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1.
Kathryn L. Sobocinski Jeffery R. Cordell Charles A. Simenstad 《Estuaries and Coasts》2010,33(3):699-711
In coastal environments, the supratidal zone bridges marine and terrestrial ecosystems and is important for energy exchange.
However, it is also subject to extensive anthropogenic disturbance, such as armoring of shorelines. Shoreline armoring is
extensive along many coasts, but the impacts on biota are comparatively unknown. Between 2000 and 2002, paired and synoptic
sampling regimes were employed to assess armoring effects on insects and benthic macroinvertebrates in the supratidal zone
of Puget Sound beaches. Paired sampling showed natural beach sites had significantly more deposited wrack. Infauna was dominated
by oligochaetes and nematodes; talitrid amphipods, insects, and collembolans were significantly more numerous at natural beaches,
and crustaceans were more abundant at altered beaches. Insect assemblages were diverse, with taxon richness higher at natural
beach sites. In the synoptic sampling, where sites with higher elevation modifications were used, there were fewer differences
in invertebrate assemblages between armored and nonarmored sites. The results show that, where shoreline armoring lowers the
land–sea interface, benthic infauna and insect assemblages are disrupted. Widespread shoreline modifications may decrease
the availability of prey resources for fish and wildlife and decrease the contribution of organic material entering the nearshore
ecosystem. 相似文献
2.
作为河、湖以及滨海湿地生态系统中必不可少的组成部分,水生植被具有重要的生态服务价值,且许多生态服务价值是通过改变水体动力条件实现的。含植被水流研究不仅可用于科学阐明水生植被的生态环境效应,还能指导河湖生态系统修复及污染治理的工程实践。本文考虑单向明渠流与波浪2种水动力环境,对国内外有关水生植被对水流结构以及泥沙运动影响研究的主要成果进行梳理。单向明渠流条件下,植被对水动力的影响研究主要集中于植被对水流阻力的影响以及冠层内水体的紊动结构与紊动尺度特征;波浪条件下,植被对波高与波浪流速的减弱作用以及冠层内水体的时均与紊动结构特征是研究重点。受水动力条件控制,植被影响下的泥沙运动特征也受到广泛关注,且研究焦点为单向明渠流条件下水生植被对泥沙起动与输移的影响以及波浪条件下植被对床底泥沙再悬浮的影响。 相似文献
3.
岛屿海岸所处的水动力泥沙环境以及工程实施后引起的相关变化都具有自身的独特性和复杂性。根据历史资料,在对嵊泗中心渔港海区已建工程影响下的水沙动力过程变化深入分析的基础上,利用波浪和潮流共同作用下的二维泥沙数学模型,对拟建工程引起的潮流场、含沙量场以及海床冲淤变化进行了分析和预测。研究表明,已建与拟建防波堤工程会引起港区水动力减弱,海床演变以淤积作用为主,年淤积强度0.1~0.3 m;已围与拟围海造地工程则会束窄潮流通道,导致水动力增强,海床以轻微冲刷为主。拟建工程与已建工程作用下的水沙动力过程具有良好的类比性。 相似文献
4.
A coupled hydrodynamic and sediment transport model (Delft3D) was used to simulate the water levels, waves, and currents associated
with a seagrass (Zostera marina) landscape along a 4-km stretch of coast in Puget Sound, WA, USA. A hydroacoustic survey of seagrass percent cover and nearshore
bathymetry was conducted, and sediment grain size was sampled at 53 locations. Wave energy is a primary factor controlling
seagrass distribution at the site, accounting for 73% of the variability in seagrass minimum depth and 86% of the variability
in percent cover along the shallow, sandy portions of the coast. A combination of numerical simulations and a conceptual model
of the effect of sea-level rise on the cross-shore distribution of seagrass indicates that the area of seagrass habitat may
initially increase and that wave dynamics are an important factor to consider in predicting the effect of sea-level rise on
seagrass distributions in wave-exposed areas. 相似文献
5.
