Sub-kilometer length scales in coastal waters

Abstract

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.

Bioluminescence to reveal structure and interaction of coastal planktonic communities

“…The size of the sliding window was equivalent to 25 m linear distance traveled by the REMUS vehicle for data collected in Monterey Bay and San Luis Obispo Bay and was objectively determined by identifying the length scales of variability, detailed in Moline et al (2005) and Blackwell et al (2007). For the time series tests performed with the profiling bathyphotometers a data window of 12.5 s was used (25 observations).…”

Integrated measurements of acoustical and optical thin layers II: Horizontal length scales

“…While a number of studies have quantified the scales of chlorophyll fluorescence as it relates to variance of temperature and salinity over larger domains (Lee et al, 2000;Rudnick et al, 2004;Hodges and Rudnick, 2006;Cheriton et al, this issue), significantly less has been done on small scales and, in particular, layers (Blackwell et al, 2008). This is despite evidence showing decreasing length scales and their importance in modulating distributions of biological communities and optical variability when approaching coastlines (Yoder and McClain, 1987;Lovejoy et al, 2001;Chang et al, 2002;Bissett et al, 2004).…”

Platform effects on optical variability and prediction of underwater visibility

“…For this study, the REMUS was configured with a Teledyne RD Instruments 1200 kHz upward-and downward-looking Workhorse ADCP; a Neal Brown, Incorporated, conductivity-temperature (CT) sensor; a WET Labs, Incorporated, ECO Triplet for turbidity, chlorophyll fluorescence, and colored dissolved or ganic matter (CDOM) fluorescence; and Satlantic, Incorporated, OCR-507 spectral irradiance and radi ance sensors for measuring upwelling and downwelling light fields. A complete description of this vehicle, navigational capabilities, and applications in scientific studies are detailed elsewhere [16][17][18][19][20][21][22][23].…”