. Meanwhile, citizens have
been encouraged to report any incidences of
Asparagopsis species proliferation they have
noticed, especially divers and marine parks
managers. In these ways, the Seaprolif team
hopes to cement the foundations for better
understanding and monitoring of marine
biodiversity and its interconnectivity in relation
to climate change consequences.