New England Aquarium researchers are reporting from the Biodôme in Montréal, Quebec, where they are conducting an experiment on the stress physiology of two species of wolffish. 

Greetings! We hope everyone made it through “Irene” safely, and with minimal damage to property (and mind!). As you have been following since the initial post, members of our research team have been involved in an exciting research project at the Biodôme (Montréal, QC), studying the physiological effects of stress on two species of wolffish (Atlantic, and spotted). Similar to the New England Aquarium, the Biodôme has a distinct research program in addition to their wonderful exhibits, and we have been extremely fortunate to collaborate with such a talented and welcoming group. The purpose of this concluding post is to report on the background and progress of the study, and acknowledge those aiding our efforts along the way.



Taking a step back, it might be interesting to know about the study’s conception. The Aquarium has funding to investigate the biological impacts of small marine protected areas surrounding offshore (~ 22 miles from Boston, and 15 miles from Gloucester) liquid natural gas (LNG) terminals in Massachusetts Bay. Because fishing activities are prohibited, potentially damaging habitat impacts – such as degradation of the seafloor associated with commercial bottom trawl fishing (for cod, haddock and flounder species among others) – are prevented within these protected areas. As such, the bottom (“benthic”) habitat in these areas has slowly been restored, to the benefit of the many marine species that reside on the seafloor in these areas. One of the species we’ve examined in Montréal, the Atlantic wolffish, depends on the nooks and crannies on the seafloor for refuge.


Simply, our study is seeking to evaluate how the presence/absence of habitat influenced the response of these animals to different types of stress. Crudely, when happy in the comforts of refuge, were they more resilient in coping with stress? We all certainly were in recent days, while nesting in our homes as Hurricane Irene ravaged the region. The study results will be provide important info on the factors that influence the responses of these species, which have suffered declining population numbers, to human-induced stress.


You might also be curious as to why we’re conducting this study way up in Montréal when we work at the Aquarium, and one of these wolffish species resides right here in the Gulf of Maine. Well…two reasons: firstly, our collaborator at the Biodôme, Dr. Nathalie Le Francois, is a renowned expert in rearing wolffish. In fact, our research animals were raised under her guidance from the egg stage after being collected from the wild. Secondly, staging the study at the Biodôme provided a spacious (research) tank system, and the ability to investigate many individuals across the two species at the same time without the worry of overcrowding the animals during the study.

Following a masterful execution of the study by our students (Emily, Alena and Hope), all blood samples were transported back home to the Aquarium, where they will soon be examined to indicate the comparative levels of stress in our research animals under the various stages of the study. Among the ultimate goals of this study will be to provide vital information to aid conservation and management of these species, and to disseminate the results to a scientific audience via publication in technical journals. We will hopefully blog again when the study’s results are revealed!

On behalf of the students and the Research Department at the Aquarium, we would like to close these posts by thanking those at the Biodôme instrumental in making our stay so incredibly smooth. Aside from Dr. Le Francois and the vet and husbandry staff, we would also like to give a special thanks to Salvador Rojas, who went above and beyond to provide all of the amenities needed to allow execution of the study unencumbered. Merci Beacoup!!!!!

Dr. John Mandelman and Dr. Randi Rotjan

Bonjour, my name is Blueberry and I am a spotted wolffish, and also a guest blogger today!

I live at the Biodôme in Montreal in a tank with four of my closest friends and conspecifics. I'm 65 cm long and weigh about 2.5 kg, and I am olive green with handsome black spots running down my sides. I don't mean to toot my own horn, but I have been told on several occasions that I am a very good looking fish.


Check out how pretty I am!

My friends call me Blueberry because of the color of my eyes. I've never actually tasted a blueberry before but if one fell into my tank, I'd probably eat it. In the Biodôme, I generally get to eat capelin, squid and shrimp, but sometimes I have a craving for the crunchy sea urchins and rock crabs that wolffish in the wild also eat. My favorite movies are Finding Nemo and Deep Blue Sea, and in my free time I enjoy playfully biting the fins of my tankmates and playing water polo.

