School of Biological and Marine Sciences Seminar Series 2020/2021

Laboratory experiments on wave interaction with vegetated beds

Dr Dominic van der A, University of Aberdeen

Friday 7 May 2021, 11:00am via Zoom

Sea level rise and increased frequency and intensity of storms associated with climate change have led to an increased interest in the role of vegetation (e.g. sea grass meadows, salt marshes and mangroves) for protection against coastal erosion and flooding. Nature-based coastal protection, including the use of vegetation, offers the possibility of coastal solutions that adapt to climate change, while also providing other ecosystem services. However, predicting the performance of nature-based solutions is a challenge because of a lack of understanding of the fundamental processes at work as waves interact with vegetation.

In this seminar I will present an overview of some recent laboratory experiments conducted in the Fluid Mechanics Laboratory at the University of Aberdeen to study the interaction between waves and submerged vegetation canopies. The main approach in these experiments is to isolate the key hydrodynamic processes and obtain insights and data that can be used to develop models for use in coastal engineering practice.

The experiments were conducted in two different facilities: a 20m long random wave flume and an oscillatory flow tunnel - a unique research facility capable of generating wave-induced oscillatory flows with periods and amplitudes equivalent to large wave conditions in the field.

Insights from novel research organisms: from crustacean limbs to the beauty of butterflies

Professor Nipam Patel, Director, Marine Biological Laboratory, Woods Hole, USA, Professor, University of Chicago, USA

Friday 23 April 2021, 11:00am via Zoom

I will present two studies in which new research organisms have been used to gain insight into the mechanisms of development, and how development evolves to create novel body plans and coloration. 

In the first example, I will describe our comprehensive analysis of Hox gene expression in the amphipod crustacean, Parhyale hawaiensis, and more importantly, our results from using CRISPR/Cas9 gene editing to functionally address the role of Hox genes in crustacean development. 

I will then describe how this experimental data leads to some new views on the evolution of the arthropod body plan.

The emergence of light pollution as a threat to biodiversity 

Dr Thomas Davies, Lecturer in Marine Conservation, University of Plymouth

Friday 19 March 2021, 11:00am via Zoom

The last decade has seen a resurgent interest in the ecological impacts of one of man’s most conspicuous pollutants, night time lighting. Artificial Light at Night (ALAN) is a globally widespread and rapidly growing pollutant that alters natural regimes, spectra and intensities of light at night that have remained remarkably constant throughout evolutionary history. This is causing impacts on species in all biomes, across many phyla, and all levels of biological complexity. During this this seminar I will discuss the recent emergence of light pollution as a threat to biodiversity from the perspective of an early career research scientist immersed in the modern movement since its inception. The seminar will present the case for light pollution as a major challenge in 21st-century conservation for both terrestrial and marine ecosystems through my own experiments and experiences.

Introgression, hominin dispersal and megafaunal survival in Late Pleistocene Island Southeast Asia

Dr João Teixeira, Australian Centre for Ancient DNA, University of Adelaide

Friday 5 March 2021, 11:00am via Zoom

The hominin fossil record of Island Southeast Asia (ISEA) indicates that at least two endemic ‘super-archaic’ species – Homo luzonensis and H. floresiensis – were present around the time anatomically modern humans (AMH) arrived in the region >50,000 years ago.

Contemporary human populations carry signals consistent with interbreeding events with Denisovans in ISEA – a species that is thought to be more closely related to AMH than the super-archaic endemic ISEA hominins. To query this disparity between fossil and genetic evidence, we performed a comprehensive search for super-archaic introgression in >400 modern human genomes. Our results corroborate widespread Denisovan ancestry in ISEA populations but fail to detect any super-archaic admixture signals. By highlighting local megafaunal survival east of the Wallace Line as a potential signature of deep, pre-H. sapiens hominin-faunal interaction, we propose that this understudied region may hold the key to unlocking significant chapters in Denisovan prehistory.

Watch a recording of the seminar (available to University of Plymouth students and staff).

