scholarly journals Benthic Habitat Morphodynamics-Using Remote Sensing to Quantify Storm-Induced Changes in Nearshore Bathymetry and Surface Sediment Texture at Assateague National Seashore

2019 ◽  
Vol 7 (10) ◽  
pp. 371 ◽  
Author(s):  
Arthur Trembanis ◽  
Alimjan Abla ◽  
Ken Haulsee ◽  
Carter DuVal
Keyword(s):  
Multiple Scales ◽  
Habitat Type ◽  
Hurricane Sandy ◽  
Temporal Association ◽  
Benthic Habitat ◽  
Offshore Area ◽  
Side Scan Sonar ◽  
Marine Habitats ◽  
Induced Changes ◽  
National Seashore

This study utilizes repeated geoacoustic mapping to quantify the morphodynamic response of the nearshore to storm-induced changes. The aim of this study was to quantitatively map the nearshore zone of Assateague Island National Seashore (ASIS) to determine what changes in bottom geomorphology and benthic habitats are attributable to storm events including hurricane Sandy and the passage of hurricane Joaquin. Specifically, (1) the entire domain of the National Parks Service offshore area was mapped with side-scan sonar and multibeam bathymetry at a resolution comparable to that of the existing pre-storm survey, (2) a subset of the benthic stations were resampled that represented all sediment strata previously identified, and (3) newly obtained data were compared to that from the pre-storm survey to determined changes that could be attributed to specific storms such as Sandy and Joaquin. Capturing event specific dynamics requires rapid response surveys in close temporal association of the before and after period. The time-lapse between the pre-storm surveys for Sandy and our study meant that only a time and storm integrated signature for that storm could be obtained whereas with hurricane Joaquin we could identify impacts to the habitat type and geomorphology more directly related to that particular storm. This storm impacts study provides for the National Park Service direct documentation of storm-related changes in sediments and marine habitats on multiple scales: From large scale, side-scan sonar maps and interpretation of acoustic bottom types, to characterize as fully as possible habitats from 1 to 10 m up to many kilometer scales, as well as from point benthic samples within each sediment stratum and these results can help guide management of the island resources.

scholarly journals Benthic Habitat Morphodynamics- Using Remote Sensing to Quantify Storm-Induced Changes in Nearshore Bathymetry and Surface Sediment Texture at Assateague National Seashore

2019 ◽  
Author(s):  
Arthur Trembanis ◽  
Alimjan Abla ◽  
Ken Haulsee ◽  
Carter DuVal
Keyword(s):  
Multiple Scales ◽  
Habitat Type ◽  
Hurricane Sandy ◽  
Temporal Association ◽  
Benthic Habitat ◽  
Offshore Area ◽  
Side Scan Sonar ◽  
Marine Habitats ◽  
Induced Changes ◽  
National Seashore

This study utilizes repeated geoacoustic mapping to quantify the morphodynamic response of the nearshore to storm-induced changes. The aim of this study was to quantitatively map the nearshore zone of Assateague Island National Seashore (ASIS) to determine what changes in bottom sediments, benthic fauna and fish habitat are attributable to storm events including hurricane Sandy and the passage of hurricane Joaquin. Specifically, (1) the entire domain of the National Parks Service offshore area was mapped with side-scan sonar and multibeam bathymetry at a resolution comparable to that of the existing pre-storm survey, (2) a subset of the benthic stations were resampled that represented all sediment strata previously identified, and (3) newly obtained data were compared to that from the pre-storm survey to determined changes that could be attributed to specific storms such as Sandy and Joaquin. Capturing event specific dynamics requires rapid response surveys in close temporal association of the before and after period. The time-lapse between the pre-storm surveys for Sandy and our study meant that only a time and storm integrated signature for that storm could be obtained whereas with hurricane Joaquin we could identify impacts to the habitat type and geomorphology more directly related to that particular storm. This storm impacts study provides for the National Park Service direct documentation of storm-related changes in sediments and marine habitats on multiple scales: from large scale, side-scan sonar maps and interpretation of acoustic bottom types, to characterize as fully as possible habitats from 1 to 10 m up to many kilometer scales, as well as from point benthic samples within each sediment stratum and these results can help guide management of the island resources.

scholarly journals Towards spatial management of fisheries in the Gulf: benthic diversity, habitat and fish distributions from Qatari waters

2017 ◽  
Vol 75 (1) ◽  
pp. 178-189 ◽  
Author(s):  
Mark E M Walton ◽  
Jamie Hayes ◽  
Mohsin Al-Ansi ◽  
Mohamed Abdallah ◽  
Ibrahim Al Maslamani ◽  
...  
Keyword(s):  
Coral Reef ◽  
Fish Assemblages ◽  
Habitat Type ◽  
Fish Communities ◽  
Video Data ◽  
Benthic Habitat ◽  
Soft Sediment ◽  
Benthic Habitats ◽  
Marine Habitats ◽  
Spatial Management

