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Del Bohnenstiehl

Professor

Jordan Hall 4138

Publications

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Grants

Date: 03/17/20 - 12/31/22
Amount: $389,794.00
Funding Agencies: NC Division of Marine Fisheries

Setting attainable oyster restoration targets is necessary to quantify restoration success and recovery of oyster populations and additional ecosystem services that these habitats provide. In North Carolina, oyster cultch planting provides oysters for commercial harvest (i.e. jobs), as well as key ecosystem services that have additional monetary value, such as essential fish habitat. Existing cultch reef monitoring is limited in space and time such that targets established from these data may not be appropriate for optimizing the long-term economic and ecosystem benefits of restoration. Establishing more appropriate restoration targets for long-term persistence of reefs is especially important for increasing reef resilience to fishing pressure and natural disturbances, such as increased freshwater flooding events from coastal storms (e.g., Hurricane Florence). This study aims to establish long-term targets for oyster cultch restoration in North Carolina by (1) assessing the impacts of oyster harvest on habitat complexity, oysters, and fish habitat value, and (2) evaluating the relationship between habitat complexity and reef recovery following harvest. Our overarching hypothesis is that reef resilience and long-term persistence will vary as a function of habitat complexity and location with the (sea)landscape. Our objectives are to conduct a before-after-impact control study to quantify (a) habitat complexity and habitat loss following oyster harvest; (b) oyster density and biomass following harvest, and oysters’ ability to recover from harvest; (c) estuarine fish production and diversity among the reefs and unstructured control sites following oyster harvest using a combination of: (i) gill nets, (ii) fish traps, and (iii) passive acoustic monitoring. The “before” component of this study will be represented by data from a 3-year study which evaluated the initial, pre-harvest, oyster and fish response to cultch planting (CRFL 2017-H-063). The proposed study will (1) recommend restoration targets for the NC DMF cultch planting program, (2) generate sound scientific information on the long-term nature and value of ecosystem services provided by (restored) oyster reefs, and (3) support making informed, science-based decisions about the use and management of one of the State’s key estuarine restoration programs. The proposed study addresses Objective 1, Strategy 7 described in funding priorities for the NC CRFL program.

Date: 11/01/20 - 10/31/22
Amount: $29,752.00
Funding Agencies: National Science Foundation (NSF)

An Mw 5.1 earthquake occurred on 9 August 2020 at 8:07AM, near Sparta, North Carolina. It was strongly felt in the town of Sparta (Intensity VI) and across the Southeastern, Midwest, and Northeastern US, a MMI II as far away as Cincinnati (OH), Atlanta (GA), Washington DC and Wilmington (NC). A field survey was initiated on the day of the earthquake by researchers from NCSU (including the members of this proposal), UNC, NCGS and USGS. Surprisingly, they found that this moderate earthquake caused a displacement (rupture) of the ground surface. This is the first time that surface rupture has been documented in the eastern USA and immediate efforts to document its characteristics were undertaken. Observations suggest that the surface deformation may be associated to re-activation of sub-surface pre-existent discontinuities, whose tectonic activity is poorly understood. Preliminary data indicate that the surface fault is expressed by a narrow zone of deformation, traceable for ~2.2 km along strike. Along the length of the surface rupture, deformation is accommodated by reverse displacement and/or folding/flexure of the hanging wall (south side): the maximum vertical displacement is ~20 cm, with an average of 8–10 cm. We hypothesize that the surface rupture has not yet been fully recognized due to its subtlety and crossing of vegetated areas. To fully assess and to help answer fundamental questions on the earthquake dynamics, we request support to acquire a high-resolution LiDAR airborne data (NCALM), and to continue the acquisition of terrestrial LiDAR scan survey data, high resolution aerial imagery, subsurface geophysical survey data and to collect additional geologic and geomorphic observations. Funds for high resolution LiDAR will be requested by NCALM if this RAPID proposal is awarded. The goal of this proposed research is to complete the field documentation of the earthquake surface rupture before natural processes and anthropogenic activities destroy the subtle surface topographic features produced by the earthquake. These acquisitions will provide information and data to correlate with present and future observations.

