Adrian Glover,  Deep-Sea Systematics and Ecology Group, Department of Life Sciences

Wednesday 28 January 11:00

Sir Neil Chalmers seminar room, Darwin Centre LG16 (below Attenborough studio)

The deep oceans contain a vast and untapped wealth of minerals useful to humans. In geological terms, there is much known with regard the distribution of these minerals at different types of deep-sea environment. The first polymetallic (or manganese) nodules were recovered by the Challenger expedition in 1873, in the deep Atlantic. In the 1960s, the first estimates were made of the total mineral wealth of the oceans, and the first surveys undertaken. In 1978, the first fully integrated mining trials recovered several hundred tonnes of nodules from the central abyssal Pacific at depths of 5500m; in the preceding year, hydrothermal vents were discovered on the Galapagos rift. Since then, an average of 5 hydrothermal vent fields have been discovered every year, and 19 exploration licences for deep-sea minerals in both abyssal nodule and deep-sea vent environments have been issued by the United Naitons International Seabed Authority, 5 of these in 2014 alone. The United Kingdom government is sponsor to 2 exploration licence claims in the central Pacifc covering 267,000 square km, an area larger thant the UK itself.

Despite our accumulated knowledge of the mineral wealth of deep-sea ecosystems, our biological data remains extremely patchy. The central Pacific nodule regions have been well-sampled for nodules, but the majority of species are undescribed and fundamental questions such as the biogeographic distributions of animals unstudied. The diversity and ecological resilience of species to disturbance regimes are largely untested. At hydrothermal vents, critical data such as degrees of endemicity and gene-flow between vent fields is lacking.

The NHM is in a unique position to provide advice to industry and government, as well as academic research, in deep-sea mining from both the geological and environmental point of view. This has potential to be a key area in our Sustainable Futures strategy. In my research group, we have been working with an industrial contractor on the UK-1 deep-sea mining claim in the central Pacific for the last 18 months and are part of an EU FP7 deep-sea mining project. In this talk I will outline some of the history of deep-sea mining, the fundamental science at stake, our role in current projects, the importance of taxonomy, open data and bioinformatics and some of our plans for our forthcoming fieldwork (we sail for a 2-month trip on Feb 12).

More information on attending seminars at http://www.nhm.ac.uk/research-curation/news-events/seminars/

Chris Yesson

Department of Life Sciences, NHM

Friday 13 June 11:00

Earth Sciences (Mineralogy) Seminar Room, Basement, WEB 05

Chris Yesson will be talking about his two concurrent research projects.  On first sight it may seem that examining the distribution of coastal seaweeds of the UK may not have much overlap with a study assessing the impact of trawling on benthic habitats on the continental shelf of west Greenland, but commonalities in approaches to spatial and imaging analysis means there is more overlap that just one researcher jumping between topics.

More information on attending seminars at http://www.nhm.ac.uk/research-curation/news-events/seminars/

Ana Cristina Furtado Rebelo – University of the Azores, Department of Biology

NHM Earth Sciences Seminar Room (Basement, WEB 05, formerly Mineralogy Seminar Room)

20th May - 4.00 pm

Rhodoliths are the response of Coralline algae to unstable substrates; their calcified structures preserve well and may, after death, be incorporated into sediments, providing insights into geological processes. Despite being widely distributed, studies on the distribution and ecology of extant and fossil rhodoliths are few and, as a consequence, rhodoliths are still poorly understood.

The ongoing research in the Azores will provide more insight on why those islands are so different from others in Macaronesia with respect to rhodolith deposits in the geological record and the general lack of coastal rhodolith deposits today.

The comparison of type material in the Botany and Palaeobotany collections of the NHM with material from the Azores collection is expected to yield information on the Azorean rhodolith taxonomy identification, and will provide a model for palaeobiogeographic distribution. Such task needs the knowledge of the most advanced curatorial techniques and a profound taxonomic understanding of this specific algae group.

More information on attending seminars at http://www.nhm.ac.uk/research-curation/news-events/seminars/

Tom Richards from the Museum's Life Science department is an author on a paper in Nature that explores the genome of one of the most abundant species of planktonic plant - the coccolithophore Emiliania huxleyi.  Coccolithophores occur in great numbers in the ocean: the chalk cliffs at Dover are made up of the remains of their calcium carbonate skeletons.

The World's oceans are tremendously complex.  Currents move over thousands of kilometres, some descending as they are cooled by weather systems, or mixing at the surface with fresh waters, sediments and nutrients from continental rivers.  Life is immensely diverse, ranging from corals to the deep-sea vent faunas.  The highest biomass of life is in the shallow seas near to land, but the open ocean contains a constantly shifting system of tiny planktonic organisms ranging from bacteria to single-celled plants to grazing zooplankton and their predators. 