PATRICK J. BRENCHLEY 《Geology Today》1989,5(4):133-137
Storm-driven currents can carry sand from the shoreline tens of kilometres out onto the continental shelves where it is moulded by storm waves into a storm-sand bed showing distinctive sedimentary structures, including hummocky crossstratification. An understanding of the nature of the depositional currents and the processes that form hummocky cross-stratification comes from the work of oceanographers, observations by geologists and experimental studies in the laboratory, although the conclusions reached are sometimes conflicting. Storm-sandstone beds provide valuable information about sediment dispersal and depositional systems in nearshore and shelf environments. Hummocky crossstratification indicates the activity of storm waves and hence the approximate depth of ancient shelf seas. 相似文献
6.
Storm deposits and storm-generated coarse carbonate breccias on a pelagic outer shelf (South-East Basin, France) 总被引：2，自引：0，他引：2
Michel Seguret Alexis Moussine-Pouchkine Guilherme Raja Gabaglia & Frederic Bouchette 《Sedimentology》2001,48(2):231-254
Uppermost Jurassic limestones of the South‐East Basin (France) are organized into four facies associations that were deposited in four distinct zones: (1) peritidal lagoonal limestones; (2) bioclastic and reefal limestones; (3) pelagic lime mudstones; (4) lime mudstones/calcarenites/coarse breccias. Calcarenite deposits of zone 4 exhibit sedimentary structures that are diagnostic of deposition under wave‐induced combined flow. In subzone 4a, both vertical and lateral transitions from lime mudstone/calcarenite to breccia indicate in situ brecciation under wave‐cyclic loading. Breccias were produced by heterogeneous liquefaction of material previously deposited on the sea floor. Deposits in subzone 4a record relatively long periods (>400 kyr) of sedimentation below wave base, alternating with periods of deposition under wave‐induced currents and periods of in situ deformation. In this zone, storm waves were attenuated by wave–sediment interaction, and wave energy was absorbed by the deformation of soft sediment. With reference to present‐day wave attenuation, water depths in this zone ranged between 50 and 80 m. Landwards of the attenuation zone, in zone 3, storm waves were reduced to fair‐weather wave heights. Storm wave base was not horizontal and became shallower landwards. As a consequence, water depth and wave energy were not linearly related. On a small area of the seaward edge of subzone 4a, cobbles were removed by traction currents and redeposited in subzone 4b. There, they formed a 100‐m‐thick wedge, which prograded over 3 km and was built up by the stacking of 5‐ to 20‐m‐thick cross‐stratified sets of coarse breccia. This wedge records the transport and redeposition of cobbles by a high‐velocity unidirectional component of a combined flow. The increase in flow velocity in a restricted area is proposed to result from flow concentration in a channel‐like structure of the downwelling in the gulf formed by the basin. In more distal subzone 4c, the hydrodynamic effect of wave‐induced currents was quasi‐permanent, and brecciation by wave–sediment interaction occurred only episodically. This indicates that, seawards of the attenuation zone, hydrodynamic storm wave base was deeper than mechanical storm wave base. Uppermost Jurassic carbonates were deposited and soft‐sediment deformed on a hurricane‐dominated ramp of very gentle slope and characterized by a zone of storm wave degeneration, located seawards of a zone of sedimentation below wave base. 相似文献
7.