Date: 04/30/21 - 6/30/22
Amount: $104,628.00
Funding Agencies: Center for Sponsored Coastal Research (NOAA)

Channel dredging maintenance of deep-water ports along the U.S. Atlantic and Gulf Coasts is critical to maintaining local, state and regional economies. The expansion of port facilities to accommodate the new generation of large-capacity vessels, as well as the continued development of offshore energy resources, and an increasing frequency and intensity of shoaling from storms, is leading to increasing demand for shipping channel maintenance via hopper dredge. Increasing demand for dredging is leading to scheduling challenges for the U.S. Army Corps of Engineers (US ACOE) due to dredging activities generally being restricted to winter months to avoid impacting protected species such as marine mammals and sea turtles, as well as recreationally and commercially important fishery species. Despite the necessity of dredging for commerce and defense, its potential impacts on the environment are of particular concern as multiple potential stressors associated with dredging activities have been well documented, including direct impacts such as hydraulic entrainment of animals, and indirect effects such as sediment stress (suspended and deposited), release of toxic contaminants, and noise pollution. The overarching objectives of this research program are to: (1) quantify potential impacts of marine dredging on key commercial and recreational fish and shellfish in Beaufort Inlet, NC, (2) communicate the results to key stakeholders including the NC Division of Coastal Management, NC Division of Marine Fisheries, National Marine Fisheries Service, and ACOE to inform decisions regarding mitigation and seasonal closures of dredging to maintain North Carolina’s State Ports, and (3) provide undergraduate and graduate training with a focus on under-represented and under-served minorities. The proposed research program is innovative because it: (1) Integrates traditional sampling methods, such as trawls which provide measures of relative abundance at discrete times, with application of passive acoustics using underwater hydrophones that can record soniferous (i.e., vocalizing) species 24/7, (2) Integrates with related studies examining changes in water quality during dredging operations (lead by Co-PI B. Puckett), and (3) Provides hands-on-training for graduate students and an explicit training program for minorities.

Date: 05/15/19 - 5/14/22
Amount: $139,500.00
Funding Agencies: National Oceanic & Atmospheric Administration (NOAA)

As a result of a recent legal settlement, the US Navy and NOAA have initiated a program to characterize soundscapes within NOAA-managed US National Marine Sanctuaries. In support of this program, NOAA/NEFSC will deploy a network of calibrated passive acoustic recording devices within the Florida Keys National Marine Sanctuary to expand understanding and protection of these potentially vulnerable acoustic habitats. These recordings will provide a holistic sampling of the underwater soundscape, capturing anthropogenic, natural abiotic, and biological sound sources. Integration of these acoustic recordings with other data that characterize habitat conditions and species presence, as well as human activity levels in proximity to recording locations, is recognized as being critical to efforts to understand and manage these acoustic habitats. The acoustic monitoring network will include sites within the Western Dry Rocks (WDR), Eastern Sambo (ESB) and Nine-Foot Stake (NFS) reefs within the Florida Keys National Marine Sanctuary (FKNMS). Since early 2017, North Carolina State University (NCSU) has been conducting acoustic monitoring and periodic visual surveys within portions of these reefs, with these studies scheduled to continue through at least the summer of 2019 (Simmons et al., 2018). Through this project, NCSU has developed a set of skilled divers who are trained at conducting visual surveys for habitat and associated organisms, as well as personnel with expertise in the analysis of underwater sound, within the FKNMS. A similar set of visual surveys is needed seasonally at NOAA’s 3 newly established (recordings started in November 2018) passive acoustic monitoring sites (located several hundred meters seaward of the NCSU study sites). Analysis of these newly acquired acoustic data is also needed in order to better understand how traditional visual survey techniques can be used effectively in conjunction with passive acoustic recordings to better manage marine protected areas within the FKNMS, and elsewhere. The objective of this contract is to provide funds to support collaborative work using the existing expertise of the NCSU team in conducting visual surveys within the FKNMS and identifying prominent acoustic signals within the soundscape. This work will improve the ability of NOAA to integrate passive acoustic and visual fish survey data and will move forward our ability to manage and monitor marine sites throughout the Western Atlantic Ocean. This project will take place over a 2 year period from 1st of April 2019 through 30th of March 2021 or starting as soon as the agreement is signed.

