Hot and cold spot maps for <i>Beringraja binoculata</i> and <i>Raja rhina</i>.

<p>Getis-GI Hot Spot Analysis Z-score plots of catch-per-unit-effort (kg/km) for the hardnose skates, <i>Beringraja binoculata</i> (A) and <i>Raja rhina</i> (B), in the western Gulf of Alaska, as calculated from NMFS–AFSC trawl surveys conducted during 1999–2011.</p

Descriptive statistics, depth range, and mesoscale habitat electivity for central California skates as calculated from manned submersible data in the greater Monterey Bay region.

<p><i>n</i> = sample size, %FO = frequency of occurrence, km = kilometers, m = meters.</p><p>* = p<0.05 for Chi-square test. Number (<i>n</i>), frequency of occurrence (%FO), density (#/km²), depth range and mesoscale habitat electivity (after Manly et al. 1993) of the California skate assemblage among 1203 submersible dive transects conducted at depths of 24–316 m.</p><p>Descriptive statistics, depth range, and mesoscale habitat electivity for central California skates as calculated from manned submersible data in the greater Monterey Bay region.</p

ZIP model predictions of median and maximum count, and associated depth and latitude ranges, and GAM model predictions of temperature for central California skate species/life stages throughout the study site.

<p>N = number of hauls, m = meters, C = degrees Celcius, Max = maximum. Results were calculated from National Marine Fisheries Service–Northwest Fisheries Science Center trawl data collected during 2003–2010 among 235 tows throughout the study region. Common depth, temperature, and latitudinal range are included (see methods), as well as the depth and latitude at which the maximum number of skates were predicted.</p><p>ZIP model predictions of median and maximum count, and associated depth and latitude ranges, and GAM model predictions of temperature for central California skate species/life stages throughout the study site.</p

Trawl locations among regions in the west-central Gulf of Alaska.

<p>Alaska Department of Fish and Game trawl survey regions located within the larger study site in the western Gulf of Alaska. The total number of trawls conducted during 2003–2012 among regions was, as follows: Kodiak Island (<i>n</i> = 1836), Shelikof Strait (<i>n</i> = 278), Alaska Peninsula (<i>n</i> = 1368), and Kamishak Bay (<i>n</i> = 160).</p

Hot and cold spot maps for <i>Raja inornata, R. stellulata, and Bathyraja kincaidii</i>.

<p>Getis-GI Hot Spot Analysis Z-score plots of catch-per-unit-effort (kg/km) for the California skate, <i>Raja inornata</i> (A); starry skate, <i>R. stellulata</i> (B), and sandpapaer skate, <i>Bathyraja kincaidii</i> (C) off central California, as calculated from NMFS–AFSC and NMFS–NWFSC trawl surveys conducted during 1997–2010.</p

ANOVA and t-test comparisons of mean total length among co-occurring skates in the western Gulf of Alaska.

<p><i>n</i> = number of individuals, TL (cm) = mean total length, SD = standard deviation. Comparisons are based on co-occurrence among NMFS-AFSC trawls conducted in the western Gulf of Alaska during 1999–2011.</p><p>ANOVA and t-test comparisons of mean total length among co-occurring skates in the western Gulf of Alaska.</p

Spatial analysis results for the central California skate assemblage.

<p>NS = not significant. N = number, WT = weight (kilograms), %FO = frequency of occurrence among hauls, CPUE = catch-per-unit-effort (#/km², kg/km²), ISA = incremental spatial autocorrelation, K = K Function, km = kilometers. Significant p-value thresholds are indicated as follows: * = <0.05, ** = <0.001. Data were collected during National Marine Fisheries Service, Northwest Fisheries Science Center and Alaska Fisheries Science Center trawl surveys (<i>n</i> = 422) conducted during 1997–2010 on the continental shelf and upper slope of central California.</p><p>Spatial analysis results for the central California skate assemblage.</p

Details of sampling surveys conducted in the western Gulf of Alaska and off central California.

<p>Note: Data were collected yearly for the indicated ranges, with the following exceptions: NMFS–AFSC* = 1998, 2001, 2004; NMFS–AFSC** = 1997, 1999, 2001; NMFS–SWFSC–FED (submersible) = 1992–1994, 1997, 1998, 2002–2004, 2007–2009; western GOA = biennially; Kamishak Bay = 2003–2007, 2010, 2012.</p><p>* = effort was focused on continental shelf,</p><p>** = effort was focused on continental slope;</p><p>NMFS = National Marine Fisheries Service, AFSC = Alaska Fisheries Science Center, NWFSC = Northwest Fisheries Science Center, SWFSC–FED = Southwest Fisheries Science Center–Fisheries Ecology Division, MBARI = Monterey Bay Aquarium Research Institute, ADFG = Alaska Department of Fish and Game, ROV = remotely operated vehicle, N = number of samples for each method, Oct = October, Jan = January, Dec = December, Aug = August, Nov = November, Sept = September, m = meters.</p><p>Details of sampling surveys conducted in the western Gulf of Alaska and off central California.</p

Hot and cold spot maps for species richness of all Californian skates.

<p>Getis-GI Hot spot Analysis Z-score plot of species richness of skates collected from NMFS–AFSC and NMFS–NWFSC trawl surveys conducted during 1997–2010.</p

Original and updated habitat suitability probability profiles for <i>Raja inornata</i>.

<p>Reconstruction of original (A) and updated (B) habitat suitability probability profiles for adult and transitional/adult <i>Raja inornata</i> throughout the U.S. West Coast. The original profile (A) was depicted in the 2005 Essential Fish Habitat Amendment to the Pacific Coast Groundfish Fishery Management Plan (Anonymous 2005). The black line offshore depicts the limit of the U.S. EEZ.</p