ECOMAR Students

Jessica Craig

PhD student

Bioluminescent fauna of the deep-sea

Oceanlab, University of Aberdeen

Supervisors: Prof Monty Priede & Dr Alan Jamieson

Bioluminescence is the only visually relevant source of light at depths greater than 1000m. Many deep sea invertebrates and fish have eyes in both the pelagic and benthic realms indicating the importance of bioluminescence to understanding the visual ecology of the deep-sea. Previous studies conducted in the Atlantic Ocean, using an ISIT (Intensified Silicon Intensifier Target) video camera, have shown high densities of bioluminescent animals in the water column in relation to seasonal and hydrographic conditions at various sites in the N Atlantic. Additionally, elevated levels of benthic bioluminescence have been captured on video in the NE Atlantic corresponding to the predation of ostracods by deepwater eels.

As part of the first year of my PhD studies a new camera system, ICDeep, has been developed by Oceanlab, marking an advance in in-situ bioluminescence imaging. The camera integrates I 2CCD (Image Intensified Charge Coupled Device) technology with a custom built computer system for device control and image capture. The capability of the ICDeep surpasses previous in-situ bioluminescence imaging technology in terms of sensitivity control and recording capacity.

During the 2009 and 2010 Ecomar cruises to the Mid-Atlantic ridge, observations of benthic bioluminescence are planned at different depths and latitudes to determine the prevalence, intensity, source and function of bioluminescent displays in relation to new hypotheses on the causes of zonation of fauna in the deep sea.

In addition to this, whale bones were deployed during the 2008 Ecomar cruise at two sites NW of the CGFZ. The ICDeep will be mounted on the ISIS ROV to investigate bioluminescent activity in the vicinity of these whalebones, to test hypotheses of the presence of bioluminescence at whale fall sites.

Pelagic bioluminescence will also be studied during a transect across the CGFZ to assess the distribution of bioluminescent zooplankton in the water column in relation to the sub-polar front. Measurements of pelagic bioluminescence are taken by mounting the ICDeep profiler system on a CTD carousel. This summer I have been employing this technique to measure the density of bioluminescent animals in the vicinity of two proposed neutrino telescope sites in the Ionian Sea. These bioluminescence data, along with previously collected data, will be also be used to describe the density of deep sea bioluminescence fauna in relation to surface productivity, from the West to the East Mediterranean Sea.

Figure 1 Preparing to deploy the ICDeep for pelagic bioluminescence measurements in the Ionian Sea, September 2008.

Claudia Alt

PhD student

Benthic megafauna of the Mid-Atlantic Ridge

National Oceanography Centre, Southampton

Supervisors: Dr Alan Hughes

I started my PhD in October 2008 with the Deepseas group at NOC, Southampton, to examine the ecology and biodiversity of the benthic megafauna on the Mid Atlantic Ridge. This will help us understand the ecological significance of the ridge for the fauna. The communities are likely to be structured by a combination of food inputs, the ridge topography, and water currents. In particular the megafauna present at the different sites are likely to reflect variations in organic matter inputs, which may be reflected in the species composition, biomass, abundance, and diversity. Studying the benthic assemblages at the ridge will improve our understanding of faunal adaptation and feeding types. Further, the ridge habitats can be compared to the continental margins, but without terrestrial influences. Benthic communities in the deep sea play a key role in carbon cycling, which is a subject of high relevance to global climate change. The deep-sea fauna is in general very diverse, but only little is known about its ecological functions. Therefore, it is crucial to understand these systems.

Currently I am analyzing the still photographs that were taken during the 5 SHRIMP deployments on JC011 in 2007 in order to obtain data on the benthic megafauna at 3 of the sites. Based on the photographs I will be able to get information on faunal abundances, as well as information on species living in different ridge habitats. This will give a good account of the overall species found in the region. In addition to the still photographs, videos were taken by 3 different cameras that were positioned at different angles on SHRIMP. The information from these videos will complement the still photographs and will give me a good indication of heterogeneity in the area investigated

Following the photographic analyses the specimens recovered in the trawls will be further analyzed. I will quantify the species, as well as obtaining measurements of body size, weight etc. This data will provide important background information which will aid our sampling strategies when we return to the ECOMAR sites in 2009.


