Louisiana Association of
Professional Biologists
2009 Fall Symposium
Recent Natural Resource
Research in Louisiana
With a Focus Session on
Invasive Exotic Species in Louisiana
August 13th and 14th
The NOAA Estuarine Habitats and Coastal
Fisheries Center
646 Cajundome Blvd.
Lafayette, LA 70506
Thursday, August 13th – Large Conference Room #119
8:30 – 8:40
Welcome and Introduction: Kim Marie Tolson,
LAPB President-Elect
Session I
Moderator: Dr. Aaron Pierce (Nicholls)
8:40 – 9:00
BARRIER ISLAND WATERBIRD COLONIES AND
MAMMALIAN PREDATORS: A PRE AND POST HURRICANE
ASSESSMENT ON THE ISLES DERNIERES BARRIER ISLANDS
REFUGE. Edward J. Raynor1, Aaron R. Pierce1, Cecilia Leumas2, and Frank
Rohwer2 1Department of Biological Sciences, Nicholls State University, 2School
of Renewable Natural Resources, Louisiana State University.
9:00 – 9:20
HURRICANE IMPACTS ON BROWN PELICAN NESTING COLONIES.
Walter, S.T., P. Leberg, M. Carloss, T. Hess, Department of Biology, University
of Louisiana at Lafayette.
9:20 – 9:40
SOCIAL FACILITATION AND PREDATION AS FACTORS IN COLONY
SITE SELECTION OF SEABIRDS ON LOUISIANA BARRIER ISLANDS.
Cecilia Leumas1, Dr. Frank Rohwer1, Edward Raynor2, and Dr. Aaron Pierce2,
1
School of Renewable Natural Resources, LSU Agricultural Center, 2Department
of Biological Sciences, Nicholls State University.
9:40 – 10:00 BREAK
Session II
Moderator: Dr. Sammy King (LSU)
10:00 – 10:20 THE EFFECT OF CLIMATE AND RIVER STAGE ON OVERCUP OAK
(Quercus lyrata) TREE GROWTH IN A HYDROLOGICALLY
DISCONNECTED FLOODPLAIN. Hugo K. W. Gee, Louisiana State
University, AgCenter, 307 School of Renewable Natural Resources, Baton
Rouge, LA 70803.
10:20 – 10:35 PRAIRIE RESTORATION EFFORTS ON OUACHITA WILDLIFE
MANAGEMENT AREA TO BENEFIT GRASSLAND BIRDS. Matt Pardue
and Kim Marie Tolson, Department of Biology, College of Arts and Sciences,
University of Louisiana at Monroe, Monroe, LA 71209.
10:35 – 10:50 PRELIMINARY RESULTS OF DICKCISSEL (Spiza americana) NESTING
SUCCESS IN NORTHEAST LOUISIANA. Matt Pardue and Kim Marie
Tolson, Department of Biology, College of Arts and Sciences, University of
Louisiana at Monroe, Monroe, LA 71209-0520.
10:50 – 11:10 LICHENS: BIODINDICATORS OF AIR QUALITY. Jessica Wakefield and
Joydeep Bhattacharjee, Department of Biology, College of Arts and Sciences,
University of Louisiana at Monroe, Monroe, LA 71209.
11:10 – 11:15 ANNOUNCEMENTS
11:15 – 1:00 LUNCH
Session III
Moderator: Dr. Andy Nyman (LSU)
1:00 – 1:20
QUANTIFIYING THE EFFECTS OF PREDATOR MANAGEMENT ON
MALLARD RECRUITMENT IN NORTH DAKOTA. Matthew R. Pieron1
and Courtney L. Amundson2, 1School of Renewable Natural Resources, LSU,
2
University of Minnesota.
1:20 – 1:40
UTILIZING GEOSPATIAL ANALYSIS AND VEGETATION PATTERNS
FOR MORE EFFECTIVE WOOD DUCK NEST BOX PLACEMENT. Justin
Martin and Kim M. Tolson. Department of Biology, College of Arts and
Sciences, University of Louisiana at Monroe, Monroe, LA. 71209-0520.
1:40 – 2:00
SHOREBIRD USE OF MOIST SOIL UNITS. Rachel Villani, School of
Renewable Natural Resources, LSU AgCenter, Baton Rouge, and Michael
Seymore, Louisiana Department of Wildlife and Fisheries, Baton Rouge, LA.
2:00 – 2:20
BREAK
Session IV
Moderator: Dr. Andy Nyman (LSU)
2:20 – 2:40
REPRODUCTIVE BIOLOGY OF A BOPYRID ISOPOD, Probopyrus
pandalicola, AND ITS HYPERPARASITE, Cabirops sp., PARASITIC ON
THE RIVER SHRIMP, Macrobrachium ohione . Sara LaPorte Conner and
Raymond T. Bauer, Department of Biology, University of Louisiana at Lafayette.
2:40 – 3:00
HIGHER GROUND: REDUCED FLOODING IMPROVES Spartina patens
PRODUCTION IN LOUISIANA’S COASTAL MARSHES. V.D. Tobias1,
J.A. Nyman1, R.D. DeLaune2, J.D. Foret3 1School of Renewable Natural
Resources, Louisiana State University, Baton Rouge, LA, USA, 2Department of
Oceanography and Coastal Sciences, Louisiana State University, Baton Rouge,
LA, USA, 3National Oceanic and Atmospheric Administration, National Marine
Fisheries Service Estuarine Habitats and Coastal Fisheries Center, Lafayette, LA.
