Photo courtesy Mike Suchy
ConCservianag ptphe e FeVaoal. III Irsrsue 1 Winter 2005
A semiannual publication of the
North Carolina Aquarium at Fort Fisher
Conserving the
Inside this issue...
Managing a Fishery: A
Complicated Answer to a
Simple Question. P. 2
Turtle Trails: Where Do Our
Turtles Go? P. 4
The Butterflies of Ft. Fisher P. 6
Why Do Marine Mammals
Strand? P. 8
Conservation Through
Appreciation...A Different
Approach P. 9
Why Recycle Oyster Shells? P.10
Fisheries
Management
“A
complex
answer to
a simple
question.”
By Fritz Rohde
Fisheries Biologist
NC Division of Marine Fisheries
Continued page 3
Catch of the Day: Grouper, porgy and snapper, respectively ( Fritz Rohde) Page 2
What does it take to manage a
fishery? This may seem like a simple
question, but it is one that requires a
complex answer. In the “old” days, it may
have been by the seat of your pants or by
the “Bell System,” wherein whoever called
the most often got the management
decisions they wanted. But since the early
1980s for fisheries in the Atlantic Ocean,
and since 1997 for our state fisheries,
documents called Fishery Management
Plans (FMPs for short) are prepared to
ensure the long-term viability of these
fisheries.
These FMPs are developed, with
public input, to describe the nature and
problems of a fishery and to propose
management regulations to conserve the
fishery. The goal of an FMP is to prevent
overfishing while allowing optimum yield.
Overfishing can be defined as harvesting at
a rate greater than what will meet the
management goal (i.e., sustain the species)
while optimum yield can be summed up as
the harvest level for a species that achieves
the greatest overall benefits, including
economic, social, and biological
considerations.
So, what is needed for an FMP?
An FMP contains a great deal of
information on the biology of the fish
stock (a harvested or managed unit of fish
may be a single species or a multi-species
complex) and the fishery (recreational and
commercial landings, gear, areas fished,
and socio-economic data). The Plan
identifies the problems in a fishery and
proposes management measures (fishing
regulations) to correct the problems. One
of the key components of a FMP is the
stock assessment that describes the
conditions or status of the stock. This
incorporates as much as possible about
the biology of the species in the stock and
about the fishery on this stock. The
biological information can include the
age at which it first spawns, the ages of
the fish in the population, how many eggs
are produced, and the ratio of females to
males. Information on the fishery may
include types of gear used, the
commercial and recreational landings
over a large number of years, the age
structure of the fish that are harvested, the
fishing effort expended, and the ratio of
females to males. Since the goals of an
FMP are to prevent overfishing and to
rebuild overfished stocks, how are we
doing? The first state FMP was approved
in 1998 (blue crab). Since then, nine
others have been completed (two are still
in draft form).
“Whether the fishermen or the
modelers (scientists) are right is
difficult to ascertain. Undoubtedly,
the answer lies somewhere in
between.”
Page 3
Snapper, iced down prior to market. (Fritz Rohde)
Commercial fishing is a major industry on our coast. (Fritz Rohde)
Given the relatively short period of
time involved, it is too soon to tell for most
of them but there have been some
encouraging signs with the red drum stock
and striped bass in Albemarle Sound. On
the federal level, the Snapper-Grouper FMP
has been around since 1983. It is such a
complex fishery (with 73 species being
managed in it) that currently the South
Atlantic Management Council is
undergoing the 13th amendment to the Plan.
Previous amendments have established size
limits, bag limits and spawning season
closures, and have limited or prohibited
certain types of fishing gear and reduced
the number of commercial fishermen. One
idea that has been discussed by the Council
for a number of years is Marine Protected
Areas where fishing for these species
would be off limits. There is disagreement
as to how successful the current
management measures have been.
Many fishermen believe that the
regulations have had a positive impact on
the fish stocks and they are catching fish at
the same rates and sizes as they did years
ago. On the other side of the coin are
results of computer modeling done by the
National Marine Fisheries Service
indicating that many of these species are
still overfished and that the current
regulations will not allow the stocks to
recover.
Managing a fishery does not have
the preciseness present in the other
sciences. Whether the fishermen or the
modelers are right is difficult to ascertain.
Undoubtedly, the answer lies somewhere in
between.
A complex answer to a simple
question.
