Acoustical study of the spatial distribution of plankton on Georges Bank and the relationship between volume backscattering strength and the taxonomic composition of the plankton

Wiebe, Peter H.; Mountain, David; Stanton, Timothy K.; Greene, Charles H.; Lough, Greg; Kaartvedt, Stein; Dawson, Jim; Copley, Nancy J.

doi:10.1016/s0967-0645(96)00039-2

Cited by 74 publications

(59 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is finally stressed that the divergences observed between Franks' conclusions [72] and those presented here might also stem from the differences in the approaches used. First, the observational platforms used by Franks and co-workers [72,82] return horizontal 32 × 32 cm 2D fluorescence distributions sampled vertically every 6 to 24 cm, significantly differ from the fluorescence data analysed here that correspond to a time series recorded from a fixed depth at a rate of 2 Hz. Second, Franks data were collected in stratified waters 250-450 m deep 10 km offshore of San Diego (California, USA) where chlorophyll a concentrations were typically bounded between 0.1 and 0.6 µg l −1 ; [82]; their figure 2.…”

Section: Spikes Intermittence and Power Spectral Analysis: Demixing mentioning

confidence: 80%

“…First, the observational platforms used by Franks and co-workers [72,82] return horizontal 32 × 32 cm 2D fluorescence distributions sampled vertically every 6 to 24 cm, significantly differ from the fluorescence data analysed here that correspond to a time series recorded from a fixed depth at a rate of 2 Hz. Second, Franks data were collected in stratified waters 250-450 m deep 10 km offshore of San Diego (California, USA) where chlorophyll a concentrations were typically bounded between 0.1 and 0.6 µg l −1 ; [82]; their figure 2. In contrast, the data analysed here were collected in the tidally mixed shallow coastal waters of the eastern English Channel where chlorophyll a concentrations ranged from 6 to 30 µg l −1 .…”

Section: Spikes Intermittence and Power Spectral Analysis: Demixing mentioning

confidence: 80%

See 1 more Smart Citation

Microscale Complexity in the Ocean: Turbulence, Intermittency and Plankton Life

Seuront

2008

Math. Model. Nat. Phenom.

View full text Add to dashboard Cite

Abstract. This contribution reviews the nonlinear stochastic properties of turbulent velocity and passive scalar intermittent fluctuations in Eulerian and Lagrangian turbulence. These properties are illustrated with original data sets of (i) velocity fluctuations collected in the field and in the laboratory, and (ii) temperature, salinity and in vivo fluorescence (a proxy of phytoplankton biomass, i.e. unicelled vegetals passively advected by turbulence) sampled from highly turbulent coastal waters. The strength of three of the most popular models describing intermittent fluctuations (the lognormal, log-Lévy and log-Poisson models) to fit the distribution of in vivo fluorescence has subsequently been critically assessed. A theoretical formulation for the stochastic properties of biologically active scalars is also provided and validated. Finally, the potential effect of the intermittent properties of turbulent velocity fluctuations on processes relevant to the life of plankton organisms are theoretically investigated. It is shown that the intermittent nature of microscale turbulence may result in (i) a decrease in the rate of nutrient fluxes towards non-motile phytoplankton cells (6-62 %), (ii) a decrease in the physical coagulation of phytoplankton cells (25-48 %) and in the subsequent phytoplankton aggregate volumes (22-41 %), and (iii) a decrease of the turbulence contribution to predator-prey encounter rates (25-50 %).

show abstract

Section: Spikes Intermittence and Power Spectral Analysis: Demixing mentioning

confidence: 80%

Section: Spikes Intermittence and Power Spectral Analysis: Demixing mentioning

confidence: 80%

Microscale Complexity in the Ocean: Turbulence, Intermittency and Plankton Life

Seuront

2008

Math. Model. Nat. Phenom.

View full text Add to dashboard Cite

show abstract

“…Measurements of the intensity of echoes returned from sonic pulses emitted into the water column therefore can be used to make estimates of more biologically-meaningful quantities such as animal abundance and size. This process of inferring the abundance and distribution of zooplankton in a quantitative sense from acoustic measurements, however, is not straightforward (Stanton et al, 1994;Wiebe et al, 1996). Scattering in the water column can result from both physical oceanic processes (e.g., microstructure; Warren et al, 2003) and the biota, where scattering from the latter is a complex function of the taxonomic composition of animals present, and the associated variability in their size, shape, physical properties, and behavior.…”

Section: History Of Krill Research and The Krill Fisherymentioning

confidence: 99%

Distribution, patchiness, and behavior of Antarctic zooplankton, assessed using multi-frequency acoustic techniques

