Tuesday, August 10, 2010

A huge thanks to ROPOS and their crew

To finish off the blog, on our last day, after our last dive we thought we’d write a little about one of the aspects that made this research cruise so special - ROPOS and their crew. ROPOS which is short for the Remotely Operated Platform for Ocean Science is an extraordinary, highly technical underwater vehicle that comes with an incredibly talented group of guys able to operate and maintain it. Their job is most certainly the envy of many, as since 1996 the ROPOS has visited and recorded high-definition imagery of 21 major mid-ocean and black-arc ridges, 31 major ecological and biological surveys and 95 gas hydrate subduction zone dives!! The ROPOS crew (along with their satellite radio blasting anything from Marilyn Manson to Celine Dion) were fantastic to work with. Not only because ROPOS and it’s supporting equipment is state of the art (including 15 computers and 23 computer and TV monitors packed into one small room), but the crew are true professionals with amazing technical skills that are only enhanced by their adaptability, brains, sense of humour and general can-do attitude.
This is the crew’s fifth week offshore, a longer trip in comparison to their average deployments. Some of the crew have been around since the dawn of ROPOS, in 1986, although the ROPOS has since been significantly upgraded with it’s most recent re-fit completed in 2005.
When these guys are not at sea, Keith Tamburri (assistant manager, electrical & robotics technologist), Ray Morgan (imaging and navigation guru), and Reuben Mills (mechanical technologist) work back at their shop in Victoria, BC with their colleagues who also go to sea, but didn’t on this trip (Keith Shepherd, Ian Murdock, Roger Adamson, Jonathan Lee, Andy Fines, Jason Williams and Yvonne Baier). Another crew member with us, Vincent Auger, goes back to Halifax, Nova Scotia where he’s recently moved and works remotely as a navigation, IT and programming specialist. Last, but certainly not least, were Dan Cormany (Oregon) and Steve Bucklew (California) who only work offshore.
We would like to thank them for all their hard work, dedication and enthusiasm, and for providing us with a window to the deep sea!

We made Dalhousie University News


Extraordinary diversity of life

Today may just top all days at sea here onboard the Hudson. That’s a bold statement to make considering all we have been fortunate to see thus far. But today…the marine life was incredible, and the surprises just kept coming. The site is in the Northeast Channel and is just inside the Coral Conservation Area. As the ROPOS entered the water and began to prepare for descent, a pod of Common dolphins journeyed over to check out the ROV, and our now familiar pod of pilot whales turned up at the same time to swim along side the ship, while rafts of Greater shearwaters (and even a Sooty shearwater!) were sitting at the surface. It certainly seemed to be a productive spot! To top it all off there was deep-fried ice cream at lunch.
As ROPOS descended into the deep blue we encountered a school of squid – and one hungry swordfish! As the swordfish came into the lights of ROPOS and approached a squid we collectively held our breath and then cheered as it swam closer to the camera, proceeded to slap the squid with its large sharp bill (to stun it perhaps?), and then bolted in to gulp it down. It felt surreal to see it in front of our eyes. You could feel the excited energy in the room. The school of squid stayed with us for awhile, taking advantage of the shadow of the ROV. A school of squid is spectacular – their chromatophores shimmer in the light, and they appear both graceful and powerful as they propel through the water.
Eventually we reached bottom at around 1,500 m and found the seafloor to be mud covered and flat, with some depressions. The site had a great diversity of fish including the odd looking batfish, cutthroat eels, grenadiers, and many still to be identified! We also encountered an octopus sitting on the bottom.
Mudcoring is going well and the CTD group took their last water samples today for analysis. It is hard to believe the trip is winding down and we’ll be back in Halifax on Wednesday morning. First though- bbq on the back deck tonight. J

Monday, August 9, 2010

The Deep Sea!

During the last few days we have been exploring the deepest depths of our Hudson cruise. ROPOS descended to nearly 3,000 m in the Northeast Fan on Sunday and to 2,500 m on Monday. At these deep depths life (and the ROPOS!) are subject to 300x the pressure experienced at the surface of the Earth, and the temperature is around 4C. The ROPOS team expertly collected rocks and sea urchin specimens for later analyses, carried out a video transect, did a plankton tow, a multibeam survey, and collected mud core samples. The multicorer was also used to collect mud samples at depth, and several CTD casts were carried out.

