Deep-water Sites Research Articles

Effects of climate change and industrialization on Lake Bolshoe Toko, eastern Siberia

Industrialization in the Northern Hemisphere has led to warming and pollution of natural ecosystems. We used paleolimnological methods to explore whether recent climate change and/or pollution had affected a very remote lake ecosystem, i.e. one without nearby direct human influence. We compared sediment samples that date from before and after the onset of industrialization in the mid-nineteenth century, from four short cores taken at water depths between 12.1 and 68.3 m in Lake Bolshoe Toko, eastern Siberia. We analyzed diatom assemblage changes, including diversity estimates, in all four cores and geochemical changes (mercury, nitrogen, organic carbon) from one core taken at an intermediate water depth. Chronologies for two cores were established using 210Pb and 137Cs. Sedimentation rates were 0.018 and 0.033 cm year−1 at the shallow- and deep-water sites, respectively. We discovered an increase in light planktonic diatoms (Cyclotella) and a decrease in heavily silicified euplanktonic Aulacoseira through time at deep-water sites, related to more recent warmer air temperatures and shorter periods of lake-ice cover, which led to pronounced thermal stratification. Diatom beta diversity in shallow-water communities changed significantly because of the development of new habitats associated with macrophyte growth. Mercury concentrations increased by a factor of 1.6 since the mid-nineteenth century as a result of atmospheric fallout. Recent increases in the chrysophyte Mallomonas in all cores suggested an acidification trend. We conclude that even remote boreal lakes are susceptible to the effects of climate change and human-induced pollution.

Comparative analysis of offshore support structures for two-bladed large wind turbines (10+MW) in deep waters

The offshore wind market is developing towards exploiting wind resources in deeper water sites. Inevitably, this fuels new research and feasibility studies on alternative solutions for the wind turbine support structures. Within this context, this work aims at comparing three different support structure design concepts for a 14 MW two-bladed downwind wind turbine: an XXL monopile, a hybrid jacket-tower and a lattice tower. To ensure a fair comparability of the three design concepts, a load capacity analysis is first performed to assess the yield strength of each concept and guarantee a similar material utilization. The comparative analysis is then carried out in terms of total mass, dynamic behaviour of the interaction between rotor and support structure, soil-structure interaction and resulting hydrodynamic forces. Based on the given design constraints, the preliminary results of this study favour a lattice tower solution. The study also highlights peculiar dynamic phenomena such as veering, mode hybridization and mode coalescence for the dynamic interaction between the lattice tower and the two-bladed rotor which need to be taken into account during the design phase.

Fault Detection of the Mooring system in Floating Offshore Wind Turbines based on the Wave-excited Linear Model

Floating Offshore Wind Turbines (FOWTs) are more prone to suffer from faults and failures than bottom-fixed counterparts due to the severe wind and wave loads typical of deep water sites. In particular, mooring line faults may lead to unacceptably high operation and maintenance costs due to the limited accessibility of FOWTs. Detecting the mooring line faults is therefore critical, but the application of Fault Detection (FD) techniques has not been investigated yet. In this paper, an FD scheme based on a wave-excited linear model is developed to detect in a reliable way critical mooring line faults occurring at the fairlead and anchor ends. To reach the goal, a linear model of the FOWT is obtained by approximating the wave radiation and incident wave forces. Based on this model, an observer is built to predict the rigid rotor and platform dynamics. The FD scheme is thus implemented by comparing the Mahalanobis Distance of the observer prediction error against a probabilistic detection threshold. Numerical simulations in some selected fault scenarios show that the wave-excited linear model can predict the FOWT dynamics with good accuracy. Based on this, the FD scheme capabilities are demonstrated, showing that it is able to effectively detect two critical mooring line faults.

