Digital Commons Network^™

Isolation And Transcriptome Analysis Of Adult Zebrafish Cells Enriched For Skeletal Muscle Progenitors, Matthew S. Alexander, Genri Kawahara, Alvin T. Kho, Melanie H. Howell, Timothy J. Pusack, Jennifer A. Myers, Federica Monanaro, Leonard I. Zon, Jeffrey R. Guyon, Louis M. Kunkel

United States Department of Commerce: Staff Publications

Introduction: Over the past 10 years, the use of zebrafish for scientific research in the area of muscle development has increased dramatically. Although several protocols exist for the isolation of adult myoblast progenitors from larger fish, no standardized protocol exists for the isolation of myogenic progenitors from adult zebrafish muscle.

Methods: Using a variant of a mammalian myoblast isolation protocol, zebrafish muscle progenitors have been isolated from the total dorsal myotome. These zebrafish myoblast progenitors can be cultured for several passages and then differentiated into multinucleated, mature myotubes.

Results: Transcriptome analysis of these cells during myogenic differentiation revealed a strong …

Small-Scale Fisheries Of Peru: A Major Sink For Marine Turtles In The Pacific, Joanna Alfaro-Shigueto, Jeffrey C. Mangel, Francisco Bernedo, Peter H. Dutton, Jeffrey A. Seminoff, Brendan J. Godley

United States Department of Commerce: Staff Publications

1. Over the last few decades, evidence of marine vertebrate bycatch has been collected for a range of industrial fisheries. It has recently been acknowledged that large impacts may also result from similar interactions with small-scale fisheries (SSF) due largely to their diffuse effort and large number of vessels in operation. Marine mammals, seabirds, turtles as well as some shark species have been reported as being impacted by SSF worldwide.

2. From 2000 to 2007, we used both shore-based and onboard observer programmes from three SSF ports in Peru to assess the impact on marine turtles of small-scale longline, bottom …

Seasonal And Interannual Effects Of Hypoxia On Fish Habitat Quality In Central Lake Erie, Kristin K. Arend, Dmitry Beletsky, Joseph Depinto, Stuart A. Ludsin, James J. Roberts, Daniel K. Rucinski, Donald Scavia, David J. Schwab, Tomas O. Höök

United States Department of Commerce: Staff Publications

1. Hypoxia occurs seasonally in many stratified coastal marine and freshwater ecosystems when bottom dissolved oxygen (DO) concentrations are depleted below 2–3 mg O₂ L^-1.

2. We evaluated the effects of hypoxia on fish habitat quality in the central basin of Lake Erie from 1987 to 2005, using bioenergetic growth rate potential (GRP) as a proxy for habitat quality. We compared the effect of hypoxia on habitat quality of (i) rainbow smelt, Osmerus mordax mordax Mitchill (young-of-year, YOY, and adult), a cold-water planktivore, (ii) emerald shiner, Notropis atherinoides Rafinesque (adult), a warm-water planktivore, (iii) yellow perch, Perca …

The Response Of Fish Larvae To Decadal Changes In Environmental Forcing Factors Off The Oregon Coast, Toby D. Auth, Richard D. Brodeur, Heather L. Soulen, Lorenzo Ciannelli, William T. Peterson

United States Department of Commerce: Staff Publications

We conducted a statistical analysis to characterize the influence of large-scale and local environmental factors on presence-absence, concentration, and assemblage structure of larval fish within the northern California Current (NCC) ecosystem, based on samples collected at two nearshore stations along the Newport Hydrographic line off the central Oregon coast. Data from 1996 to 2005 were compared with historical data from the 1970s and 1980s to evaluate pseudo-decadal, annual, and seasonal variability. Our results indicate that the most abundant taxa from 1996 to 2005 differ from those of earlier decades. Concentrations of the dominant taxa and total larvae were generally greater …

Movements Of Two Satellite-Tagged Pygmy Killer Whales (Feresa Attenuata) Off The Island Of Hawai‘I, Robin W. Baird, Gregory S. Schorr, Daniel L. Webster, Dan J. Mcsweeney, M. Bradley Hanson, Russel D. Andrews

