Strengthening Coastal Landscapes Room 201B
Jan 24, 2023 09:35 AM - 10:35 AM(America/Chicago)
20230124T0935 20230124T1035 America/Chicago Strengthening Coastal Landscapes Room 201B 2023 Bays and Bayous Symposium mbnep@mobilebaynep.com
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Avian Use of Marsh Terraces in Coastal Louisiana
09:35 AM - 09:50 AM (America/Chicago) 2023/01/24 15:35:00 UTC - 2023/01/24 15:50:00 UTC
Louisiana's coastal wetlands support millions of resident and migratory birds annually. Louisiana accounts for approximately half of the coastal wetlands in the continental United States but has experienced a disproportionate amount of coastal land loss compared to other Gulf Coast states. Projections of future land loss indicate that Louisiana's coast may be incapable of supporting historically vast populations of migratory and resident birds. Marsh terracing is a common restoration technique used to combat coastal wetland loss. This technique uses in situ sediment to construct segmented ridges in open water areas to enhance marsh conditions, subsequently establishing vegetation that benefits wetland-dependent fauna. Despite widespread use, past research and monitoring provided limited results on their value as avian habitat. Using ground and aerial surveys, our study evaluated avian use of marsh terraces across 24 paired sites (terraced and adjacent non-terraced sites) in coastal Louisiana. Avian surveys focused on breeding secretive marsh birds (SMB) and wintering waterfowl. Results indicate that presence/absence of marsh terraces influenced numbers of ducks detected, though relative abundance varied spatially and temporally. Preliminary results of the SMB analysis reveal that non-terraced sites were used by a greater abundance and diversity of SMBs than terraced sites, though analysis is ongoing. I suspect that site-specific characteristics and the occurrence of two catastrophic hurricanes influenced observed patterns of avian use of paired sites. Our study will better inform decisions on restoration techniques used to minimize marsh loss and improve avian habitat availability at local and regional scales.
Presenters
BD
Brian Davis
Mississippi State University
Co-Authors
MM
Madelyn McFarland
Mississippi State University
MB
Michael Brasher
Ducks Unlimited Inc.
MW
Mark Woodrey
Mississippi State University - Coastal Research & Extension Center
LR
Larry Reynolds
Louisiana Department Of Wildlife And Fisheries
Comparing Finfish and Crustacean Assemblages Among Established Marsh Terraces, New Marsh Terraces and Open Water in a Restored Brackish Marsh
09:50 AM - 10:05 AM (America/Chicago) 2023/01/24 15:50:00 UTC - 2023/01/24 16:05:00 UTC
Louisiana has lost approximately a quarter of coastal lands that were present in 1932 from a variety of natural and anthropogenic factors, thus necessitating restoration activities. One technique is creating marsh terraces in areas where marsh has been degraded to open water. Terraces provide edge habitat and slow land loss by reducing wave energy in surrounding marsh. This study evaluated the influence of marsh terraces on finfish and crustacean assemblages in a brackish marsh east of Golden Meadow, Louisiana. The habitats evaluated were new terraces built in 2022, established terraces built in 2017, and an open water area. Gee's minnow traps, gill nets and a shrimp trawl were used to sample along terrace edges, terraces channels and in open water. Sampling occurred twice a month May through October 2022. Finfish and crustaceans were identified to species, counted and measured (mm). Catch per unit effort (CPUE) was calculated as number of individuals collected per unit of effort for each gear type. Fundulus grandis (Gulf Killifish) collected in minnow traps had a higher mean CPUE (± SE) in established terraces (0.26 ± 0.08) than new terraces (0.01 ± 0.01; F1,22 = 13.43, P = 0.001), but no differences were detected for other species. Differences between established and new terraces may indicate changes in edge habitat quality for some species while trawl data indicate finfish assemblages are not different among habitats. Examining finfish and crustacean assemblages provided insight into possible ecological effects of terraces and how those effects may change over time.