Date: 07/01/17 - 12/31/21
Amount: $361,662.00
Funding Agencies: NC Department of Environmental Quality (DEQ)

As oyster populations have reached historic lows, restoration efforts have expanded worldwide, and there is increasing recognition of the role oyster reefs play in providing key ecosystem services such as removing excess nutrients, stabilizing shorelines and creating essential fish habitat (EFH). The North Carolina Division of Marine Fisheries (NC DMF) conducts two distinct, yet inter-related, oyster restoration programs that involve (1) the creation of no-harvest brood stock reserves that provide larval subsidies (i.e., spat) to fished areas, and (2) cultch-planting to provide substrate for oyster larvae and commercial harvest following a 2-3 year closure. This study will focus on cultch-planting restoration sites, whose value in creating EFH has not been well studied. Our overarching hypothesis is that oyster cultch sites will show enhanced production and diversity of certain recreationally important fish species compared to unstructured control sites, and that fish production and diversity will increase with the complexity of reef habitat. We propose to work with the NC DMF Shellfish/Oyster Program (Garry Wright) to: (1) identify 7-8 oyster cultch sites that vary in habitat complexity (e.g., mounds vs flat reefs vs shell vs marl), as well as several unstructured control sites. We will then (1) map the oyster reefs and quantify their habitat complexity using an Unmanned Surface Vehicle capable of high resolution seafloor mapping, and then (2) quantify estuarine fish production and diversity among the reef sites and unstructured control sites using a combination of: (i) gill-nets, (ii) fish traps, (iii) hydrophones, and (iv) possibly a Didson acoustic transducer. The hydrophones will record species-specific fish vocalizations 24/7, which is a tremendous compliment to periodic surveys with nets and traps. The proposed study addresses two overarching Objectives and four Specific Strategies described in funding priorities for the NC Coastal Recreational Fishing License (CRFL) program. Examples range from (i) Quantifying linkages between coastal fish habitat and fish production, to (ii) Evaluation of the success of restoration/enhancement projects, to (iii) Research into restoration techniques to maximize long-term ecological function.

Date: 06/01/20 - 5/30/21
Amount: $9,999.00
Funding Agencies: NCSU Sea Grant Program

The overall objective of this project is to address the data gap in artificial reef usage by using high temporal and high spatial resolution satellite imagery. Specifically, we will use the imagery provided by the commercial satellite company Planet through their Education and Research Program. Planet satellites record reflected green, blue, and near-infrared light with very high spatial (~3 m pixel) and temporal (~daily repeat) resolution. The goals of this project will be to 1) develop a deep learning model to detect small recreational boats in this satellite imagery, 2) deploy the model to detect boats and establish a visitation time-series at four pilot artificial reef sites selected in consultation with NCDMF, and 3) produce a summary report of data quantity and quality for all 43 artificial reef sites. When paired with reef material information and existing recreational fishing survey data from NCDMF, this visitation time-series will be used to answer the following: 1) What are the spatiotemporal patterns in boat use at NCDMF pilot reef sites?, 2) Do spatial patterns in boat presence relate to underlying reef material?, and 3) How do usage patterns generated from remotely sensed boat detections compare to the current survey methodology used by NCDMF?. Answers to these spatiotemporal usage pattern questions can help inform program priorities including evaluating benefits/costs of existing reefs and supporting construction of additional reefs to reduce user-conflict and/or fishing pressure.