3:15 – 4:30
LAPB Fall Business Meeting (Room #119)
-Special Guest, Billy Minser, Representative Southeastern Section of TWS
5:00 – 8:00
Evening Social and Dinner at Hilton Garden Inn
-Student Presentation and Publication Awards announced
Friday, August 14th
8:00 – 9:50
POSTER SESSION – Conference Room #116
FOCUS SESSION
INVASIVE EXOTIC SPECIES IN LOUISIANA
9:50 – 10:00 Opening Remarks: Kim Marie Tolson, LAPB President-Elect
10:00 – 10:30 INTRODUCTION TO INVASIVE SPECIES IN LOUISIANA: WHAT WE
HAVE, WHAT WE DON’T WANT AND WHAT WE’RE DOING ABOUT
IT. Hallie Dozier, LSU AgCenter, School of Renewable Natural Resources, 227
Renewable Natural Resources, LSU, Baton Rouge, LA 70803.
10:30 – 11:00 THE DISCOVERY OF, AND RAPID RESPONSE TO, A WILD
POPULATION OF TILAPIA IN PORT SULFUR, LOUISIANA. Brac
Salyers, Louisiana Department of Wildlife and Fisheries, Inland Fisheries
Biologist, ANS, 2000 Quail Drive, Post Office Box 98000, Baton Rouge, LA
70898-9000.
11:00 – 11:30 GIANT SALVINIA (Salvinia molesta) IN LOUISIANA WATERWAYS – A
MULTIPLE MANAGEMENT APPROACH. Alexander J. Perret, Louisiana
Department of Wildlife and Fisheries, Aquatic Plant Control, Inland Fisheries
Division, 2000 Quail Drive, Post Office Box 98000, Baton Rouge, LA 708989000.
11:30 – 12:00 COGONGRASS: BIOLOGY, DISTRIBUTION, IMPACTS AND
CONTROL STRATEGIES FOR LOUISIANA . Scott Edwards, USDA,
Natural Resources Conservation Service, Acadiana RC&D Council, Inc, 3419
NW Evangeline Thruway, Suite B-9, Carencro, LA 70520.
12:00 – 12:10 Presentation of Poster Award
Closing Comments
ABSTRACTS FOR STUDENT PRESENTATIONS
Thursday, 13 August 2009
BARRIER ISLAND WATERBIRD COLONIES AND MAMMALIAN PREDATORS: A
PRE AND POST HURRICANE ASSESSMENT ON THE ISLES DERNIERES BARRIER
ISLANDS REFUGE. Edward J. Raynor1, Aaron R. Pierce1, Cecilia Leumas2, and Frank
Rohwer2 1Department of Biological Sciences, Nicholls State University, 2School of Renewable
Natural Resources, Louisiana State University.
Barrier islands provide critical breeding habitat for several species of colonial waterbirds that are
of conservation concern in Louisiana. However, this habitat is subject to degradation, especially
from high-energy storms. Two strong hurricanes, Gustav and Ike, impacted the Isles Dernieres
Barrier Islands Refuge, Terrebonne Parish, Louisiana in September 2008. To determine the
affects of these hurricanes on breeding waterbirds and mammalian predators we compared pre
and post hurricane assessments of colonial waterbird population size and composition, hatching
success of two waterbird species, and mammalian predator presence based on data collected
before and after the 2008 hurricane season on the Isles Dernieres Barrier Island Refuge. To
determine the breeding waterbird species composition and abundance at the refuge we conducted
boat/ground surveys during May and June 2008 and 2009. We also monitored the hatching
success of two waterbird species, Sandwich Tern (Thalasseus sandvicensis) and Royal Tern
(Thalasseus maxima). We monitored 7 colonies of Sandwich Tern (N=307 nests) and Royal Tern
(N=500 nests) in 2008 and 5 colonies of Sandwich Tern (N=340 nests) and Royal Tern (N=470
nests) in 2009 to assess their hatching success. We conducted predator scent station surveys
during the colonial waterbird breeding season in 2008 (N= 2 surveys) and 2009 (N=4 surveys).
Future work will focus on identifying important habitat characteristics for these breeding
waterbirds and comparing these characteristics between 2008 and 2009.
HURRICANE IMPACTS ON BROWN PELICAN NESTING COLONIES. Walter, S.T., P.
Leberg, M. Carloss, T. Hess, Department of Biology, University of Louisiana at Lafayette.
Since the 1963 extirpation of the brown pelican in Louisiana due to DDT pesticide
contamination, and subsequent restoration efforts that repopulated the region, maintaining viable
nesting numbers of the endangered species have been of concern. Given destructive hurricane
threats to barrier island nesting habitat, attempts to initiate new nesting colonies via
translocations of chicks to islands without nesting colonies, as well using decoys to attract
nesting adults, are a currently under assessment. Knowing what fine-scale habitat values are
most commonly used by pelicans, and how those conditions affect nest success would provide
critical information to select target islands for new colonies. This study tracked 603 nests on
Raccoon and Wine Islands, LA during 2008-09, and measured nest-site habitat characteristics.
These nest-site characteristics were compared to measurements from 289 random plots to assess
what factors lead to nest choice and success. Hurricanes Gustav and Ike in fall 2008 allow for
pre- and post-hurricane assessments of nest success and habitat composition. Preliminary results
suggest woody vegetation is most commonly used for nesting platforms, yet have been reduced
due to storm effects. Furthermore, an average of 1.1m /wk shoreline loss on Wine Island during
May-July 2009 has further reduced nesting habitat.
Understanding how hurricanes and vegetation availability affect brown pelican nesting can
provide useful information for future coastal conservation efforts.