United States Department of Commerce: Staff Publications

Pygmy killer whales (Feresa attenuata) are a rare tropical oceanic odontocete that are normally found close to shore only around oceanic islands (Donahue and Perryman 2009, McSweeney et al. 2009). In the Exclusive Economic Zone (EEZ) surrounding the Hawaiian Islands there is a single stock of pygmy killer whales recognized (Carretta et al. 2010). In the Hawaiian EEZ they are the third-least abundant of the 12 species of delphinids documented, with an estimated abundance of 956 individuals (CV = 0.83; Barlow 2006). Around the island of Hawai‘i a long-term photo-identification study has identified a small population that exhibits …

Dramatic Shifts In Hawaiian Monk Seal Distribution Predicted From Divergent Regional Trends, Jason D. Baker, Albert L. Harting, Tracy A. Wurth, Thea C. Johanos

United States Department of Commerce: Staff Publications

Total estimated abundance of Hawaiian monk seals was just 1,161 individuals in 2008 and this number is decreasing. Most monk seals reside in the remote Northwestern Hawaiian Islands (NWHI) where the decline is approximately 4%/yr, whereas relatively fewer seals currently occupy the main Hawaiian Islands (MHI). It is widely accepted that the MHI population is increasing, although there are no formal estimates of total abundance, population growth rate or vital rates. This lack of information has hampered efforts to anticipate future scenarios and plan conservation measures. We present the first estimates of MHI monk seal survival and age-specific reproductive rates. …

Humpback Whale Abundance In The North Pacific Estimated By Photographic Capture-Recapture With Bias Correction From Simulation Studies, Jay Barlow, John Calambokidis, Erin A. Falcone, C. Scott Baker, Alexander M. Burdin, Phillip J. Clapham, John K. B. Ford, Christine M. Gabriele, Richard Leduc, David K. Mattila, Terrance J. Quinn Ii, Lorenzo Rojas-Bracho, Janice M. Straley, Barbara L. Taylor, Jorge Urbán R., Paul Wade, David Weller, Briana H. Witteveen, Manami Yamaguchi

United States Department of Commerce: Staff Publications

We estimated the abundance of humpback whales in the North Pacific by capture recapture methods using over 18,000 fluke identification photographs collected in 2004–2006. Our best estimate of abundance was 21,808 (CV=0.04). We estimated the biases in this value using a simulation model. Births and deaths, which violate the assumption of a closed population, resulted in a bias of +5.2%, exclusion of calves in samples resulted in a bias of−10.5%, failure to achieve random geographic sampling resulted in a bias of −0.4%, and missed matches resulted in a bias of +9.3%. Known sex-biased sampling favoring males in breeding areas did …

A Riverscape Perspective Of Pacific Salmonids And Aquatic Habitats Prior To Large-Scale Dam Removal In The Elwha River, Washington, Usa, S. J. Brenkman, J. J. Duda, C. E. Torgersen, E. Welty, G. R. Pess, R. Peters, M. L. Mchenry

United States Department of Commerce: Staff Publications

Dam removal has been increasingly proposed as a river restoration technique. In 2011, two large hydroelectric dams will be removed from Washington State’s Elwha River. Ten anadromous fish populations are expected to recolonise historical habitats after dam removal. A key to understanding watershed recolonisation is the collection of spatially continuous information on fish and aquatic habitats. A riverscape approach with an emphasis on biological data has rarely been applied in mid-sized, wilderness rivers, particularly in consecutive years prior to dam removal. Concurrent snorkel and habitat surveys were conducted from the headwaters to the mouth (rkm 65–0) of the Elwha River …

Fin Whale (Balaenoptera Physalus) Population Identity In The Western Mediterranean Sea, Manuel Castellote, Christopher W. Clark, Marc O. Lammers

United States Department of Commerce: Staff Publications

Archival bottom-mounted audio recorders were deployed in nine different areas of the western Mediterranean Sea, Strait of Gibraltar, and adjacent North Atlantic waters during 2006–2009 to study fin whale (Balaenoptera physalus) seasonal presence and population structure. Analysis of 29,822 recording hours revealed typical long, patterned sequences of 20 Hz notes (here called “song”), back-beats, 135–140 Hz notes, and downsweeps. Acoustic parameters (internote interval, note duration, frequency range, center and peak frequencies) were statistically compared among songs and song notes recorded in all areas. Fin whale singers producing songs attributable to the northeastern North Atlantic subpopulation were detected crossing …

Migration And Behavior Of Juvenile North Pacific Albacore (Thunnus Alalunga), John Childers, Stephanie Snyder, Suzanne Kohin

