scholarly journals In Situ Effects of Shoreline Type and Watershed Land Use on Submerged Aquatic Vegetation Habitat Quality in the Chesapeake and Mid-Atlantic Coastal Bays

2017 ◽  
Vol 41 (S1) ◽  
pp. 101-113 ◽  
Author(s):  
J. Brooke Landry ◽  
Rebecca R. Golden
Keyword(s):  
Land Use ◽  
Habitat Quality ◽  
Submerged Aquatic Vegetation ◽  
Aquatic Vegetation ◽  
Population Pressure ◽  
Watershed Land Use ◽  
Coastal Bays ◽  
Shoreline Hardening ◽  
Atlantic Coastal

Abstract Submerged aquatic vegetation (SAV) is an ecologically and economically valuable component of coastal estuaries that acts as an early indicator of both degrading and improving water quality. This study aimed to determine if shoreline hardening, which is associated with increased population pressure and climate change, acts to degrade SAV habitat quality at the local scale. In situ comparisons of SAV beds adjacent to both natural and hardened shorelines in 24 subestuaries throughout the Chesapeake and Mid-Atlantic Coastal Bays indicated that shoreline hardening does impact adjacent SAV beds. Species diversity, evenness, and percent cover were significantly reduced in the presence of riprap revetment. A post hoc analysis also confirmed that SAV is locally affected by watershed land use associated with increased population pressure, though to a lesser degree than impacts observed from shoreline armoring. When observed over time, SAV recovery at the local level took approximately 3 to 4 years following storm impacts, and SAV adjacent to natural shorelines showed more resilience to storms than SAV adjacent to armored shorelines. The negative impacts of shoreline hardening and watershed development on SAV shown here will inform coastal zone management decisions as increasing coastal populations and sea level rise drive these practices.

scholarly journals Effects of Local Watershed Land Use on Water Quality in Mid-Atlantic Coastal Bays and Subestuaries of the Chesapeake Bay

2017 ◽  
Vol 41 (S1) ◽  
pp. 38-53 ◽  
Author(s):  
Thomas E. Jordan ◽  
Donald E. Weller ◽  
Carey E. Pelc
Keyword(s):  
Water Quality ◽  
Land Use ◽  
Chesapeake Bay ◽  
Shallow Waters ◽  
Nutrient Inputs ◽  
Inorganic P ◽  
Estuarine Waters ◽  
Watershed Land Use ◽  
Coastal Bays ◽  
Atlantic Coastal

Abstract Nutrient inputs have degraded estuaries worldwide. We investigated the sources and effects of nutrient inputs by comparing water quality at shallow (< 2m deep) nearshore (within 200 m) locations in a total of 49 Chesapeake subestuaries and Mid-Atlantic coastal bays with differing local watershed land use. During July–October, concentrations of total nitrogen (TN), dissolved ammonium, dissolved inorganic N (DIN), and chlorophyll a were positively correlated with the percentages of cropland and developed land in the local watersheds. TN, DIN, and nitrate were positively correlated with the ratio of watershed area to subestuary area. Total phosphorus (TP) and dissolved phosphate increased with cropland but were not affected by developed land. The relationships among N, P, chlorophyll a, and land use suggest N limitation of chlorophyll a production from July–October. We compared our measurements inside the subestuaries to measurements by the Chesapeake Bay Program in adjacent estuarine waters outside the subestuaries. TP and dissolved inorganic P concentrations inside the subestuaries correlated with concentrations outside the subestuaries. However, water quality inside the subestuaries generally differed from that in adjacent estuarine waters. The concentration of nitrate was lower inside the subestuaries, while the concentrations of other forms of N, TP, and chlorophyll a were higher. This suggests that shallow nearshore waters inside the subestuaries import nitrate while exporting other forms of N as well as TP and chlorophyll a. The importance of local land use and the distinct biogeochemistry of shallow waters should be considered in managing coastal systems.