《Proceedings of the Geologists' Association. Geologists' Association》2017,128(3):340-359
Four Middle–Upper Jurassic sections from central Saudi Arabia have been investigated to evaluate microfacies types and macro-invertebrate paleocommunities and to interpret their paleoecology and paleoenvironments. The studied Jurassic successions are part of the Middle–Upper Callovian Tuwaiq Mountain Limestone and the Middle–Upper Oxfordian Hanifa Formation. Three main facies were recorded, including mud-supported microfacies, grain-supported microfacies and boundstones. A data matrix comprising 48 macrobenthic species in 35 samples collected from four sections were grouped into fifteen assemblages and one poorly fossiliferous interval by means of a Q-mode cluster analysis. The recorded macrofaunal assemblages have been subdivided into low-stress and high-stress on the basis of hydrodynamic conditions, substrate type, nutrient supply and hypoxia. The low-stress assemblages occur in (a) high-energy paleoenvironments with firm substrates; (b) high-energy shoals with unstable substrates of low cohesion and in (c) low-energy open marine environments with soft-substrates. The moderate- to high-stress assemblages occur in (a) oligotrophic environments with reduced terrigenous input in shelf lagoonal or in restricted inner ramp settings; (b) low-energy, soft substrate environments with hypoxia below the sediment–water interface; and, in (c) high-energy shoals and shelf lagoonal environments. The temporal distribution patterns of epifaunal and infaunal bivalve taxa are controlled by variations in water energy, substrate characteristics and productivity level. The reported litho- and biofacies confirmed that the Callovian Tuwaiq Mountain Limestone and the Oxfordian Hanifa Formation were deposited across wide spectrum of depositional environments, ranging from restricted lagoon to moderately deeper open marine basin, and providing the perfect conditions for macrofossils. 相似文献
8.
针对渤海湾曹妃甸海域波浪、潮流、泥沙及海床演变特点,应用波流共同作用下二维泥沙数学模型研究港区开发方案。2006年冬季和夏季大、小潮潮流泥沙验证表明,该海域潮位及15条同步垂线流速、流向、含沙量过程的计算值与实测值吻合良好,并进行了矿石码头港池前沿海域在潮流与波浪共同作用下悬沙引起的冲淤验证,计算的冲淤厚度及其分布趋势与实测值比较接近。在此基础上,研究了曹妃甸前岛后陆的港区围垦方案对水动力环境的影响问题,包括该工程引起的曹妃甸甸头以南深槽、老龙沟深槽及各港池的流速变化及底床的冲淤变形等。 相似文献
9.
Carbonate sediment transport pathways based on foraminifera: case study from Frank Sound, Grand Cayman, British West Indies 总被引：2，自引：0，他引：2
Foraminifera can be used to determine the source(s) of carbonate sediment and the directions of sediment transport in shallow, coastal lagoons such as Frank Sound on the south-central coast of Grand Cayman. These determinations, based on the distribution of foraminiferal assemblages and ‘tracer species’ (numerically abundant species that live in known physiographic units and/or ecological conditions), show that the lagoonal sediments are a mixture of grains that originated in the lagoon and forereef. The variable proportions of these foraminifera throughout the lagoon reflects the dynamic processes that control lagoonal sedimentation. Amphistegina gibbosa, Discorbis rosea, and Asterigerina carinata lived in the forereef environment. The fact that these ‘tracer species’ are found throughout Frank Sound and in the beach sands, shows that they were transported across the reef crest and the lagoon. Abrasion-resistant Archaias angulatus, a‘tracer species’ indicative of a lagoonal setting, forms up to 50% of foraminiferal assemblages found in the lagoonal sediments. Preferential winnowing of small tests from these populations indicates sorting under high energy conditions. The vertical distribution of the forereef and lagoonal foraminifera in the sediment blanket that covers the floor of Frank Sound indicates that these processes are temporally persistent. Transportation of forereef foraminifera into and around the lagoon and sorting of the lagoonal foraminifera cannot take place under ‘normal’ conditions when the tranquil lagoon is characterized by weak currents. Storms and/or hurricanes, however, generate short-lived high-energy events that can move and sort the sediment and foraminifera. At the height of a storm, water and sediment are moved over the reef and then piled and held onshore by the onshore winds and the constant flow of water over the reef and across the lagoon. These currents can mix some of the lagoonal and forereef sediments. As a storm wanes, however, the ‘piled water’ flows offshore via strong rip currents that pass into the ocean through the channels which transect the reef. These currents winnow and/or strip sediment from the lagoon and may transport lagoonal sediments into the forereef area. As a result, residual lagoonal sediment is commonly characterized by larger and abrasion-resistant foraminifera. 相似文献
10.