United States Department of Commerce: Staff Publications

Archival tags were used to study the seasonal movements, migration patterns and vertical distribution of juvenile North Pacific albacore (Thunnus alalunga). Between 2001 and 2006, archival tags were deployed in North Pacific albacore in two regions of the Northeast Pacific: (i) off Northern Baja California, Mexico and Southern California, and (ii) off Washington and Oregon. Twenty archival tagged fish were recovered with times at liberty ranging from 63 to 697 days. Tagged albacore exhibited five distinct, seasonal migratory patterns. Depth and temperature data also showed a broad range of vertical behaviors. In certain regions such as off Baja …

What’S The Catch? Patterns Of Cetacean Bycatch And Depredation In Hawaii-Based Pelagic Longline Fisheries, Karin A. Forney, Donald R. Kobayashi, David W. Johnston, Jamie A. Marchetti, Michael G. Marsik

United States Department of Commerce: Staff Publications

U.S. Pacific pelagic longline fisheries operating in the central North Pacific have been subject to a series of regulations to reduce bycatch of protected species, including seabirds and sea turtles. Cetaceans are also occasionally caught, and the bycatch of false killer whales, Pseudorca crassidens, in the Hawaii-based deep-set longline fishery currently exceeds allowable levels under the Marine Mammal Protection Act (MMPA). In this study, we examined longline observer data collected between 1994 and 2009, with emphasis on 2003–2009, to identify patterns of cetacean bycatch and depredation in relation to area, time, vessel, habitat variables, fishing gear, and set characteristics. …

Global Mismatch Between Research Effort And Conservation Needs Of Tropical Coral Reefs, Rebecca Fisher, Ben T. Radford, Nancy Knowlton, Russell E. Brainard, Frances B. Michaelis, M. Julian Caley

United States Department of Commerce: Staff Publications

Tropical coral reefs are highly diverse and globally threatened. Management to ensure their persistence requires sound biological knowledge in regions where coral reef biodiversity and/or the threats to it are greatest. This paper uses a novel text analysis approach and Google Maps™ to examine the spatial coverage of scientific papers on coral reefs listed in Web of Science^® . Results show that research is highly clumped spatially, positively related to per capita gross domestic product, negatively related to coral species richness, and unrelated to threats to coral reefs globally; indicating a serious mismatch between conservation needs and the knowledge …

Distribution And Abundance Of Stream Fishes In Relation To Barriers: Implications For Monitoring Stream Recovery After Barrier Removal, C. Gardner, S. M. Coghlan Jr., J. Zydlewski, R. Saunders

United States Department of Commerce: Staff Publications

Dams are ubiquitous in coastal regions and have altered stream habitats and the distribution and abundance of stream fishes in those habitats by disrupting hydrology, temperature regime and habitat connectivity. Dam removal is a common restoration tool, but often the response of the fish assemblage is not monitored rigorously. Sedgeunkedunk Stream, a small tributary to the Penobscot River (Maine, USA), has been the focus of a restoration effort that includes the removal of two low-head dams. In this study, we quantified fish assemblage metrics along a longitudinal gradient in Sedgeunkedunk Stream and also in a nearby reference stream. By establishing …

Inference Without Significance: Measuring Support For Hypotheses Rather Than Rejecting Them, Tim Gerrodette

United States Department of Commerce: Staff Publications

Despite more than half a century of criticism, significance testing continues to be used commonly by ecologists. Significance tests are widely misused and misunderstood, and even when properly used, they are not very informative for most ecological data. Problems of misuse and misinterpretation include: (i) invalid logic; (ii) rote use; (iii) equating statistical significance with biological importance; (iv) regarding the P-value as the probability that the null hypothesis is true; (v) regarding the P-value as a measure of effect size; and (vi) regarding the P-value as a measure of evidence. Significance tests are poorly suited for inference because they pose …

Comparative Metabolic Rates Of Common Western North Atlantic Ocean Sciaenid Fishes, A. Z. Horodysky, R. W. Brill, P. G. Bushnell, J. A. Musick, R. J. Latour