Mercury Elevator in Lakes: A Novel Vector of Methylmercury Transfer to Fish via Migratory Invertebrates

Fisheries in highly productive prairie lakes of Canada and the United States frequently have fish consumption advisories due to elevated mercury concentrations. This occurrence is unexpected because such alkaline lakes often exhibit lower methylmercury (MeHg) concentrations in basal trophic levels than those expected in less productive basins with circumneutral pH. As sources of MeHg to fish are largely dietary, components of the food web are expected to be critical controls of the transfer of MeHg to fish. Here, we investigated how Leptodora kindtii, a large (1.5 cm) translucent predatory invertebrate that exhibits pronounced diel vertical migration (in sediments by day, upper water column by night), plays a key role in regulating the contamination of fish with MeHg in a well-studied, eutrophic, prairie lake in western Canada. Estimates of diel fluxes of invertebrate biomass and MeHg revealed that migratory adult Leptodora, but not other adult zooplankton or juvenile Leptodora, acted as a vector, uniquely transferring MeHg from presumptive deepwater sites of methylation to pelagic fish communities. This cryptic process suggests that piscivorous fish may experience greatly elevated exposure to MeHg even in circumstances when biogeochemical features, MeHg sources, and daytime food-web configuration suggest that trophic transfers should be minimal.

Variations of wave parameter statistics as influenced by water depth in coastal and inner shelf areas

Wave height, pressure and orbital velocity statistics, as influenced by the factor of water depth, are analyzed on the basis of five data sets collected in situ from two intertidal sites with a mean water depth of 0.8–2.7 m and three inner shelf sites (water depths 14.6–27.6 m). Acoustic Doppler Velocimeters (ADVs) were used to measure instantaneous wave pressure and current velocity at 0.20–0.35 m above sea bed. The zero-crossing wave analysis method was applied to analyze the wave data to determine the wave pressure amplitude P and orbital velocity amplitude U of individual waves, together with the frequency of occurrence distributions of P and U, which are compared with the three commonly-used, classic Rayleigh, modified Rayleigh and Weibull distributions. It is found that the distribution of P is almost identical to that of U for each of the five study sites. The distributions of P and U for the intertidal flat sites fit the Weibull distribution better than the classic or modified Rayleigh ones, indicating a shallowness effect which is associated with finite-banded wind-wave spectra and possible wave breaking or near-bed turbulence. On the other hand, the distributions of P and U measured at the three inner shelf sites agree almost equally with the three distributions. With increasing water depth, the distributions of P and U are shown to reduce from the two-parameter Weibull distribution at the shallow intertidal sites to the classic Rayleigh at the deep-water sites. For coastal engineering applications, an empirical formula is proposed to estimate more accurately the significant wave height in intermediate coastal waters based on the surface water elevation data.

Testing assumptions about sex change and spatial management in the protogynous gag grouper, Mycteroperca microlepis

Gag grouperMycteroperca microlepisare protogynous hermaphrodites, for which the assumption of female-driven reproductive potential may be inaccurate. In protogynous species, male abundance, fertilization success, and stock productivity are affected by where and when sex change occurs and how fishing pressure affects male recruitment and survivorship. In this study, we integrated large spatial-scale data with high-resolution data from a 3 yr study sampling gag at deep-water sites with varying spatial management (a marine protected area [MPA], a seasonally closed area, and an 'Open area'). Gag exhibited complex spatial ecology; females formed pre-spawning aggregations before migrating to deep-water spawning sites, which overlapped with locations where males were sampled year-round. The observed male sex ratio in the MPA was 5% compared to the expected 15%. It was 0% in less protected areas. Sex change occurred occasionally in small fish and before, during, and after the spawning season. In addition, sex change was observed in pre-spawning female-only aggregations as well on the spawning grounds, indicating that male social cues are not requisite. We propose that shallow-water, pre-spawning aggregations are a key spatio-temporal bottleneck to gag productivity. They appear to be an important source of transitionals and are heavily fished, which may negatively impact male recruitment to the spawning grounds. Our results indicate that overall gag abundance is low, MPAs do not protect all recruiting males (as previously assumed), and current regulations are not sufficient for the male population to recover to historic levels (~17% male).

Hatchery technology restores the spawning ground of phytophilic fish in the urban river of Yangtze Estuary, China