For specific fisheries stock status
and other information log on to
www.ncfisheries.net
Imagine walking along the
beach and spotting a live sea
turtle, weighing more than 100
pounds, stranded in the surf. Each
year North Carolina's Sea Turtle
Volunteers are called on to carry
sick or injured sea turtles to one of
two rehabilitation facilities in the
state. Dedicated volunteers staff
both the NEST Rehabilitation
Facility at the North Carolina
Aquarium on Roanoke Island and
the Topsail Sea Turtle Hospital
located in Topsail Beach. The
goal of both programs is to release
healthy sea turtles back into the
wild.
Rehabilitating sea turtles
requires long hours, and
appropriate husbandry and
veterinary care. But watching
greens, loggerheads and Kemp's
ridleys crawl back into the ocean
after spending months in tanks is
an incredible reward. For years
we wondered whether these
animals survived, and where they
traveled after release. A study
designed to answer these
questions, and funded by the
Institute of Museum and Library
months when water temperature
dropped. A second group migrated
farther south, along the coasts of
South Carolina, Georgia, and as far
as Florida. The third group moved
offshore into the mid north Atlantic,
and over wintered in the warmer
waters of the Gulf Stream current.
Once coastal water temperature
warmed, loggerheads returned north
of Cape Hatteras. Some entered the
sounds behind the barrier islands,
while others continued migrating
offshore, one as far north as
Maryland.
We have yet to determine why
a particular sea turtle chooses one
pattern over another. Water
temperature does appear to be a
critical factor in loggerhead
migration, with most preferring to
remain in waters above 10 C (50 F).
Sea turtles can become stranded for
many reasons, some of which are
human caused. For example, some
sea turtles will ingest plastic bags or
other pieces of trash thinking they
might be food. Contaminants in the
water may also sicken sea turtles.
“Bogue” surfacing to breathe after having the transmitter attached (Joanne Harcke)
Services, has yielded some
incredible results.
Since September 2003, ten
loggerhead sea turtles (Caretta
caretta) were released from the
NEST Rehabilitation Facility at the
Aquarium on Roanoke Island and
four loggerheads were released from
the Topsail Sea Turtle Hospital, all
with satellite transmitters attached to
the carapace (upper shell).
Biologists from Wildlife
Resources Commission used a two-part
epoxy resin to securely fasten
the transmitters. Each transmitter
was programmed to send location
coordinates and water temperature
data to satellites, which then beamed
the information to a receiving station
on the ground.
Using data collected from a
Duke University study on wild-caught
loggerheads, we were able to
compare the post-release movements
of our rehabilitated sea turtles.
Regardless of whether they were
wild-caught or rehabilitated, three
patterns emerged. One group of
loggerheads remained in the coastal
waters of North Carolina, migrating
south of Cape Hatteras in the winter
Where in
the World
Do Our
Sea
Turtles
Go?
TURTLE
TRAI
By Joanne Harcke LS
Conservation and Research Coordinator
North Carolina Aquarium at Ft. Fisher
Continued page 5 Page 4
All species of sea turtle must
surface to breathe, which makes
them vulnerable to boat strikes.
With proper care, we now know,
these animals can be successfully
rehabilitated and released back to
the wild.
But rehabilitation takes time
and money; therefore preventing sea
turtle strandings is a critical
component of saving these
endangered and threatened species.
Picking up trash, watching from a
safe distance, always disposing of
used fishing equipment properly,
and improving water quality are
actions each of us can take to help
preserve and protect sea turtles.
So, the next time you're
walking along the beach looking out
across the ocean, consider the
amazing journey of the loggerhead.
And while we have learned the
Transmitter attached, “Obie's” released at Topsail Beach (Jacob Rudolph)
answers to some questions,
many others are waiting to be
discovered.
http://www.ncaquariums.com/turtletrails/
For more information on the
Turtle Trails Project, log on to:
Page 5
A visit to the North Carolina Aquarium
at Fort Fisher just wouldn't be complete
without a stroll through the Memorial
Garden. There are native trees and
shrubs, salt-tolerant landscape plants,
colorful flowerbeds, a birding deck and
beautiful memorial sculptures. There are
also butterflies - lots of butterflies!
Late summer and early autumn
are the perfect time for butterfly
watching. Spring caterpillars have
become adults and migrants move
through the area, coming from both north
and south. The highest diversity of
species occurs in September.
