Collecting season

As the water warms this spring, our collecting opportunities expand. I generally have a mental list of species we would like to have here, but there are always fishes we need each year as they outgrow their exhibits and are transitioned to larger ones (e.g. striped bass, flounder). Some species are popular not only among guests and staff, but other facilities often inquire about for trade, such as lookdowns and spadefish. Fortunately, I have many locations that I have catalogued over my many years in VA through personal experience, research/professional (VIMS) or through the museum. 

Juvenile Spadefish, a popular catch each summer

Collecting (with requisite permits of course) is one of the more pleasurable parts of this type of work. Although I never truly enjoy taking an animal out of its element, I use that sentiment to ensure a personal and professional quality of care for the animals we do keep. I DO NOT keep animals I feel are unsuitable for captivity, doubt we can handle, or care for adequately. And there are many species I would like to have, even have had, but do not fit that requirement (octopus). Back to the pleasurable part; it is hard to beat late spring through fall in VA. July and August can be brutal at times, but then again we are in the water when collecting. 

Moonfish

Most commonly we use a 100 x 6 foot beach seine that I acquired from my old bosses at VIMS originally used for the Juvenile Bluefish Survey. It needs repair after just about every trip anymore but it is very effective. Not only is the weather and scenery a huge highlight of collecting trips but it is also the thought of getting interesting fishes that we rarely see or do not currently display. Every now and then there are a few surprises - bluntnose ray pups (13 total), banded drum, leatherjack, moonfish - and large scale changes in species by year (2010 was an excellent spotted sea trout/bluefish year, 2009 was a striped bass/flounder year).

Bluntnose Ray pup caught at Cape Charles

So this year we can look forward to the unexpected and we certainly expect to enjoy it.

Skate Exhibit up and running

A few months ago on a recreational trip to Oregon Inlet, North Carolina I noticed an unusually large amount of flotsam around the southern jetty. Always on the lookout for interesting exhibit props, I discovered wooden poles, formally from a pound net, that would make excellent pilings in the skate exhibit. Treated wood is toxic for fishes so wood pilings could not be purchased, and our budget would not allow for fabrication of pilings from textured cement.

So...two aquarium staff members went down ASAP and discovered the wooden poles still washed up and left on the beach. They then sawed the pole down to five, 5- foot sections and brought them back to the VLM. The new "pilings" were then drilled through the bottom to hold bolts and lightly scrubbed and set aside for the project of remodeling the Skate/Ray Exhibit. The stingray that was then on exhibit was removed to a holding system, and the renovation began!

The next step was to drain the exhibit. Then the substrate was removed. Outside of the tank, the five pilings were attached to a large piece of high-strength resin that served as a base to keep the pilings stationary and stable. After the piling structure was installed inside the exhibit, sand that had also been previously collected and washed was then added to cover the base, and the tank was filled. We let the tank run for a few days and plumbed in a chiller before placing the animals in the new habitat. Once the chiller was installed, the exhibit was ready and now home to three Little Skates (Raja erinacea) and five spotted hake (Urophycis regia)!

                       Notice the diamond - shaped outline of the skate in the center of the sand!

To the left, a hake is poking out of the sand. On the right, notice the skate's outline in the sand.

RAW 2011 - by Patrycja Lawryniuk

On Tuesday and Thursday of this week, my colleague Jessi Shupe and I attended the Regional Aquatics Workshop (RAW), hosted by the Virginia Aquarium in Virginia Beach, VA. At the workshop, we attended lecture sessions with different speakers from all over the world!

On Tuesday, the sessions focused on water quality and life support systems, fee-based and animal interactive programs, and fish propogation. It was really neat to see what other facilities do with their animals. I even learned how to get started on any potential animal-interaction programs. I was especially interested in all Jeff Marliave from Vancouver Aquarium had to say on catching and raising wolf eels.

Thursday's sessions focused on husbandry, animal enrichment, and exhibit design. These three sessions were particularly useful to me as an aquarist, and the animal enrichment/behavioral conditioning was especially interesting. I really enjoyed learning how to train eagle-spotted rays and white sea bass to feed by hand. I also walked away with multiple new ideas for changing and maintaining our exhibits.

Overall I had a very pleasant experience at RAW 2011, and I really appreciate the museum allowing us to experience the workshop; we had a great time and learned a lot.

Sharks and Rays

Last Thursday prior to our weekly SCUBA program, we added our two male lemon sharks to the 30,000 gallon Chesapeake Bay tank.