SOCIAL FACILITATION AND PREDATION AS FACTORS IN COLONY SITE
SELECTION OF SEABIRDS ON LOUISIANA BARRIER ISLANDS. Cecilia Leumas1,
Dr. Frank Rohwer1, Edward Raynor2, and Dr. Aaron Pierce2, 1School of Renewable Natural
Resources, LSU Agricultural Center, 2Department of Biological Sciences, Nicholls State
University.
Colonial nesting seabirds face a variety of threats, including habitat loss and degradation, human
disturbance, and predation. Louisiana contains large breeding colonies of many of these birds,
and several species of conservation concern concentrate high percentages of their total U.S.
populations here. However, some areas with apparently suitable nesting habitat do not host
colonies. We are studying the assemblage of seabirds, including Royal Terns, Sandwich Terns,
and Black Skimmers, nesting on Isles Dernieres barrier islands along the Gulf coast of Louisiana.
Two of the four islands in this chain host extensive seabird colonies and two do not. Our
objective is to better understand what factors limit the use of available habitat on barrier islands.
We used an experimental approach to test two hypotheses that may explain seabird preference
for one island over another. We used decoys and call broadcast to test the hypothesis that social
facilitation is required for these species to form new colonies. To test the hypothesis that
disturbance by potential predators prevents new colony formation, we erected fences around half
of our experimental plots, and conducted predator surveys on all four islands. Only one pair of
seabirds was induced to nest by our social facilitation, although behavioral observations indicate
that seabirds showed more interest in decoy than in control plots, and that sound enhanced the
attractiveness of the decoys. We were unable to test disturbance without nests; however, predator
surveys revealed the presence of raccoons, rats, and coyotes on non-colony islands, and no
mammalian predators on colony islands.
THE EFFECT OF CLIMATE AND RIVER STAGE ON OVERCUP OAK (Quercus
lyrata) TREE GROWTH IN A HYDROLOGICALLY DISCONNECTED FLOODPLAIN.
Hugo K. W. Gee, Louisiana State University, AgCenter, 307 School of Renewable Natural
Resources, Baton Rouge, LA 70803 USA.
Floodplain tree growth has been found to be more strongly influenced by local scale climate
factors (precipitation and temperature) than river stage following completion of a hydroelectric
dam in North Dakota. In Concordia Parish (Louisiana), construction of a ring levee for flood
protection and then a lock and dam system for navigation has dramatically altered seasonal
variability in river stage. Our objective was to determine the effect of local scale climate factors
and river stage patterns on tree growth during three periods in time: 1) pre-levee, 2) post-levee
but pre-lock and dams, and 3) post-lock and dams. Dendrochronological techniques were used
to develop tree-ring chronologies of the flood tolerant, overcup oak (Quercus lyrata), from three
closed canopy forest stands at Red River Wildlife Management Area. A climate-growth model
was developed for overcup oak using local scale climate factors (monthly total precipitation,
monthly average temperature, and monthly Palmer Drought Severity Index). Age-related and
climatic effects were removed from the tree-ring chronology and correlation analysis was used to
compare the residual chronology for each stand with monthly river stage (maximum, mean, and
minimum) of the adjacent Red and Mississippi Rivers. Future plans include comparing overcup
oak growth with local hydrology (surface and subsurface) in monitoring wells within and among
stands and historical flooding regime (since the last hydrologic modification) at water wells
extrapolated from nearby river gauges.
PRAIRIE RESTORATION EFFORTS ON OUACHITA WILDLIFE MANAGEMENT
AREA TO BENEFIT GRASSLAND BIRDS. Matt Pardue and Kim Marie Tolson,
Department of Biology, College of Arts and Sciences, University of Louisiana at Monroe,
Monroe, LA 71209-0520.
Only about 600 acres of native prairie remain in Louisiana with most of the remnants located in
the southern portion of the state. Coastal prairie once comprised between two and three million
acres. However, prairies could also once be found throughout scattered localities in north
Louisiana. These prairies were known as “pocket prairies” due to their small size and general
isolation from similar biomes. Dominant grasses within these communities include Andropogon
gerardii, Schizacharium scoparius, Sorghastrum nutans, and Tripsacum dactyloides. Many birds
rely on these prairie ecosystems during there life cycle for feeding, cover, nesting, and broodrearing. Grassland birds have seen some of the sharpest declines of bird species throughout
North America. Partners in Flight along with the Cornell Lab of Ornithology have listed several
species of grassland birds as species of concern, and have placed them on their Continental
Watchlist. The Louisiana Department of Wildlife and Fisheries recognized a site of ~ 110 acres
within Ouachita Wildlife Management Area that is thought to be of the Mississippi Terrace
Prairie type which holds an S1 ranking by the Louisiana Natural Heritage Program. Restoration
efforts were initiated in the fall of 2007 in a cooperative agreement between ULM and LDWF.
Status of the restoration efforts will be presented during the meeting. This site is reclaimed
agricultural land that was previously used for rice and corn production, and has seen multiple
reforestation efforts fail. Preliminary results have identified over 132 species of plants on the
site, as well as 107 species of avifauna.
PRELIMINARY RESULTS OF DICKCISSEL (Spiza americana) NESTING SUCCESS IN
NORTHEAST LOUISIANA. Matt Pardue and Kim Marie Tolson, Department of Biology,
College of Arts and Sciences, University of Louisiana at Monroe, Monroe, LA 71209-0520.
Grassland birds have experienced some of the sharpest declines of any birds in North America.