Due to the concrete slope protection projects conducted around urban rivers in many megalopolises, increased attention has been paid to fish biodiversity losses accompanying urban development. Hatchery technology is a promising method for restoring fisheries where spawning substrates are degraded and/or lacking. In the current study, a Phragmites australis stereo artificial floating wetland (SAFW) was constructed in an urban river (Tuanwang River, Shanghai), and palm sheets were laid under the SAFW frame to imitate the spawning grounds for phytophilous fish. Fish species with five spawning types were distinguished from nineteen fish species in the study area. After viscid eggs were found to be attached to the palm sheets, the eggs were distinguished by the subunit of the mitochondrial cytochrome C oxidase I gene. All of the eggs belonged to six fish species: Culter ilishaeformis, Cyprinus carpio, Cyprinus auratus, Cultrichthys erythropterus, Rhodeus sinensis, and Hemiculter leucisculus. Cyprinus auratus and Cyprinus carpio accounted for the vast majority, and the number of these species was significantly greater than that of the other species. Dissolved oxygen and light intensity at the water surface were significantly higher than those at the deep water sites (p < 0.05), and all viscid eggs were inclined to be distributed at water depths of -0.5 and − 1.5 m. The results of redundancy analysis (RDA) showed that both water depth and dissolved oxygen were the main environmental variables in all spawning periods. The current study suggested that the relatively inexpensive P. australis SAFW was a useful hatchery technology for creating spawning grounds for phytophilous fish in urban rivers.

Mesozoic biochronostratigraphy and paleoenvironment of the South Atlantic: A revised framework based on 20 DSDP and ODP deep-water sites

The South American and West African margins of the South Atlantic and the Southern Ocean are characterized by Mesozoic black shales that serve as source rocks of known and unknown petroleum systems. The knowledge of regional chronostratigraphy and paleoenvironment enables the prediction of the stratigraphic and geographic distribution of black shales with precision, as well as the understanding of local heterogeneity in regional- or global-scale oceanographic changes, such as oceanic anoxic events. Through sample re-analyses, this study provides a high-resolution Mesozoic chronostratigraphic and paleoenvironmental framework with the help of new micropaleontological data generated from 17 DSDP and ODP sites (out of 20 study sites), ranging from the Equatorial South Atlantic to the Southern South Atlantic. A series of eight regional Mesozoic unconformities are proposed and correlated to previously known unconformities or seismic reflectors. The regional paleoenvironmental interpretation, which utilizes the standardized chronostratigraphic framework, is herein accomplished for four time-horizons, namely, Middle Jurassic–Valanginian, Hauterivian–Albian, Cenomanian–Turonian, and Coniacian–Maastrichtian. Chronostratigraphic cross-sections and reconstruction maps for the time-horizons show that significant changes in paleoenvironmental parameters, such as bottom-water oxygenation and allochthonous sedimentation, were governed by the tectonic evolution of the South Atlantic margins.

Collection Grid Optimization of a Floating Offshore Wind Farm Using Particle Swarm Theory

Floating substructures for offshore wind turbines is a promising solution in order to harness the vast wind potential of deep water sites where bottom-fixed turbines are not feasible. The electrical system of large scale floating offshore wind farms will experience the application of new technologies and installation procedures that likely affect the cost-competitiveness. Thus, in this work, an optimization model based on the particle swarm theory is presented that allows optimizing the collection grid of a floating offshore wind farm. The developed model is applied to a study case consisting of a 500MW floating offshore wind farm located at the Golfe de Fos in the Mediterranean Sea. The resulting layout allows to reduce the total cost of the collection grid by more than 6% and to decrease the energy losses by 8% compared to the actual layout. Besides this, a further study analyzes the effect of a quantity discount with a reduced number of power cable cross sections.

Innovative Design and Execution Lead to Successful Grand Banks Platform Operations

