Visitor Centers
New
England Aquarium -- Central Wharf, Boston
Sanctuary's Deep Boulder Reefs Revealed in New England Aquarium
Exhibit
How
do you get aquarium-goers to want to visit an exhibit that features
a pile of rocks? How do you keep them once they've arrived?
The
New England Aquarium has been able to meet those challenges with
a new Gulf of Maine exhibit that features the Stellwagen Bank
National Marine Sanctuary - the centerpiece being an innovative
bow-front tank showcasing a deep boulder reef.
In
the darkened halls of the aquarium the voices of entranced children
and astounded adults echo off the walls, while noses bump against
the convex one-and-a-half-inch thick acrylic barrier that separates
the visitors from the boulder reef inhabitants. Through the effects
of special lighting and design, it appears that the reef extends
far more deeply into the distance than in a typical tank.
Here
wolffish rest in their dens, lobsters lurk among the rocks, and
anemones extend their graceful tentacles into the cold currents
of this simulated environment. These piled rocks are one of the
many types of habitats in the sanctuary - a habitat filled with
nooks and crannies, strange creatures and surprising colors. The
exhibit offers viewers glimpses of an unimagined and fascinating
marine world just off the Massachusetts shore.
"The
boulder reef tank was one of our bigger remodeling jobs and has
become the largest exhibit on our upper level," noted Billy
Spitzer, vice president for exhibits and education at the aquarium.
"It may not be quite as exotic as our sea dragon tank, but
its size and scope make it stand out. We're really pleased with
the responses we're getting from viewers," he said.
Installing
a 4,220 gallon tank in a 40 year old building required a significant
amount of infrastructure renovation, including new structural
supports, piping and filtration. The quarter million dollar project
was made possible by funding from a number of institutions, including
the sanctuary and the National Marine Sanctuary Foundation.
"Working
with a pile of rocks was a challenge," said aquarist Tony
Davi, who was one of the initial proponents for the project in
2003 when the idea was raised about a sanctuary exhibit. Davi
had come to the New England Aquarium from the Aquarium of the
Americas in New Orleans, where he had shepherded an exhibit on
the Flower Garden Banks National Marine Sanctuary. Familiar with
the sanctuary program, Davi saw great possibilities in the aquarium's
cold water tank wing.
"Not
only did we have to get the tank to work right, but we had to
get the right collection of animals together - to get interesting
specimens that can cohabit in a small space," said Davi.
He gave the example of sun stars and sea cucumbers, which show
a predator-prey relationship in the wild (in the aquarium tank
the sea cucumbers are placed on a higher level, out of reach of
the voracious sea stars). "We definitely didn't want to put
our goosefish in here - he would decimate our fish population
in a matter of days," he added.
The
tank designers and aquarists decided on a tiered effect that simulates
a boulder field that extends outward, and settled on an initial
mix of species that exhibit a variety of shapes, textures and
colors. They worked with scientists from the National Undersea
Research Center at the University of Connecticut, reviewing hours
of videotape and still images from sanctuary research cruises
to get the right feel and mix of animals.
"We
settled on several key species to start, and will be adding additional
animals as the tank becomes more stable," said Davi. The
first inhabitants of the tank include frilled and northern red
anemones, smooth and spiny sunstars, horse mussels, and redfish,
animals that have had good success in aquariums. Other residents
include sea cucumbers, Atlantic cod, hermit crabs, and lobsters
(including the aquarium's new light blue specimen).
"Unlike
coral reefs, rocky reefs in northern waters do not have a strong
public image. Most people think of northern seafloor environments,
as not only cold, but brown and boring," said Brian Nelson,
another aquarist with the aquarium. But he notes that that impression
is unjustified. "Like coral reefs, the deep boulder reefs
offer complex three-dimensional structure," he said, pointing
out that the rocks provide dens for fish, hard substrate for benthic
invertebrates, and protective barriers for a variety of species.
The
new tank and its population of cold water species required more
water flow, more penetrations (openings through which water can
flow into the tank), and more current (the speed of the water
flowing through the tank). "We wanted to make the exhibit
as large as possible, with as much water flow as could be generated
by the system," said Nelson. "The investment in generating
the current is almost as great as is used in keeping the tank
clean. We definitely pushed the envelope here, but our initial
results have been great."
One
indicator of tank success, according to the aquarists is the happy
state of the anemones. "You normally don't see the tentacles
of these animals extended as fully or for as long a time as these
specimens have been showing," said Nelson. "The strong
currents are continuously sweeping food particles their way -
part of the special chum or 'chowder' that continuously enters
the tank through a drip feeder." He notes that larger food
particles are batch fed to larger species in the tank during the
middle of the day.
The
life support systems for the tank include mechanical filtration
for particulates, biological filters for ammonia, chemical filters
for skimming of proteins and carbon (from fish food and bodily
processes), and disinfection with an ultraviolet filter. The water
in the tank turns over four times an hour, with two pumps used
for life support, and an additional two pumps devoted to creating
current. The New England Aquarium filters local seawater from
Boston Harbor to fill its tanks, rather than create artificial
seawater.
The
specimens in the deep boulder reef tank were collected from waters
off Eastport, Maine. Although the water depths are shallower than
in the sanctuary, the more northern location provides a variety
of species equivalent to what is found in the deeper sanctuary.
"Rather than dive the 75 to 120 feet necessary at Stellwagen
Bank, we could spend a lot more time in the 20 to 30 foot depths
near the coast," said Davi. The initial collecting trip included
baskets of anemones and some 50 redfish - animals that could survive
an extended period in holding tanks until the main tank was completed.
Plans call for additional collecting trips to more fully populate
the tank with representative species, many of which are more delicate
and require a stable environment. Nelson noted that future trips
will target stalked tunicates and small wolffish, as well as additional
fish, crabs, and sea stars.
"We're
extremely pleased with the appearance and functioning of the new
boulder tank right now," said Spitzer, "but we're even
more optimistic about its potential. As the initial animals take
hold and get established, and as we add to the community, we will
probably find that this becomes one of the most dynamic and exciting
displays at the aquarium. We're looking forward to its growth
and development."
In
addition to the boulder reef exhibit, the aquarium has also renovated
its former Georges Bank tank as a second Stellwagen Bank tank.
Here, Atlantic cod, pollock, winter flounder, skates, and other
demersal fish swim in a simulated sand/gravel environment. Additional
tanks feature Gulf of Maine species that can also be found in
the sanctuary. For aquarium goers who are more attuned to video
images than live specimens, the sanctuary exhibit also includes
a controllable video loop (action can be slowed or sped up) that
showcases sanctuary natural and cultural resources, including
scenes from the wreck of the passenger steamship Portland. The
sanctuary and Gulf of Maine wing is part of the aquarium's regular
exhibit space; there is no additional charge to view these displays
beyond normal aquarium admission fees.
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