One grassland species, the dickcissel, (Spiza americana) is listed as a species of concern by the
Cornell Lab of Ornithology and Partners in Flight (Rich et al., 2004), and has been placed on the
Audobon Watch List. The dickcissel is a neotropical migratory bird that once utilized vast
grassland and prairie habitat for foraging and nesting purposes (Weidenfeld and Swan, 2000).
The Cornell Lab of Ornithology lists several conservation concerns for the dickcissel. The dearth
of knowledge of nesting ecology and nest predation is one such concern. With the loss of prairie
habitat, dickcissels are now found in a wide range of habitats, particularly in lands enrolled in
federal programs, such as WRP, CRP, and CREP. These programs provide early successional
habitat for the first few years of enrollment. However, after several years, succession takes place,
allowing for larger trees to take over, shading out low growing forbs and grasses. Thick ground
cover is preferred by nesting dickcissels for a variety of reasons, to include visual isolation from
predators and brown-headed cowbirds, which parasitize many passerine nests (Winter et al.,
2006). Nest searches were performed from the beginning of May through early August in 2008
and 2009. Once a nest was located, it was marked with flagging tape at least 5 m away, a GPS
coordinate taken, and data were collected on height to rim, plant species harboring nest,
vegetation data surrounding nest, overhead obstruction(s), clutch size, and presence of
female/male dickcissels. Once the fate of the nest was determined, visual obstruction
measurements were taken in each of the cardinal directions from a distance of 4 m, using a Robel
pole. Over 200 dickcissel nests were located on three WRP fields in Ouachita Parish, as well as
two CREP, and one WRP field in Richland Parish. Nests were monitored every 4-5 days to
observe nesting success. Successful nests were defined by the fledging of at least one young.
LICHENS: BIODINDICATORS OF AIR QUALITY. Jessica Wakefield and Joydeep
Bhattacharjee, Department of Biology, College of Arts and Sciences, University of Louisiana at
Monroe, Monroe, LA.
Different volatile organic compounds present in the atmosphere in high concentrations have been
shown to have damaging effects on the surrounding environment and human health. This project
is designed to use lichens as a “passive” monitor to identify areas that are at risk for pollution
damage. This research compares air pollution levels at different sites by using lichen disc
transplants. Lichens were transplanted from an area of known low pollution (control site) to
areas of potentially higher pollution levels and monitored over time to evaluate the use of lichens
as bioindicators of air quality. Five sites surrounding Monroe, Louisiana were selected which
include: one city park (Restoration Park in West Monroe), one wildlife management area
(Russell Sage), and three national wildlife refuges (D’Arbonne, Upper Ouachita and Black
Bayou Lake). Within each site two stations were delineated. One station represented an outer
edge of the site close to a highway with predicted higher pollution levels while the other station
represented a more secluded and pristine area within the site. Air quality samples were taken
using SUMMA air canisters. At each station there were three 1ft sq boards containing six lichen
bark discs and three suspended twigs. The lichen transplants were taken from Russell Sage
WMA (control site) where the levels of pollution are low. Monitoring of the lichens will include
photographic comparisons over time, chlorophyll analysis using a spectrophotometer, and
morphological changes in the lichen thallus. This study will continue through 2009. Preliminary
monitoring results will be presented.
QUANTIFIYING THE EFFECTS OF PREDATOR MANAGEMENT ON MALLARD
RECRUITMENT IN NORTH DAKOTA. Matthew R. Pieron1 and Courtney L. Amundson2,
1
School of Renewable Natural Resources, LSU, 2 University of Minnesota.
Since 1994, Delta Waterfowl Foundation (DWF) has trapped mammalian meso-predators in
North Dakota (ND) during spring and summer in an attempt to increase waterfowl nest success
and subsequent production. DWF has derived rough predictions of “incremental ducks”
produced as a result of predator management, however, many of the vital rate estimates used for
these analyses were obtained piecemeal from various studies in varying times and locations.
Here, we present an assessment of operational predator management’s impact on mallard
production with vital rate estimates from the same study areas in the same years (2006-2007).
We conducted our study on eight, township-scale (93.2 km2) sites; five had mammalian meso-
predators removed as part of DWF’s predator management program, three had no predator
removal and served as controls. To evaluate the efficacy of predator management for increasing
mallard production in ND’s drift prairie we: 1) modeled the impact of predator reduction on
mallard duckling survival, pair numbers, and nest success, 2) built a matrix model to estimate
recruitment into the fall population, and 3) conducted a sensitivity analysis to explore the relative
contribution of vital rates to overall recruitment.
Average mallard nest success was significantly higher on trapped sites (x̄ =55%) than control
sites (x̄ =33%), but trapping had no effect on pair numbers (x̄ Trapped = 1340, and x̄ Control =1414)
or duckling survival (x̄ Trapped = 19.2%, and x̄ Control = 23.0%). Our model predicts that trapped
sites produced 30 more mallards than control sites (852 vs. 822, respectively), at an approximate
cost of $300 per incremental duck. These results suggest the benefits of predator management to
mallard recruitment have not materialized, even with a substantial increase in nesting success,
which is believed to be the most important vital rate influencing production. Our sensitivity
analysis indicates that during our study, duckling survival, not nest success, was the most
important factor regulating mallard population growth. In our site-years, when hen success was
greater than approximately 25% (11% nest success), duckling survival was the most important
driving factor in mallard recruitment.
Our study illustrates the need for local assessment of vital rates in order to a) determine which
vital rates drive population growth, and b) what management actions may increase those rates.