Abstract As with many other regions in the world, more complete information on the distribution of marine habitats in the Gulf is required to inform environmental policy, and spatial management of fisheries resources will require better understanding of the relationships between habitat and fish communities. Towed cameras and sediment grabs were used to investigate benthic habitats and associated epifauna, infauna and fish communities in the central Gulf, offshore from the east coast of Qatar, in water depths of between 12 and 52 m. Six different habitats were identified: (i) soft sediment habitats of mud and (ii) sand, and structured habitats of (iii) macro-algal reef, (iv) coral reef, (v) mixed reef, and (vi) oyster bed. The epibenthic community assemblage of the mud habitat was significantly different to that of sand, which in turn differed from the structured habitats of coral reef, mixed reef and oyster bed, with the macroalgal assemblage having similarities to both sand and the other structured habitats. Fish assemblages derived from video data did not differ between habitats, although certain species were only associated with particular habitats. Epibenthic diversity indices were significantly lower in mud, sand and macro-algal habitats, with no differences recorded for fish diversity. Soft sediment grab samples indicated that mud habitats had the highest benthic diversity, with Shannon-Weiner values of >4, and were more diverse than sand with values of 3.3. The study demonstrates high biodiversity in benthic habitats in the central and southwestern Gulf, which may in part be due to the absence of trawling activity in Qatari waters. There is a strong influence of depth on benthic habitat type, so that depth can be used to predict habitat distribution with a high level of accuracy. The presence of outcrops of hard substrata creates a mosaic of patchy shallow structured benthic habitat across extensive areas of the offshore seabed. Such heterogeneity, and the association of commercially exploited fish species with specific habitats, indicates that this region is well suited to a spatial approach to fisheries management.

Responses of lizards to three experiments fires in the savanna forests of Kakadu National Park

1994 ◽  
Vol 21 (2) ◽  
pp. 131 ◽  
Author(s):  
CR Trainor ◽  
JCZ Woinarski
Keyword(s):  
National Park ◽  
Habitat Type ◽  
Detrended Correspondence Analysis ◽  
Fire Regimes ◽  
Direct Effects ◽  
Short Term ◽  
Lizard Species ◽  
Savanna Communities ◽  
Induced Changes ◽  
Term Response

A species-rich lizard community responded variably to a range of experimental fire regimes in a tropical savanna. Heteronotia binoei was the only lizard species that showed a short-term response to fire, decreasing in abundance directly after the early- and late-burns. H. binoei and Diporiphora bilineata were significantly more abundant in early-burn treatments. Carlia amax was more abundant in unburnt and early-burn treatments. C. munda was more abundant in unburnt and early-burn sites. Differences in the relative abundance of species between treatments is attributed to site differences in vegetation structure, and fire-induced changes to the structure of habitat. Early-burn sites were significantly richer in lizard species (P< 0.05); however, overall lizard abundance, Shannon-Wiener diversity and Detrended Correspondence Analysis (DCA) 1 and DCA 2 scores were not significantly different, suggesting that habitat partitioning has a stronger influence than the direct effects of fire. Many lizards were associated with a direct gradient of moisture availability, including a seepage assemblage, with Carlia gracilis and Sphenomorphus darwiniensis correlated with increased moisture, a well-developed canopy and abundant leaf litter. An assemblage associated with the drier end of the gradient included Carlia triacantha, Ctenotus kurnbudj, Diporiphora magna and D. bilineata. The lizard composition of most quadrats was intermediate along the moisture gradient and was associated with typical eucalypt savanna communities. Lizard species that largely are restricted to the moist seepage zones may be particularly sensitive to late dry-season fires which alter this habitat type.

scholarly journals Scaling distributional patterns of butterflies across multiple scales: Impact of range history and habitat type

2018 ◽  
Vol 24 (10) ◽  
pp. 1453-1463 ◽  
Author(s):  
Juha Pöyry ◽  
Risto K. Heikkinen ◽  
Janne Heliölä ◽  
Mikko Kuussaari ◽  
Kimmo Saarinen
Keyword(s):  
Multiple Scales ◽  
Habitat Type ◽  
Distributional Patterns

Benthic Habitats and the Effects of Fishing

2005 ◽  
Keyword(s):  
Habitat Type ◽  
High Energy ◽  
Benthic Habitat ◽  
Commercial Fishing ◽  
Placopecten Magellanicus ◽  
Benthic Species ◽  
Habitat Types ◽  
Closed Area ◽  
Sea Scallops ◽  
Moderate Complexity

