Environmental Sciences Commons^™

The Global Drought Monitor Portal: The Foundation For A Global Drought Information System, Richard R. Heim Jr., Michael J. Brewer

United States Department of Commerce: Staff Publications

The international scientific community has long recognized the need for coordinated drought monitoring and response, but many factors have prevented progress in the development of a Global Drought Early Warning System (GDEWS): some of which involve administrative issues (coordinated international action and policy) while others involve scientific, technological, and logistical issues. The creation of the National Integrated Drought Information System (NIDIS) Portal within the United States provided an opportunity to take the first steps toward building the informational foundation for a GDEWS: that is, a Global Drought Information System (GDIS). At a series of workshops sponsored by the World Meteorological …

Spatial Complexity In Fragmenting Amazonian Rainforests: Do Feedbacks From Edge Effects Push Forests Towards An Ecological Threshold?, Graeme S. Cumming, Jane Southworth, Xanic J. Rondon, Matthew Marsik

United States Department of Commerce: Staff Publications

Deforestation and resulting landscape fragmentation are important concerns in many tropical areas. Deforestation is a complex process with many potential feedback loops, many of which are ignored in models that attempt to interpolate forest loss based on past deforestation rates. In addition, most ecological studies of the impacts of deforestation have focused on landscapes that are already fragmented. These studies ignore the fact that edge effects, such as anthropogenic fire, reach their maximum well before habitat connectivity is lost and may create positive feedbacks that result in further fragmentation. We developed a simple model to explore the potential influence of …

Responses Of Antarctic Pack-Ice Seals To Environmental Change And Increasing Krill Fishing, Jaume Forcada, Philip N. Trathan, Peter L. Boveng, Ian L. Boyd, Jennifer M. Burns, Daniel P. Costa, Michael Fedak, Tracey L. Rogers, Colin J. Southwell

United States Department of Commerce: Staff Publications

The compound effects of changing habitats, ecosystem interactions, and fishing practices have implications for the management of Antarctic krill and conservation of its predators. For Antarctic pack-ice seals, an important group of krill predators, we estimate the density and krill consumption in the West Antarctic Peninsula (WAP)–Western Weddell Sea area, the main fishery region; and we consider long-term changes in suitable pack-ice habitat, increased fishing pressure and potential krill declines based upon predictions from declines in sea ice cover. More than 3 million crabeater seals consumed over 12 million tonnes of krill each year. This was approximately 17% of the …

A Multi-Beach Study Of Staphylococcus Aureus, Mrsa, And Enterococci In Seawater And Beach Sand, Kelly D. Goodwin, Melody Mcnay, Yiping Cao, Darcy Ebentier, Melissa Madison, John F. Griffith

United States Department of Commerce: Staff Publications

Incidences of Staphylococcus aureus and methicillin resistant S. aureus (MRSA) have risen worldwide prompting a need to better understand routes of human exposure and whether standard bacterial water quality monitoring practices adequately account for this potential threat. Beach water and sand samples were analyzed during summer months for S. aureus, enterococci, and MRSA at three southern California beaches (Avalon, Doheny, Malibu Surfrider). S. aureus frequently was detected in samples of seawater (59%, n = 328) and beach sand (53%, n = 358). MRSA sometimes was detected in seawater (1.6%, n = 366) and sand (2.7%, n = 366) at …

State Of The Art Satellite And Airborne Marine Oil Spill Remote Sensing: Application To The Bp Deepwater Horizon Oil Spill, Ira Leifer, William J. Lehr, Debra Simecek-Beatty, Eliza Bradley, Roger Clark, Philip Dennison, Yongxiang Hu, Scott Matheson, Cathleen E. Jones, Benjamin Holt, Molly Reif, Dar A. Roberts, Jan Svejkovsky, Gregg Swayze, Jennifer Wozencraft

United States Department of Commerce: Staff Publications

The vast and persistent Deepwater Horizon (DWH) spill challenged response capabilities, which required accurate, quantitative oil assessment at synoptic and operational scales. Although experienced observers are a spill response's mainstay, few trained observers and confounding factors including weather, oil emulsification, and scene illumination geometry present challenges. DWH spill and impact monitoring was aided by extensive airborne and spaceborne passive and active remote sensing.

Oil slick thickness and oil-to-water emulsion ratios are key spill response parameters for containment/cleanup and were derived quantitatively for thick (>0.1 mm) slicks from AVIRIS (Airborne Visible/Infrared Imaging Spectrometer) data using a spectral library approach based …

Reconstructing Disturbance History Using Satellite-Based Assessment Of The Distribution Of Land Cover In The Russian Far East, T.V. Loboda, Z. Zhang, K.J. O'Neal, G. Sun, I.A. Csiszar, H.H. Shugart, N.J. Sherman

United States Department of Commerce: Staff Publications

Russian boreal forests are the largest forested zone on Earth and a tremendous pool of organic carbon. Current limited records on forest structure, composition, successional stage and disturbances contribute to large uncertainties in estimates of carbon stocks and fluxes in this zone. Our ability to monitor ongoing changes in forest cover has improved with the influx of remotely sensed data products since 2000 from multiple satellite platforms. Here we present a method aimed at reconstructing disturbance history from a known distribution of land cover. We developed and tested the method over a biologically and topographically diverse region of the Russian …