Date: 06/01/20 - 5/30/21
Amount: $10,001.00
Funding Agencies: NCSU NC Space Grant Consortium

The overall objective of this project is to address the data gap in artificial reef usage by using high temporal and high spatial resolution satellite imagery. Specifically, we will use the imagery provided by the commercial satellite company Planet through their Education and Research Program. Planet satellites record reflected green, blue, and near-infrared light with very high spatial (~3 m pixel) and temporal (~daily repeat) resolution. The goals of this project will be to 1) develop a deep learning model to detect small recreational boats in this satellite imagery, 2) deploy the model to detect boats and establish a visitation time-series at four pilot artificial reef sites selected in consultation with NCDMF, and 3) produce a summary report of data quantity and quality for all 43 artificial reef sites. When paired with reef material information and existing recreational fishing survey data from NCDMF, this visitation time-series will be used to answer the following: 1) What are the spatiotemporal patterns in boat use at NCDMF pilot reef sites?, 2) Do spatial patterns in boat presence relate to underlying reef material?, and 3) How do usage patterns generated from remotely sensed boat detections compare to the current survey methodology used by NCDMF?. Answers to these spatiotemporal usage pattern questions can help inform program priorities including evaluating benefits/costs of existing reefs and supporting construction of additional reefs to reduce user-conflict and/or fishing

Date: 08/01/18 - 12/31/20
Amount: $65,053.00
Funding Agencies: US Dept. of Commerce (DOC)

Hurricane Irma directly impacted the Florida Reef Tract, including sites within the lower Keys portion of the Florida Keys National Marine Sanctuary. Large-scale rapid reef assessments and emergency restoration efforts are currently underway to assess the relative resilience of Florida coral reefs, and identify influential drivers of resiliency. In the proposed study, visual fish surveys and passive acoustic recordings will be used to characterize reef fish diversity, relative abundance, and spawning events among management zones at eight sites within the lower keys. Data collected prior to Hurricane Irma (spring-fall of 2017) by our group will be compared with new survey data to be collected in 2018 and 2019. Habitat photogrammetry surveys will be collected at each site to assess habitat structural complexity, percent live coral cover, and coral diversity. Characterizing these reef habitats at fine spatial and temporal scales will allow us understand how management regime, biodiversity and habitat complexity may influence resilience.

Date: 08/15/16 - 7/31/19
Amount: $187,766.00
Funding Agencies: National Science Foundation (NSF)

Our comprehensive goal is to better understand how stress and strain evolve through the inter-eruptive period and how these patterns are linked to with magma flux and fluid flow within a submarine volcano. Our study system is Axial volcano, on the Juan de Fuca Ridge, which has recently been instrumented with a suite of seismic, geodetic, hydrothermal and geochemical sensors. We hypothesis that: (1) Stress evolves primarily in response to the inflation and deflation of the magma reservoir and the extraction of heat by hydrothermal processes. (2) The volcanic crust’s sensitivity is external forcing is a function of its overall state of stress and will evolve through time. (3) Eruption dynamics are reflected in the rate of explosive activity and acoustic flux.

Date: 09/01/12 - 6/30/18
Amount: $456,414.00
Funding Agencies: National Science Foundation (NSF)

The overall goal of this study is to advance our general understanding of the role of underwater sound in biological oceanography by characterizing spatiotemporal variation in an estuarine soundscape, and determining if this variation affects the settlement of larval invertebrates. We propose to use larval bivalves and subtidal oyster reefs in Pamlico Sound, North Carolina as a study system. Specifically, we propose to: (1) Quantify habitat-specific acoustic characteristics of the estuarine soundscape across space/time scales that match major oyster and clam recruitment periods in Pamlico Sound. (2) Quantify which space/time scales of variation in the estuarine soundscape affect larval behavior and settlement. The proposed study has three main components: (1) comprehensive field characterization of the estuarine soundscape, including measurements of pressure and particle motion (2) laboratory experiments that test the effects of sound on larval behaviors and settlement, and (3) field experiments that test the effects of sound on larval settlement. The preliminary data presented in this proposal support the proposed approach and technologies, and highlight the need for more comprehensive quantification of acoustic spectra in space and time in the context of marine biological processes. The underwater sonic environment has the potential to provide meaningful sensory information to all aquatic animals, since acoustic signals are transmitted relatively large distances, are present at all depths, and reflect biological and physical characteristics of the environment, while other cues (e.g. light, chemicals) are rapidly attenuated from the source.


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