These planktonic ecosystems change with currents, seasons, nutrient availability and predation. Their growth, population explosions, deaths and decline interact with the planet's cycling of carbon and other nutrients.  These interactions are important in understanding ocean productivity and climate: there are links to carbon dioxide fluctuation, for example, as the plants absorb it during growth and release some at death.  Despite the tiny size of the organisms, their huge numbers over two-thirds of the planet's surface means that their role in planetary systems is very significant.

E. huxleyi experiences huge population explosions in the open ocean - planktonic blooms. Some species of phytoplankton bloom under very particular conditions of temperature and nutrient availability, but E. huxleyi thrives in a wide range of conditions, occuring from the warm waters of the equator to polar regions.

Emiliania huxleyi, showing the distinctive calcium carbonate plates that cover its exterior. 

These may have important protective and light-reflecting qualities for the organism.

The paper finds that E. huxleyi strains from different areas share a core genome - this gives them a robust abilty to resist the inhibiting and damaging effects of intense sunlight, together with genes that allow effective growth in low phosphorus conditions.  There are genetic differences between the strains that lead to distinct abilities to thrive in different nitrogen, ammonia and metal conditions.  It seems that this, and other characteristics, give E. huxleyi the ability to bloom in very different oceanic environments - it is described as a species complex because of its genetic diversity.

This work will enable scientists to understand better the responses and influences of this very widespread species, and to investigate the complex processes and systems of the ocean that determine productivity and influence climate change.

Read, B.A. et al. (2013) Pan genome of the phytoplankton Emiliania underpins its global distribution. Nature doi:10.1038/nature12221

Friday 24 of May 11:00
Sir Neil Chalmers seminar room, Darwin Centre LG16 (below Attenborough studio)

Octocorals of the family Xeniidae in Red Sea and beyond

Yehuda Benayahu - Department of Zoology, Tel Aviv University, Ramat Aviv, Tel Aviv,  Israel

Octocorals are common throughout the Indo-Pacific reefs and play an important role in the ecology of the ecosystem, yet they remain dramatically understudied. The seminar will deal with octocorals of the family Xeniidae, a highly abundant component of Indo-Pacific coral reefs, particularly in the Red Sea. Aspects concerning their life history and acquisition of symbiotic algae (zooxanthellae) at early ontogenetic stages will be addressed. Opportunistic Xeniidae are taking over degraded reefs but taxonomic difficulties force researchers to recognize them as a group whichprecludes detailed understanding of the reef environment and processes on impacted reefs by genera or even species. Our ongoing project deals with phylogeny of the family including provision of species identifications based on their morphological characters. Recent findings reveal that novel microstructural features of their sclerites might be critically important in resolving taxonomic difficulties. Such a study requires introduction of high resolution scanning electron microscopy at magnifications never used before by octocoral taxonomists. Insights on microstructural features of xeniid sclerites also enabled us to examine the effect of ocean acidification on these octocorals and understand the possible function of their living tissue in protection against deteriorating effects of acidic conditions.  It is anticipated that studies on xeniids will facilitate future surveys aimed at the maintenance and greater understanding of coral reef diversity and reef-environment function and sustainability.

For additional details on attending this or other seminars see http://www.nhm.ac.uk/research-curation/seminars-events/index.html

Friday 17 May 11:00

Sir Neil Chalmers seminar room, Darwin Centre LG16 (below Attenborough studio)

The Energetic Niche of Species: Lessons from the Deep Sea

Craig R. McClain, Assistant Director of Science, National Evolutionary Synthesis Center

Life requires energy. Biological organization—the culmination of life in all its forms—is determined largely by the flow and transformation of energy. Three distinct types of energy affect biological systems: solar radiation (in the form of photons), thermal kinetic energy (as indexed by temperature), and chemical potential energy stored in reduced carbon compounds (i.e. food). 

I contend and will discuss that much like organisms possess thermal niches so do they possess chemical energetic niches (CEN). Evidence from both local and oceanic scale studies of beta-diversity, i.e. species turnover, suggests unique suites of species inhabit different regimes of carbon availability.  The evolution of body size and life history strategies in molluscs appear to be linked to productivity gradients and may have promoted diversification in this group.  Thus, changes in ocean productivity as a result of climate change may greatly impact biodiversity by modifying available niche space for ocean species.