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper OTC 28803, “Hebron Platform: Innovative Design and Efficient Execution,” by Widianto, Justin Chichester, Adel Younan, and Jameel Khalifa, ExxonMobil; Krishna Komperla, WorleyParsons; and Knut Bidne, Kvaerner, prepared for the 2018 Offshore Technology Conference, Houston, 30 April–3 May. The paper has not been peer reviewed. Copyright 2018 Offshore Technology Conference. Reproduced by permission. The Hebron platform was successfully installed on the Grand Banks offshore Newfoundland and Labrador in June 2017. It consists of a single-shaft concrete gravity-based structure (GBS) supporting an integrated drilling and production topsides. The design of the platform was challenged by sub-Arctic and extreme metocean conditions that required innovative design and layout approaches for many elements considered routine for typical platforms. This complete paper highlights the underlying technologies, analytical and design methods, and capital-efficient execution strategies employed. Introduction The Hebron platform comprises a GBS and topsides installed in 93-m water depth. Produced crude oil is stored in storage cells and pumped to shuttle tankers by an offshore loading system. The topsides facilities (operating weight 65,000 tonnes) include the following major modules: Utilities and process module (UPM) Derrick equipment set (DES) Drilling support module (DSM) Ancillaries (flare boom, east and west liftboat stations) Living quarters (LQ) designed to accommodate 220 personnel during steady-state operations The total height of the platform with GBS is approximately 235 m, topsides length is approximately 183 m, and the width is approximately 75 m. The GBS concept includes a single shaft supporting the topsides and encompasses all wells in the initial development. It is designed to withstand sea ice, icebergs, and other meteorological and oceanographic conditions at the offshore Hebron site. The GBS is designed for an in-service life of 50 or more years to support future developments. The lower portion of the GBS up to an elevation of approximately 27 m was constructed in a drydock created by building a bund wall and dewatering the site behind it. Subsequently, the dock was flooded, the bund wall was removed, and the GBS base was towed approximately 3 km to a deepwater site. The floating GBS was held in place with mooring lines while the remaining construction was completed. All walls were constructed using the slip-forming technique. The topsides structure was fabricated in modules at various locations in Newfoundland and Labrador and South Korea. Two of the topsides modules, UPM and DES, were fabricated in South Korea using block/pancake construction methods (Fig. 1). After UPM and DES fabrication was completed, the modules were loaded out separately to heavy vessels for transportation to Bull Arm, Newfoundland and Labrador. All other topsides modules were integrated with the main UPM module at the finger pier in Bull Arm and the completed topsides structure was mated with the GBS while floating at the deepwater site. The mated platform then was towed offshore and installed at the final offshore location.

Shear strength variability analysis for design of on-bottom pipelines in deep water Gulf of Mexico

A large portion of the uncertainty involved in the design of high-pressure-high- temperature oil and gas pipelines installed subsea is associated with the variability in the shear strength of soil supporting the pipeline. This study investigates variability of shear strength in the top half-meter of the seabed at three deep water sites in the Gulf of Mexico. Nearly 400 undrained shear strength data from minivane tests conducted on soft clay from 38 box core samples are evaluated for the presence of spatial correlation (autocorrelation) structure. Findings show a high degree of scatter and a lack of spatial correlation in both undisturbed and remolded shear strengths. Classical linear regression modelling, which is applicable in the absence of autocorrelation, is used to determine (i) the mean strength, (ii) 95% confidence intervals for the mean strength and (iii) 95% prediction intervals for a single new observation for different depths. The linear regression approach implemented may be used to identify characteristic strength profiles corresponding to different levels of confidence. This approach produces strength profiles suitable for use in typical pipe-soil interaction analysis and is easily implemented. Although not new, to the author’s best knowledge, it hasn’t been used for seabed soils for pipeline design.

Effect of Culture Depth and Season on the Condition and Reproductive Indices of Blue Mussels (Mytilus edulis L.) Cultured in a Cold-Water Coastal Environment

Condition, growth, and reproductive indices of blue mussels (Mytilus edulis) grown in deep and shallow sites were studied from May to December 2016 in the South Arm region of Notre Dame Bay, Newfoundland. The region was shown to be characterized by a seasonal thermocline that formed in April and lasted to October annually, resulting in a cold-water deep layer (mean annual temperature: 4.36 ± 5.1°C) and a comparatively warmer surface layer (mean annual temperature: 5.81 ± 6.3°C). The deepwater culture sites extended into the cold-water layer and the shallow sites were typically in the warmer layer above. Mussels grown in shallow sites had longer and heavier shells than those from deepwater sites, likely linked to warmer surface waters. Both reproductive and physiological condition indices were high for mussels from both culture depths in May. Physiological condition declined for both deep and shallow cultured mussels from May through to August. Mussels from deep sites, however, had a higher overall mean dry tissue weight: wet tissue weight ratio for the study period. Reproductive indices, including measurements of reproductive output, declined for shallow mussels from May through to August, but remained high for deep mussels until August when a significant spawn occurred for mussels from both depths. In addition, mussels from deep sites were observed to maintain themselves in a prespawning ripe stage for a longer period than those from shallow sites. Variations in physiological and reproductive indices for mussels from each respective culture depth were thought to be linked to differences in the environmental characteristics of the deep and shallow water layers, including rate of temperature change and potential differences in phytoplankton quality and energetics. The additional data provided in the present study add to the current understanding of the effects of the deepwater environment on mussel reproduction patterns and its relationship to production meat yield. The data will help in highlighting the benefits of using deepwater sites leading to increased environmental sustainability for mussel culture in subarctic coastal environments such as those on the north coast of Newfoundland.