United States Department of Commerce: Staff Publications

The resting metabolic rates (RR) of western North Atlantic Ocean sciaenids, such as Atlantic croaker Micropogonias undulatus, spot Leiostomus xanthurus and kingfishes Menticirrhus spp., as well as the active metabolic rates (R_A) of M. undulatus and L. xanthurus were investigated to facilitate inter and intraspecific comparisons of their energetic ecology. The R_R of M. undulatus and L. xanthurus were typical for fishes with similar lifestyles. The R_R of Menticirrhus spp. were elevated relative to those of M. undulatus and L. xanthurus, but below those of high-energy-demand species such as tunas Thunnus spp. …

Functional Responses And Scaling In Predator–Prey Interactions Of Marine Fishes: Contemporary Issues And Emerging Concepts, Mary E. Hunsicker, Lorenzo Ciannelli, Kevin M. Bailey, Jeffrey A. Buckel, J. Wilson White, Jason S. Link, Timothy E. Essington, Sarah Gaichas, Todd W. Anderson, Richard D. Brodeur, Kunk-Sik Chan, Kun Chen, Göran Englund, Kenneth T. Frank, Vània Freitas, Mark A. Hixon, Thomas Hurst, Darren W. Johnson, James F. Kitchell, Doug Reese, George A. Rose, Henrik Sjodin, William J. Sydeman, Henk W. Van Der Veer, Knut Vollset, Stephani Zador

United States Department of Commerce: Staff Publications

Predator–prey interactions are a primary structuring force vital to the resilience of marine communities and sustainability of the world's oceans. Human influences on marine ecosystems mediate changes in species interactions. This generality is evinced by the cascading effects of overharvesting top predators on the structure and function of marine ecosystems. It follows that ecological forecasting, ecosystem management, and marine spatial planning require a better understanding of food web relationships. Characterising and scaling predator– prey interactions for use in tactical and strategic tools (i.e. multi-species management and ecosystem models) are paramount in this effort. Here, we explore what issues are involved …

Life History Of The Indo-Pacific Humpback Dolphin In The Pearl River Estuary, Southern China, Thomas A. Jefferson, Samuel K. Hung, Kelly M. Robertson, Frederick I. Archer

United States Department of Commerce: Staff Publications

We studied life history characteristics of the Hong Kong/Pearl River Estuary population of Indo-Pacific humpback dolphins (Sousa chinensis), based on data from 120 specimens stranded between 1995 and 2009, 40 individuals biopsied at sea, and a long-term (14+ yr) photo-identification study. Ages were determined for 112 specimens by thin-sectioning teeth and counting growth layer groups. Estimated length at birth was 101 cm. Longevity was at least 38 yr, and there was little difference in growth patterns of males and females. Growth was described by a Bayesian two-phase Gompertz model; asymptotic length was reached at 249 cm. The tooth …

Small Founding Number And Low Genetic Diversity In An Introduced Species Exhibiting Limited Invasion Success (Speckled Dace, Rhinichthys Osculus), Andrew P. Kinziger, Rodney J. Nakamoto, Eric C. Anderson, Bret C. Harvey

United States Department of Commerce: Staff Publications

Molecular evaluations of successful invaders are common, however studies of introduced species that have had limited invasion success, or have died out completely, are rare. We studied an introduced population of speckled dace (Rhinichthys osculus) from northern California, USA that has rapidly increased in abundance but remained restricted to a 25-km stretch of river since its introduction in the mid-1980s. Field and laboratory analyses indicate that invasion success of speckled dace is constrained by the combined effects of multiple predators. The role of bottleneck effects associated with the introduction has not been studied. We assayed variation in seven …

Water Chemistry And Its Effects On The Physiology And Survival Of Atlantic Salmon Salmo Salar Smolts, T. Liebich, S. D. Mccormick, D. Kircheis, K. Johnson, R. Regal, T. Hrabik

United States Department of Commerce: Staff Publications

The physiological effects of episodic pH fluctuations on Atlantic salmon Salmo salar smolts in eastern Maine, U.S.A., were investigated. During this study, S. salar smolts were exposed to ambient stream-water chemistry conditions at nine sites in four catchments for 3 and 6 day intervals during the spring S. salar smolt migration period. Plasma chloride, plasma glucose, gill aluminium and gill Na⁺- and K⁺-ATPase levels in S. salar smolts were assessed in relation to ambient stream-water chemistry during this migration period. Changes in both plasma chloride and plasma glucose levels of S. salar smolts were strongly correlated …

Lipid Class Dynamics And Storage Depots In Juvenile Weakfish Cynoscion Regalis And Their Application To Condition Assessment, S. Y. Litvin, V. G. Guida, M. P. Weinstein