Analysis Of Inconsistencies In Multi-Year Gridded Quantitative Precipitation Estimate Over Complex Terrain And Its Impact On Hydrologic Modeling, Naoki Mizukami, Michael B. Smith

United States Department of Commerce: Staff Publications

It is common that bias trends of long term precipitation data change over time due to various factors such as gauge relocation and changes in data processing methods. Temporal consistency of this error characteristic of precipitation data is as important as accuracy itself for reliable streamflow prediction with a hydrologic model. The main goal of this paper is to illustrate the detection and adverse effect of inconsistent precipitation data on distributed hydrologic model simulations over a mountainous basin in the Sierra Nevada Mountains of California. We used 1-h 4 km gridded precipitation time series intended for the second phase of …

Linking Ciguatera Poisoning To Spatial Ecology Of Fish: A Novel Approach To Examining The Distribution Of Biotoxin Levels In The Great Barracuda By Combining Non-Lethal Blood Sampling And Biotelemetry, Amanda C. O'Toole, Marie-Yasmine Dechraoui Bottein, Andy J. Danylchuk, John S. Ramsdell, Steven J. Cooke

United States Department of Commerce: Staff Publications

Ciguatera in humans is typically caused by the consumption of reef fish that have accumulated Ciguatoxins (CTXs) in their flesh. Over a six month period, we captured 38 wild adult great barracuda (Sphyraena barracuda), a species commonly associated with ciguatera in The Bahamas. We sampled three tissues (i.e.,muscle, liver, and blood) and analysed them for the presence of ciguatoxins using a functional in vitro N2A bioassay. Detectable concentrations of ciguatoxins found in the three tissue types ranged from 2.51 to 211.74 pg C-CTX-1 equivalents/ g. Blood and liver toxin concentrations were positively correlated (ρ=0.86, P=0.003), indicating …

Using Microwave Brightness Temperature Diurnal Cycle To Improve Emissivity Retrievals Over Land, Hamidreza Norouzi, William Rossow, Marouane Temimi, Catherine Prigent, Marzieh Azarderakhsh, Sid Boukabara, Reza Khanbilvardi

United States Department of Commerce: Staff Publications

To retrieve microwave land emissivity, infrared surface skin temperatures have been used as surface physical temperature since there is no global information on physical vegetation/soil temperature profiles. However, passive microwave emissions originate fromdeeper layerswith respect to the skin temperature. So, this inconsistency in sensitivity depths between skin temperatures and microwave temperaturesmay introduce a discrepancy in the determined emissivity. Previous studies showed that this inconsistency can lead to significant differences between day and night retrievals of land emissivity which can exceed 10%. This study proposes an approach to address this inconsistency and improve the retrieval of land emissivity using microwave observations …

A Pollen-Based Reconstruction Of Summer Temperature In Central North America And Implications For Circulation Patterns During Medieval Times, Eugene R. Wahl, Henry F. Diaz, Christian Ohlwein

United States Department of Commerce: Staff Publications

We present a reconstruction of mean summer temperature for the northern Midwest of the USA based on lacustrine pollen records from three different lakes in Wisconsin. The results suggest a relatively warm period during the earlier part of the record (~1200–1500 CE) followed by a cooler Little Ice Age (~1500–1900) and a subsequent warming to modern conditions. The reconstructed modern summer mean temperature is in good agreement with observations, and the decades of the 1930s to 1950s appear to be the warmest such period in the proxy record (through 1974).

Analyses of circulation features associated with the warmest summers in …

Identification Of Ovarian Gene Expression Patterns During Vitellogenesis In Atlantic Cod (Gadus Morhua), Timothy S. Breton, Janet L. Anderson, Frederick W. Goetz, David L. Berlinsky

United States Department of Commerce: Staff Publications

Follicular maturational competence and ovulatory competence in teleost fish refer to the ability of the ovarian follicle to undergo final oocyte maturation and ovulation, respectively, in response to gonadotropin stimulation and other external cues. Some gene products related to competence acquisition are likely synthesized during vitellogenic growth, as these follicles gain in vivo responsiveness to exogenous gonadotropin stimulation and can be induced to undergo maturation and ovulation. In Atlantic cod (Gadus morhua), gonadotropin responsiveness has been shown to be oocyte size-dependent, and only ovaries containing late-stage vitellogenic follicles can be induced to ovulate. The purpose of the present …

Arctic Cloud Macrophysical Characteristics From Cloudsat And Calipso, Yinghui Liu, Jeffrey R. Key, Steven A. Ackerman, Gerald G. Mace, Qiuqing Zhang

United States Department of Commerce: Staff Publications

The lidar and radar profiling capabilities of the CloudSat and Cloud-Aerosol Lidar and Infrared Pathfinder (CALIPSO) satellites provide opportunities to improve the characterization of cloud properties. An Arctic cloud climatology based on their observations may be fundamentally different from earlier Arctic cloud climatologies based on passive satellite observations, which have limited contrast between the cloud and underlying surface. Specifically, the Radar–Lidar Geometrical Profile product (RL-GEOPROF) provides cloud vertical profiles from the combination of active lidar and radar. Based on this data product for the period July 2006 to March 2011, this paper presents a new cloud macrophysical property characteristic analysis …

