5th ISDSC, Amsterdam

Well, Amsterdam is certainly a unique city and was the recent host of the International Deep-sea Coral Symposium 2012. This was the 5th conference and the 3rd that I’ve been to since I started working on cold-water corals. Whilst not as distant as Florida (3rd ISDSC) or New Zealand (4th ISDSC), there was an enthusiasm to the conference which was organised by our friends Furu Mienis and Tjeerd van Weering. We were located slap-bang in central Amsterdam at the Artis Zoo conference centre, which has a magnificent butterfly house, on par with Anglesey’s Pilli Pallas but without the meerkats!

Myself and our newest PhD student Craig went along, luckily I had been asked to present a keynote on our recent predictive modelling work which saved me from having to think of something to present! We stayed at a hotel on Prinze Hendricks, which I do not recommend but will not name… Those of you who heard me complain about it will understand, over priced and horrid… But, was a place to bed down after a long day of networking and conferencing.

All in all, an absolutely fantastic conference, in great surroundings with great friends. For those of you who are interested, you can download a PDF copy of my presentation

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Davies Presentation 5th ISDSC Amsterdam 2012

Citation

Davies, A.J. (2012) “Locating vulnerable marine ecosystems in the greatest wilderness on earth” Keynote presentation at the 5th International Symposium for Deep-sea Corals, Amsterdam, 1st-6th April.

 Abstract

Predictive habitat models are increasingly being used by conservationists, researchers and governmental bodies to identify vulnerable ecosystems (VMEs) and species’ distributions in areas that have not been sampled. Despite improvements in model algorithms, environmental data and species presences, there are still significant limitations in the reliability of this technique, especially in the deep sea. Recent studies have begun to address a key limitation, the quality of data, by using multibeam echosounder surveys and species data from video surveys to acquire high resolution data. Whilst these data are often amongst the very best that can be acquired in the deep ocean, the surveys are highly localised, often targeted towards known VME-containing areas, are very expensive and time consuming. Whilst these local surveys are useful for site-specific management, they are less useful for identifying areas not yet sampled or for influencing regional or basin-scale management. It is impossible to survey whole regions (although Ireland has mapped their entire EEZ) or ocean basins using these techniques, so alternative approaches are required. Predictive modelling in data poor areas is difficult, limited heavily by the quality of data. There is no doubt that the adoption of predictive modelling is increasing amongst researchers who work in areas that are poorly studied. But, there are still significant improvements that need to be made to increase the reliability and thus adoption of this technique.

Classifying rasters in ArcMap 8-10

Gerard Duineveld, Rachel Jeffreys, Marc Lavaleye, Andrew Davies, Magda Bergman, Thalia Watmough, Rob Witbaard

The finding of a previously undescribed cold-water coral reef (Banana Reef) in the Scottish Mingulay reef complex, with denser coverage of living Lophelia pertusa than the principal Mingulay 1 Reef, was the incentive for a comparative study of the food supply to the 2 reefs. Suspended particulate matter (SPM) samples from the surface and bottom water covering a tidal cycle were compared with respect to lipids, pigments, and δ13C and δ15N. Lipid profiles and stable isotope signatures of SPM were compared with those of coral tissue samples. Concurrently, hydrographic measurements were conducted to track the movement of the water masses across both reefs. Between-reef differences in SPM lipid concentrations were small compared to those in coral tissue. Corals at Banana Reef had lower lipid concentrations, pointing to less favourable food conditions than at Mingulay 1. Stable isotopes signatures and lipid profiles showed that corals on both reefs feed primarily on surface algal matter, within the timeframe of our study. At Mingulay 1, fresh microalgae are supplied to the coral reef by local downwelling. This downwelling pulse is tidally advected to Banana Reef. Food conditions observed during this study at both reefs do not explain the between-reef difference in coral coverage. A speculative explanation for the denser coral coverage at the deeper Banana Reef encompasses the slightly lower temperature that exhibits lower metabolic stress on corals, in combination with a higher current speed and particle encounter rate.

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Full citation

Duineveld GCA, Jeffreys RM, Lavaleye MSS, Davies AJ, Bergman MJN, Watmough T & Witbaard R (2012) Spatial and tidal variation in food supply to shallow cold-water coral reefs of the Mingulay Reef complex (Outer Hebrides, Scotland). Marine Ecology Progress Series 444: 97-115.

 DOI

doi:10.3354/meps09430

The functioning of canyons on the US East Coast.

3 year PhD studentship at the School of Ocean Sciences, Bangor University with Dr Andrew J Davies.