United States Department of Commerce: Staff Publications

Lipid class dynamics, the pattern of change in the primary form and location of lipid stores and their relationship with standard length (L_S), were investigated in collections of young-of-the-year weakfish Cynoscion regalis for the purpose of determining the utility of this analysis as an indication of condition. The separation of total lipids into individual classes and the analysis of potential storage depots revealed the general patterns of lipid class dynamics and energy storage in C. regalis during their period of juvenile estuarine residency. Phospholipid and cholesterol exhibited moderate but variable (8·1–40·0 and 1·3–21·5 mg g⁻¹, respectively) …

Predicting The Hypoxic-Volume In Chesapeake Bay With The Streeter–Phelps Model: A Bayesian Approach, Yong Liu, George B. Arhonditsis, Craig A. Stow, Donald Scavia

United States Department of Commerce: Staff Publications

Hypoxia is a long-standing threat to the integrity of the Chesapeake Bay ecosystem. In this study, we introduce a Bayesian framework that aims to guide the parameter estimation of a Streeter–Phelps model when only hypoxic volume data are available. We present a modeling exercise that addresses a hypothetical scenario under which the only data available are hypoxic volume estimates. To address the identification problem of the model, we formulated informative priors based on available literature information and previous knowledge from the system. Our analysis shows that the use of hypoxic volume data results in reasonable predictive uncertainty, although the variances …

Use Of Fatty Acid Analysis To Determine Dispersal Of Caspian Terns In The Columbia River Basin, U.S.A., Christina J. Maranto, Julia K. Parrish, David P. Herman, André E. Punt, Julian D. Olden, Michael T. Brett, Daniel D. Roby

United States Department of Commerce: Staff Publications

Lethal control, which has been used to reduce local abundances of animals in conflict with humans or with endangered species, may not achieve management goals if animal movement is not considered. In populations with emigration and immigration, lethal control may induce compensatory immigration, if the source of attraction remains unchanged. Within the Columbia River Basin (Washington, U.S.A.), avian predators forage at dams because dams tend to reduce rates of emigration of juvenile salmonids (Oncorhynchus spp.), artificially concentrating these prey. We used differences in fatty acid profiles between Caspian Terns (Hydroprogne caspia) at coastal and inland breeding colonies …

Long-Term Survival Of Humpback Whales Radio-Tagged In Alaska From 1976 Through 1978, Sally A. Mizroch, Michael F. Tillman, Susan Jurasz, Janice M. Straley, Olga Von Ziegesar, Louis M. Herman, Adam A. Pack, Scott Baker, Jim Darling, Debbie Glockner-Ferrari, Mark Ferrari, Dan R. Salden, Phillip J. Clapham

United States Department of Commerce: Staff Publications

Invasive tags designed to provide information on animal movements through radio or satellite monitoring have tremendous potential for the study of whales and other cetaceans. However, to date there have been no published studies on the survival of tagged animals over periods of years or decades. Researchers from the National Marine Mammal Laboratory and the Woods Hole Oceanographic Institution tracked five humpback whales with implanted radio tags in southeastern Alaska in August 1976 and July 1977, and tracked two humpback whales in Prince William Sound, Alaska, in June 1978. All seven of these individually identified humpback whales were resighted at …

Using Aerial Photography To Investigate Evidence Of Feeding By Bowhead Whales, Julie A. Mocklin, David J. Rugh, Sue E. Moore, Robyn P. Angliss

United States Department of Commerce: Staff Publications

Aerial photographs were analyzed to investigate the feeding habits of the Bering- Chukchi-Beaufort (BCB) population of bowhead whales (Balaena mysticetus), particularly epibenthic feeding near Barrow, Alaska. Evidence of epibenthic feeding was based on mud visible on the dorsal surface of whales, resulting from feeding near the seafloor. Other cues used to assess feeding were an open mouth or the presence of feces in photographs. Over 3,600 photographs were analyzed including photos from surveys in spring and late summer and in both the western and eastern Beaufort Sea. Of all the photographs analyzed, 64% were scored as definitively muddy. …

Bayesian State-Space Model Of Fin Whale Abundance Trends From A 1991–2008 Time Series Of Line-Transect Surveys In The California Current, Jeffrey E. Moore, Jay Barlow

United States Department of Commerce: Staff Publications

1. Estimating temporal trends in animal abundance is central to ecology and conservation, but obtaining useful trend estimates is challenging when animal detection rates vary across surveys (e.g. because of differences in observers or conditions). Methods exist for obtaining abundance estimates using capture–recapture and distance sampling protocols, but only recently have some of these been extended to allow direct estimation of abundance trends when detection rates vary. Extensions to distance sampling for >2surveys have not yet been demonstrated.

