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Unusual sedimentation of a Galveston Bay wetland at Pine Gully, Seabrook, Texas: implications for beach renourishmentCulver, Wesley Richard 02 June 2009 (has links)
Excess sedimentation began affecting the wetland dynamics of Pine Gully in Seabrook, Texas during the first quarter of 2004. This sedimentation was sudden and became a serious problem for the dynamics of the Pine Gully wetland because the fine, well sorted, quartz rich sediments began plugging the main channel of the previously tidally dominated wetland. Progressive sedimentation has produced overbank deposits in the marine grasses, contributing to the death of wetland grasses by sediment chocking. The main purpose of this study is to determine the new source and mechanism of sedimentation in Pine Gully, document changes from sedimentation, and determine a solution to prevent future sedimentation. Sedimentation in Pine Gully and coastal areas adjacent to Pine Gully has occurred in a region that has experienced subsidence and sea level rise. The sedimentation in Pine Gully is a direct result of new and sustained sediment at the mouth of Pine Gully. These new sediments are transported into Pine Gully by displacement waves from ships moving through the Houston Ship Channel. Beach renourishment at Wright Beach, located a half mile north of Pine Gully, occurred as Pine Gully experienced sedimentation. Construction of a breakwater at the mouth of Pine Gully and subsequent removal of sediment in Pine Gully itself is ultimately the solution to revitalizing the wetland to its pre-sedimentation state. Replanting of native vegetation killed off by sedimentation is recommended and would hasten the recovery of the wetland. Documenting the effects of this unique sedimentation in Pine Gully has implications for the future. Beach renourishment or coastal projects that may contribute excess sediment to the coastline should be concerned with unintended effects they may cause. Although an historically eroding shoreline exists, the effects of excess sedimentation can be severe. A coastal study should be done before sediment is added to the shoreline to identify any areas within the sphere of influence of the project. Ecosystems determined to be within the sphere of influence by a coastal study should implement preventative measures at those locations to avoid an ecological disaster similar to that in Pine Gully.
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Unusual sedimentation of a Galveston Bay wetland at Pine Gully, Seabrook, Texas: implications for beach renourishmentCulver, Wesley Richard 02 June 2009 (has links)
Excess sedimentation began affecting the wetland dynamics of Pine Gully in Seabrook, Texas during the first quarter of 2004. This sedimentation was sudden and became a serious problem for the dynamics of the Pine Gully wetland because the fine, well sorted, quartz rich sediments began plugging the main channel of the previously tidally dominated wetland. Progressive sedimentation has produced overbank deposits in the marine grasses, contributing to the death of wetland grasses by sediment chocking. The main purpose of this study is to determine the new source and mechanism of sedimentation in Pine Gully, document changes from sedimentation, and determine a solution to prevent future sedimentation. Sedimentation in Pine Gully and coastal areas adjacent to Pine Gully has occurred in a region that has experienced subsidence and sea level rise. The sedimentation in Pine Gully is a direct result of new and sustained sediment at the mouth of Pine Gully. These new sediments are transported into Pine Gully by displacement waves from ships moving through the Houston Ship Channel. Beach renourishment at Wright Beach, located a half mile north of Pine Gully, occurred as Pine Gully experienced sedimentation. Construction of a breakwater at the mouth of Pine Gully and subsequent removal of sediment in Pine Gully itself is ultimately the solution to revitalizing the wetland to its pre-sedimentation state. Replanting of native vegetation killed off by sedimentation is recommended and would hasten the recovery of the wetland. Documenting the effects of this unique sedimentation in Pine Gully has implications for the future. Beach renourishment or coastal projects that may contribute excess sediment to the coastline should be concerned with unintended effects they may cause. Although an historically eroding shoreline exists, the effects of excess sedimentation can be severe. A coastal study should be done before sediment is added to the shoreline to identify any areas within the sphere of influence of the project. Ecosystems determined to be within the sphere of influence by a coastal study should implement preventative measures at those locations to avoid an ecological disaster similar to that in Pine Gully.