基于波浪边界层理论及单向流泥沙起动Shields曲线,推证出波浪泥沙起动Shields曲线;基于波流边界层理论,提出表述波流边界层动力特征的波流比因子X及非线性作用因子Y,并建立了Y与X的相关关系;在此基础之上,结合单向流及波浪泥沙起动Shields曲线,推证出波流共同作用下泥沙起动Shields曲线。结果表明:波浪泥沙起动Shields曲线在层流区与单向流光滑紊流区曲线保持一致,粗糙紊流区与单向流粗糙紊流区曲线保持一致,过渡区线型为折线,由层流区及粗糙紊流区曲线延长交汇获得;X及Y能够合理地表征波流边界层动力对比特征及非线性作用特征;波流泥沙起动Shields曲线介于波浪及单向流泥沙起动Shields曲线之间,随着波流比因子X的不同,依据非线性作用因子Y,自动在波浪及单向流泥沙起动Shields曲线之间非线性过渡。建立的波流泥沙起动Shields曲线与试验结果吻合较好,且能够概括单向流、波浪及波流等不同动力及细沙、粗沙等不同粒径的泥沙起动条件。 相似文献
11.
Shoreline armoring is extensive in urban areas worldwide, but the ecological consequences are poorly documented. We mapped
shoreline armoring along the Duwamish River estuary (Washington State, USA) and evaluated differences in temperature, invertebrates,
and juvenile salmon (Oncorhynchus spp.) diet between armored and unarmored intertidal habitats. Mean substrate temperatures were significantly warmer at armored
sites, but water temperature similar to unarmored habitats. Epibenthic invertebrate densities were over tenfold greater on
unarmored shorelines and taxa richness double that of armored locations. Taxa richness of neuston invertebrates was also higher
at unarmored sites, but abundance similar. We did not detect differences in Chinook (O. tshawytscha) diet, but observed a higher proportion of benthic prey for chum (O. keta) from unarmored sites. Given that over 66% of the Duwamish shoreline is armored—similar to much of south and central Puget
Sound—our results underscore the need for further ecological study to address the impacts of estuary armoring. 相似文献
12.
Micro-organisms producing microbially induced sedimentary structures, particularly epibenthic cyanobacteria, are not facies-dependent and could flourish in any environment if appropriate ecological conditions were provided. Hence, the changes in environmental parameters are the controlling factors on ecological tolerance of the producers. This study on the lower Cambrian successions of the Lalun Formation in Central Iran shows that paralic environments reacted differently to changes in parameters such as river and tide energy, palaeo-topography, the rate of sediment supply and fluctuations in sea-level, even though all were characterized by sandy substrates suitable for the development of microbially induced sedimentary structures. Therefore, the abundance and preservation of microbially induced sedimentary structures varied in the different paralic environments. From a sequence stratigraphic viewpoint, this study demonstrates that erosional discontinuities lacked the conditions required for the substrate stabilization by microbial communities. The distribution, size and type of microbially induced sedimentary structures within high frequency cycles generally follow the trends of changes in vertical facies stacking patterns. Within systems tracts, the pattern, morphological diversity and size of microbially induced sedimentary structures are not dependent on the type of systems tract, but on the type of depositional system developed such as delta, incised valley, coastal plain, estuaries and shoreline to shelf systems. Generally, estuarine and peritidal carbonates record an increase in the development of mat colonization during the transgressive systems tract, owing to decreased sedimentation rate as well as extended shallow water habitats. In contrast, the existence of microbially induced sedimentary structures depends on the pattern of shoreline shift in depositional systems developed during the highstand systems tract, such as open coast tidal flat and delta environments. If a shoreline regression was continuous (depositional trend and stacking pattern are a set of high frequency cycles), a greater increase in the aggradational component than the progradational component would cause intensified destructive processes hindering the development of microbial communities. 相似文献
13.