Before moving the sharks, we had to first remove the southern stingray from the exhibit, as skates and rays are natural prey for many shark species. Our presence inside the exhibit helps to disrupt any potential territorial behaviors by the fishes already in the tank and allows us to closely monitor the situation and even to remove the sharks if things go poorly. In holding, these two sharks were very active and rather aggressive; in fact they ate several smaller tankmates, so caution was needed. But so far so good. Inside CBA each shark has established one half the tank as their own "territory", circling near the surface of the tank, always alert for food. They are still fed off tongs three times a week, but get several peices of food each when the fishes in the main tank are fed during the 2pm program. They showed no fear of us during the dive and swam directly in front of me whenever I was near the surface totally unafraid. Juveniles of top predators and animals that get to be very large often are fearless, perhaps instinctively knowing that one day they will be quite formidable.

Are You Feeding?

Probably the most common question we get from the visitors as we work in or around the exhibits is, "Are you feeding?" People love to watch the animals eat so I think the question may be born from wishful thinking. We do have feedings for the public at 11am and 2pm on selected days, but mostly we try to feed the exhibits before we open because feeding usually clouds the water a bit afterwards. Also, some fishes are skittish and will not feed well surrounded by activity; others are being trained for a particular feeding time.

(A typical weekly food order often includes: (clockwise from top) squid, smelt, live clams, and fresh spanish mackerel.)

 The VLM houses over 100 species of both fresh and saltwater fishes of all life-stages so their diets range from flake food to whole herring.

 

(Atlantic herring are a staple for the saltwater fishes, fed out in chunks, fillets, or even whole)



We attempt to mimic as closely as possible what they would eat in the wild, while providing maximum variety coupled with suppliments to ensure proper nutrition. We prepare diets every day and constantly adjust the amounts as the fishes grow. Fishes that prey on other fishes in the wild, often have the ability (and the desire) to eat their exhibit-mates, so we move them often as they become too large or aggressive for a particular exhibit. We also try to keep them well-fed but not fat; it is no simple task to ensure the most passive fishes get enough food while the most aggressive do not get too much. Successful feeding and nutrition - and their ability to be housed together - relies on the fishes' natural ecology.


(Shad roe, salvaged from fresh whole shad we ordered as a food fish, are occasionally fed out for extra nutrition.)



Trip to Duke Marine Lab

Every spring, students from local Christopher Newport University make a trip to the Duke University Marine Lab in Beaufort, NC.  A couple of aquarium employees from the VLM accompany them on the trip to help with identification and to lend an extra hand to the chaperoning professor. This year aquarists Jessi Shupe and Heidi Pankratz were selected to go. The trip, started almost 30 years ago, is a favorite tradition for biology students at CNU.  Students get a chance to experience a boat trip on the RV Susan Hudson that includes trawling and dredging, walking through mud flats in the Beaufort Inlet Channel, and a visit to the North Carolina Aquarium at Pine Knoll Shores.  The aquarium department at the VLM also gets a chance to collect specimens for use in exhibits.

We brought coolers on board to hold collected animals

The trawl allows us to catch species living just above sediment (hake, flounder, crabs) and the dredge pulls up species living in the sediment. The catch from the boat this year was good, but less diverse than usual because of the long winter and cold waters (~55 F).  

Students sort through catch from the dredge

The mud flats we visit are home to a variety of mollusks that thrive in an environment of changing tides, including oysters, whelks, conchs, and clams. We visit at low tide, which allows us to cover more area and find animals to collect.

Jessi fights through the deep mud

CNU student Emily Wolford shows off the lightning whelk she found (eating a clam)

After the boating and trekking through mud flats, students have a lab session that gives them a chance to go through and identify the collected specimens.

Dr. Gwynne Brown, professor of biology at CNU, talks about the water vascular system of sea urchins

The wet labs allowed us to hold our collected animals overnight until the drive back to the VLM

Jessi and I enjoyed a behind-the-scenes tour of the NC Aquarium

Species that we collected for the museum this year included white and purple urchins, lightning and channeled whelk, spider, stone, mud, and portunid crabs, spotted hake, and windowpane flounder. These species will soon be used in exhibits including the "crusty" crustacean tank and the touch tank.

Lemon Shark update

One issue with introducing the lemon sharks is that the loggerhead is still somewhat passive competing for food, while the lemons are aggressive towards everything edible. The sharks are trained with tongs just as the turtle was (see pics below) , but the turtle has not yet established its position (with regards to feeding) in the big tank.

Before they go in, the turtle needs to be able to fend off attempts to take food from it. Sea turtles can inflict serious damage when they want to, but they also need a little attitude and training. The Chesapeake Bay exhibit is over 30 times the size of any previous enclosure it has been in and is filled with many large fishes so as usual it takes a little time before getting comfortable. But it "gets it" a little more each day.