<strong><em>Abstract. </em></strong>In late 1994, substantial portions of Georges Bank were closed to commercial fishing to assist with stock rebuilding. These areas were Closed Area I (CAI), located on the western portion of the bank, and Closed Area II (CAII), on the eastern portion. After about 5 years of closure, the southern portion of CAII and the central portion of CAI, having exhibited substantial increases in biomass and density of sea scallops <em>Placopecten magellanicus</em>, were reopened to scallop fishing. Before the industry was allowed entry, we conducted surveys to monitor the recovery of benthic habitat and fauna inside both areas. Sampling sites were selected in a paired station design for an inside–outside comparison representative of major habitat types in each closed area; other stations were chosen to survey the remainder of the closed areas. At each station, we examined a suite of biotic and abiotic variables ranging from substrate type to benthos to nekton. Our results suggest few differences between the inside–outside paired stations in both closed areas for nekton and benthic species composition and species richness. Fish abundance and biomass were similar inside and outside the closed areas. However, individuals of species such as skates (<em>Raja </em>spp.), haddock <em>Melanogrammus aeglefinus</em>, and flounders (Pleuronectiformes) were generally larger inside than outside the closed areas. Additionally, habitat type was important in determining the distribution, abundance, biomass, size, and feeding ecology for some of the more benthic-oriented species studied. In CAI, the differences we observed in the suite of biotic metrics are likely a result of the high diversity of habitat types, with many of the habitat types composed of higher-relief material (e.g., cobble, gravel, etc.) in the region. The seabed in the southern portion of CAII is a relatively high-energy sand habitat of low to moderate complexity and has a relatively low vulnerability to trawling and dredging, which may explain why there were less pronounced differences in abundance or biomass across habitat types in that closed area as compared to CAI. Other parts of closed areas on the northeastern shelf may exhibit more obvious changes in the same biological metrics due to the presence of more complex habitats and increased vulnerability to bottom tending fishing gear. Those differences we observed for CAI and CAII may have implications for the population dynamics of commercially valuable benthic species, yet that question remains a major challenge.

Relict iceberg furrows on the Laurentian Channel and western Grand Banks

1976 ◽  
Vol 13 (8) ◽  
pp. 1082-1092 ◽  
Author(s):  
Lewis H. King
Keyword(s):  
Sea Level ◽  
Late Pleistocene ◽  
Northwest Atlantic ◽  
Offshore Area ◽  
Side Scan Sonar ◽  
Grand Banks ◽  
Level Curves ◽  
History Of

A side-scan sonar survey along the western bank of the Laurentian Channel and on the western Grand Banks revealed the occurrence of iceberg furrows that are probably of Late Pleistocene age. The occurrence of furrows in the Gulf of St. Lawrence is significant in that it helps to date iceberg furrows along the northeast Newfoundland–Labrador margin of the northwest Atlantic, provides data on the history of deglaciation of the offshore area of the Atlantic Provinces, provides a means of evaluating sea level curves, and provides additional evidence for the broad regional extent of the Late Pleistocene shoreline at 115 to 120 m.

scholarly journals BATHYMETRY EXTRACTION FROM SPOT 7 SATELLITE IMAGERY USING RANDOM FOREST METHODS

2019 ◽  
Vol 16 (1) ◽  
pp. 23
Author(s):  
Kuncoro Teguh Setiawan ◽  
Nana Suwargana ◽  
Devica Natalia Br. Ginting ◽  
Masita Dwi Mandini Manessa ◽  
Nanin Anggraini ◽  
...  
Keyword(s):  
Random Forest ◽  
Satellite Imagery ◽  
Coefficient Of Determination ◽  
Shallow Waters ◽  
Benthic Habitat ◽  
Benthic Habitats ◽  
Depth Data ◽  
Marine Habitats ◽  
Random Forest Method

The scope of this research is the application of the random forest method to SPOT 7 data to produce bathymetry information for shallow waters in Indonesia. The study aimed to analyze the effect of base objects in shallow marine habitats on estimating bathymetry from SPOT 7 satellite imagery. SPOT 7 satellite imagery of the shallow sea waters of Gili Matra, West Nusa Tenggara Province was used in this research. The estimation of bathymetry was carried out using two in-situ depth-data modifications, in the form of a random forest algorithm used both without and with benthic habitats (coral reefs, seagrass, macroalgae, and substrates). For bathymetry estimation from SPOT 7 data, the first modification (without benthic habitats) resulted in a 90.2% coefficient of determination (R2) and 1.57 RMSE, while the second modification (with benthic habitats) resulted in an 85.3% coefficient of determination (R2) and 2.48 RMSE. This research showed that the first modification achieved slightly better results than the second modification; thus, the benthic habitat did not significantly influence bathymetry estimation from SPOT 7 imagery.