Lastly, although suggested as a cost effective management tool, predator management may have
diminishing returns in areas where removing mammalian meso-predators doesn’t influence
duckling survival and when background nest success levels are well above those needed to
maintain populations .
UTILIZING GEOSPATIAL ANALYSIS AND VEGETATION PATTERNS FOR MORE
EFFECTIVE WOOD DUCK NEST BOX PLACEMENT. Justin Martin and Kim M. Tolson.
Department of Biology, College of Arts and Sciences, University of Louisiana at Monroe,
Monroe, LA. 71209-0520.
Artificial nest-boxes were first used in 1937 to provide alternative nesting sites for wood ducks
(Aix sponsa). The Louisiana Department of Wildlife and Fisheries began its nest box monitoring
program in 1990. During this study, 141 boxes were surveyed. Out of the 141 boxes, 67 were
located in and around Wetlands Reserve Program land, 36 were located in/around bottomland
hardwood forests, and 38 were located in/around a mature mixed bald cypress and water tupelo
brake. Nest-boxes were checked bi-weekly beginning on 19 Feb 2008 and continued until 1
August 2008. Variations in clutch size, nest initiation, nest success, and nest-box utilization
were recorded. The average clutch size of WRP was 12.67 ± 2.94. The average clutch size for
BLH was 12.84 ± 3.14. CWT had an average clutch size of 13.03 ± 3.42 eggs. The first nest
initiation in this study was 11 Feb 2008 while the last nest was initiated on 28 June 2008. WRP
had the greatest amount of nest success. Average nest box utilization for WRP was 42.2%, BLH
30.2%, and CWT 23.1% during the study. Nest predators were also documented. Other animals
that utilized the boxes were also documented. A base map of the study areas were constructed
using ARCMAP GIS. Additionally a land use/land cover map of the study areas was created to
diagram the current nest-box placement of the study areas. Nest-box data along with the
mapping data will be combined to develop a strategic plan for wood duck nest-box management
in Louisiana.
SHOREBIRD USE OF MOIST SOIL UNITS. Rachel Villani, School of Renewable Natural
Resources, LSU AgCenter, Baton Rouge, and Michael Seymore, Louisiana Department of
Wildlife and Fisheries, Baton Rouge, LA.
The Mississippi Alluvial Valley (MAV) provides important stopover habitat for waterbirds
during fall migration, however, unmanaged habitat is usually limited. Moist soil units in the
MAV can potentially provide more predictable habitat resources for shorebirds, wading birds,
marsh birds, and waterfowl during fall migration. In this study, we evaluate waterbird species
presence, abundance, and density on moist soil units on six wildlife management areas (WMAs)
in the MAV of Louisiana to determine habitat use in relation to management activities and
habitat conditions. We conducted 14-15 weekly surveys of moist soil units on 6 WMAs during
the fall of 2007 and 2008. We visually identified all waterbirds present at survey points on each
moist soil unit. In addition, we recorded distance, behavior, habitat, and water depth for all birds
observed, and completed vegetation surveys during the season at each survey point. We observed
21,135 and 23,942 waterbirds in 2007 and 2008, respectively. In 2007 we recorded 7,900
shorebirds, and in 2008 we recorded 7,796 shorebirds. Shorebird density was highest during 5-11
August 2007 and 29 September-5 October 2008. The amount of herbaceous vegetation and water
depth were factors limiting shorebird use of moist soil units.
REPRODUCTIVE BIOLOGY OF A BOPYRID ISOPOD, Probopyrus pandalicola, AND
ITS HYPERPARASITE, Cabirops sp., PARASITIC ON THE RIVER SHRIMP,
Macrobrachium ohione . Sara LaPorte Conner and Raymond T. Bauer, Department of Biology,
University of Louisiana at Lafayette.
Macrobrachium ohione is a caridean river shrimp that migrates downstream to brackish water to
release its larvae. The larvae must be exposed to saline water (optimal salinity of 15o/oo) in order
to complete their development. Post larvae then migrate upstream to adult freshwater habitats.
Probopyrus pandalicola is a bopyrid isopod parasite that lives in the branchial chamber of M.
ohione. The epicaridium larvae of this parasite must find brackish water calanoid copepods, their
intermediate hosts. The cryptoniscus larva, the infective stage, then finds a definitive host, in this
case M. ohione. The hypothesis that the bopyrid parasite times its larval release to that of the host
shrimp’s larval release was tested. Even though both species require saline water for larval
development, it does not appear that the bopyrid parasite has to time its larval release to the
shrimp’s arrival in estuarine waters. Preliminary results indicate that the epicaridium larvae
survive longer in freshwater than the shrimp larvae, possibly long enough for the downstream
river flow to take them into a suitable saline habitat. It is here noted that P. pandalicola was
found to be parasitized itself by another isopod, the hyperparasite Cabirops sp. Studies on this
species have been initiated and a brief overview of its reproductive biology will be presented.
HIGHER GROUND: REDUCED FLOODING IMPROVES Spartina patens
PRODUCTION IN LOUISIANA’S COASTAL MARSHES. V.D. Tobias1, J.A. Nyman1, R.D.
DeLaune2, J.D. Foret3 1School of Renewable Natural Resources, Louisiana State University,
Baton Rouge, LA, USA, 2Department of Oceanography and Coastal Sciences, Louisiana State
University, Baton Rouge, LA, USA, 3National Oceanic and Atmospheric Administration,
National Marine Fisheries Service Estuarine Habitats and Coastal Fisheries Center, Lafayette,
LA, USA 70506.