Wolffish like me are native to the deep cool waters of the North Atlantic where we spend much of our time in small caves and rocky outcrops. Though wolffish are generally described as slow moving, I like to think of myself more as easy going. All of my neighbors and I were collected as egg masses in the wild and raised in a laboratory in northern Canada, and then we moved to the Biodôme at the beginning of the summer.


Here is a picture of my tank in the Biodôme and the three neighboring tanks. Mine is the one on the bottom left.


I look forward to the visits by my friends from the New England Aquarium. I'm helping them to study the physiological effects of stress on wolffish. The pay's not good but the benefits are great, particularly the free food and housing. When the researchers Emily, Alena, and Hope come to visit, they take us out of our tank one by one and put us in an anesthetic bath which makes us super sleepy. Then, they take a sample of our blood, and put us in a recovery bath. The whole process usually takes about 15 minutes and is relatively painless.

After the researchers' first visit, they put little houses in our tank for us to relax in. Some of our neighboring tanks did not get houses because the researchers are trying to determine if access to shelter decreases our stress levels. We can’t tell the researchers how stressed we are feeling because silly humans don’t speak our language, so they take samples of our blood to measure cortisol, a hormone that many organisms (including humans) produce when under stress. The absence of houses in our tanks over the course of this experiment is meant to simulate long term, or chronic stress.

During one visit by the researchers, they also wanted to expose us to short term, or acute stress, by perturbing us underwater and then exposing us to air briefly. It was definitely uncomfortable but we are all willing to help out the researchers however we can. For more information on the experiment itself, check out our other blogs on blood processing and the differences between two types of wolffish in this post and this post.



Here on the is a picture of Alena taking a sample of my blood.


This is a picture of my tankmates and I in the recovery bath.

Some of my Atlantic wolffish neighbors from the tank next door are moving to the New England Aquarium to join a few of our cousins already on display there in the Northern Waters Gallery. Feel free to stop by any time to say Bonjour!

Au revoir for now!
-Blueberry

We can get a lot of information from the blood we collected from our wolffish. Over a one month period we collected four 3mL samples from each fish (for 20 Atlantic and 20 spotted wolffish, that's 160 samples, almost a half a liter of fish blood!). We carefully calculated the amount of blood we could safely draw without compromising the health of the animals. We used an anesthetic to sedate the fish to make them easier to handle and reduce the stress of air immersion and handling.


We started analyzing the blood samples immediately after they were drawn. The first test we conducted was to determine the levels of hematocrit. Hematocrit is the volume of blood that is made up by red blood cells. It indicates any number of things about the overall health of the animal. We are interested in hematocrit because low levels can result if an animal is stressed. Hematocrit levels are determined by drawing blood into microcapillary tubes and centrifuging the tubes at high speeds for a short amount of time. This force compacts red blood cells at the bottom of the tube. Hematocrit is read as the volume of packed red blood cells.




Hematocrit is the volume of packed red blood cells as a percent of the whole blood. This sample from A. minor has a hematocrit value of 10 percent, which is relatively low for the species. Until all the data is analyzed we cannot determine whether stress is a factor in depressed hematocrit levels.

After we read the hematocrit levels, we loaded the whole blood samples into a larger, chilled centrifuge. We did this so that we could isolate the plasma, which contains hormones such as cortisol (a stress hormone released as part of the primary stress response) as well as other molecules of interest. The plasma was pipetted and divided into three aliquots, which were frozen and will be used in different tests. One test is radioactive immunoassay (RIA) analysis, which will determine the concentrations of cortisol. Another test will determine concentrations of ions and glucose.



-Alena Gerlek

Working with wolffish is challenging and exciting. These large, feisty fish definitely keep you on your toes. They have a lot of personality to go along with their sharp teeth and if they are hungry, they can be a bit grumpy. This is one of the reasons we sedate the fish before taking blood samples from them; working with a sleeping wolffish reduces the risk of injury to both the researcher and the animal.