So what lives at those depths? We saw long stretches of mud with an abundance of brittlestars; bright yellow and purple sea cucumbers; large sea urchins; stalked crinoids, fish called grenadiers, bright red shrimp, and a silvery chimaera that looked like something out of the imagination of Dr.Seuss. The mud had evidence of bioturbation and was often covered in tracks of epifauna (such as brittlestars and sea cucumbers). Boulders were few, but when we did come across them they were commonly covered in dense epifaunal communities - the basketstars were particularly stunning - like a large flower at the bottom of the sea.

We could also see a continuous shower of large concentrations of 'marine snow' in the water column - marine snow is a term for the organic detritus (i.e. dead plankton, diatoms, sand, fecal matter, sand) falling from the productive sunlit surface layer (upper 200 m) down to the depths where light is absent (and so photosynthesis can not occur). As such, deep sea organisms are dependent upon this fall of marine snow as an energy source.

Loggerhead Sea Turtle

We were all excited to come across a loggerhead sea turtle yesterday afternoon. The loggerhead has a wide distribution in the Atlantic, Pacific and Indian oceans, and the Mediterranean Sea. Loggerheads spend most of their life in the open ocean and shallow coastal waters and rarely come to shore except when females deposit their eggs. Adult loggerheads weight up to 300 lb and only reach sexual maturity between the ages of 17-33. They can life up to 67 years, but unfortunately loggerheads are considered endangered as there are many threats to their habitat, either to their eggs onshore, being trapped in fishing gear offshore or because they eat plastic from garbage released into the sea.

Student Profile: Lina Stolze

I am a Ph.D. student in the Earth Science Department at Memorial University of Newfoundland (MUN). Before I started with my Ph.D. thesis at MUN, I studied “Marine Environmental Sciences” at the Institute for Chemistry and Biology of Marine Environment (ICBM), Carl von Ossietzky University of Oldenburg (Germany).
My work within the CHONe (Canadian Healthy Oceans Network) project aims to identify key geological and geochemical factors that significantly influence bioturbation processes in marine benthic environments. Therefore, I am characterizing bioturbation processes at three sampling sites with contrasting climates and bathymetries (Canadian Arctic Archipelago, Labrador Fjords, and Gulf of Maine) as indicator for biological activities. Bioturbation rates and biological mixing depth will be determined by describing the sedimentary fabric and the mixing of tracers (radioisotopes: 210Pb, 137Cs, 228Th and 234Th and chlorophyll-a) within the sediment column. Also, geological and geochemical benthic characteristics, in particular sedimentation rate, organic matter content (TOC), and organic matter source will be analyzed. Correlations among environmental factors and bioturbation processes identified in this study may be useful to predict and interpret effects of natural and anthropogenic environmental alterations on the biological activity of benthic habitats and, thus, may be beneficial for establishing guidelines regarding conservation and sustainable use of marine biodiversity resources.
Being part of CHONe also gives me the great opportunity to collaborate with CHONe students from different universities in Canada, and to see fascinating country sites of Canada by taking part in research cruises to the Arctic, the Labrador Fjords and the Gulf of Maine.
On board the CCGS Hudson I am part of the MUD team that is working with the multicorer in order to collect sediment cores from the sea bottom. For the purposes of my work, I slice some of the obtained cores into centimeter sections and subsample others by using plexi glass trays that will be X-ray imaged back at MUN.

Sunday, August 8, 2010

Pilot Whale Baby Photos

Here are some photos of the pilot whale babies being helped to the surface by their parents.

Saturday, August 7, 2010

Pilot Whales

We've been fortunate to have pilot whales showing up daily for most of our trip. We've been able to see (and Conor has been able to photograph) much of their surface behaviour, including spyhopping, playing in the waves, and even caring for their young when the parents cradle the really young calves on occasion to bring them up out of the water.

