Old Woman Creek (OWC) is a naturally functioning estuary,
which is an environment where sources of water with different chemical
properties combine. Backflow from Lake Erie into OWC creates a unique habitat
for a diverse floral and faunal community. Located in Huron, OWC is a state
nature preserve and the only national estuarine sanctuary in Ohio.
Ben gathers a plankton tow sample from Lake Erie
On the first night of our trip, we went to the beach
to get algae samples with plankton tows from Lake Erie and OWC. Plankton towing
is an algal sampling method in which a funnel shaped mesh fabric attached to a
collection jar is tossed into the water and then dragged across the surface to
collect specimens.
The tow obtained from the estuary had a large quantity of
zooplankton (Daphnia). According to
Dr. Johansen, depending on the density, the zooplankton can sometimes consume
most of the algae from a tow before you take it back to the lab and get a
chance to look at it under a microscope! In the samples we found cyanobacteria
(Merismopedia and Afanizomenon), a cryptomonad (Cryptomonas), diatoms (Fragilaria crotonensis and Aulocosira gramulata),
green algae (Pediastrum), and
dinoflagellates (Peridinium and Ceratium).
Alex and Ben are stoked to begin the canoe trip! (Photo credit: Kim Daut)
The
next morning, we set off in canoes to explore the diversity of OWC. As
we traveled along the creek, we collected algal samples by scraping
partially submerged logs and by attaching a plankton tow net to the
canoe. Our guide informed us that the plankton tow sample we collected
for the OWC research center was only qualitative. For a quantitative
measure of phytoplankton, a GPS device is necessary to standardize tow
length.
Curran's Lotus Lillies, 1888 (left, Photo credit) The floating-leaf macrophyte, Nelumbo (right, Photo credit: Kim Daut)
One of the first organisms identified by our tour guide
belonged to a genus of water lotus called Nelumbo.
These plants occupied the open water area of the estuary and were the featured
in well-known paintings of the OWC estuary, created by Charles Courtney Curran
in the late 1800's. The white water lily (Nymphaea
odorata) was another floating macrophyte
that we encountered. On the bottom of these leaves, Dr. Johansen pointed out lophotrochozoan
worms.
We were able to see the nest of a bald eagle (left) in an open spot near the top of the treeline (Photo credit). The high-pitched rattle of the belted kingfisher (center) was unmistakeable (Photo credit).
The great egret (right) uses it's sharp bill to catch unsuspecting prey,
such as fish and amphibians, with quick jabs (Photo credit: Kim Daut).
There
was a great diversity of
avian species present at OWC, which serves as an important nesting
ground. Our guide informed us of the incredibly successful bald eagle
conservation effort at OWC. Spanning 30 years, the reestablishment
project, which involved field work such as climbing trees to get blood
samples from eaglets, increased the eagle population from 4 to 250 nests
per year. Since the bald eagle population is now thriving, the nest
monitoring has ceased and avian research is currently focused on the
migration of the sandhill crane. Other exciting bird species that were
seen while canoeing through the
estuary include, ospreys (Pandion haliaetus), great blue herons (Ardea herodias), belted kingfishers (Megaceryle alcyon), and great egrets (Ardea alba). The distinctive "meow-like" call of the gray catbird (Dumetella carolinensis) was also heard at various locations throughout the creek.
In the photo on the left, Phragmites
dominates the edge of the estuary. In the photo on the right, our guide
explains how coconut logs containing plant "plugs" of native species
are being used to combat Phragmites invasion. (Photo credit: Kim Daut)
As we progressed through the
estuary, our knowledgeable guide frequently identified Phragmites,
a European invasive reed species that was introduced by ballast water from
ships. Phragmites has recently been
the focus of a great deal of management and restoration research at OWC. Phragmites will disrupt the community by
displacing native plants and drying out the wetlands. This alteration results
in negative environmental impacts including the acceleration of eutrophication,
reduction of open water, and loss of habitat and food sources for many species.
This resilient reed is not consumed by other species and does not die off on
its own. The success of Phragmites is
aided by a high reproduction rate and rhizomes that can reestablish organisms despite
damage to other parts of the plant body. Management strategies
include burning, mowing with a Marsh Master (a machine similar to a
bulldozer), spraying herbicides from a helicopter, and flooding. Of those
methods, only flooding with four feet of water was greatly effective, but unfortunately
flooding to that degree is not feasible in most situations. After removing Phragmites from an area, restoration is
achieved by using coconut logs to replant native macrophyte “plugs” before
invasive species have a chance to reestablish their populations. The coconut
logs slowly decay and the native species repopulate and restore the community.
Cameron startles nekton into our nets by splashing around with his hands and feet. (Photo credit: Kim Daut)
Following
the canoe trip, we
strapped on our waders and headed back into the estuary to sample the
fish
population. The method we used to capture fish specimens involved the
use of a
large seine net held against the sediment. Two people held poles at the
ends of
the seine net and walked in unison with the net in a "U-shape" behind
them toward another group of people. The other group walked toward the
net, disturbing the
area and causing fish to swim into the net. Once the pair and group met,
the poles
attached to the net were brought together and the bottom of the net was
gathered so none of the trapped fish could escape. The net was carried
back to
shore so that the specimens could be identified and placed in a bucket
of water
for later use.
As we searched through the seine net (left, Photo credit: Kim Daut), we found emerald shiners (center, Photo credit) and placed them in a bucket (right, Photo credit: Kim Daut), so that the living specimens could be used by the OWC-ERR staff.
The only species of fish we caught in our net was the emerald
shiner (Notropis atherinoides).
The emerald shiner belongs to the family Cyprinidae, which is composed of carp
and minnow species. The emerald green coloration on its lateral sides
distinguishes this species of fish.