2. We demonstrate a Bayesian approach for estimating abundance and population trends, using a time series of line-transect data for endangered fin …

Estimated Field Metabolic Rates And Prey Requirements Of Resident Killer Whales, Dawn P. Noren

United States Department of Commerce: Staff Publications

Killer whales are large animals that often feed in groups and thus have the potential to deplete prey populations. Determining predator energy requirements is essential to assessing whether prey availability is sufficient. This is important because one risk factor facing the endangered Southern Resident killer whale distinct population segment is limited prey availability. Body mass, field metabolic rate (FMR), and daily prey energy requirements (DPERs) were estimated for each individual in the population. FMRs were calculated from body mass, assuming they range from five to six times Kleiber-predicted basal metabolic rates. FMRs of adults were also calculated from resident killer …

High Species Density Patterns In Macrofaunal Invertebrate Communities In The Marine Benthos, John Oliver, Kamille Hammerstrom, Erika Mcphee-Shaw, Peter Slattery, James Oakden, Stacy Kim, S. Ian Hartwell

United States Department of Commerce: Staff Publications

Species density of macrofaunal invertebrates living in marine soft sediments was highest at the shelf-slope break (100–150 m) in Monterey Bay (449 m^-2). There were 337 species m^-2 in the mid-shelf mud zone (80 m). There were fewer species along the slope: 205 m^-2 from the lower slope (950-2000 m) and 335 m^-2 on the upper slope (250-750 m). Species density was highest inside the bay (328-446 m^-2) compared to outside (336-339 m^-2), when examining samples at selected water depths (60-1000 m). There was little difference in local species density from …

Ontogenetic Dietary Information Of The California Sea Lion (Zalophus Californianus) Assessed Using Stable Isotope Analysis, Anthony J. Orr, Seth D. Newsome, Jeffrey L. Laake, Glenn R. Vanblaricom, Robert L. Delong

United States Department of Commerce: Staff Publications

We used stable carbon (δ¹³C) and nitrogen (δ¹⁵N) isotopes to examine ontogenetic dietary changes in 289 California sea lions (Zalophus californianus) at San Miguel Island, California during 2004–2007. Tissues analyzed included fur, red blood cells, plasma, and serum. For all tissues, pups had higher δ¹⁵N values and lower δ¹³C values compared to adults, which indicated that pups were feeding higher trophically than older conspecifics and on a lipid-rich milk diet prior to weaning. Yearling δ¹⁵N values were slightly lower than pup or nearly indistinguishable from adult values depending …

The Effect Of Stimulation Frequency On The Transmural Ventricular Monophasic Action Potential In Yellowfin Tuna Thunnus Albacares, S. M. Patrick, E. White, R. W. Brill, H. A. Shiels

United States Department of Commerce: Staff Publications

Monophasic action potentials (MAPs) were recorded from the spongy and compact layers of the yellowfin tuna Thunnus albacares ventricle as stimulation frequency was increased. MAP duration decreased with increase in stimulation frequency in both the spongy and compact myocardial layers, but no significant difference in MAP duration was observed between the layers.

A Simple Photograph-Based Approach For Discriminating Between Free-Ranging Long-Finned (Globicephala Melas) And Short-Finned (G. Macrorhynchus) Pilot Whales Off The East Coast Of The United States, Brenda K. Rone, Richard M. Pace Iii

United States Department of Commerce: Staff Publications

Line transect based abundance estimation is complicated for long-finned (LFPW, Globicephala melas) and short-finned (SFPW, G. macrorhynchus) pilot whales because of their similarity in appearance and their overlapping summertime range in some areas.We developed a photograph-based approach to distinguish between species of free-ranging pilot whales in the northwest Atlantic.We collected skin samples and photographs during the summers of 2004–2007 and used skin samples to distinguish species based on mitochondrial DNA. Relative morphometric measurements from photographs were examined using mixed-effect models and logistic regression. The best model among 94 candidate models had an overall classification error rate of 2.5%. …