A beautiful sunset on the Hudson

Friday, August 6, 2010

Research Profile: Dr. Paul Snelgrove

I am a Professor at Memorial University of Newfoundland's Ocean Sciences Centre and Biology Department, where I have been since 1996. I am also the Director of the NSERC Canadian Healthy Oceans Network, a research collaboration of 65 marine scientists from coast to coast in Canada that grew out of my active involvement in the international Census of Marine Life (www.coml.org). The Hudson cruise and the data we are collecting on this trip are a key component of that Network.
I completed his PhD at Woods Hole Oceanographic Institution/Massachusetts Institute of Technology following an MSc at McGill University and a BSc Hons. at Memorial. During my PhD I worked in deep-sea ecology using the submersibles Johnson SeaLink and Alvin. When I returned to Canada, opportunities for deep-sea research were few, but with the emergence of tools like ROPOS and the opportunities provided by CHONe, I have returned to the deep to ask what factors determine patterns of species diversity in deep-sea ecosystems and what is the importance of that diversity for the health of the oceans. Keep in mind that deep-sea sediments represent the largest habitat on Earth in area! During this cruise one of our major tools is a multicorer, a sampler we lower over the side to collect sediments and the diverse animals that live between the sediment grains. Because of the multiple objectives of this cruise, most of our work is during the night when the ROPOs team is getting some sleep – our goal is to make maximum use of the time we are on Hudson! We also use smaller cores, which ROPOS pushes into the sediment and then recovers so that we can sample very precisely near specific seafloor features that we cannot know are there when we sample blindly with the multicorer.

Science Staff Profile: Michelle Greenlaw

Even though having a the job title “marine geospatial biologist” would make it seem like I frequently experience trips to sea like the one I’m on now, this trip has been an extraordinary event during my first 2 years with the Department of Fisheries and Oceans. This is not my first time at sea, and not my first time on the CCGS Hudson, but having the ROPOS out here makes this trip special. With the ROPOS and their team we are collecting samples from deeper and with greater precision than with any equipment we would be able to access within DFO - and this is probably a once in a lifetime event for me. On the Hudson I am coordinating station planning, involved in data management and managing the blog. Station planning involves communicating with the science staff and the bridge then using GIS to plan locations for sampling in the upcoming hours and days.
Before working for DFO I earned my B. Sc. in Zoology at the University of Guelph in Ontario, then returned to the east coast and trained in GIS and Remote Sensing at the Centre of Geographic Sciences in Nova Scotia. I moved onto my M. Sc. in Applied Geomatics at Acadia University where I recently completed a thesis entitled "A Classification of Coastal Inlets of Mainland Nova Scotia, Using Geophysical Information to Define Ecological Representation and to Evaluate Existing and Proposed Protected Areas". This thesis
examined geophysical and hydrologic properties of coastal inlets on Nova Scotia’s exposed Atlantic shore; to create a classification of inlets (bays, estuaries and coves) designed to be representative of the biology that would reside there. This classification has been used for marine protected area planning in Nova Scotia.
In my current position at DFO I am involved in numerous projects including:

· An analysis of relationships between seabed species/assemblages and their physical environment in the Gulf of Maine

· Synthesis of the patterns, drivers and pressures on biodiversity in the coastal and benthic Gulf of Maine

  • The relationship between biodiversity and benthic complexity in southwest Bay of Fundy and implications for an ecosystem approach to management.

I am also very involved in the promotion, training and support of GIS within DFO, having taught two seminars on the use of GIS in science, one in graduate school and the other for DFO science staff.

Northeast Fan 2000 m

Our plan today was to dive at 2000 m on the Northeast Fan, however, the weather is putting a kink in our plans at the moment. Heavy winds and large sea swells are making it impossible to put the ROPOS in the water until things calm down slightly. Once we get in the water this should be an exciting dive for us, around 2000 m is where we start to see deep sea creatures that rarely are seen by people. Stay updated for photos, hopefully later today.

Thursday, August 5, 2010

More Northeast Channel Photos......