These
collected macroinvertebrates (specimens include members of family Belostomatidae, family Corixidae, order Odonata, and a pouch snail) are in a petri dish with
70% ethanol and ready to be examined under a dissecting microscope.
Macroinvertebrate sampling was
accomplished with the use of dipnets. Triangle dipnets were bumped along the
bottom of the estuary, stirring up the sediment, and then quickly lifted to the
surface to trap organisms. Edges of the estuary with macrophytes
in shallow water were excellent areas for macroinvertebrate collection.
After fish and macroinvertebrate
sampling, we visited the laboratory at the Ohio Division of Wildlife’s
National Estuarine Research Reserve (OWC-ERR) to examine our specimens. Using dichotomous
keys provided by the research center, algae identification books, our familiar
macroinvertebrate guide, and the assistance of resident algae expert Dr.
Johansen, we were able to achieve finer taxonomic identification for our
samples. One of the highlights of our algal identifications included Bacillaria, the "accordion-like" diatom(Bacillariophyta).
A colony of these pennate diatoms will slide back and forth with an
appearance similar to an accordion. Among our samples were the familiar
genera of Euglena (Euglenophyta), which possess a red "eyespot" and Synura (Syurophyta), which have distinctive siliceous scales.
A
hemipteran (true bugs) commonly called a toe-biter was found in a
dipnet catch. Toe-biters, or the giant water bugs, are members of family
Belostomatidae and in addition to feeding, can use their piercing
mouthpart to inflict a painful bite to humans. Some of the other
macroinvertebrate families collected included members of Gerridae (water
striders), Corixidae (water boatmen), and Coenagrionidae (narrow-winged
damselflies).
Water quality testing equipment
During
our time at the research
center, we were able to take a behind the scenes tour of the facility
and find
out a little more about the research currently taking place at OWC.
Throughout our canoe trip we were cautioned not to bump into the expensive
water monitoring equiment throughout the estuary. Our guide explained
that those instruments measure water conditions and transmit information
to the National Oceanic and Atmospheric Administration (NOAA). We were
also
shown laboratories where chemical properties of water, such as dissolved
oxygen (DO)
and pH are measured. Our guide stressed the importance of biomonitoring
and how
phytoplankton is an indicator of community health, as primary producers
impact on all levels of the food web above them. The water samples
collected from that morning produced a DO value of 8.1 for the lake and
6.3 for the estuary. The amount of DO can vary with sunlight due to
photosynthetic activity, so the cloudy conditions of the morning most
likely affected the DO value of our sample. As expected, both Lake Erie and the estuary had a pH around 7.
Sheldon
Marsh
Sheldon Marsh
Sheldon
Marsh State Nature Reserve is located in Erie County. As we learned in
lecture, marshes are a type of wetland that represents a transitional
zone between aquatic and terrestrial habitats. Marshes are characterized
by the presence of herbaceous plants.
An interesting feature of the marsh
was the barrier beach. A piece of land perpendicular to the shoreline protects the
lagoon from the harsh wave action of the lake that can be produced during
storms. Plants, such as purple sand grass (Triplasis
purpurea), which is unique to the barrier beach, are able to survive in
this environment because of the protection provided by the barrier.
Zebra mussel shells were easy to identify due to their characteristic striped pattern.
Invasive zebra mussel shells were also found on the shore of the beach.
As we learned in lecture, zebra mussels are contributing to the toxic
blooms of Microcystis by selectively consuming diatoms, which compete with Microcystis, from the phytoplankton, while rejecting the cyanobacteria. With reduced competition from diatoms and available phosphorus, Microcystis can form blooms.
While
exploring the marsh, we came across a wildlife viewing enclosure that
shielded organisms from seeing us so that we could observe their
behavior. Turbulence in the water drew our attention, and someone
proposed that the disturbance could be due to sparring snapping turtles.
Unfortunately, after closer examination, we discovered that the
activity at the surface was just an invasive carp splashing around. Like
the emerald shiner that we caught in our seine net at OWC, the common
carp belongs to the Cyprinidae family.
Sheldon Marsh
Immediately
adjacent to Sheldon
Marsh is the Sawmill Creek Resort Golf Course. We discussed the
detrimental
environmental effects of the chemicals that are used to maintain golf
courses
and how the run-off from fertilizers can enter the wetlands. As we
learned in lecture, wetlands are fortunately able to function as buffers
from this type of
nutrient input and prevent its spread through the watershed.
Magee
Marsh
Magee Marsh
Magee
Marsh is located in Oak Harbor, OH. The marsh is a popular spot for
birders
because of the large amount of migratory birds that use the area as a
pit stop.
Although the boardwalk was closed for controlled waterfowl hunting, we
did get
to check out the nature center and take a lap around one of the loop
trails.
The nature center was very informative and had detailed descriptions of
many of the bird species that can be
found at Magee Marsh throughout the year. There was also an impressive
taxidermy collection of most of the species that can be encountered at
the marsh, as well as a few live specimens, such as the blanding's
turtle (Emydoidea blandingii) and the common snapping turtle (Chelydra serpentia).
The brown snake specimen was determined to be male because female snakes typically have a greater taper after their cloaca.
As we walked around the trail, we noticed native (Typha latifolia) and non-native (Typha angustifolia)cattail
species. Native cattails have wider leaves, measuring 1/2-1 in., and
adjacent female and male parts. Invasive cattails have more narrow
leaves, measuring 1/4-3/4 in., and female and male parts separated by a
1-4 in. gap. Since it was rainy and a little chilly, we were surprised
when we found two brown snakes (Storeria dekayi) on our hike. We
ended our trip with an encounter with a non-native praying mantis (order Mantodea) that
we found on a path. The praying mantis was most likely a female due to
its large size.
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