Melanie J. Bishop 《Estuaries and Coasts》2005,28(4):510-518
Estuarine assemblages are exposed to multiple disturbances that overlap in time and space. Along the Atlantic Intracoastal
Waterway (east coast, United States), two disturbances that frequently co-occur are the production of wake by boats and the
disposal of sediment dredged from boat channels. Boat wake generally coarsens sediments by eroding finer particles while deposition
of dredge spoil decreases mean grain size. If previously demonstrated effects of boat wake on infauna are due to coarsening
of grain size, deposition of dredge spoil on wake affected sites may, through compensatory effects, prevent an effect of wake
from being detected. Epifaunal assemblages associated with seagrass blades that are more likely to be structured by hydrodynamic
forces than granulometry may instead be affected by boat wake irrespective of the previous deposition of fine materials. To
test these hypotheses, in fauna and epifauna were sampled in patchy seagrass habitat at sites with and without boat wake that
were affected by historic deposition of dredge spoil and at sites without wake that had not received dredge spoil. Sediment
granulometry and infaunal assemblages differed between sites with and without dredge spoit but not between spoil affected
sites differing in exposure to wake. Epifaunal assemblages differed between sites with and without wake irrespective of sediment
granulometry. The effect of wake on epifauna was primarily due to lesser abundances of the gastropodBittiolum varium and the slipper limpet,Crepidula fornicata, at wake exposed sites. These results suggest that because of their opposing effects on sediment granulometry, boat-wake
and sediment disposal may have compensatory effects on infaunal assemblages. The detection of an effect of wake on epifauna
despite the absence of a sedimentological effect of the disturbance shows that ecological impacts do not necessarily mirror
physical effects and should be considered separately when adopting strategies of management. 相似文献
14.
Diann J. Prosser Thomas E. Jordan Jessica L. Nagel Rochelle D. Seitz Donald E. Weller Dennis F. Whigham 《Estuaries and Coasts》2018,41(1):2-18
The nearshore land-water interface is an important ecological zone that faces anthropogenic pressure from development in coastal regions throughout the world. Coastal waters and estuaries like Chesapeake Bay receive and process land discharges loaded with anthropogenic nutrients and other pollutants that cause eutrophication, hypoxia, and other damage to shallow-water ecosystems. In addition, shorelines are increasingly armored with bulkhead (seawall), riprap, and other structures to protect human infrastructure against the threats of sea-level rise, storm surge, and erosion. Armoring can further influence estuarine and nearshore marine ecosystem functions by degrading water quality, spreading invasive species, and destroying ecologically valuable habitat. These detrimental effects on ecosystem function have ramifications for ecologically and economically important flora and fauna. This special issue of Estuaries and Coasts explores the interacting effects of coastal land use and shoreline armoring on estuarine and coastal marine ecosystems. The majority of papers focus on the Chesapeake Bay region, USA, where 50 major tributaries and an extensive watershed (~ 167,000 km2), provide an ideal model to examine the impacts of human activities at scales ranging from the local shoreline to the entire watershed. The papers consider the influence of watershed land use and natural versus armored shorelines on ecosystem properties and processes as well as on key natural resources. 相似文献
15.
Omran E. Frihy 《Natural Hazards》1984,5(1):65-81
Studies of the Nile Delta coast have indicated wide values of local subsidence, ranging from 0.4 to 5 mm/yr. Trend analysis of sea-level rise and shoreline retreat at two Nile Delta promontories have been studied. Records from tide gauges at Alexandria (1944–1989) and Port Said (1926–1987), north of the Nile delta coast, indicate a submergence of the land and/or a rise of the sea-level of 2 and 2.4 mm/yr, respectively.Dramatic erosion has occurred on some beaches of the Nile Delta. This is greatest at the tips of the Rosetta and Damietta promontories, with shoreline retreat up to 58 m/yr. Relationship between the shoreline retreat and sea level trends in terms of correlation analysis and application of the Bruun Rule indicates that the sea level rise has, by itself, a relatively minor effect on coastal erosion. The sea-level trend at the Nile delta coast is found to be only one of several effects on shoreline retreat. Major recent effects include a combination of cut-off of sediment supply to the coast by damming the River Nile and local hydrodynamic forces of waves and currents. Estimates of local future sea-level rise by the year 2100 at Alexandria and Port Said, respectively, is expected to be 37.9 and 44.2 cm. These expectations, combined with other factors, could accelerate coastal erosion, inundate wetlands and lowlands, and increase the salinity of lakes and aquifers. 相似文献
16.
