By Dr. Chris Harvey-Clark
This guest post is brought to you by Dr. Chris Harvey-Clark who is the University Veterinarian as well as the Director of Animal Care in the Department of Psychology at Dalhousie University. In an interview on CBC's Mainstreet program, Dr. Harvey-Clark spoke to the success of small-scale aquarium such as the ones found in St. Andrew's, New Brunswick and Petty Harbour, Newfoundland. We reached out to him following this interview at which point Dr. Harvey-Clark agreed to serve as one of our valuable advisors. He has taken the time to tell us more about one of his areas of interest in the post below.
People might be surprised to know that a big marine predator that kills fish using electrical shock is coming in increasing numbers to shallow waters around Nova Scotia!
This late summer visitor is the Atlantic torpedo ray, Tetronarce (formerly Torpedo) nobiliana, a large, enigmatic member of the skate and ray family (the Batoids) found from tropical to temperate waters on both sides of the North Atlantic inshore and in deep waters. By far the largest of 17 species of electric rays worldwide, the torpedo ray can weigh 90kg and have a body disc diameter approaching 2m in mature females.
This species uses electrogenic organs comprised of modified muscle cells in the lateral margins of the body disc to generate controlled DC current bursts in excess of 200 volts. This shocking power can snap the back of a mackerel in tetanic convulsions and is also used for discouraging predators. A friend of mine who was shocked by this species while diving lived to tell the tale and likened the sensation to putting your finger into a dryer socket.
Dr. Fred Whoriskey views the first ever satellite tagged Atlantic torpedo ray
Photo credit: Dr. Chris Harvey-Clark
The electrogenic tissues of torpedo rays have been extensively studied at the cellular and molecular level, with thousands of citations in the scientific literature. Some of the earliest work on the neurotransmitter acetylcholine and its effects on muscle tissue were first characterized in torpedo ray tissues. It is a paradox that despite extensive study at the cellular level, little is known of the ecology, movement and behaviour of T. nobiliana. In fact, decades of fishing for use in neuroscience research depleted local populations of this species in the vicinity of the Marine Biological Laboratory at Woods Hole Mass.
The fact remains that virtually nothing is known about the basic biology of T. nobiliana. The size and age structure of the Atlantic population, depth, substrate and temperature preferences, onshore/offshore movements of this species, prey preferences, longevity, reproductive parameters and life cycle are all poorly known.
The IUCN (International Union for Conservation of Nature) Red List indicates the species is data deficient, in common with the majority of sharks, skates and rays. In this respect, our knowledge of T. nobilana resembles the former state of knowledge of many large charismatic species such as sharks, tunas, sea turtles and many marine mammal species prior to the development of modern electronic tracking technology beginning two decades ago.
Like the curious case of the dog that failed to bark in the night, the fact that this species is rarely reported as bycatch despite intense commercial fishing within its known range begs the question: where do these animals go? What is their role in the seasonal summer assemblage of large pelagic and forage fish species that occurs in boreal seas around Europe and North America annually?
The habit and habitat of this species remains a mystery. Observations exist of occasional individuals in shallow water sand and mud bottom habitats from Nova Scotia to the Florida keys and from northern Scotland to West Africa, into the Mediterranean, usually from fisheries bycatch inside continental shelf depths. Fishbase and similar database sources cite depth data for this species from shallow water to 800 meters and report their presence as rare fisheries bycatch in the Mediterranean. Several references claim the rays are benthic bottom dwellers when younger and become more pelagic dwellers as they get older, but there is little evidence in the primary scientific literature to support this claim.
In the fall of 2015, Dr. Fred Whoriskey and myself tagged a female Atlantic torpedo ray with a satellite tag near Halifax, NS. The tag was programmed to pop up to the surface 95 days later, and report its position and other data to a geosynchronised satellite. I had theorized that the rays were following the shallow continental shelf migrations of forage fish like herring and mackerel - north in the summer and south in the winter. Imagine my surprise when the tag reported 95 days later from an offshore location over 900 km out in the North Atlantic, from an area where the bottom is in excess of 4000 m. This single record indicated that in at least one case, this species does in fact act as a pelagic animal, quite amazing for a ray we had found dug in to the bottom while scuba diving in 20 m of water.
This discovery has led to plans for a more extensive study of the movement and behaviour of this species. Volunteers interested in helping the torpedo ray tagging team can contact me at Dalhousie University: email@example.com.