Sources and transformations of iron in the sediments of the Gulf of Aqaba (Red Sea)

The Gulf of Aqaba is an oligotrophic marine system with an oxygen-rich water column. Aeolian dust from the Arabian, Sinai, and Sahara deserts is an important source of sedimentary material to the gulf, especially at 700 m water depth. The head of the gulf is affected by sediment transport from the Arava desert during winter flash floods. In this work, we have studied the speciation of iron in the dust, dry creek sediments and sediments of the Gulf of Aqaba at various water depths in order to understand sources and transformations of iron. Two sources of iron, dust and flash floods transported material, were found to possess distinct geochemical signatures: dust was found to be enriched in total and highly reactive iron relative to the sediments in creek beds. Combination of these two sources leads to an increase of highly reactive iron in sediments with water depth. This increase, in turn, results in formation of a lateral redox gradient with sulfidic pore-waters near the shore, and ferruginous-manganous pore-waters and cryptic sulfur cycling at the deeper water sites. Another result of dry aeolian deposition of desert dust to the sediments of the Gulf of Aqaba, overlaid by deep well‑oxygenated waters, is anomalously high ratios of highly reactive to total iron, which have been proposed to be diagnostic for anoxic, iron-rich water columns, when applied as a paleoproxy.

Past President's Address: Protists of the Mesopelagic and a Bit on the Long Path to the Deep Sea.

The deep sea has long been a mysterious and attractive habitat for protistologists. However, logistical difficulties severely limit sampling opportunities. Consequently, our knowledge of the protists in the deep sea, (arguably the largest habitat on earth), is relatively sparse. Here, we present a unique time-series concerning three different protist taxa that share only the characteristics of being relatively large, robust to sampling, and easily identifiable to species level using light microscopy: tintinnid ciliates, phaeogromid cercozoans (e.g. Challengerids) and amphisolenid dinoflagellates. We sampled a near-shore deep water site in the N.W. Mediterranean Sea at 250m depth over a 2-yr period at approximately weekly intervals from January 2017 to December 2018. To our knowledge, no previous studies have employed sampling on a similar time scale. We found taxa that appear to be restricted to deep waters, distinct seasonal patterns of abundance in some taxa, and in others nonseasonal successional patterns. Based on data from sampling following a flash flood event, the Challengerid population appeared to respond positively to a pulse of terrigenous input. Some of the distinct mesopelagic tintinnid ciliates and amphisolinid dinoflagellates were also found in two samples from the North Atlantic mesopelagic gathered from near the Azores Islands in September 2018. We conclude that there are a variety of protist taxa endemic to the mesopelagic, that the populations are dynamic, and they may be widely distributed in the deep waters of the world ocean.

Viral Infection of Picocyanobacteria in the Rybinsk Reservoir During the Freezing Period

The abundances of virioplankton and planktonic picocyanobacteria in deep and shallow water sites of Rybinsk Reservoir during the freezing period (water temperature 0.3–0.9°C) varied from (37.1 to 84.1) × 106 ((57.3 ± 2.1) × 106, on average) particles/ml and from 13.5 to 75.0 × 103 ((48.7 ± 3.4) × 103, on average) cells/ml, respectively. The fraction of picocyanobacteria with viruses attached to their cell surface was 6.5–29.0% (12.0 ± 0.8%, on average). The proportion of visible infected cells was 0.7–7.6% (2.2 ± 0.3%, on average) of the numbers of picocyanobacteria. It is likely that viruses play an important role in the regulation of picocyanobacteria abundance during the freezing period.