Lawson¹

2006

View full text Add to dashboard Cite

The physical and biological forces that drive zooplankton distribution and patchiness in an antarctic continental shelf region were examined, with particular emphasis on the Antarctic krill, Euphausia superba. This was accomplished by the application of acoustic, video, and environmental sensors during surveys of the region in and around Marguerite Bay, west of the Antarctic Peninsula, in the falls and winters of 2001 and 2002. An important component of the research involved the development and verification of methods for extracting estimates of ecologically-meaningful quantities from measurements of scattered sound. The distribution of acoustic volume backscattering at the single frequency of 120 kHz was first examined as an index of the overall biomass of zooplankton. Distinct spatial and seasonal patterns were observed that coincided with advective features. Improved parameterization was then achieved for a theoretical model of Antarctic krill target strength, the quantity necessary in scaling measurements of scattered sound to estimates of abundance, through direct measurement of all necessary model parameters for krill sampled in the study region and survey period. Methods were developed for identifying and delineating krill aggregations, allowing the distribution of krill to be distinguished from that of the overall zooplankton community. Additional methods were developed and verified for estimating the length, abundance, and biomass of krill in each acoustically-identified aggregation. These methods were applied to multifrequency acoustic survey data, demonstrating strong seasonal, inter-annual, and spatial variability in the distribution of krill biomass. Highest biomass was consistently associated with regions close to land where temperatures at depth were cool. Finally, the morphology, internal structure, and vertical position of individual krill aggregations were examined. The observed patterns of variability in aggregation characteristics between day and night, regions of high versus low food availability, and in the presence or absence of predators, together reinforced the conclusion that aggregation and diel vertical migration represent strategies to avoid visual predators, while also allowing the krill access to shallowly-distributed food resources. The various findings of this work have important implications to the fields of zooplankton acoustics and Antarctic krill ecology, especially in relation to the interactions of the krill with its predators.

show abstract

“…Considerable attention has been given to determine scales of biological and physical oceanographic processes and to identify the drivers of plankton patchiness. These questions have been addressed using a variety of different methods, including spectral analysis (Denman and Platt, 1976;Losee et al, 1989;Lovejoy et al, 2001;Washburn et al, 1998;Wiebe et al, 1996), autocorrelation or autocovariance functions (Chang et al, 2002;Mackas, 1984;Yu et al, 2002) correlograms or variograms (Dustan and Pinckney, 1989;Mackas, 1984;Yoder et al, 1987), wavelet analysis (Deutschman et al, 1993;Machu et al, 1999;Charria et al, 2003), and multifractal analysis (Seuront et al, 1996(Seuront et al, , 1999. Better understanding of the scales of variability can be used to help identify the physical and biological processes structuring biomass distribution and community structure, and help distinguish which processes are responsible at different scales (Chang et al, 2002;Cunningham et al, 2003;Dustan and Pinckney, 1989;Seliger et al, 1981).…”

Section: Introductionmentioning

confidence: 99%

“…Better understanding of the scales of variability can be used to help identify the physical and biological processes structuring biomass distribution and community structure, and help distinguish which processes are responsible at different scales (Chang et al, 2002;Cunningham et al, 2003;Dustan and Pinckney, 1989;Seliger et al, 1981). Previous research addressing these questions in the open ocean has examined scales of variability of current patterns (Flagg and Kim, 1998), of hydrography in the Faroes frontal region (Aranuvachapun et al, 1997), and of the spatial distribution of zooplankton on Georges Bank (Wiebe et al, 1996). Washburn et al (1998) found through coherence analysis of the scales of chlorophyll fluorescence (FL), salinity, and attenuation at 490 nm in the North Atlantic that phytoplankton distributions at larger scales (horizontal wavelengths 47 km) were controlled by eddy advection and that non-conservative processes of phytoplankton growth, grazing, and sinking controlled distributions at smaller scales.…”

Section: Introductionmentioning

confidence: 99%

Sub-kilometer length scales in coastal waters

Blackwell

Moline

Schaffner

et al. 2008

Continental Shelf Research

View full text Add to dashboard Cite

Patchiness or spatial variability is ubiquitous in marine systems. With increasing anthropogenic impacts to coastal resources and coastal systems being disproportionately large contributors to ocean productivity, identifying the spatial scales of this patchiness, particularly in coastal waters, is of critical importance to understand coastal ecosystem dynamics. The current work focuses on fine scale structure in three coastal regions. More specifically, we utilize variogram analyses to identify sub-kilometer scales of variability in biological and physical parameters measured by an autonomous underwater vehicle (AUV) in the Mid-Atlantic Bight, Monterey Bay, and in San Luis Obispo Bay between 2001 and 2004. Critical scales of variability in density, turbidity, fluorescence, and bioluminescence are examined as a function of depth and distance offshore. Furthermore, the effects of undersampling are assessed using predictive error analysis. Results indicate the presence of scales of variability ranging from 10s to 100s of meters and provide valuable insight for sampling design and resource allocation for future studies.

show abstract

Acoustical study of the spatial distribution of plankton on Georges Bank and the relationship between volume backscattering strength and the taxonomic composition of the plankton

Cited by 74 publications

References 15 publications

Microscale Complexity in the Ocean: Turbulence, Intermittency and Plankton Life

Microscale Complexity in the Ocean: Turbulence, Intermittency and Plankton Life

Distribution, patchiness, and behavior of Antarctic zooplankton, assessed using multi-frequency acoustic techniques

Sub-kilometer length scales in coastal waters

Contact Info

Product

Resources

About