scholarly journals Regional High-Resolution Benthic Habitat Data from Planet Dove Imagery for Conservation Decision-Making and Marine Planning

2021 ◽  
Vol 13 (21) ◽  
pp. 4215
Author(s):  
Steven R. Schill ◽  
Valerie Pietsch McNulty ◽  
F. Joseph Pollock ◽  
Fritjof Lüthje ◽  
Jiwei Li ◽  
...  
Keyword(s):  
High Resolution ◽  
Marine Protected Area ◽  
Accuracy Assessment ◽  
Marine Conservation ◽  
Benthic Habitat ◽  
Storm Damage ◽  
Ecological Data ◽  
Management Actions ◽  
Marine Habitats ◽  
High Resolution Imagery

High-resolution benthic habitat data fill an important knowledge gap for many areas of the world and are essential for strategic marine conservation planning and implementing effective resource management. Many countries lack the resources and capacity to create these products, which has hindered the development of accurate ecological baselines for assessing protection needs for coastal and marine habitats and monitoring change to guide adaptive management actions. The PlanetScope (PS) Dove Classic SmallSat constellation delivers high-resolution imagery (4 m) and near-daily global coverage that facilitates the compilation of a cloud-free and optimal water column image composite of the Caribbean’s nearshore environment. These data were used to develop a first-of-its-kind regional thirteen-class benthic habitat map to 30 m water depth using an object-based image analysis (OBIA) approach. A total of 203,676 km2 of shallow benthic habitat across the Insular Caribbean was mapped, representing 5% coral reef, 43% seagrass, 15% hardbottom, and 37% other habitats. Results from a combined major class accuracy assessment yielded an overall accuracy of 80% with a standard error of less than 1% yielding a confidence interval of 78%–82%. Of the total area mapped, 15% of these habitats (31,311.7 km2) are within a marine protected or managed area. This information provides a baseline of ecological data for developing and executing more strategic conservation actions, including implementing more effective marine spatial plans, prioritizing and improving marine protected area design, monitoring condition and change for post-storm damage assessments, and providing more accurate habitat data for ecosystem service models.

The impacts of hydraulic clamming in shallow water and the importance of incorporating anthropogenic disturbances into habitat assessments

2020 ◽  
Vol 33 ◽  
pp. 13
Author(s):  
Bryan Legare ◽  
Agnes Mittermayr ◽  
Mark Borrelli
Keyword(s):  
Habitat Type ◽  
Anthropogenic Disturbances ◽  
Benthic Invertebrate ◽  
Grain Size Analysis ◽  
Size Analysis ◽  
Benthic Habitat ◽  
Significance Level ◽  
Type D ◽  
Sample Statistic ◽  
Post Impact

Hydraulic dredging for shellfish is known to create some of the highest levels of disturbance, affecting the benthic microfaunal community and the physical characteristics of the substrate. Properly conducted benthic habitat assessments are complex and time consuming, resulting in assessments not being conducted increasing the uncertainty in post impact studies. Hydraulic dredging for Atlantic surfclams (Spisula soldidissima) took place at Herring Cove, Massachusetts in the winter of 2014–2015 resulting in areas of high impact disturbance of the seafloor. Surveys conducted in the summer of 2015 included hydroacoustics, benthic invertebrate sampling, video, and grain size analysis for the creation of a habitat map of Herring Cove. The four habitats (A–D) identified were a mix of sand, shell, cobble, algae, and eelgrass. Habitat type “D” is a mix of sand, algae and cobble material and occurred at 12 of 18 stations. These 12 stations were distributed across areas of “high” (n = 4), “low” (n = 2), and “no” (n = 6) hydraulic dredge disturbance. Once habitat was accounted for, benthic invertebrate community structure varied significantly (Analysis of similarity; significance level of sample statistic: 0.3%) between areas of “high”, “low” to “no” disturbance. Areas of “low” to “no” dredge track coverage contained high abundances of bivalves, echinoderms, and isopods, whereas highly disturbed areas had highest abundances of polychaetes and oligochaetes. Future mapping efforts, especially surveys with biological components, need to include and quantify the level, type and spatial distribution of anthropogenic alterations. More attention should be given to “reference maps” instead of “baseline maps”. The latter of which omits to acknowledge pre-existing anthropogenic disturbances and has the potential to skew monitoring of restoration and management efforts.

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