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Factors limiting piping plover nesting pair density and reproductive output on Long Island, New YorkCohen, Jonathan B. 03 May 2005 (has links)
Storm-created nesting habitat and low wave energy moist sediment habitat (MOSH), such as intertidal sandflats, have long been considered important to the recovery of the piping plover (Charadrius melodus), a federally threatened shorebird. Beach renourishment is a common practice on the U.S. Atlantic Coast for the protection of human property from storms, but it also prevents normal MOSH formation. We examined factors limiting piping plover nesting pair density and reproductive output on Atlantic Barrier Islands, 2001-2004, including one site that had been breached by a storm in 1992, and subsequently repaired and renourished by the U.S. Army Corps of Engineers. We also investigated the short-term impact of beach renourishment at these sites. Number of pairs at a site increased with beach area. Pair density increased with MOSH availability at the site level. Home range size increased as the distance from plover nests to MOSH increased. Home range size was smaller for plovers with higher foraging rates in the territory-establishment period, but this effect was most likely independent of distance to MOSH. Reproductive output was not apparently related to availability of MOSH to adults or broods, and was limited by predation. Habitat widths, prey abundance, and brood habitat selection changed at two of our sites after renourishment. However, similar changes occurred in reference areas. Other research shows that in addition to long-term loss of storm-created features, beach stabilization can lead to loss of habitat and low reproductive success due to human development and an increased presence of introduced predators. Management for recovery of this species should thus include permitting natural storm-mediated habitat creation to occur where feasible. However, since we found no direct negative short-term impact of renourishment on prey or habitat availability, habitat restoration via renourishment of eroded beaches could be a viable strategy for plover recovery, if negative indirect short and long-term effects are mitigated. Restoration projects should include restoration or creation of MOSH adjacent to nesting habitat, because MOSH attracts a high density of pairs and to offset long-term loss of storm-created habitat. Human disturbance and predation must also be controlled at restoration sites. / Ph. D.
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Piping plover population dynamics and effects of beach management practices on piping plovers at West Hampton Dunes and Westhampton Beach, New YorkHoughton, Lawrence Mitchell 08 September 2005 (has links)
In the early 1990's, a series of habitat changes caused by storms and subsequent beach management by the U.S. Army Corps of Engineers (USACE, The Corps) provided a unique opportunity to study piping plover population dynamics in a changing environment. In this study, 1993-2004, we attempt to determine the factors that limit or influence the abundance and distribution of piping plovers in West Hampton Dunes (WHD), Long Island, NY, a renourished, highly developed, and high human disturbance area.
The piping plover population on Westhampton Island increased after the hurricane of 1938, and declined thereafter. The decline co-occurred with beach development and vegetative succession. After storms in the winter of 1992-1993 breached the island at West Hampton Dunes, piping plovers re-colonized the area. The New York District USACE filled the breach in 1993, and renourished the beach in 1996 and 2000-2001. USACE renourished parts of the groinfield in Westhampton Beach in 1997.
Each spring and summer, we monitored plovers intensively at WHD and part of the adjacent town of Westhampton Beach (The Reference Area) 1993-2004. We located nests and estimated reproductive and nest and chick survival rates. We monitored plover management efforts and determined causes of nest loss when possible. We monitored piping plover behaviors and obtained an index to plover food supply. We estimated area of plover habitats and defined areas unsuitable for piping plover nesting. We also obtained indices to human and predator presence on the beach.
The WHD piping plover population increased from 0 pairs in 1992 to 39 in 2000 then decreased to 18 pairs in 2004. This decline was closely associated with changes in potential nesting habitat which increased from 22.4 ha in 1992 to 50.1 ha in 2000 then declined to 31.1 ha in 2004
The primary process regulating the WHD population appears to be density dependent immigration and emigration. No other vital rates (clutch size, renest rate, fertility, egg survival, nest survival, chick survival, brood survival, chicks fledged/pair) were correlated with density. The higher equilibrium density at WHD (~1 pair/ha) than at The Reference Area (~0.4 pair/ha) appeared to be a function of the large bay intertidal flats at WHD.