Presenters
SK
Shasta Kamara
Nicholls State University
Co-Authors
AF
Allyse Ferrara
Nicholls State University
GL
Gary LaFleur
Nicholls State University
JW
Jonathan Willis
Nicholls State University
QF
Quenton Fontenot
Nicholls State University
Integration of Aquaculture Techniques in Oyster Reef Restoration: The Little Dauphin Bay Oyster Restoration Project
10:05 AM - 10:20 AM (America/Chicago) 2023/01/24 16:05:00 UTC - 2023/01/24 16:20:00 UTC
Oyster reef restoration projects often focus on planting cultch and occasionally seeding of hatchery-reared spat on shell requiring large logistical efforts. Fresh set spat experience high mortality due to predation and sedimentation. The Auburn University Shellfish Lab (AUSL) is conducting a three-year oyster reef restoration in Little Dauphin Bay (LDB), AL utilizing aquaculture techniques to improve survival and remove logistical concerns by using smaller setting material Six paired plots (750m2) were cultched with oyster shell in LDB followed by seeding of spat clusters on one plot per pair (shell height=25mm). Spat clusters are produced by setting pediveliger larvae on small shell at the AUSL hatchery and then moved to an AUSL oyster farm. At the farm, aquaculture gear is used to accelerate growth and protect spat from predation prior to planting seed on plots. Three sets of paired plots are trapped for oyster drills to analyze predator mitigation. Plots are assessed semi-annually for differences in oyster populations between seeded and non-seeded plots and predator mitigation effects. At the project midpoint (October 2022), 628,000 oysters were planted with further deployments slated through Fall 2023. Sampling indicates a bi-modal distribution of oysters suggesting two recruitment classes, but no significant population difference is currently observed between seeded and non-seeded plots. Oyster drills appeared on reefs in March 2022 with trapping efforts showing little effect on oyster populations. Sampling of plots through Spring 2024 will determine overall interaction of seeding and trapping in enhancement of restored oyster populations.
Presenters
CL
Christina LoBuglio
Auburn University Shellfish Laboratory
CG
Caroline Golightly
Auburn University
Co-Authors
MC
Meghan Capps
Auburn University
SR
Scott Rikard
Auburn University Shellfish Laboratory
Pedigree Reconstruction and Estimates of Genetic Parameters for Growth Traits in Gulf of Mexico Eastern Oyster Families Reared Communally
10:20 AM - 10:35 AM (America/Chicago) 2023/01/24 16:20:00 UTC - 2023/01/24 16:35:00 UTC
The eastern oyster, Crassostrea virginica, supports large markets throughout the United States. In recent decades, wild stocks have incurred major declines across the species' range including in the Gulf of Mexico (Gulf). In 2019, the SALT consortium initiated a breeding program to support the developing Gulf industry with oysters bred for improved performance in different salinity environments. In September of 2020, the first generation was produced at the Auburn University Shellfish Lab using 102 males and 102 females collected from 17 natural reefs between San Antonio Bay (Texas), and Cedar Key (Florida). Families were bred according to a series of 51 non-overlapping 2 x 2 factorial crossing design, pooled for common garden culture, and deployed at 7 growout sites in April 2021. Based on salinity conditions recorded during the growout period, sites that represented high (one site), and variable-low (three sites) salinity environments were selected and harvested for phenotype measurement and genetic analysis. The 204 founders and 6,414 offspring were assayed at 192 Single Nucleotide Polymorphism markers and the obtained genotypes were used to assign offspring to parent pairs using a likelihood ratio approach. Family distributions differed between the high-salinity site (66% mortality), and the three lower-salinity sites (7-22% mortality) supporting separate breeding for performance at high and low salinity. Heritability estimates for growth rate characterized as shell height at harvest were above 0.38 ± 0.05. Genetic correlations across environments were high (average 0.87, range 0.79-1) suggesting low genotype x environment interactions for growth.
Presenters
HK
Heather King
Auburn University Shellfish Laboratory
Mississippi State University
Nicholls State University
Auburn University Shellfish Laboratory
Auburn University Shellfish Laboratory
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