By Magali Grégoire
If you're following us on Facebook or have browsed this site even a little, you'll know that we plan to launch an event series called Touch Tank Days in the near future. And if you haven't done either of those things, do it now! (Or at least, right after you read this post.)
We're almost ready to launch the Touch Tank Days, but we're still missing one important element - the animals! The little critters we'll be showcasing are still chilling in the ocean for the time being. Why is that? Because we want to do things right, and that includes collecting our animals in a safe and ethical way.
Desta Frey, 2014 Curator of the Petty Harbour Mini Aquarium collecting
animals prior to the start of the season.
We've applied for a collection permit that we're hoping will also allow us to release the animals back to the ocean where they were collected from.
This allows for a close to zero environmental impact, the fondation of the catch-and-release philosophy.
In terms of the Touch Tank Days, this means we would like to release the animals at the end of the event series in early October.
A sea star returning to its home! Photo curtesy of the Petty Harbour Mini Aquarium.
But what does catch-and-release mean for the proposed Back to the Sea Aquarium and the other "mini aquariums" in Canada?
Due to our East Coast weather, the Back to the Sea Aquarium will have a short season similar to the Petty Harbour Mini Aquarium. At this aquarium, all the animals are collected in May so they can be in the exhibits when the doors open in early June. After their summer-long vacation away from predators, they are released in mid-October with the help of local children and families. This is called the Release Party and it's BYOB - Bring Your Own Bucket!
Children handing off an urchin at the Petty Harbour Mini Aquarium's 2015 Release Party
Things are a little different on the West Coast. For example, the Ucluelet Aquarium is open from March to December, making for a much longer season. Although this aquarium still hosts a release party at the end of the year, animals are also periodically released and caught throughout the season.
Some of Ucluelet Aquarium's animals being released back to their permanent home.
As soon as we receive our required permits, we'll be hitting the water to collect some animal friends. Can you guess what animals we'll be collecting? Leave your answers in the comments!
By Ruby Banwait
I’m a west coast girl to my core. I grew up in what was at the time, a small fishing and farming community in the mouth of the mighty Fraser River. I spent countless hours playing in tide pools and splashing around the emerald sea. Few things give me greater joy. However, in 2012 when I traveled across the country to discover the deep blue of the Atlantic Ocean around St. John’s, Newfoundland, I realized just how easy it is to fall in love with any Canadian coastline. So when I had the opportunity to travel to the Maritimes in June of this year, I simply couldn’t pass it up!
Ruby spotting her first iceberg in St. John's, Newfoundland
Halifax is a fun place boasting more pubs per capita than any other city in Canada. Visiting from Vancouver, which caters to foodies and desperately tries to be the country’s “greenest” city, I was elated to find organics receptacles beside every garbage and recycling bin as well as some great vegetarian restaurants. My only regret is not dining in Nova Scotia before becoming a vegetarian. I’m sure I missed out on some of the best lobster dishes around!
The invitation to visit Halifax and stay with good friends in their seaside home combined with scouting out locations for a new mini aquarium while adventuring around the beautiful province couldn’t have been a sweeter combination for this fish geek.
Nova Scotia is rich in maritime history yet there are few places where you can meet live marine animals that call this part of the world home. What better location for the Back to the Sea Society to build a mini aquarium than within the greater Halifax area? As the founding curator and general manager of the Petty Harbour Mini Aquarium in Newfoundland, I felt honoured to be included in the search for potential homes of the Back to the Sea Mini Aquarium! I couldn’t be more excited to see the perfect location that Magali has found for her seasonal, hands-on, conservation and education based facility. Stay tuned!
Interpreting a tank at the Petty Harbour Mini Aquarium
One of the highlights of our trip was an extensive private tour of Hope for Wildlife, an animal rescue and rehab center located in Seaforth, Nova Scotia. I watch the show on the Knowledge Network and even PVR it so I don’t miss any episodes. Yes, it’s true. This fish geek is just a lover of all animals. Thanks to Alison Dube for an absolutely wonderful tour. I got to cuddle a three legged skunk named Maxwell and discovered I have a great love for porcupines. Special thanks to all the staff and volunteers at Hope for Wildlife for your dedication to animals and passion for better wildlife education!
Look out for the Back to the Sea Society’s marine animal touch tanks at the Hope for Wildlife Open House on August 28th.
Hope, Ruby and Maxwell the three-legged skunk
My time in Nova Scotia was entirely too short and I was already looking forward to a return visit before I even left. This is a province not to be missed!