Northeast Channel

The Northeast Channel is a unique and extraordinary place in the Gulf of Maine. It is the largest and deepest entrance feature into the Gulf of Maine from the Atlantic Ocean. Here the seabed morphology becomes canyonized and the depth proceeds to get deeper, beginning at 400 meters to deepening to more than 1000 meters. This area has strong currents which makes it difficult to navigate the ROPOS on a straight path at times, but the imagery is worth it. A coral conservation area is located here - the area is home to large gorgonian corals, which grow very large and may topple over as a result of the strong currents. All these unique features provide stunning imagery during our ROPOS dives like those posed here.

Northeast Channel Larval Settlement Collectors

All the larval settlement arrays in the Northeast Channel were found successfully!! We began searching for one of three arrays on August second. The arrays had been placed in 2006 on the same cruise when the array in Jordan Basin was placed. As we did not find the array in Jordan Basin a couple days ago, we were nervous that all the Northeast Channel arrays would not be found either. But finally, success!! Not long after we touched the bottom on our first dive we located a marker we’d placed near the first array, then seconds later the array was in view. The array was covered in brittle stars and some anemones. The ROPOS crew then began the meticulous process of placing the array, with the ROPOS’s robotic arms (and with minimum disturbance) into a box on the ROPOS. The process of loading the array into the box took approximately 2 hours on the sea bottom.

Nightly Multicoring Team

So far, we have had really nice and exciting night shifts on the CCGS Hudson. The sea is pretty calm (and we hope it stays that way…), it is warm, the sky is cloudless, and the sunsets and sunrises are just amazing. By using a multicorer, we collect soft sediment samples (also called mud) for different analyses. Some of us focus on studying the geology and geochemistry of the sediment, others the biodiversity at different scales, while others are interested in the nutrient fluxes at the water-sediment interface and the oxygen consumption of the infaunal communities found in different environments.
In shallower waters (~ 200 m), we usually have to wait for about half an hour for the multicorer to reach the seafloor and to come back to the surface, while on other nights such as yesterday (or better said, this morning at 4am!), we had to wait almost two hours for the multicorer to come back from about 1500 m depth… a long wait for rare and priceless mud! However, waiting times are used with pre-labeling countless sample containers and preparing the lab for processing the sediment, eating lots of ice cream and discussing whether Cheese-Whizz is a real cheese or not.

Tuesday, August 3, 2010

Multibeam Surveys

Acoustic surveys using a high-resolution multibeam sonar system mounted on ROPOS are providing detailed data relating to the seafloor topography. The multibeam system is capable of resolving centimetre-resolution structure which can be used to map fine-scale geological and biological features. On-board processing of the multibeam data enables high-resolution (20cm resolution) digital elevation models (DEMs) of the seafloor to be produced immediately following data collection. This information can help plan and select sampling locations whilst at sea. Following the cruise, the multibeam data will be further processed for in-depth investigation into the geological characteristics of the study areas, and to examine biological-environmental interactions.

Researcher Profile: Sam Bentley

I am a marine sedimentologist, at Memorial University of Newfoundland. Marine sedimentology is the study of sediments on the seafloor, and more specifically I study mud (my kids once gave me a tee-shirt labelled with “Mud Cowboy”). Sediments deposited on the seafloor carry the environmental history of how those sediments were carried to their oceanic resting place, and also provide a home for organisms living on and in the seabed. So, from studying seafloor sediments we can learn both about the history of seafloor ecosystems and also about how geological processes, like sediment transport by currents for example, control the quality and extent of seafloor habitats. I think that mud is much more interesting to study than sand, gravel, or rock, because mud particles carry chemical clues to age and origin that one cannot find in sand or gravel. The work is fun, challenging, and very interesting, sort of like being an “ecosystem detective.” To study these habitats, we map the ocean floor with sonar, and sample the sediments. We can then analyze and age-date the sediments, allowing us to learn about relative physical stability or change in the habitat. On this cruise, we are mapping the seabed using a very sophisticated sonar system mounted on ROPOS, giving us highly detailed 3-D maps of the seabed. We are also collecting rock samples (on hard seabed, using the manipulators of ROPOS) and mud core samples (on soft seabed, using either ROPOS or a device called a multicorer, lowered from the ship). Analysis of these maps and samples will help us about geological and physical processes that occur on the seabed, and influence the organisms that live there.