Turbidity is an important habitat component in estuaries for many fishes and affects a range of other ecological functions. Decadal timescale declines in turbidity have been observed in the San Francisco Estuary (Estuary), with the declines generally attributed to a reduction in sediment supply to the Estuary and changes to the erodible sediment pool in the Estuary. However, we analyzed hourly wind data from 1995 through 2015 and found statistically significant declines of 13 to 48% in wind speed around the Estuary. This study applied a 3-D hydrodynamic, wave, and sediment transport model to evaluate the effects of the observed decrease in wind speed on turbidity in the Estuary. The reduction in wind speed over the past 20 years was predicted to result in a decrease in turbidity of 14 to 55% in Suisun Bay from October through January. These results highlight that the observed declines in both wind speed and sediment supply over the past 20 years have resulted in reduced turbidity in the San Francisco Estuary from October through January. This decline in turbidity in Suisun Bay potentially has negative effects on habitat for fish like the endangered Delta Smelt which are more commonly caught in relatively turbid water. 相似文献
17.
This research is conducted as part of a Spanish International Cooperation Agency project with the aim to investigate the sustainable protection of Tunisian coastal zones, as in the case of Beni Khiar and Dar Chaabane coasts (Hammamet Gulf) separated by Oued El Kebir river. The sedimentary dynamic of these beaches is studied in order to identify the main causes responsible for their erosion by the use of different approaches of in situ measurements and numerical methods. Geophysical surveys and sedimentary analyses have demonstrated that sediments are finer and less carbonated from Beni Khiar to Dar Chaabane. Then, the shoreline mapping of several missions of aerial photos has illustrated a mean shoreline retreat between 3 and 4 m/year. In terms of sand volume, a sediment loss more than 30,000 m3/year at Dar Chaabane has been observed since the hill lake structures were built within Oued El Kebir river in 1996. Finally, modelled hydrodynamic and sedimentary patterns have illustrated the refraction of waves in deep water close to shoals and a high-energy concentration along Dar Chaabane coast. The sediment transport direction is mainly of NE-SW induced by ESE-SE wave-driven alongshore current. Results provided by these approaches have shown the importance of Oued El Kebir sediment yield in supplying the neighbouring beaches. Changes in sedimentary dynamics are affected by the modification of hydrodynamic patters caused by the presence of hydrological dams and the implementations of hotels close to the shoreline. This finding underlines the key role of Oued El Kebir fluvial activity in controlling the equilibrium of beaches and their sensitivity to coastal managements induced by man activities, as in the case of the most Mediterranean beaches. 相似文献
18.
Backwater tidal sloughs are commonly found at the landward boundary of estuaries. The Cache Slough complex is a backwater tidal region within the Upper Sacramento–San Joaquin Delta that includes two features that are relevant for resource managers: (1) relatively high abundance of the endangered fish, delta smelt (Hypomesus transpacificus), which prefers turbid water and (2) a recently flooded shallow island, Liberty Island, that is a prototype for habitat restoration. We characterized the turbidity around Liberty Island by measuring suspended-sediment flux at four locations from July 2008 through December 2010. An estuarine turbidity maximum in the backwater Cache Slough complex is created by tidal asymmetry, a limited tidal excursion, and wind-wave resuspension. During the study, there was a net export of sediment, though sediment accumulates within the region from landward tidal transport during the dry season. Sediment is continually resuspended by both wind waves and flood tide currents. The suspended-sediment mass oscillates within the region until winter freshwater flow pulses flush it seaward. The hydrodynamic characteristics within the backwater region such as low freshwater flow during the dry season, flood tide dominance, and a limited tidal excursion favor sediment retention. 相似文献
19.