Traits of Biology of European Wels Catfish Silurus glanis from the Volga–Ahtuba Water System, the Lower Volga

Seasonal distribution, biology of reproduction, body length/weight composition, age of sexual maturation, and features of feeding in wels catfish Silurus glanis from the Volga River channel areas within the Volga–Ahtuba water systems (the lower Volga) have been studied. Within the study region, wels habitats are confined to the system of river-channel pits and to the deep-water sites of the main river channel; the fish roam within the surroundings of the pits. Wels spawns in the waterbodies of the subordinate system of the river: eriks (shallow channels) and branches between the Volga and Ahtuba rivers. In the study region, wels is represented by a long-lived late-maturing group. The fish of different body lengths/weights differ in the feeding modes: the specimens with body weights of <5 kg consume various small-sized prey, including nonfish food; larger individuals feed on large fish prey. Comparative analysis of the structures of wels populations from the Volga River delta and channel areas revealed considerable differences indicating the presence of two spatial groups of the population or subpopulation ranks: deltaic migrant and river channel settled. Development of an optimal strategy for exploitation of this valuable fish necessitates a differentiated approach and detailed analysis of biological traits of this species within the Volga basin. Such analysis should include population-genetic methods.

Exploring the Phoenician shipwreck off Xlendi bay, Gozo. A report on methodologies used for the study of a deep-water site

Exploring the Phoenician shipwreck off Xlendi bay, Gozo. A report on methodologies used for the study of a deep-water site

Critical review of floating support structures for offshore wind farm deployment

Floating structures enable offshore wind power deployment at numerous deep water sites with promising wind potential where bottom-fixed systems are no longer feasible. However, the large diversity in existing floater concepts slows down the development and maturing processes of floating offshore wind turbines. Thus, in this work, different floating support structures are assessed with respect to their suitability for offshore wind farm deployment. A survey is conducted to examine the capacities of selected floater types, grouped into ten categories, with respect to ten specified criteria focusing on wind farm deployment. By this means, a multi-criteria decision analysis (MCDA) is carried out, using the technique for order preference by similarity to ideal solution (TOPSIS). With the individual scores of the different systems, considering the weighting of each criterion, suitable concepts are identified and potential hybrid designs, combining advantages of different solutions, are suggested.

Stratigraphic Hiatuses in the Sedimentary Cover of the Ninetyeast Ridge

The Ninetyeast Ridge is one of the longest structures in the World Ocean. Owing to the seismostratigraphic analysis, three seismic complexes are distinguished in the sedimentary cover of this ridge, lower subaerial—shallow-water (SC3), transition (SC2), and upper deep-water (SC1), and nine reflectors: 0, 0a, 1, 1a, 2, 3, 4, 5, and F. On the basis of the results of correlation of seismic sections with those of deepwater sites recording the entire period of formation of the sedimentary cover of the Ninetyeast Ridge (Late Cretaceous—Quaternary), several nondepositional hiatuses are distinguished. The following reasons for these hiatuses are proposed. The hiatus in the beginning of the Early Paleocene coincides in time with the general decrease in the World Ocean level and is recorded only within the northern part of the ridge. The first “soft” collision of the Indian and Eurasian plates, as well as Paleocene—Eocene Thermal Maximum (PETM), could have been a reason for the most long-lasting hiatus in the Early—Middle Eocene in the northern and central parts of the Ninetyeast Ridge. The hiatus in the Early Oligocene is also distinguished in these parts of the ridge and is likely associated with underwater erosion. The formation of the Antarctic Circumpolar Current (ACC) and the change in the hydrodynamic regime of the Indian Ocean could have been reasons for the hiatus in the Middle Miocene, which is traced in the sedimentary cover throughout the entire Ninetyeast Ridge.

Identification of a Deep-water B-29 WWII Aircraft via ROV Telepresence Survey

American-produced B-29 Superfortress bomber aircraft flew missions against Imperial Japan in the Pacific Theater from air bases in the Mariana Islands from November 1944 until the end of WWII. Mechanical failures forced many B-29s into the ocean surrounding Saipan and Tinian. Terrestrial wreckage of these aircraft has been located in the Pacific region, but no losses in deep water were located until 2016, when a NOAA exploration cruise investigated sonar targets in the Saipan Channel, between Saipan and Tinian. Disarticulated wreckage from a B-29 was located at 370 m over a large area of the seabed. Telepresence-enabled, non-invasive exploration from NOAA Ship Okeanos Explorer allowed scientists on shore to view live streaming video and to work collaboratively to guide the investigation. Experts in aviation archaeology, corrosion studies, WWII history, forensic studies, marine biology, and oceanography participated in the survey using an ROV, highlighting components which could lead to possible identification of the B-29 in situ, and conducting an environmental characterization of the site. This deep-water aircraft site exemplifies multiple-stakeholder driven research in aviation archaeology and highlights several issues in the value of individual site identification.