Science Staff Profile: Chelsie Archibald

While aboard CCGS Hudson, I wake up around 530am when the sun starts streaming in my porthole, and every evening I watch the sun colour the sky pink and orange and then sink into the sea. In between those two stunning events, I spend my day helping out with the survey, looking out to sea, enjoying a few too many of the home-baked goods, and enjoying my time with the fantastic people aboard the ship. You could say I’m in my element, and I feel very lucky to be here.
My main role on this cruise is to help with recording some of the information we gain from the ROPOS surveys – specifically recording information about each dive and using software to characterize the habitats and fauna encountered. ROPOS (Remotely Operated Platform for Ocean Science) and the amazing team that operates and maintains this ROV, provides us with a close-up view of the seafloor in the Gulf of Maine – a view you couldn’t imagine seeing not that long ago. Its such a thrill to see first-hand the incredible life and diversity of Atlantic Canada’s deep sea – the beautiful sponge and anemone ‘gardens’, the giant boulder fields, the steep rock walls covered in epifauna, the scallop beds, and the ancient cold-water corals. We’ve also had the pleasure of looking off the deck to be greeted by pods of pilot whales, an enormous finback whale, rafts of seabirds, sharks and sunfish!
After this journey, I’ll return to St. Andrews Biological Station in St. Andrews, NB where I work in Peter Lawton’s lab on the Census of Marine Life’s Gulf of Maine Area project. I have previously completed my BSc. (Marine Biology) at Dalhousie University and MSc. (Marine Science) at Otago University in New Zealand. This is the furthest offshore I’ve ever been and it is such a pleasure to be working at sea and to contribute to understanding more about life in the Discovery Corridor.

German Bank

Our dives on German Bank, to determine seabed characteristics in relation to scallop fishing intensity, were completed successfully. It was difficult to maintain a linear transect with the ROPOS because of heavy currents at times, but we did seem to see higher densities of scallop in the middle of the track as expected based on fishing intensity maps. Other organisms of interest that were seen were coral, lobster, a lion's mane jellyfish, sponges and anemones. There was one interesting area of underlying bedrock covered in sand where anemones persisted, but were almost completely covered in sand.

Sunday, August 1, 2010

Peter Lawton is the Chief Scientist for this 2010 CCGS Hudson mission. He has been a Research Scientist with the Department of Fisheries and Oceans (DFO) since 1989, working on invertebrate fisheries and marine biodiversity research problems. His own research emphasises the linkage of marine ecological and marine geological approaches in the description and analysis of seabed habitat structure, in connection with habitat suitability and sensitivity for commercial invertebrates, such as lobsters, and for seabed biological assemblages. Currently he is the Executive Director of the Centre for Marine Biodiversity, and Co-Principal Investigator for the Gulf of Maine Area Program of the Census of Marine Life. Starting in 2004 he has been coordinating a program of collaborative research focussed on the Gulf of Maine Discovery Corridor, working with researchers and graduate students from several Canadian universities, and with other DFO researchers. He led two previous Hudson missions to the offshore portions of the corridor, and also conducts coastal research investigations using SCUBA diving approaches, and seabed video systems deployed from smaller research vessel platforms.

“The Hudson missions in 2009 and 2010 form one of the major contributions of DFO to the Canadian Healthy Oceans Network (CHONe). I am one of three DFO researchers that have responsibility for helping to coordinate departmental contributions to this innovative Canadian national marine biodiversity research network. It has been a real privilege to help provide significant opportunities for the next generation of Canadian marine scientists to conduct leading-edge research in what are still, essentially, frontier and largely unexplored areas of the marine environment. Coordinating the diverse elements of the corridor research program, which spans everything from microbial ecology to marine mammal and seabird studies remains a significant challenge, but we are making significant progress towards our eventual goal of making this one of the best described ocean spaces, extending as it does from the intertidal to the continental shelf break.”