Variation in parasite communities and health indices of juvenile Lepomis gibbosus across a gradient of watershed land-use and habitat quality

2015 ◽  
Vol 57 ◽  
pp. 564-572 ◽  
Author(s):  
Jacqueline M. Chapman ◽  
David J. Marcogliese ◽  
Cory D. Suski ◽  
Steven J. Cooke
Keyword(s):  
Land Use ◽  
Habitat Quality ◽  
Lepomis Gibbosus ◽  
Watershed Land Use ◽  
Health Indices ◽  
Parasite Communities

scholarly journals Spatiotemporal Dynamics of Submerged Aquatic Vegetation in a Deep Lake from Sentinel-2 Data

Water ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 563 ◽  
Author(s):  
Nicola Ghirardi ◽  
Rossano Bolpagni ◽  
Mariano Bresciani ◽  
Giulia Valerio ◽  
Marco Pilotti ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Satellite Data ◽  
Submerged Aquatic Vegetation ◽  
Aquatic Vegetation ◽  
In Situ Measurements ◽  
Spatiotemporal Variability ◽  
Annual Variations ◽  
Bare Sediment ◽  
Sentinel 2

We mapped the extent of submerged aquatic vegetation (SAV) of Lake Iseo (Northern Italy, over the 2015–2017 period based on satellite data (Sentinel 2 A-B) and in-situ measurements; the objective was to investigate its spatiotemporal variability. We focused on the southern sector of the lake, the location of the shallowest littorals and the most developed macrophyte communities, mainly dominated by Vallisneria spiralis and Najas marina. The method made use of both in-situ measurements and satellite data (22 Sentinel 2 A-B images) that were atmospherically corrected with 6SV code and processed with the BOMBER (Bio-Optical Model-Based tool for Estimating water quality and bottom properties from Remote sensing images). This modeling system was used to estimate the different substrate coverage (bare sediment, dense stands of macrophytes with high albedo, and sparse stand of macrophytes with low albedo). The presented results substantiate the existence of striking inter- and intra-annual variations in the spatial-cover patterns of SAV. Intense uprooting phenomena were also detected, mainly affecting V. spiralis, a species generally considered a highly plastic pioneer taxon. In this context, remote sensing emerges as a very reliable tool for mapping SAV with satisfactory accuracy by offering new perspectives for expanding our comprehension of lacustrine macrophyte dynamics and overcoming some limitations associated with traditional field surveys.

scholarly journals Mapping Submerged Aquatic Vegetation along the Central Vietnamese Coast Using Multi-Source Remote Sensing

2020 ◽  
Vol 9 (6) ◽  
pp. 395
Author(s):  
Tran Ngoc Khanh Ni ◽  
Hoang Cong Tin ◽  
Vo Trong Thach ◽  
Cédric Jamet ◽  
Izuru Saizen
Keyword(s):  
Remote Sensing ◽  
Coastal Area ◽  
Submerged Aquatic Vegetation ◽  
Aquatic Vegetation ◽  
Marine Ecosystem ◽  
Atmospheric Effects ◽  
Landsat 8 ◽  
Distribution Maps ◽  
South Central

Submerged aquatic vegetation (SAV) in the Khanh Hoa (Vietnam) coastal area plays an important role in coastal communities and the marine ecosystem. However, SAV distribution varies widely, in terms of depth and substrate types, making it difficult to monitor using in-situ measurement. Remote sensing can help address this issue. High spatial resolution satellites, with more bands and higher radiometric sensitivity, have been launched recently, including the Vietnamese Natural Resources, Environment, and Disaster Monitoring Satellite (VNREDSat-1) (V1) sensor from Vietnam, launched in 2013. The objective of the study described here was to establish SAV distribution maps for South-Central Vietnam, particularly in the Khanh Hoa coastal area, using Sentinel-2 (S2), Landsat-8, and V1 imagery, and then to assess any changes to SAV over the last ten years, using selected historical data. The satellite top-of-atmosphere signals were initially converted to radiance, and then corrected for atmospheric effects. This treated signal was then used to classify Khanh Hoa coastal water substrates, and these classifications were evaluated using 101 in-situ measurements, collected in 2017 and 2018. The results showed that the three satellites could provide high accuracy, with Kappa coefficients above 0.84, with V1 achieving over 0.87. Our results showed that, from 2008 to 2018, SAV acreage in Khanh Hoa was reduced by 74.2%, while gains in new areas compensated for less than half of these losses. This is the first study to show the potential for using V1 and S2 data to assess the distribution status of SAV in Vietnam, and its outcomes will contribute to the conservation of SAV beds, and to the sustainable exploitation of aquatic resources in the Khanh Hoa coastal area.

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