Ruby Banwait is an Aquarium Biologist at the Vancouver Aquarium and was the founding Curator and General Manager at the Petty Harbour Mini Aquarium. She is one of Back to the Sea's valuable advisors. We are so thankful to her for taking time during her vacation to scout locations for the future Back to the Sea Aquarium and for contributing to the blog.
By Magali Grégoire
Early in June, I visited Darren Porter's weir fishing operation located on the mudflats of the Minas Basin, located at the end of the Bay of Fundy. Darren is one of the few fishermen still using this ancient technique, one of the oldest known methods of fishing as well as one of the most sustainable. Other than my curiosity and sincere interest in this fishing method, I visited the weir to see if it might be a collection method for the Back to the Sea Aquarium. I discovered that the weir would in fact be a great collection method and that Darren was happy to say he would be willing to help out!
The weir is a fascinating method of fishing! It is approximately 700 meters long and made up of wooden poles about 2 meters in height with netting in between. Shaped as a semi-circle, the fish are directed towards the trap as the water pulls back with the tide. The weir must be harvested twice daily, no matter at what time of the day the low tide occurs. The trap holds mackerel, herring, shad, flounder, skate, squid and will often trap less common fish such as striped bass, sturgeon and dogfish. Darren's daughter Erica, who works the weir, told me her most exciting find was an adorable lumpfish!
Sturgeon being carried out to the pool to be released
This year, it took Darren and his team approximately 100 low tides to build the weir and they will spend over 400 consecutive tides harvesting the fish from May to August before tearing it down. Talk about hard work! Keeping the mackerel, herring, shad, squid and flounders, the other fish caught by the weir's trap get released downstream where they land into a "pond". The fish remain in the pond (except for a few unlucky ones who make a yummy lunch for some bird predators!) until the tide comes back up allowing them to swim away.
The catch-and-release philosophy of the Back to the Sea Society means that we plan to catch all the animals in the spring prior to the opening of the Aquarium and release them all in the fall at the end of the season. The animals will be collected by various methods, including scientific diving, beach seines and with the help of fishermen such as Darren. The weir will be a great opportunity to collect animals that should do well in captivity as they are accustomed to the harsh conditions of the Minas Basin, that is, the huge variation in temperature and salinity that comes from the world's largest tide.
A huge thank you to Darren for allowing me to spend the afternoon with him and his team observing the workings of the weir and to Matt Grégoire who organized the trip for me and took me out to Bramber!
Navigate through the slideshow below to see more pictures from this day out in the field!
By Magali Grégoire
On Saturday June 11th, Back to the Sea Society will be leading a workshop as part of the Ocean Literacy Conference 2016: Ocean Optimism being held in Halifax, Nova Scotia. This second annual conference is lead by the Canadian Network for Ocean Education (CaNOE). Our workshop, titled A Seasonal Aquarium for Halifax Metro: Come be Part of the Creation!, will engage participants with hands-on and interactive activities that will get them to think creatively, reconnect with their inner child and unleash their imagination.
This workshop will allow participants to contribute to the making of the Back to the Sea Aquarium. We will be inviting participants to think big in terms of how we can all approach ocean conservation. The group will be invited to think outside the box, beyond the containment of an exhibit tank. Our exercises are sure to generate surprising ideas that will be valuable contributions to the Back to the Sea Society as well as bring insight to other ocean-related work that the conference participants are involved with.
The deadline to register for this year's conference is June 1st, so be sure to register today if you are interested in attending and participating in our workshop.
I attended last year's conference held in Vancouver and was blown away by all the top notch presentations! I am positive that this year's conference is sure to please all educators, researchers and other ocean enthusiasts.
If we don't see you there, be sure to check back here for an update on how it went!
By Magali Grégoire
On January 18th, myself and Melanie Knight had a great time on air with CBC Radio One to discuss the concept of mini aquariums. We told listeners all about the catch and release philosophy and how these seasonal educational facilities can spark curiosity for local marine life.
"Why doesn't Halifax have an aquarium?" is a question that come up time and time again in Nova Scotia. Both locals and tourists are surprised that this coastal city is without an aquarium. It's time for that to change!
We received positive responses from this interview, a great sign that we are moving in the right direction and working towards a goal that we all want to see happen in greater Halifax.
If you would like to hear the interview, submit your email below.
Thanks to Melanie for phoning in from Vancouver to join in on this interview. Melanie is the Founder of the Petty Harbour Mini Aquarium and CEO of Ocean to Eye Level Consulting, one of our valuable advisors.