One of the most interesting aspects of the project has been observing the very different behavior of the two species we are studying. While the spotted wolffish (A. minor) tend to be more docile, the Atlantic wolffish (A. lupus) are much more active and aggressive. For example, since these fish prefer to shelter under rocky outcroppings in the wild, we provided all the tanks with structures for the fish to hide in. These plastic structures were weighted down with fishing weights. Whether it was because they resented the decoration or thought that the shiny silver weights looked like tasty fish, within a few days the Atlantic wolffish had chewed many of the weights right off of the bottom of their shelters. The spotted wolffish, on the other hand, left the weights on their shelters alone.


Members of the Atlantic species will also swim right to the surface when you lift the lid in their tank, especially if they want to be fed. All those teeth coming at you can be very intimidating!


The fish aren’t always friendly towards each other either. Most of the animals bear scars from the sharp teeth of their tankmates. Members of the Atlantic species are definitely more scarred than members of the spotted species, indicating higher aggression levels.


One of our coolest wolffish experiences was stripping eggs from a couple of pregnant female Atlantic wolffish. Some of the females were heavily pregnant and if these animals are stressed, they are sometimes unable to release the eggs, which can endanger the health of the animal. To prevent this, while the pregnant females were asleep, we massaged their abdomens from head to tail to push the eggs out; this is known as “stripping” the animals. It took about 20 minutes for us to strip all of the eggs and by the end we had removed about 400g of eggs from each female, roughly one fifth of their body weight!


Although they are not perhaps the most cute and cuddly of creatures, by the end of our Biodome experience, all three of us felt a lot of affection for our wolffish friends!


- Emily Jones

Hello again! Emily, Alena and Hope here. In addition to being a great place to conduct research, the Biodôme in Montreal is a fantastic place to visit. The Biodôme is a branch of the Montreal Nature Museum. It was built in the velodrome that housed the track cycling events during the 1976 Summer Olympics in Montreal. Today it is an educational attraction that showcases models of four different ecosystems and the species that make them unique.

After a full morning working with the wolffish, we toured the Biodôme. The walk through begins in the tropical ecosystem. This room is kept between 25 and 28˚C (77 and 82.4˚F) and at a relative humidity of 70% during the day; visitors in the winter months probably welcome the respite from the cold! Several species of birds and tree frogs roam free along the path, and golden tamarins and sloths hang out in the trees.


Next is a marine ecosystem, the Gulf of St. Lawrence. This habitat has two levels; the first is an underwater view of a 2.5 million liter tank that houses many species of fish, including several resident wolffish! Above the water, sea birds swoop overhead and small conifers and lichens cover steep granite cliff faces. An intertidal pool is filled with sea cucumbers, urchins and sea stars, and one lone, handsome Atlantic wolffish. While wolffish in the wild live deep in the water, the shallow intertidal pool provides visitors with a better look of this smaller specimen.


From the St. Lawrence coast we traveled north to a Laurentian maple forest. Here there were several charismatic mammals on display: river otters slide down a gently sloping stream, a beaver splashes in a freshwater pond, porcupines climb trees and gnaw on twigs and tree bark, and two lynx pace along a cliff and watch visitors with wary yellow eyes. This habitat is controlled to change with the seasons and reflect the actual conditions outside. Now, in the summer, everything is green and lush, but soon the leaves will change and fall, and in the winter the plants will go into dormancy until the spring.


Finally we did some pole-hopping in the subpolar exhibits, where two analogous but distinct ecosystems are represented. These two habitats display birds that play and splash in the water: notably Atlantic puffins from the Labrador Coast, and penguins as would be found on an island between the tip of South America and Antarctica.



For an afternoon at the Biodôme, we were transported to amazingly different ecosystems across the Americas. More soon...

-Alena, Emily, Hope, Randi 

Bonjour from Montréal! We are from the research department at the New England Aquarium, writing to you from the Biodôme in Montréal, Quebec, where we are conducting an experiment on the stress physiology of two species of wolffish. One of us (Emily) is a masters students with the Northeastern University Three Seas Program, conducting this work as part of her thesis. The rest of us (Alena and Hope) are New England Aquarium interns. The three of us are working under the supervision of Dr. John Mandelman and Dr. Randi Rotjan (NEAq), and Dr. Nathalie Le François of the Biodôme. Our study is investigating the possible effects of shelter on mediating the wolffish's stress response, which could have implications in aquaculture and conservation endeavors.