Katharine A. Smith Elizabeth W. North Fengyan Shi Shih-Nan Chen Raleigh R. Hood Evamaria W. Koch Roger I. E. Newell 《Estuaries and Coasts》2009,32(4):748-757
Seagrass beds have declined in Chesapeake Bay, USA as well as worldwide over the past century. Increased seston concentrations,
which decrease light penetration, are likely one of the main causes of the decline in Chesapeake Bay. It has been hypothesized
that dense populations of suspension-feeding bivalves, such as eastern oysters (Crassostrea virginica), may filter sufficient seston from the water to reduce light attenuation and enhance seagrass growth. Furthermore, eastern
oyster populations can form large three-dimensional reef-like structures that may act like breakwaters by attenuating waves,
thus decreasing sediment resuspension. We developed a quasi-three-dimensional Seagrass-Waves-Oysters-Light-Seston (SWOLS)
model to investigate whether oyster reefs and breakwaters could improve seagrass growth by reducing seston concentrations.
Seagrass growth potential (SGP), a parameter controlled by resuspension-induced turbidity, was calculated in simulations in
which wave height, oyster abundance, and reef/breakwater configuration were varied. Wave height was the dominant factor influencing
SGP, with higher waves increasing sediment resuspension and decreasing SGP. Submerged breakwaters parallel with the shoreline
improved SGP in the presence of 0.2 and 0.4 m waves when sediment resuspension was dominated by wave action, while submerged
groins perpendicular to the shoreline improved SGP under lower wave heights (0.05 and 0.1 m) when resuspension was dominated
by along-shore tidal currents. Oyster-feeding activity did not affect SGP, due to the oysters’ distance from the seagrass
bed and reduced oyster filtration rates under either low or high sediment concentrations. Although the current implementation
of the SWOLS model has simplified geometry, the model does demonstrate that the interaction between oyster filtration and
along-shore circulation, and between man-made structures and wave heights, should be considered when managing seagrass habitats,
planning seagrass restoration projects, and choosing the most suitable methods to protect shorelines from erosion. 相似文献
20.
Matthew S. Kornis Denise Breitburg Richard Balouskus Donna M. Bilkovic Lori A. Davias Steve Giordano Keira Heggie Anson H. Hines John M. Jacobs Thomas E. Jordan Ryan S. King Christopher J. Patrick Rochelle D. Seitz Heather Soulen Timothy E. Targett Donald E. Weller Dennis F. Whigham Jim UphoffJr 《Estuaries and Coasts》2017,40(5):1464-1486
Human alteration of land cover (e.g., urban and agricultural land use) and shoreline hardening (e.g., bulkheading and rip rap revetment) are intensifying due to increasing human populations and sea level rise. Fishes and crustaceans that are ecologically and economically valuable to coastal systems may be affected by these changes, but direct links between these stressors and faunal populations have been elusive at large spatial scales. We examined nearshore abundance patterns of 15 common taxa across gradients of urban and agricultural land cover as well as wetland and hardened shoreline in tributary subestuaries of the Chesapeake Bay and Delaware Coastal Bays. We used a comprehensive landscape-scale study design that included 587 sites in 39 subestuaries. Our analyses indicate shoreline hardening has predominantly negative effects on estuarine fauna in water directly adjacent to the hardened shoreline and at the larger system-scale as cumulative hardened shoreline increased in the subestuary. In contrast, abundances of 12 of 15 species increased with the proportion of shoreline comprised of wetlands. Abundances of several species were also significantly related to watershed cropland cover, submerged aquatic vegetation, and total nitrogen, suggesting land-use-mediated effects on prey and refuge habitat. Specifically, abundances of four bottom-oriented species were negatively related to cropland cover, which is correlated with elevated nitrogen and reduced submerged and wetland vegetation in the receiving subestuary. These empirical relationships raise important considerations for conservation and management strategies in coastal environments. 相似文献