For additional details on attending this or other seminars see http://www.nhm.ac.uk/research-curation/seminars-events/index.html

Bryozoans are widespread aquatic colonial animals living both in the sea (sea mats) and fresh waters, with an extensive marine fossil record over almost 500 million years. Collaborating research groups in the NHM Departments of Zoology and Palaeontology represent arguably the strongest concentration of bryozoan research expertise anywhere in the world.

Wilbertopora woodwardi (Brydone) from the Upper Cretaceous Chalk, Hampshire

Andrea Waeschenbach (NERC Postdoctoral Fellow, Zoology), Paul Taylor (Palaeontology) and Tim Littlewood (Zoology) have had accepted for publication the most comprehensive molecular phylogeny of bryozoans to date, using mitochondrial and ribosomal genes.

This has resulted in a well supported topology (the shape of the phylogenetic tree), providing unambiguous evidence for the interrelationship of the taxonomic classes.  It also provides strong evidence that several presently recognized taxonomic units at various hierarchical levels are each in fact of more than one origin in evolutionary terms - they are non-monophyletic (a monophyletic group has a single ancestor)

Using this topology, the work tried to establish the likely larval form and strategy of the ancestral bryozoans, but this gave ambiguous results.  It seems most likely that multiple shifts have occurred between different types of larval nutrition – dependency on yolk provided to the egg (lecithotrophy) and feeding by the bryozoan larva on phytoplankton (planktotrophy).

This result, combined with their long fossil record, promises bryozoans to be a suitable phylum to studying links between reproductive strategy and large scale evolutionary patterns, such as speciation rates. This paper is a significant contribution for assessing the interrelationships in a relatively neglected group that offers much promise as an evolutionary model. This work was funded by NERC (NE/E015298/1).

Waeschenbach, A., Taylor, P.D., Littlewood, D.T.J. (2011) A molecular phylogeny of bryozoans, Molecular Phylogenetics and Evolution. http://dx.doi.org/10.1016/j.ympev.2011.11.011

How do new species form?  One key process is by genetic divergence following geographical isolation – allopatric speciation.  This can happen when different populations of a single species are separated, cease to have contact over time and no longer interbreed.  This separation, divergence and formation of new species will often be attributed to changes in genetic makeup as a result of adaptation to different environments or ecosystems, or simply to accumulated genetic changes - genetic drift.

When it's difficult for individuals from the population to cross geographical barriers, it's possible to explain how isolation of populations occurs, and therefore why speciation has happened. An example would be the different but related species found on islands separated from the mainland, where a few individuals managed to cross the water barrier and form a new population that eventually became a distinct new species.  Charles Darwin collected specimens of mockingbirds on the Galapagos, for example, that are related to mainland species but which have diverged from the parent population to become a separate species, living in a new and different environment.

In the sea, however, many animals have pelagic larvae – free-floating planktonic forms - that can be carried for many hundreds of kilometres in currents, even though the adults have limited mobility on the sea bed.  This pelagic mobility means that closely related species from different places are potentially connected over distances of 1,000 km or more, so it is unclear how allopatric speciation is achieved – the populations appear to be capable of connection in geographical terms.

Zoology PhD student Martine Claremont, together with her Museum supervisors Drs Suzanne Williams and David Reid, and university supervisor Professor Tim Barraclough, sampled populations of the intertidal muricid gastropod genus Stramonita (a marine snail) throughout the Atlantic Ocean and used statistical analysis of DNA sequences to identify the number of distinct species, their distributions and relationships.

For species in which the larvae spend only a short time in the plankton, it is possible for populations to be clearly isolated geographically by currents, island chains or other factors such as the immense flow of fresh water flowing from the mouth of the Amazon. However, Stramonita spends 2-3 months as a planktonic larval form, theoretically permitting genetic contact across the entire ocean basin, which might lead to expectations that a single population would be found around the Atlantic. 

Stramonita brasiliensis, the new species described in the work (E, Plymouth, Tobago, BMNH acc. no. 2341; F, holotype, Sao Paulo, Brazil, BMNH 20100324)

However, Martine and her supervisors found five distinct species in the Atlantic (one of which is described as new).  They suggest that this speciation might be attributed in part to past changes or interruptions in ocean currents, preventing free circulation and isolating populations for sufficient time to enable speciation.  Other factors that seem to be of importance are the ancient separation of the Caribbean and Gulf of Mexico and the development of ecological specialization.

Claremont, M., Williams, S.T., Barraclough, T.G., Reid, D.G. (2011) The geographic scale of speciation in a marine snail with high dispersal potential. Journal of Biogeography, 38: 1016–1032.