Project description:

This is an exciting opportunity to join an international team of researchers investigating the functioning of deep-sea canyons on the US East Coast. This studentship is part of a larger project funded by BOEMRE (now the Bureau of Energy Management), incorporating elements of archaeology, physics, geology and biology. The successful candidate will be based in Menai Bridge, but will be expected to conduct fieldwork on NOAA vessels off the coast of the USA in collaboration with Dr Steve Ross of the University of North Carolina at Wilmington and Dr Sandra Brooke of the Marine Conservation Institute. The candidate will also be expected to travel to the Netherlands Institute for Sea Research (NIOZ) on the Island of Texel to conduct data analysis and project preparation with Drs Furu Mienis and Gerard Duineveld.

Overall, the study will conduct a full ecosystem evaluation of deep-water hard bottom, coral and soft substrata communities, and shipwreck sites off Virginia and Maryland within and adjacent to submarine canyons. The project essentially has three main components, 1) initially the student will be expected to develop habitat suitability models of the canyons based on archived and current data, but will develop these further as we collate more information of the canyons. 2) Investigate the physical setting and transport of sediment and organic material through the canyons using deep-sea lander technology developed by the NIOZ. 3) Devise observations and experiments to determine distributional drivers of sessile fauna within the physical context of the canyon.

The successful candidate:

This is a 3 year funded position, the successful candidate will be expected to hold an upper second class honours degree and a master’s degree in relevant science, preferentially with training in marine ecology. The project is available as soon as possible, so preference will be given to candidates who can start in January or February 2012. The successful candidate will be expected to travel to the US to conduct research, and as such must hold a valid passport and a full clean driving license. To apply please send a CV and a comprehensive covering letter, outlining your plans and your reasons for wanting to complete this project. The application deadline is the 13^th January 2012.

Informal enquiries and submission of an application should be made to:

Dr Andrew Davies at andrew.j.davies @ bangor.ac.uk.

The Nancy Foster was our base in the GoM

Near-bed hydrodynamic conditions were recorded for almost one year in the Viosca Knoll area (lease block 826), one of the most well-developed cold-water coral habitats in the Gulf of Mexico. Here, a reef-like cold-water coral ecosystem, dominated by the coral Lophelia pertusa, resembles coral habitats found off the southeastern US coast and the North East Atlantic. Two landers were deployed in the vicinity and outside of the coral habitat and measured multiple near-bed parameters, including temperature, salinity, current speed and direction and optical and acoustic backscatter. Additionally, the lander deployed closest to the coral area was equipped with a sediment trap that collected settling particles over the period of deployment at 27 day intervals. Long-term monitoring showed, that in general, environmental parameters, such as temperature (6.5–11.6 °C), salinity (34.95–35.4) and current speed (average 8 cm s⁻¹, peak current speed up to 38 cm s⁻¹) largely resembled conditions previously recorded within North East Atlantic coral habitats. Major differences between site VK 826 and coral areas in the NE Atlantic were the much higher particle load, and the origin of the particulate matter. Several significant events occurred during the deployment period beginning with an increase in current speed followed by a gradual increase in temperature and salinity, followed by a rapid decrease in temperature and salinity. Simultaneously with the decrease in temperature and salinity, the direction of the current changed from west to east and cold and less turbid water was transported upslope. The most prominent event occurred in July, when a westward flow lasted over 21 days. These events are consistent with bottom boundary layer dynamics influenced by friction (bottom Ekman layer). The Mississippi River discharges large quantities of sediment and dominates sedimentation regimes in the area. Furthermore, the Mississippi River disperses large amounts of terrestrial organic matter and nutrients, resulting in increased primary productivity, whereby marine organic matter is produced that will sink to the seafloor and can serve as food for the cold-water corals and associated species. As a result mass fluxes from the sediment trap were higher (1120–4479 mg m⁻² day⁻¹) than those observed in the North East Atlantic and were highest during periods of westward-flow, which corresponded to warm turbid water. During eastward-flow, colder and less turbid water was pushed upslope, resulting in lower mass fluxes. Trap samples had a low CaCO₃, high organic carbon content and high C/N ratios, suggesting a fluvial origin. The high sediment load in the water column can be a limiting factor for coral growth, especially since the corals can be smothered with sediment. However, eastward-flows provided periods of relatively clearer water that can remove sediment from the coral area and allow corals to expel sediment from their polyps. Around Viosca Knoll food supply comes from two possible sources. During April and June several fluorescence peaks were observed near the seabed, showing the arrival of phytodetritus in the area. Furthermore, a consistent diel vertical migration of zooplankton was observed that might provide an additional food source.

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Full citation

F. Mienis, G.C.A. Duineveld, A.J. Davies, S.W. Ross, H. Seim, J. Bane & T.C.E. van Weering (2012) “The influence of near-bed hydrodynamic conditions on cold-water corals in the Viosca Knoll area, Gulf of Mexico” Deep-sea Research vol 1 60(1): 32-45.