Ecology and conservation of neglected rock outcrop habitats in Western Ghats, India

Dr Aparna Watve, Red List Authority Coordinator, IUCN SSC Western Ghats Plants Specialist Group. MIT World Peace University, India

Friday 19 February 2021, 11:00am via Zoom

Terrestrial rocky habitats are globally threatened ecosystems whose biology is poorly understood. Because of their unique character, they make a significant contribution to the exceptional species richness found in the Western Ghats/Sri Lanka Biodiversity Hotspot. The ecology of the rocky outcrops and their associated cliffs in the Western Ghats had not received attention until recently. Historically mapped as ‘wastelands’ because of their barren appearance for much of the year they are dynamic systems that function as habitat islands. Isolated from each other by changes in elevation and contrasting habitats, they alternate between dry desiccated environments to seasonal wetlands. Seasonal climatic extremes provide competitive advantage to species with specific adaptations such as desiccation tolerance, carnivory and ephemeral nature. They function as terrestrial habitat islands influencing speciation and niche specificity in flora as well as fauna. So far approximately 200 endemic plants are reported from the habitats and new species have been described in diverse taxa. Field investigations have shown elevated levels of species richness (356) and endemism (19%) in plateau vegetation in which 58% of endemics are unique to plateaus. Endemism and plateau specificity is also seen in amphibians and reptiles. Prevalence of invasive flora is low and is limited to areas of heavy anthropogenic disturbance. Mining, infrastructure development including windfarms and hill cities and tourism are major threats to the habitat. In 2012, Rock Outcrop Network was established as a network of individuals and institutions dedicated to conservation of the threatened habitat. The network has encouraged ecological research and contributed towards development of conservation and management programmes of rock outcrop sites in the Western Ghats. Major contribution has been increased awareness of the habitat amongst regional administrators, policy makers and local communities. In future we hope to encourage research on key ecological processes and restoration efforts to conserve the unique habitat type.

Resolving the animal tree using multiple lines of evidence

Professor Davide Pisani, School of Biological & School of Earth Sciences, University of Bristol

Friday 5 February 2021, 11:00am via Zoom

Understanding relationships at the root of the animal tree is key to clarify animal evolution and the origin of modern marine ecosystems. Traditionally, sponges were considered the sister group to all the other animals and the last common ancestor of all animals was assumed to be a sponge-like organism. However, standard analyses of amino acid data failed to provide a consistent support for this hypothesis, frequently finding support for Ctenophora (comb jellies), as the sister group of all the other animals instead (the Ctenophora-sister hypothesis). I will summarise current evidence and recent advances bearing on the topic and discuss how they impact our understanding of early animal evolution. I will illustrate results from a diversity of analyses and data types from standard analyses of amino acid sequence data, to studies investigating the presence/absence of genes in genomes to morphological and paleontological results.

Ecological and evolutionary changes in plant-herbivore interactions in a warming world​

Dr James Buckley​, School of Biological and Marine Sciences, University of Plymouth​

Friday 18 December 2020, 11am via Zoom

Climate change is having wide-ranging impacts on the distribution of species, which is predicted to result in altered or novel interactions among species. However, we still know relatively little about the extent of such changes and the potential responses of species to these changing interactions. In this seminar, I will use two different plant-herbivore systems to explore ecological and evolutionary responses to ongoing climate change. First, I will examine the vulnerability of alpine plant populations to increased levels of feeding by insect herbivores, and then I will show that the rapid evolution of insect host plant preferences can facilitate successful responses to climate change. Together, these studies highlight the importance of accounting for species interactions when understanding responses of species to climate change. ​

Climate change, adaptation and evolution in marine and terrestrial environments

Professor James Crabbe, Wolfson College, Oxford University and University of Bedfordshire

Friday 4 December 2020, 11:00am via Zoom

The lecture will cover: aspects of climate change; coral reefs and why we should care about them; reefs in the Caribbean and in the Indo-Pacific; effects of environmental stress, adaptation and evolution in extreme environments; economic aspects; moving from science to conservation; modelling of geoengineering and solar radiation management; economic, industrial and political aspects of environmental pollution; and the latest Red Listing work on coral species for the IUCN.

Understanding species-fragmentation-area relationships using experimental intertidal landscapes

Dr Lynette H. L. Loke, Macquarie University, Sydney, Australia

Friday 20 November, 11am via Zoom

Habitat loss and fragmentation are key drivers of species extinctions and biodiversity declines. Species-area relationships (SARs) are commonly used as a tool to predict species loss and are conceptually uncontroversial. The effect of fragmentation per se (i.e. spatial configuration of habitat patches in a landscape) however, is less clear and is presently a subject of intense debate. There are many reasons for this, but part of the problem is due to a lack of experiments disentangling area and configurational effects. Most studies also tend to measure diversity only within habitat patches but not the surrounding matrix in a landscape. Using intertidal sea walls as a model system, I performed a series of field experiments; first to test the independent and interactive effects of habitat area and spatial configurations (fragmentation per se) on the diversity of intertidal communities, then to understand the underlying mechanisms that could give rise to the observed diversity patterns. In particular, using spatial and movement analyses, I examined how dispersal limitation could have given rise to greater diversity in fragmented configurations. Together, these findings inform the fragmentation debate and highlight the spatial nature of the problem. Additionally, I will discuss potential applications of my work to conservation and ecological engineering strategies and my take on how efforts in this field can be scaled-up