Quantifying how flooding affects plants in coastal wetlands is important for improving
management practices and predicting the effects of sea level rise. Manipulating flooding stress
traditionally uses greenhouse studies or three levels of flooding in the field. To examine the
effects of flooding stress in Spartina patens, the most common plant in coastal Louisiana
marshes, we modified a recently developed field-based technique. This technique employs
devices, termed “marsh organs,” that create six levels of flooding stress ranging from 46 cm
above- to 30 cm below local marsh level and subjects plants to natural variations in water level.
We installed two marsh organs in intermediate marshes near the mouth of the Atchafalaya River
(Marsh Island Wildlife Refuge) and two marsh organs far from riverine influences (Rockefeller
Refuge). At each refuge, we installed one marsh organ in a relatively saline location, and one in
a relatively fresh location (total = 4 marsh organs, 144 pipes). A previous study using this
technique found that flooding stimulates growth in S. alterniflora on the Atlantic coast, a
reaction that contributed to marsh stability. Our results indicate that flooding reduces aboveand below-ground production in S. patens on the Gulf of Mexico coast. It is unclear whether
observed differences in productivity are caused by physiological differences between the species
or by the geomorphologies of the regions. Preliminary results from an inexpensive and widelyavailable elemental analysis suggest that decreased manganese concentrations in leaf tissue may
be a useful indicator for flooding stress in S. patens.
ABSTRACTS FOR FOCUS SESSION
Friday, 14 August 2009
INTRODUCTION TO INVASIVE SPECIES IN LOUISIANA: WHAT WE HAVE,
WHAT WE DON’T WANT AND WHAT WE’RE DOING ABOUT IT. Hallie Dozier, LSU
AgCenter, School of Renewable Natural Resources, 227 Renewable Natural Resources, LSU,
Baton Rouge, LA 70803.
Increased transport of non-native plant materials and animals promotes invasion of natural areas
by non-native species. Invasive populations of non-native species are considered to be second
only to ecosystem fragmentation in terms of the threat posed to natural areas. Animals and plants
are introduced intentionally for a variety of reasons, including agricultural, fiber, ornamental
purposes, and even the exotic pet trade. While most introduced species never cause problems or
become invasive, Louisiana currently faces the challenges posed by several plant and animal
species that now call Louisiana home. The economic impact of these species from degradation of
natural areas as well as the cost of their management and control is potentially enormous. Learn
the latest about spread, threat and management efforts in Louisiana for cogon grass, nutria,
Chinese privet and others.
THE DISCOVERY OF, AND RAPID RESPONSE TO, A WILD POPULATION OF
TILAPIA IN PORT SULFUR, LOUISIANA. Brac Salyers, Louisiana Department of Wildlife
and Fisheries, Inland Fisheries Biologist, ANS, 2000 Quail Drive, Post Office Box 98000, Baton
Rouge, LA 70898-9000.
Whether it’s by displacing native species, altering or destroying habitats, over competition for
resources, or excessive reproduction, aquatic invasive species are becoming a much greater and
more obvious problem across the country, especially here in Louisiana. South Louisiana’s subtropical climate provides us with longer growing seasons, milder winters, and the resulting
opportunity for many exotic species to become established here that wouldn’t be able to survive
in most other parts of the country.
In early 2009, LDWF biologists found a thriving, reproducing population of tilapia (Oreochromis
sp.) in Plaquemines Parish, around the town of Port Sulphur, LA. For many weeks following this
discovery, biologists sampled every connecting, adjacent, and nearby waterway to try to figure
out how far this population had spread. Once the range of exactly where these fish were and
were not found was established, the Secretary of LDWF, Mr. Robert Barham, issued an
immediate closure of all commercial and recreational fishing in the area. A rapid response plan
was quickly developed to attempt an eradication of all the infected waterbodies. This
presentation will discuss the efforts of that rapid response plan, along with the results, and future
plans for the areas within the fishing closure of the Port Sulphur community.
GIANT SALVINIA (Salvinia molesta) IN LOUISIANA WATERWAYS – A MULTIPLE
MANAGEMENT APPROACH. Alexander J. Perret, Louisiana Department of Wildlife and
Fisheries, Aquatic Plant Control, Inland Fisheries Division, 2000 Quail Drive, Post Office Box
98000, Baton Rouge, LA 70898-9000.
Giant salvinia (Salvinia molesta) is an invasive aquatic floating fern native to South America. It
has been considered by some to be the world’s worst aquatic weed due to its capability of
doubling in biomass every 7-10 days. Giant salvinia was first documented in Louisiana in 1998
and has since threatened the state’s freshwater natural resources. It is a difficult weed to manage
not only because of its high growth rate but also because its location can be altered quickly by
changes in wind and current direction, causing areas that were previously clear to become
clogged in just hours. Managers with the Louisiana Department of Wildlife and Fisheries have
been experimenting with several control methods over the past few years. Chemical control
through the use of foliar and injected herbicides is only moderately effective due to the physical
characteristics of the plant, and can be expensive. However, whole water body treatments have
been successful when appropriate and economically feasible. Mechanical removal of giant
salvinia is effective, but is extremely labor intensive and not efficient. Grass carp will not eat the
plant because it makes them sick, but a potentially effective biological control method is
currently being developed. Giant salvinia weevils have been shown to significantly decrease the
biomass of the plant over time. Though it could take several years to become effective, giant
salvinia weevil introductions, along with continued chemical and mechanical control efforts,
may allow us to regain control of our freshwater resources.