We began preparing our gardens
for butterflies one year ago, by seeding
copious amounts of curly parsley, dill and
fennel all host plants for several species
of butterflies, most notably the
swallowtails (we have six species that
occur along the coast here). We also
grew garden varieties of cabbage, carrots,
broccoli, and alfalfa (from sprouts sold in
supermarkets!). All these easy-to-grow
plants attract adult butterflies for the
purpose of egg laying. Perhaps the best-known
example of a butterfly host plant
is the milkweed. These moisture-loving
perennials (there are several species) are
the sole host plants for monarch (Danaus
plexippus) and queen (D. gilippus)
butterflies. We seeded milkweed in mid-summer
and had monarchs fluttering
around the young plants before we got
them planted!
Of course, all of our native
butterflies are adapted to native plant
species of the region. It ought to be taken
into consideration that as land is cleared
for development and non-native
landscape plants replace natives, many
species of butterflies (and other animals)
lose what is necessary for their
reproduction. Some examples may be
found in some of our largest and showiest
butterflies. The host plants of the
spicebush swallowtail (Papilio troilus)
include spicebush, a wetland plant, and
sassafras, a common shrub in upland
woods and edges, which are routinely
clear-cut. Another upland shrub, the
paw-paw, is host plant to the stunning
zebra swallowtail (Eurytides marcellus).
And a true southern beauty, the
palamedes swallowtail (Pterourus
palamedes), is a creature of the
wetlands. The larvae feed on red bay,
sweet bay and, again, sassafras. There
The Butterflies
Of
Fort Fisher
By Melanie Doyle
Horticulturist
North Carolina Aquarium at Fort Fisher
are almost 190 species of butterflies
occurring in North Carolina, and
many of those are found only along
the coast, some just in our
southeastern region. A few species
seen here in the fall actually have
migrated north to feed. Many of the
beautiful pale yellow sulphur species
(where the term “butter” fly may have
come from) move north in late
summer, creating eye-catching
“flocks” of flittering yellow above
open fields and gardens. The large
cloudless sulphur (Phoebis sennae)
comes our way from the tropics, South
America, the Caribbean, and southern
Florida. It isn't understood why these
animals come so far north in the fall
(as far as New York!), and why they
Page 6
Longtail skipper (Dick Roberts)
Monarch butterfly (Dick Roberts)
Continued page 7
perish with the onset of winter, not returning
south again. But while here, they feed on the
nectar of almost any flower they find (here at the
Aquarium they love our tropical hibiscus and
lantana).
So far this summer (since mid-August),
we have identified, with confidence, thirteen
species of butterflies on the Aquarium grounds.
Many, however, are small and elusive and will
require capturing in order to identify to the
species level. The skippers, hair-streaks and
satyrs are only about one inch long, and primarily
brown-- much more difficult to identify than the
larger, colorful species. While we will continue
watching, identifying and enjoying our butterflies
over the next few weeks, preparations are already
underway for next year. We continue to add both
host and nectar plants to the gardens, as well as a
feeding station in order to attract those species
(such as the red admiral) that do not feed on
nectar, but instead on sap, carrion and rotting
fruit. Also, the limitation of insecticides is very
important as any broad-spectrum chemical
sprayed for insect control readily affects
butterflies.
Remember, in addition to being beautiful
residents and visitors in our gardens, butterflies
are a good indicator of the overall health of our
surrounding environments!
Plants for adult butterflies to lay eggs
To attract migrating butterflies
Hibiscus
Lantana
Pentas
Gilardia
Echinacea
Curly parsley (lots)
Garden varieties of:
cabbage, carrots, broccoli, and alfalfa
Milkweed
Spicebush
Sassafras
Paw-paw
Sweet bay
Red bay
Sassafras
Not all la ts listed p n
a e native. se r U
nat e plant w en iv s h
ossible p .
Cut out the list when you’re ready to shop.
Page 7
Monarch butterfly (Dick Roberts)
Since Aristotle’s time, around 350
B.C., people have been attempting to
discover why marine mammals “strand.”
A stranding is defined as the beaching,
either alive or dead, of a marine mammal.
Marine mammals include whales, dolphins,
seals, sea lions, walruses, sea otters, polar
bears and others.
Focused scientific studies on
strandings really began in the 1970s
(Malakoff 2001). Some stranding of
marine mammals can be controversial, and
there is often no clear evidence as to why
these animals come ashore.