 DOI

doi:10.1016/j.dsr.2011.10.007

What a machine!

http://www.youtube.com/watch?v=wbgkMHDGCMI

Check out the video:

http://www.youtube.com/watch?v=9kICtEBJ3kk

The Hexa was bought to support an ongoing project of mine, essentially, it will be used as an aerial photography platform to monitor sites around the coast of North Wales, building on work that I did during my PhD. The Hexa will in fact support one of my PhD students who starts her project in September 2011. We will first develop a database of existing aerial photography of the Welsh coastline going back as far as we can (hopefully to the 1940′s). We will then revisit these sites at the present day with the Hexa, taking up to date imagery. We’re going to look at changing human utilisation of the coast and the dynamics of seaweed and biogenic reefs.

The Hexa was acquired from mikrocontroller.com and is the basic set. Notable additions are:

• MK GPS
• MK3 mag
• Bluetooth connectivity to PC
• LiPo holder
• 6 LiPos 6600 mah
• Ultramat 14 Plus charger
• MK HiSight II SE camera mount.

The video below shows the first test of the system. I had to wire a LED to the buzzer to visualise the beeping error codes and status updates so it took a while to get that far. It is a worthwhile addition and the LED is simply soldered to the positive and negative terminals of the buzzer.

http://www.youtube.com/watch?v=WLXp6EmQK_Q

The first test flight should be next week…

The framework-forming coral Lophelia pertusa

Andrew J. Davies and John Guinotte

Cold-water corals are found in all the oceans of the world. Usually below 200 metres, they create structurally complex habitat that gives rise to a unique deep-sea ecosystem in, what otherwise may be a relatively featureless area. Numerous other filter-feeding organisms are found, along with fish that may use the coral as a nursery ground. Yet, we don’t know where many occurrences of cold-water coral are….

This is where habitat suitability modelling comes in. By using the best available scientific information and powerful statistical tools, we are able to predict, based on the species environmental requirements where they are likely to occur. Mine and John’s work, published in PLoS ONE is an important step towards turning habitat suitability modelling into a viable tool for the protection of vulnerable marine ecosystems in the deep sea. This paper represents several years of work, designing and constructing new approaches to allow us to model coral distributions at high resolution. The outputs speak for themselves, with a 1 km resolution, we may finally be able to say to other researchers, go here, you have a good chance of finding coral in this area. Or, we may be able to say, there is a high probability of coral occurrence here, perhaps we could designate this area closed to bottom contact fishing or other exploitation.

Read the abstract below, or download the PDF from either my site or the PLoS ONE site.

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Full citation

Davies AJ, Guinotte JM (2011) Global Habitat Suitability for Framework-Forming Cold-Water Corals. PLoS ONE 6(4): e18483. doi:10.1371/journal.pone.0018483

Abstract

Predictive habitat models are increasingly being used by conservationists, researchers and governmental bodies to identify vulnerable ecosystems and species’ distributions in areas that have not been sampled. However, in the deep sea, several limitations have restricted the widespread utilisation of this approach. These range from issues with the accuracy of species presences, the lack of reliable absence data and the limited spatial resolution of environmental factors known or thought to control deep-sea species’ distributions. To address these problems, global habitat suitability models have been generated for five species of framework-forming scleractinian corals by taking the best available data and using a novel approach to generate high resolution maps of seafloor conditions. High-resolution global bathymetry was used to resample gridded data from sources such as World Ocean Atlas to produce continuous 30-arc second (~1 km²) global grids for environmental, chemical and physical data of the world’s oceans. The increased area and resolution of the environmental variables resulted in a greater number of coral presence records being incorporated into habitat models and higher accuracy of model predictions. The most important factors in determining cold-water coral habitat suitability were depth, temperature, aragonite saturation state and salinity. Model outputs indicated the majority of suitable coral habitat is likely to occur on the continental shelves and slopes of the Atlantic, South Pacific and Indian Oceans. The North Pacific has very little suitable scleractinian coral habitat. Numerous small scale features (i.e., seamounts), which have not been sampled or identified as having a high probability of supporting cold-water coral habitat were identified in all ocean basins. Field validation of newly identified areas is needed to determine the accuracy of model results, assess the utility of modelling efforts to identify vulnerable marine ecosystems for inclusion in future marine protected areas and reduce coral bycatch by commercial fisheries.

Trade-offs in macroalgal chemical defences: Battle of the sexes, invaders and consumers.