Metabolic niches and biodiversity: ​A test case in the deep sea benthos

Dr Craig McClain​, Executive Director, Louisiana Universities Marine Consortium

Friday 6 November 2020, 11am via Zoom

The great anthropogenic alterations occurring to carbon availability in the oceans necessitate an understanding of the energy requirements of species and how changes in energy availability may impact biodiversity. The deep-sea floor is characterized naturally by extremely low availability of chemical energy and is particularly vulnerable to changes in carbon flux from surface waters. Because the energetic requirements of organisms impact nearly every aspect of their ecology and evolution, we hypothesize that species are adapted to specific levels of carbon availability and occupy a particular metabolic niche. We test this hypothesis in deep-sea, benthic invertebrates specifically examining how energetic demand, axes of the metabolic niche, and geographic range size vary over gradients of chemical energy availability. We find that benthic invertebrates with higher energetic expenditures, and ecologies associated with high energy demand, are located in areas with higher chemical energy availability. In addition, we find that range size and location of deep-sea, benthic species is determined by geographic patterns in chemical energy availability. Our findings indicate that species may be adapted to specific energy regimes, and the metabolic niche can potentially link scales from individuals to ecosystems as well as adaptation to patterns in biogeography and biodiversity.​

Shedding Light on Snake Visual Evolution

Dr Bruno F. Simões, University of Plymouth​

Friday 16 October 2020, via Zoom

Much of the considerable knowledge of vertebrate vision and its evolution comes from detailed studies of mammals, birds and fish with comparatively few investigations of reptiles. In particular, until recently, there has been no modern, molecular genetic studies of vision in snakes. This is surprising considering that the diversity of snake retinal photoreceptor cell complements was summarized by visual anatomists as indicating greater evolutionary change than among all other vertebrates together, and that this exceptional retinal diversity had been incorporated in analyses of snake higher-level relationships. In addition, the eyes of snakes have played a part in debates about the origin and early evolution of the group. In this seminar I will present the results of new data on ocular media transmittance, visual pigment microspectrophotometry and genomic data across snakes in order to provide a fresh perspective on snake vision biology and evolution.

Impacts of changing coral reef ecology for reef growth and sediment supply: implications for enhanced modelling of tropical coastal vulnerability 

Professor Chris Perry, Geography, University of Exeter 

Friday 9 October 2020, 11am via Zoom

The ecology and structure of many tropical coral reefs have altered markedly over the past few decades. Drivers of this degradation range from direct damage from destructive human practices to the loss of ecological resilience because of harmful algal blooms resulting from the loss of herbivory and coastal eutrophication. Global scale climate stressors, and especially those associated with elevated sea‐surface temperature anomalies, have also extended the footprint of disturbance to even the most remote (from direct human influence) regions. A major consequence of these climatic and pervasive local stressors has often been a rapid decrease in the abundance of habitat building corals, which has consequently reduced reef structural complexity and coral carbonate production rates. Equally, many reefs have been impacted by changes (both increases and decreases) in the abundance of bioeroding taxa such as parrotfish, urchins, sponges and microendolithic organisms. The collective effect has been to alter the rates and relative balance of carbonate producing and eroding processes on many reefs. 

Such changes are of increasing interest because these processes directly regulate net rates of reef carbonate production and sediment generation, and collectively can impact upon multiple geo‐ecological functions on reefs. These functions include reef‐building and the capacity of reefs to accrete vertically in response to sea‐level rise, and the supply of sands necessary to sustain beaches and reef islands. This talk will discuss recent progress in developing methodologies to estimate rates of reef carbonate production, reef growth and sediment generation. It will then use selected recent field examples to highlight changes in these processes in response to ecological disturbance, and highlight the potential to integrate these data into increasing sophisticated numerical and lab-based modelling approaches than be used to predict coastal wave exposure under future sea level rise scenarios.