Most often, marine mammals
strand as single individuals (National
Marine Life Center). Occasionally mass
strandings, defined as three or more
individuals, occur. In some cases up to 400
individuals have stranded on the beach at
one time. In the United States, about 3,000
to 4,000 marine mammals strand per year.
About 75 percent of the time, these animals
are already dead when they wash ashore
(Malakoff 2001).
Strandings can have many
potential causes or contributing factors,
some natural and some human-related. For
single strandings, these include:
1. health complications associated with
pregnancy
2. separation of a dependent calf from its
mother
3. predation by sharks or killer whales,
4. natural biotoxins (e.g., red tide
poisoning)
5. disease, parasitism, and old age
ingestion of trash
6. entanglement in fishing gear
7. vessel strikes (Malakoff 2001, National
Marine Fisheries Service, National
Marine Life Center).
For mass strandings, hypotheses for
causes include:
1. social cohesion, (If an individual in the
group becomes ill and strands, the rest of
the pod will follow)
2. geomagnetic disturbances that may
cause navigational errors,
3. pursuit of prey too close to shore,
4. barriers to, or disturbances in,
echolocation in shallow water
5. Complex geographic oceanic
conditions such as abnormally high or
low tides (Malakoff 2001, National
Marine Fisheries Service, National
Marine Life Center).
Live marine mammal strandings
represent the most difficult event faced
by stranding-response personnel. The
decision to euthanize or
release/rehabilitate is always done in
consultation with a veterinarian. Most
often, the decision for a single stranded
individual is to euthanize, based upon the
animal’s health condition. Malakoff
(2001) stated, “There must be both a
humane society dealing with the welfare
of stranded animals and an objective
institution collecting scientific data.”
Guidelines have been set up as to when it
is proper to euthanize an animal or when
to release it back into the wild.
“Euthanasia shall only be performed by
an attending veterinarian or by a person
acting under the direct supervision of an
attending veterinarian” (Marine Mammal
Stranding Agreement 2004). Scientists
and veterinarians try to learn as much as
possible from each stranding. Tissue
samples collected from dead stranded
animals can not only help determine the
cause of death, but also aid in
discoveries about anatomy, ecology, and
evolution. The life histories of some
marine mammals are known exclusively
through stranding data. They also tell us
information about their diets, how many
young they have, and how old they are
when they first reproduce (Malakoff
2001, National Marine Fisheries
Service).
Why
Marine
Mammals
Strand
By Justin Perrault
Marine Science Student
University of North Carolina at Wilmington
Works Cited:
Malakoff, D. Marine Mammals: Why do Marine Mammals Strand?
Science 2001 293: 1755.
Marine Mammal Stranding Agreement Between National Marine
Fisheries Service of the
National Oceanic and Atmospheric Administration Department of
Commerce and [Stranding Network Organization]. Article I.
General Authority. 2004. [Available from the Internet.]
URL:<http://www.nmfs.noaa.gov/pr/pdfs/health/stranding_agreeme
nt_template.pdf>.
National Marine Fisheries Service. NOAA Fisheries Frequently
Asked Questions about Marine Mammal Strandings. [Available
from the Internet.]
URL:<http://www/nmfs.noaa.gov/pr/health/faq.htm>.
National Marine Life Center- Buzzards Bay, Massachusetts. Marine
Animal Stranding. [Available from the Internet.] Stranding.html>.
Page 8
Rare Blainsville beaked whale strands on Kure Beach in 2004. Stranding Team educates onlookers as they evaluate
the whale.(File photo)
Whether photographs of serene coastal landscapes,
the explosion of colors captured on film at an underwater
reef, the fluidity of a jellyfish ballet, or the strange chorus
from a symphony of swamp characters, art gives us
opportunities to appreciate aquatic habitats in ways the
superficial experiences of our everyday lives cannot.
Aquatic-themed photographs, linoleum prints and
kids’ art have touched numerous visitors at the North
Carolina Aquarium at Ft. Fisher. Echoes of “Ooh!,”
“Aahh!,” and “Wow!” fill the aquarium’s Spadefish
Gallery daily.
Talk with people you know who scuba dive on the
world’s reefs or trek the remote coastal wilderness. Many
have been inspired and driven from a single spark, often
from some form of art: a picture, a story, a song or even an
animated Disney film. Ask a dolphin scientist how they
were inspired and it’s a sure bet “Flipper” or “The
Adventures of Jacques Cousteau” are mentioned in the
mix. And who doesn’t care about clownfish and tropical
reefs after seeing “Finding Nemo”?