Picture taken with the SHRIMP still Camera at ~ 2500m depth, in this picture there are a couple of sponges and a coral attached to rocky substrate.

Tom Letessier

PhD student

Pelagic fauna of the Mid-Atlantic Ridge

Pelagic Ecology Research Group, University of St Andrews

Supervisors: Prof Andrew Brierley

My name is Tom Letessier, I am 25 years old and I work at the Gatty marine Lab in St Andrews. I am a PhD student, and my work in ECOMAR involves looking at zooplankton, and how the MAR affects them. Zooplankton are the various animals (often small) that are carried around by currents.

Since our last James Cook cruise in 2007, I have been busy analysing the samples caught with the mid-water trawl. The work has been very rewarding; I was able to participate in a workshop in May, collaborating with MAR-ECO scientist Tone Falkenhaug and Gregory Vinogradov. In June I did a short trip to Aberdeen, where I worked at Fisheries Research Services. Steve Hays and Jens Rasmussen kindly let me borrow their zooscan, a machine that allows me to scan, and with the right software, quickly identify many zooplankton samples. I hope to use this technology on our next cruises!

Since then I have been digging into some of the previous work that has been done on the MAR, particularly looking at long-term surveys done by the Continuous Plankton Recorder, a machine that is used to collect plankton in the North Atlantic since 1931. The result is a huge data set, and, with this and other available environmental variables (collected from satellites) I have been able to look at the global impact of the MAR on euphausiids distribution and abundance. Our preliminary results indicate that the MAR seem to reduce biodiversity of zooplankton, although the reasons for this are not quite clear yet…

Figure 1 showing mean sea surface temperature, and our cell grid, which we populated with various bits of information.

Figure 2 . Long-term surveys done with the CPR, which we used to populate our boxes with zooplankton abundance data.

William Reid

PhD student

Benthic food web studies on the Mid-Atlantic Ridge

Dove Marine Laboratory, University of Newcastle

Supervisors: Dr Ben Wigham & Prof Nick Polunin

In June, a successful application to the NERC Life Sciences Mass Spectrometry Steering Committee awarded 12 days ‘Grant in kind’ to use the mass spectrometry facilities at the Scottish Universities Environmental Research Centre (SUERC), East Kilbride. The proposal, entitled “Deep sea macro-consumer food web structure of the Mid-Atlantic Ridge under varying primary productivity regimes”, outlined the aims presented at the ECOMAR planning meeting in January 2008 to:

  1. compare food web structure of the eastern axis of the MAR under areas of high and low surface productivity,
  2. identify sources of energy,
  3. examine size specific changes in diet with size of deep sea fish.

Three hundred and thirty samples have been prepared over the summer ready for analysis between 27 th to 31 st October. The preparations are labour intensive, with the following procedure:

  1. freeze dry sample to remove water,
  2. grind sample to homogenous fine powder using a mortar and pestle,
  3. remove lipids to uniformly low levels,
  4. acidify samples to remove inorganic carbonates.

The aim will be to calculate a series of community wide metrics using δ 13C and δ 15N values, which will enable aspects of the food webs north and south of the Charlie Gibb Fracture Zone to be compared on a quantitative basis. It is hypothesised that there will be differences in the length of the food chain (range of δ 15N), niche diversification at the base of the food chain (range of δ 13C), niche width of species (variability of δ 13C and δ 15N) and niche space (total area of δ 13C - δ 15N in bi-plot space) between sites north and south of the Charlie Gibb Fracture Zone. Regional variations in the relationship between size and δ 15N will also be investigated in the following deep sea species of fish- Antimora rostrata, Coryphaenoides armatus and Coryphaenoides brevibarbis.

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