Figure 1: A. Sargassum muticum, B. Ascophyllum nodosum

Chemical defences consisting of secondary metabolites are found in some macroalgae with their primary function appearing to be as an anti-grazing deterrent (Ragan & Glombitza 1986). This project will investigate the role that phlorotannins play in the ecology of two canopy forming macroalgae, Ascophyllum nodosum and Sargassum muticum. Ascophyllum is a striking example of an important foundation species commonly found on sheltered shores throughout the North Atlantic. In contrast, Sargassum is a Japanese macroalgae that is a highly successful invader of the UK’s rocky shores, it was first observed in the UK on the Isle of Wight in 1973 and has spread rapidly throughout the coastline, reaching Northern Ireland in 1995, south-west Wales in 1997 and Loch Ryan in Scotland in 2004 (Boaden 1995, Eno et al. 1997, Farnham et al. 1973).

Ascophyllum canopies can have a high biomass and influences biodiversity by providing a stable canopy that facilitates understory algae (Jenkins et al. 1999). This species is relatively long lived, with estimated holdfast ages exceeding 50 years (Åberg 1992) and is considered to be well protected from grazers by the secondary metabolite, phlorotannin with typical  concentrations of ca. 5 % of dry weight (Pavia et al. 2003). However, Sargassum has rapid annual growth and comparatively, has lower phlorotannin concentrations of ca. 1-2% (Plouguerné et al. 2006), but has been found to be as high as 8% in certain sites at the height of its reproductive cycle (C. Fendell, MSc).

This proposed project is split into three main themes across several chapters; sexual and reproduction, invasion, and grazers and aims to answer some interesting questions about the ecology of these species.

Chapters 1 and 2, Sexual reproduction and defence: Phlorotannins are energetically costly to produce, so another process must suffer if an individual alga is to develop more in response to an external stressor, but what is sacrificed first, reproduction or growth? To investigate how phlorotannins concentrations are related to sexual reproduction two experimental approaches will be used, firstly, choice/no choice grazing experiments will be used to determine native grazer preference between sexes of Ascophyllum. Secondly, experimental caging in the field will be used to determine if grazer exclusion leads to increased fecundity in Ascophyllum and Sargassum.

Chapter 3, Growth and defence: Previous authors have found higher phlorotannin concentrations in adults of Ascophyllum than in juveniles (Pavia et al. 2003), indicating that juveniles may divert energy to growth as opposed to defence. Sargassum is an exceptionally fast growing alga, it has small perennial section, but the large fronds are annual and appear during spring and summer before breaking up in autumn. Growth will be measured in a range of different sites to determine if patterns similar to those observed in Ascophyllum are present in Sargassum.

Chapters 4, 5 and 6, Grazer palatability and the balance of native/non-native communities: One overlooked area of research for Sargassum is the interaction of this species with native grazer communities on temperate rocky shores. Last year, we found that Sargassum generally has low levels of phlorotannin but under certain circumstances can rapidly produce much greater amounts. If Sargassum is able to produce phlorotannin rapidly, it may be more resistant to grazing pressure than native algae. To determine this, choice/no choice grazing experiments will be conducted with multiple grazers in the laboratory and in the field. Several long-term exclusion and inclusion experiments will be established in the field to determine the temporal interaction of grazers, growth and phlorotannins. Finally, a broad-scale survey throughout the UK coastline will be conducted to determine geographical variability in phlorotannin  concentrations for Sargassum and Ascophyllum.

Training: This project will utilise biochemical analyses and experimentation. The student will be taught how to determine phlorotannin concentration, experimental design, field surveys and analysis. Long-term experiments will be established on local shores, and broad-scale survey extending the British coastline will be undertaken to assess the importance of phlorotannins for native and non-native species.

Application procedure

Applications are invited from suitably qualified students for several NERC Quota award PhD studentships in the School of Ocean Sciences.  You are eligible to apply if you have or expect to receive a 2.1 degree or higher, you are a UK citizen and you have always lived in the UK.  If you have a 2.2 degree, but have also obtained a masters qualification, you are also eligible (see www.nerc.ac.uk/funding/available/postgrad/eligibility.asp).

Interested candidates should send a CV, with the names and addresses of two referees who can comment on their ability and a covering letter, to Andrew Davies (andrew.j.davies @ bangor.ac.uk) by the closing date 31^st March 2011.  Candidates should ensure they are eligible to apply for NERC studentship by visiting the NERC web pages.  One candidate for each PhD will be selected by the supervisor and a further short list of candidates compiled.  Candidates will then be invited for interview in late April or early May.   Following an offer of a PhD, successful students will be invited to complete a Bangor University PhD application form. Applicants should NOT complete a Bangor University PhD application form until asked.

The PhD description can be downloaded here: Trade-offs PhD (163).