COGONGRASS: BIOLOGY, DISTRIBUTION, IMPACTS AND CONTROL
STRATEGIES FOR LOUISIANA . Scott Edwards, USDA, Natural Resources Conservation
Service, Acadiana RC&D Council, Inc, 3419 NW Evangeline Thruway, Suite B-9, Carencro, LA
70520. email: scott.edwards@la.usda.gov.
Cogongrass (Imperata cylindrica) is an invasive noxious grass that spreads by aggressive
underground rhizomes and light fluffy seed. Unchecked this grass will completely dominate and
displace desired species in non-cultivated sites, including pastures, fallow fields, forests, parks,
highway and railroad rights-of-way. Cogongrass will not persist in frequently cultivated areas,
but once established it is difficult to eliminate. Mowing or burning removes above ground
vegetation, which opens the plant canopy for emergence of seedlings and new stems from
rhizomes. Although single mechanical treatments are not effective, sequential combinations of
mechanical and chemical treatments applied in a persistent manner can eliminate a cogongrass
infestation. Various local, state and federal programs have had varying rates of success
suppressing the spread of cogongrass across the southeastern U.S. This presentation will discuss
the basic biology of the plant, mode and extent of infestation, control options and examples of
programs available for cogongrass management in Louisiana.
ABSTRACTS FOR POSTER PRESENTATIONS
Friday, 14 August 2009
EFFICACY OF AUTOMATIC VOCALIZATION RECOGNITION SOFTWARE FOR
ANURAN MONITORING. Tyler Thigpen, IAP World Services, Inc., U.S. Geological Survey,
National Wetlands Research Center, Lafayette, LA.
Call surveys are a commonly employed technique for monitoring anurans, but they are costly,
training is time-consuming, and survey protocol is difficult to standardize across sampling sites.
Digital automated recording systems (ARS) are an affordable alternative for obtaining recordings
of frog vocalizations. The hardware can be programmed to survey at a predetermined time, thus
requiring less input from operators. However, the number of audio files recorded by ARS can
overwhelm listeners quickly. We tested a commercially available vocalization recognition
software program for personal computers to assess whether the software is a viable technique for
anuran call monitoring. We created recognizer files for three species: Hyla cinerea, Lithobates
catesbeianus and Lithobates clamitans. It took from 3-20 hours for the software to scan 200
hours of recordings for each of the three species at the minimum quality rejection parameters we
chose. The software misidentified calls at rates of 2.7%-15.8% per species. In addition, the
software failed to detect calls heard by a human listener in 45%-51% of recordings. A tradeoff
exists between false positive and false negative errors, which can be manipulated by changing
recognition software parameters. It is unlikely that software recognition of frog calls will be
100% accurate, so methods for data analysis that take error rates into account need to be
developed. While the potential for automatic frog call recognition as a monitoring tool is great,
the development of the technique will require consideration of the limitations of the software
used.
EFFECTS OF PRESCRIBED FIRE ON THE HERPETOFAUNA OF A SMALL
PRAIRIE RESTORATION SITE. Kevin Jobe and Kim M. Tolson, Department of Biology,
College of Arts and Sciences, The University of Louisiana-Monroe, Monroe, LA 71209-0520
A prairie restoration site at Ouachita Wildlife Management Area, located in southeast Ouachita
Parish, was once used as agricultural land, and in recent years, has undergone failed attempts at
reforestation. Currently, the site is being converted into a tallgrass prairie of native Louisiana
grasses and forbs, using prescribed fire to set back succession of woody vegetation. Drift
fence/funnel trap arrays, coverboards, and bucket (pitfall) traps were used to estimate species
richness, evenness, and diversity of herpetofauna across two sections of the prairie site at
different levels of restoration: one unburned site and one site burned within the past year.
Throughout the fall and spring of 2008-2009, 116 individuals representing 18 species were
captured across both sites. Results of Shannon’s index, Shannon’s equitability index, and species
richness data suggested that herpetofaunal species diversity and evenness were not significantly
different between both sites. Community composition, across both trap sites, also yielded no
statistical difference (χ² = 26.39, df = 17, p = 0.068). The Eastern Narrow-mouthed Toad,
Gastrophryne carolinensis, was the only species that exhibited difference, preferring the
unburned habitat (χ² = 7.364, df = 1, p = 0.007). We hypothesize species-specific responses to
different burn regimes were due to changes in vegetation structure and microhabitat conditions
affected by prescribed fire. In order to maximize herpetofaunal diversity, sections of the prairie
could be managed with different burn regimes, therefore creating a mosaic of habitat types.
PRELIMINARY INVESTIGATION INTO HABITAT SELECTION OF NORTHERN
MYOTIS (Myotis septentrionalis) IN LOUISIANA. Bridget Nixon and Dr. Paul Leberg,
Department of Biology, University of Louisiana at Lafayette.
The Northern Myotis (Myotis septentrionalis) was first observed in Louisiana in 2000, marking
either a southern expansion of the species’ range or a previously undetected, separated
population. While this population is known to use bridges as summer roosts, it is unknown how
these bridges are selected and if any additional roosts are used. Additionally, it is unclear how
many individuals may be in this population. Our work involves bridge surveys to locate the
Northern Myotis and evaluate other species using these habitats. When discovered, Northern
Myotis are evaluated, banded, and fixed with a radio transmitter. Biopsy punches are also taken
for future genetic analysis. During this project, I have so far discovered four individuals
underneath three bridges and observed their use of three trees as additional roosts. Future work
will consist of comparisons of habitat characteristics between known roost sites and bridges that
the species does not appear to be using. This work should add to our understanding of the
ecology of what appears to be Louisiana’s newest mammal.