Science Staff Profile: Kelly Bentham

I’m on a “bus mans” holiday. No worries about underwater camera systems, winches or cables, the amazing team from ROPOS is taking care of the underwater work while I shoot video for a DVD on Fisheries and Oceans (DFO)’s involvement with CHONe (Canadian Healthy Oceans Network) and the Census for Marine Life. So far we’ve had great weather and I’ve shot some good footage but I’m excited about getting off the Hudson on to the FRC (Fast Recovery Craft) and shooting from the water, which always provides great footage. This DVD is going to be the first full HD video I’ve done and with the fantastic underwater HD footage from ROPOS the results should be spectacular.
After 25 years of going to sea on the Hudson and with 55-year-old eyes I’m looking forward to working with Cherisse Du Preez from the University of Victoria on the CHONe video. A young set of eyes and a youthful perspective will certainly help this video get the information to the students that are our target audience.

Senior Oceanographic Photographic Technician
Bedford Institute of Oceanography

Student Profile: Emily Wilson

While everyone else on the cruise is looking below the water, Conor Ryan and I are watching for seabirds and whales up at the surface! We’re conducting surveys as volunteers for the Canadian Wildlife Service. I’m also a CHONe student working with Bill Montevecchi at Memorial University of Newfoundland, looking at seabird biodiversity and habitat in the Gulf of Maine. The CWS has been conducting seabird surveys in Atlantic Canada since 2006, and they also have data from surveys from the 1970s to 1990s along the coast of North America which can make for great comparisons over time.

Conor & I work up in the bridge counting the birds, whales and dolphins (and the occasional tuna or ocean sunfish) and record our findings in a database along with our GPS location, weather & sea conditions, and any interesting behaviours (feeding frenzies, squabbles over food, or relaxing on a log floating by). We can use these data to learn how seabird communities have changed over time, and how and where seabirds spend the bulk of their lives out at sea. I’m also using satellite data of habitat features to figure out why some areas are such “hotspots” while others are empty of birds and whales.
All this time staring out at sea makes for some beautiful sights (like a fin whale 100 meters away!) & great pictures, and Conor has a few to share with you!

Jordan Basin Day 2

Yesterday was another extraordinary day diving in the Jordan Basin Rock Garden. We saw more coral (Primnoa.) today, and a nice example of how small red fish use the coral as habitat to hide from predators. The area seems very abundant in the many organisms that live here from seabirds all the way down to krill. We also saw schools of pollock, swarms of krill, many anemones, sponges, sea stars, brachiopods and a lobster. Two sea stars were also collected for specimen identification.

Saturday, July 31, 2010

Student Profile: Conor Ryan

I am a PhD student from Cork in Ireland. I am studying baleen whale ecology at Galway-Mayo Institute of Technology using stable isotope analysis and molecular genetics. My project is primarily investigating fin and humpback whales in Irish waters whose movements and ecology are poorly studied to date. I received an Ireland-Newfoundland Partnership grant to visit Memorial University of Newfoundland to take baleen samples for my project, so I'mlooking forward to spending a few days there when we get ashore. Bill Montevecchi kindly secured me a place on this cruise as a seabird and marine mammal surveyor.

I have surveyed on several research cruises in the eastern North Atlantic, but this is my first time at sea on this side of the pond. I'm enjoying the sunshine (a rare treat in Ireland!) and the slightly different selection of bird species. The good food, company, weather and abundance of blubber are making the cruise very enjoyable!

Student Profile: Cherisse Du Preez

Surprisingly, I’m not breathing compressed air, my feet aren’t wet, and I’m not enclosed in a foot-thick sphere of steel. It feels like I could be on the bottom of the ocean but I’m actually in a comfy armchair, coffee and ginger cookie at my side, aboard a Canadian Coast Guard Vessel. I’m surrounded by a dozen of my peers and the room we’re in would be pitch dark if it wasn’t for the twenty-two huge flat screen monitors displaying, in real-time, the deep seafloor from hundreds to thousands of meters directly below us. It’s misleading to refer to it as the “deep sea”, what I’m looking at could be mistaken for the tropics, some coral reef in Thailand or Bahamas, not the temperate Atlantic Ocean off the coast of Nova Scotia. The colours of the rainbow are splashed all over the seafloor: sponges, anemones, hydroids, and corals cover seemingly every inch of rock there is, and schools of fish swarm in huge groups above them.