What's a wolffish, you ask? Good question!

Join Aquarium Teen Program Coordinator Liz Whitlinger and campers with the Harbor Discoveries Schooner Adventure Camp. After a week of preparation, our crew of young explorers board a Grand Banks schooner and set sail for a five-day, four-night excursion exploring Massachusetts Bay.




Today I realized the bonds made in a two week period can be stronger than bonds made between people who have known each other forever. I wont say that I love all of things I've experience on the boat, especially the sea sick moment Tuesday night.



I have, however, met people I hope I'll know for the rest of my life.  This has been an amazing trip!

Join Aquarium Teen Program Coordinator Liz Whitlinger and campers with the Harbor Discoveries Schooner Adventure Camp. After a week of preparation, our crew of young explorers boarded a Grand Banks schooner and set sail for a five-day, four-night excursion exploring Massachusetts Bay.

Join Aquarium Teen Program Coordinator Liz Whitlinger and campers with the Harbor Discoveries Schooner Adventure Camp. After a week of preparation, our crew of young explorers boarded a Grand Banks schooner and set sail for a five-day, four-night excursion exploring Massachusetts Bay.

Its day four and it feels like we've been on this boat forever. The watches that we do are like a well known routine, and I know exactly what I'm supposed to do and exactly when. The watch shifts can be at crazy times. When the boat is anchored there are one hour and fifteen minute shifts. On the first night my shift was 3 a.m. to 4:15 a.m. When we're sailing or underway, the watch shifts are four hours long. Those four hours drag on to feel like forever.




Day two my night shift was 8 p.m. until 12 a.m. and there was a huge lighting storm in the distance over Provincetown. My crew (C watch) was on the deck in our rain gear. I had on my rain coat and pants and thoroughly enjoyed watching the lightning. There was also bioluminescent plankton that would light up the water with each little movement.

Join Aquarium Teen Program Coordinator Liz Whitlinger and campers with the Harbor Discoveries Schooner Adventure Camp. After a week of preparation, our crew of young explorers boarded a Grand Banks schooner and set sail for a five-day, four-night excursion exploring Massachusetts Bay.
At 0300 we arrived in the harbor of Provincetown to set down anchor. My watch (A) had to drop anchor, lower the sails and furl them (roll them methodically like a burrito and tie them down so they don't come loose while anchored).



We had been awake since 11:30 p.m. and by 3 a.m. we were barely on the edge of sanity. It was very hard to see as it was pitch black out, the cloud cover blocking out any residual star or moonlight we might have had. The only upside was that we were able to go back to bed and stop our watch because we could move into anchor watches.




In the end it was stimulating and tiring all at the same time.

Join Aquarium Teen Program Coordinator Liz Whitlinger and campers with the Harbor Discoveries Schooner Adventure Camp. After a week of preparation, our crew of young explorers boarded a Grand Banks schooner and set sail for a five-day, four-night excursion exploring Massachusetts Bay.
While on the Spirit of Massachusetts, we have the opportunity to take a test to be able to sit out on the headrig, which is the forward most part of the boat (bow) under the jib standing on a net. The test included knowing many different things around the boat. We had to now the names of the sails (jib, jumbo, fore, main), where the main sheet is tied off (quarter deck near the helm) and what the halyards are used for (hauling up the sails).



We also had to know some safety things including what to do if someone falls overboard, and the two places where lifejackets are stowed. There are certain things that you must do and say before going out on the headrig. You have to put on a harness, ask permission from the mate and announce to the people on the bow that you are going out.

The last part of the test was showing that you could tie three knots; reef, bowline and figure eight.  I think everyone has taken the test and passed to go out on the headrig. It's been a ton of fun because it is a great place to relax and watch the ocean go by. To get out onto the headrig you have to put on a harness and scure it to a line that runs to the front of the bow. You can then step onto a 'platform' of netting and either sit or stand.  It is so much fun to be up there because you can see everything around you including the entire 125 foot schooner. When we were at Stellwagen Bank we were even able to whale watch from the headrig. We spotted some whales while standing a few feet above the water on a net. We even saw a whale breaching in the distance. It was incredible and we can't wait for the rest of the week.