WHOOPING CRANE ENERGY AVAILABILITY IN DIFFERENT MARSH TYPES.
Sung-Ryong Kang, School of Renewable Natural Resources, LSU AgCenter, Baton Rouge, LA.
Louisiana historically supported both resident and wintering populations of Whooping Cranes
(Grus americana). A resident flock of cranes nested in the isolated freshwater marsh north of
White Lake in Vermillion Parish, whereas migratory cranes wintered on the tallgrass prairies,
brackish marshes, and salt marshes of the Chenier Plain. The current suitability of White Lake
and coastal marshes of Louisiana to support Whooping Cranes is unknown and necessitates an
understanding of marsh characteristics and life history needs of Whooping Cranes. Whooping
Crane chicks are flightless for several months and must be able to access ponds by walking.
Similarly, Whooping Cranes undergo molt from April to June and are flightless during this
period. Thus, food such as aquatic macroinvertebrate and nekton must be available in walking
distance and across suitable terrain. Diets also can provide enough energy to support chick
growth and good health condition of adult. However, little information is available on energy
availability for Whooping Crane in coastal marshes of Louisiana. An improved understanding of
temporal and spatial energy availability is needed to assess the suitability of these marshes for a
potential Whooping Crane reintroduction. The goal of this study is to determine how aquatic
macroinvertebrate and nekton community structure and biomass are affected by season and
microhabitat, and (2) to estimate Energy Availability Index models that use species richness,
biomass, and nutrient value of potential prey in different marsh types. Thus, I will investigate
seasonal variation in aquatic macroinvertebrate and nekton community assemblage structure in
the field. I will also experimentally determine threshold levels of salinity for aquatic
macroinvertebrate and nekton survival. A clear understanding of energy availability will aid an
evaluation of habitat suitability for the potential reintroduction of Whooping Cranes.
DEFINING RESTORATION TARGETS FOR FLOODING AND SALINITY IN
LOUISIANA’S INTERMEDIATE AND BRACKISH MARSHES. J. Andy Nyman1, and
Megan K. La Peyre2, 1School of Renewable Natural Resources, Louisiana State University
Agricultural Center, Baton Rouge, LA USA 70803, 2U.S. Geological Survey, Louisiana Fish and
Wildlife Cooperative Research Unit, School of Renewable Natural Resources, Louisiana State
University Agricultural Center, Baton Rouge, LA USA 70803
Biologists who manage wildlife habitat and wetland restoration projects in coastal Louisiana
often attempt to modify flooding and salinity because those stresses regulate species composition
and productivity of emergent wetland vegetation. It is widely recognized that increased flooding
and salinity can stress emergent plants, but there are few measurements to guide planning and
operation of water control structures. Marsh flooding can be estimated over large areas with few
data where winds have little effect on water levels, but quantifying flooding requires hourly
measurements over long time periods where tides are wind dominated such as the northern Gulf
of Mexico. Estimating salinity of flood water requires direct daily measurements because coastal
marshes are characterized by dynamic salinity gradients. We analyzed 399,772 hourly
observations of water depth and 521,561 hourly observations of water salinity from 14 sites in
Louisiana coastal marshes dominated by Spartina patens Ait Muhl. In stable marshes with slow
wetland loss rates adjacent to the Acadiana Bays, we found that the marsh was flooded 21% of
the time and that marsh elevation averaged 1 cm above mean high water, 15 cm above mean
water, and 32 cm above mean low water levels. Water salinity averaged 3.7 ppt in the spring
(April, May, and June), and 5.4 ppt during the summer (July, August, and September). We
assume that these conditions caused the slow marsh loss typical of this region. Daily, seasonal,
and annual variation in water levels and salinity were evident, and this finding would support the
contention that such variation be retained when designing and operating coastal wetland
management and restoration projects. In marshes adjacent to Calcasieu Lake, where marsh loss
was very rapid in the 1960s and 1970s, we found that the marsh was flooded 32% of the time and
that marsh elevation averaged at mean high water, 9 cm above mean water, and 19 cm above
mean low water levels. Water salinity averaged 10 ppt during the spring and 15 ppt during the
summer. We assume that that these conditions caused the rapid marsh loss occurring 40 years
ago.
WHAT FACTORS AFFECT THE DISTRIBUTION OF KING RAILS, Rallus elegans, IN
COASTAL MARSHES? Bradley A. Pickens, School of Renewable Natural Resources,
Louisiana State University AgCenter, Baton Rouge, LA 70803.
Spatial and temporal heterogeneity in wetlands leads to a variable distribution of species, and the
habitat quality for species can differ greatly on a landscape. Marsh birds are particularly
susceptible to changes in wetland conditions because of their dependence on aquatic
invertebrates and specific hydrologic conditions. Little is known about the habitat affinities of
marsh birds, yet they are currently a high conservation concern in the United States. Here, we
have initiated a study to examine the habitat suitability of a relatively unknown marsh bird, the
King Rail (Rallus elegans), with the objective of determining how hydrological characteristics
and vegetation composition and structure correlate to King Rail presence in managed and
unmanaged coastal marshes of southwestern Louisiana and southeastern Texas during the
breeding bird season. Our results showed that habitat with water depths of 12-15 cm in March
were most frequently occupied by King Rails, and vegetation density also played a major role in
rail distribution. In the future, we will assess the impact of Hurricane Ike and the subsequent
Texas drought on marsh birds, utilize remote sensing to characterize broad-scale hydrological
variables, and determine what vegetation communities tend to support high densities of King
Rails. This information will be used to assess the density of King Rails in coastal marsh and to
manage for the species throughout its range.