The most common nest predators, cats (WHD = 13% of known predated nests), American Crows (17% of known predated nests) and foxes (37% of known predated nests), are newcomers to piping plover habitats. Thus, plovers may be especially vulnerable to them. Predator removal from the study area appeared to improve nest success and chick survival (R2 = 0.79). Predator exclosures at nests reduced nest loss (WHD = 34% exclosed nests lost vs. 43% of unexclosed nests lost, though in one year, one or more foxes learned to exploit plovers in exclosures (22% of all exclosed nests were predated by foxes in 1995).
This study highlights the long suspected piping plover paradox: increasing beach width can temporarily raise the carrying capacity of an area, but preventing overwash can reduce or eliminate the natural formation of the bay side foraging flats that increase piping plover density, and sometimes, survival. Moreover, beach stabilization allows human development of the habitat which also reduces the carrying capacity of the environment for piping plovers, increases human/plover interactions, and attracts potential predators. / Ph. D.
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Beach Compaction Impact on Nesting Success of Loggerhead (Caretta caretta) Sea Turtles: A Comparison Between a Natural and Renourished Beach in Northern Broward County, FloridaKleppan, Danielle R. 01 August 2013 (has links)
The beaches of Broward County, Florida are a prevalent nesting site for loggerhead (Caretta caretta) sea turtles, however extensive beach erosion is threatening critical nesting habitat. Beach renourishment, the process of transporting offshore or upland sediment onshore, is a widely used method of replenishing lost sand. However, renourishment can negatively affect sea turtle nesting habitat by increasing beach compaction; the resistance to applied pressure in pounds per square inch (psi). Increased sand compaction impedes the digging of the female which affects nesting success. The influence of beach compaction on sea turtle nesting patterns has never been previously examined over the course of a nesting season on Hillsboro and Deerfield Beach. Therefore, this study was designed to examine beach compaction data for Hillsboro, a mostly natural beach, and Deerfield, a completely renourished beach, during the 2010 nesting season and analyze the compaction data against 2010 nest and false crawl (FC, non-nesting emergence) data. Compaction readings were collected during every other week March-October using a soil compaction meter at every other street address along three beach positions, the dune base, mid-beach, and average high tide line (HTL); and at three depths, 15 cm, 30 cm, and 45 cm. Values were not statistically different throughout the season for each beach, so seasonal mean compaction values were used for each beach position and depth. Hillsboro compaction values were rarely over 500 psi (35 kg/cm2), even at 45 cm depth. Deerfield compaction values exceeded the 600 psi (42kg/cm2) measurement limit of the meter in approximately 60% of the compaction values at 30 cm or 45 cm depth. Sand compaction data was analyzed for any trends between beaches as well as within each beach.
Historical data shows higher loggerhead nesting success, the number of nests/total number of crawls (including FC) x 100, on Hillsboro Beach than on Deerfield Beach. The average beach compaction values were compared to nesting success and to nest and FC density within each station area. There was a significant inverse relationship (p<0.05) between beach compaction and nesting success at each of the beach positions and depths, when both Hillsboro and Deerfield Beaches were analyzed together, except at the Mid 30 cm and Dune 45 cm depth. The strongest relationship for the combined beaches was at the HTL 15 cm depth (R2=0.3821, p<0.001). When Hillsboro was analyzed alone, beach compaction and nesting success was only significantly inversely related (R2=0.0875, p<0.02) at the HTL 15 cm depth. This demonstrates that while increased beach compaction may partially influence nesting success, there are likely other beach characteristics that contribute to nest site selection of loggerheads in Northern Broward County. The inverse relationship between Hillsboro mean beach compaction and nest density (nests per meter) was significant only at the HTL 15cm depth (p<0.002) and the inverse relationship between mean beach compaction and false crawl density (FC per meter) in Hillsboro was only significant at the Dune 15 cm (p<0.019) and the Dune 30 cm (p<0.038) depths. Although, increased beach compaction was expected to relate to higher FC density, FC density showed a significant inverse relationship to mean beach compaction at all Deerfield Beach positions and depths in and this suggests off-shore factors may be affecting nest site selection.
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