That should elude to a bit about me but let me formally introduce myself, “Hi , my names Cherisse Du Preez and I’m a PhD candidate at the University of Victoria, British Columbia”. I’m one those lucky people that work their dream job (even Gorge Costanza from Seinfeld wishes he had my job), I’m a marine biologist. I’ve temporally joined the crew of the CCGS Hudson to explore the ocean depths with the remotely operated platform for ocean science, or ROPOS. My part to play in our dives to the seafloor is a story staring deep-sea sponges, corals, and rockfish. Basically the story goes something like this: seafloor structure is to some bottom fish like trees are to birds. I am investigating fishing practices which trawl to catch their target fish and the impact on the preferred structural habitat of sponges and corals. I’ve already done work on this subject on the West coast of Canada and CHONe, with its nationwide scientific initiative, is giving me the opportunity to replicate that work on the East coast of Canada. The video imagery we collect during this cruise will feed directly into my PhD thesis, as well as open up doors for collaborations with other CHONe students and scientists.

Cherisse Du Preez
CHONe Outreach and Student Committee member

Researcher Profile: Anna Metaxas

Anna Metaxas is a benthic ecologist, interested in the factors that regulate populations of marine invertebrates, particularly early life-history stages, in different habitats ranging from the shallow subtidal to the deep sea and from temperate regions to the tropics. She holds a BSc in Ecology from McGill University, a MSc in Oceanography from University of British Columbia, and a PhD in Marine Ecology from Dalhousie University. After completing her PhD, she spent 2 years at each of Harbor Branch Oceanographic Institution and Woods Hole Oceanographic Institution as a postdoc, where she became initiated in deep-water research. She has used occupied (Alvin, Johnson Sea Link, Clelia) and remotely operated submersibles (ROPOS) for research in the Caribbean, at cold seeps in the Gulf of Mexico, hydrothermal vents in the south and northeast Pacific, and the Discovery Corridor including the continental slope in the northwest Atlantic. She is a Professor in the Department of Oceanography at Dalhousie University.
On this cruise, Anna and her students (Myriam Lacharité and Jessie Short) are continuing a long-term project that aims to identify potential dispersal pathways and associated patterns in population connectivity across the different habitats in the Discovery Corridor. These habitats include relatively shallow (150-300 m depth) muddy and sandy bottoms, and rocky outcrops in the Gulf of Maine (Jordan Basin, Georges Basin); the Northeast Channel coral conservation area (300-900 m depth); and the mostly soft-sedimented continental slope (900-3000 m depth). To achieve our goal, we are using a multi-prong approach: (1) with video and acoustic measurements, we will obtain the distribution of habitat types across the Discovery Corridor (in collaboration with Peter Lawton at SABS); (2) using a large collection of video amassed over three cruises since 2006, we will obtain measures of abundance for epifaunal macrofauna (organisms that live on the sediment surface and are large enough to identify visually on video) in each habitat type; (3) using deployed settlement plates and deep-water plankton tows, we will measure rates of larval supply to the bottom in different habitats; and (4) we will combine this information with a regional circulation model to identify potential sources and sinks of dispersing individuals from different species. Understanding patterns of population connectivity and the identification of source and sink populations will allow us to better manage these highly utilized, but in many ways quite unique, ecosystems.

Part of this project falls under the CHONe NSERC Strategic Network.

Saturday July 31, 2010

Another sunny, calm day on the waters of Jordan Basin.

Last night we were fortunate enough to encounter a pod of approximately 20 pilot whales as they passed by the Hudson, including two of this years calves. A highlight of the day for all (along with the pizza for supper). Yesterday we also sighted the fins of a small shark, trying to get some of the greater sheerwaters surrounding the boat, along with several whales in the distance, and a few sunfish basking near the surface.

Friday, July 30, 2010

Jordan Basin Dives

The Jordan Basin "Rock Garden", named in 2006 for its dense epifaunal coverage, was found successfully. However, we did not find the larval settlement collectors placed in 2006. We did, once again, see a highly diverse community of filter feeders and other species including: anemones, sponges, cold water coral, brachiopods and sea stars with sparse sightings of cod and red fish and a monk fish.