So, if you want to help protect our natural
resources, try seeding appreciation through art; view
conservation as a link between art, science, the heart, and
positive action.
Conservation
through
Appreciation
...a different
approach
By Jackie Harris
Educator
North Carolina Aquarium at Fort Fisher
Page 9
Lookdowns at the North Carolina Aquarium at Fort Fisher (file photo)
Why Recycle Oyster Shells?
By Jackie Harris
Educator
North Carolina Aquariums
Oyster Hatchery Team
Early seafarers once shunned oysters because the reefs
they created caused navigational hazards. However, these same
people eventually recognized oysters as a culinary delicacy -- a
delicacy whose population currently comprises just one percent
of its historical mass. And those treacherous reefs? If early
settlers had only known the far-reaching benefits of an oyster
reef, they might have been a little more patient.
Commercial oyster harvesting on the east coast of the
United States began in the 1800s. Initially, oysters were
harvested by hand or rake. Ingenuity quickly led to the
invention of a mechanical dredge, introduced to the industry in
the late 1800s. At that time, annual oyster harvests peaked at
1.8 million bushels per year. In 2000, less than 40,000 bushels
were harvested. This dramatic decline in oyster harvesting is
not the result of a decrease in demand or from lack of trying. It
is a clear indication that oysters are overfished, a situation
compounded by dramatic losses to disease and habitat
degradation. But numbers are once again rising, thanks to
North Carolina’s Division of Marine Fisheries, North Carolina
Coastal Federation, the North Carolina Aquariums and a host of
other organizations. Working together, they are making great
strides in the protection of natural reefs and the restoration of
lost beds.
Although most of us think of oysters only at oyster
roasts, their importance reaches much further than satiation of
our hunger. Oysters and their reefs filter waters, and they create
habitats for gamefish, crabs and – most important – for other
oysters.
Each oyster filters up to 50 gallons of water in a day.
Without oysters, far more algae, bacteria and other substances
could deplete oxygen and contaminate (or otherwise render
uninhabitable) our marshes and estuaries – important nursery
grounds for commercial shrimp, fish and blue crabs. The
economic impact of such damage could prove disastrous in
coastal regions.
The best place for a new oyster to grow is on an old
oyster. Old oysters provide strong footing for newcomers, and
their shells accumulate to build reefs. Oysters cement
themselves to each other and grow into clusters, which form
protective habitats for numerous organisms, such as polychaete
worms and soft-shelled blue crabs. Oysters provide food for
many predators, such as sea stars, drum and oystercatchers.
Oyster reefs serve as a substrate stabilizer, allowing clams and
aquatic plants a chance to thrive, and give small fish like gobies
and blennies a place to spawn. Barnacles and anemones benefit
from the sturdy roost that oyster clusters provide.
How can old oysters provide substrate for new oysters if
the oysters are collected and eaten? It’s simple: We recycle their
shells.
Collective agencies are teaming up to create
oyster shell recycling bins in coastal areas and
publicize their locations. As further encouragement,
the North Carolina legislature has mandated that
oyster shells not be allowed in landfills. Now, instead
of tossing shells in our driveways or flowerbeds, we
can gather them after a roast and take them to the
nearest bin. After six months, the shells are cleaned,
bagged and distributed to potential oyster reef sites.
Each site is seeded with oyster larvae and marked as a
no-harvest area until the habitat has been established.
Many local restaurants are also pitching in.
Before ordering those delectable morsels, ask your
waiter if they recycle. If not, ask for a “shell bag” and
recycle them yourself, or consider another appetizer.
To find the closest recycling bin in your area,
log on to www.ncfisheries.net.
The North Carolina Aquariums have been
designated to head an oyster hatchery development
team. Incorporating multiple federal, state, and public
agencies, the team will research, and eventually build
and maintain, an oyster hatchery to supply oyster
larvae for reef establishment. Educational activities
will embrace oyster education, shell recycling, oyster
habitat research and hatchery education, and will help
distribute information to public and commercial
sectors.
For more information, stay in touch online at
www.ncaquariums.com. We’ll post periodic updates
on the hatchery teams’ feasibility study, education
efforts, and links to additional oyster sites.
Background photo courtesy Peggy Sloan Page 10
Semipalmated plover feeds upon the mud flats and oyster reefs.
(Peggy Sloan)