Metabolite Profiles In Starved Diporeia Spp. Using Liquid Chromatography-Mass Spectrometry (Lc-Ms) Based Metabolomics, Suman Maity, Amber Jannasch, Jiri Adamec, Michael Gribskov, Thomas F. Nalepa, Tomas O. Höök, Maria S. Sepúlveda

United States Department of Commerce: Staff Publications

The holarctic amphipod Diporeia spp. was historically the most abundant benthic macroinvertebrate in the offshore region of the Laurentian Great Lakes basin. However, since the 1990’s, the numbers of Diporeia have declined precipitously throughout the region. Competition for food with introduced dreissenid mussels may be partly to blame for this decline. Thus, a better understanding of how Diporeia responds and adjust to starvation is needed. For this purpose, we used liquid chromatography (LC) coupled with time-of-flight mass spectrometry (TOFMS) to study the metabolite profiles of Diporeia during starvation. Diporeia were collected from Lake Michigan, brought to the laboratory and starved …

Multidecadal Otolith Growth Histories For Red And Gray Snapper (Lutjanus Spp.) In The Northern Gulf Of Mexico, Usa, Bryan A. Black, Robert J. Allman, Isaac D. Schroeder, Michael J. Schirripa

United States Department of Commerce: Staff Publications

Dendrochronology (tree-ring analysis) techniques were applied to develop chronologies from the annual growth-increment widths of red snapper (Lutjanus campechanus) and gray snapper (Lutjanus griseus) otoliths sampled from the northern Gulf of Mexico, USA. Growth increment widths showed considerable synchrony within and across species, indicating that some component of environmental variability influenced growth. The final, exactly dated red snapper chronology continuously spanned 1975 through 2003, while the gray snapper chronology continuously spanned 1975 through 2006. To determine baseline climategrowth relationships, chronologies were compared to monthly averages of sea surface temperatures, U winds (west to east), V winds …

Radar Characteristics Of Continental, Coastal, Andmaritime Convection Observed During Amma/Namma, Nick Guy, Steven A. Rutledge, Robert Cifelli

United States Department of Commerce: Staff Publications

Ground-based radar observations at three distinct geographical locations in West Africa along a common latitudinal band (Niamey, Niger (continental), Kawsara, Senegal (coastal), and Praia, Republic of Cape Verde (maritime)) are analyzed to determine convective system characteristics in each domain during a 29-day period in 2006. Ancillary datasets provided by the African Monsoon Multidisciplinary Analyses (AMMA) and NASA-AMMA (NAMMA) field campaigns are also used to place the radar observations in context. Results show that the total precipitation is dominated by propagating mesoscale convective systems. Convective characteristics vary according to environmental properties, such as vertical shear, CAPE, and the degree of synoptic …

Chilean Blue Whales As A Case Study To Illustrate Methods To Estimate Abundance And Evaluate Conservation Status Of Rare Species, Rob Williams, Sharon L. Hedley, Trevor A. Branch, Mark B. Bravington, Alexandre N. Zerbini, Ken P. Findlay

United States Department of Commerce: Staff Publications

Often abundance of rare species cannot be estimated with conventional design-based methods, so we illustrate with a population of blue whales ( Balaenoptera musculus) a spatial model-based method to estimate abundance. We analyzed data from line-transect surveys of blue whales off the coast of Chile, where the population was hunted to low levels. Field protocols allowed deviation from planned track lines to collect identification photographs and tissue samples for genetic analyses, which resulted in an ad hoc sampling design with increased effort in areas of higher densities. Thus, we used spatial modeling methods to estimate abundance. Spatial models are increasingly …

Population Structure Of Melon-Headed Whales (Peponocephala Electra) In The Hawaiian Archipelago: Evidence Of Multiple Populations Based On Photo Identification, Jessica M. Aschettino, Robin W. Baird, Daniel J. Mcsweeney, Daniel L. Webster, Gregory S. Schorr, Jessica L. Huggins, Karen K. Martin, Sabre D. Mahaffy, Kristi L. West

United States Department of Commerce: Staff Publications

Despite the presence of melon-headed whales in tropical and subtropical waters worldwide, little is known about this species. To assess population structure in Hawai‘i, dedicated field efforts were undertaken from 2000 to 2009. Using only good quality photographs, there were 1,433 unique photo-identified individuals, of which 1,046 were distinctive. Of these, 31.5% were seen more than once. Resighting data combined with social network analyses showed evidence of two populations—a smaller, resident population, seen exclusively off the northwest region of the island of Hawai‘i, and a larger population, seen throughout all the main Hawaiian Islands (hereafter the “main Hawaiian Islands” population). …

The Application Of Gis And Spatiotemporal Analyses To Investigations Of Unusual Marine Mammal Strandings And Mortality Events, Stephanie A. Norman, Jessie Huggins, Tim E. Carpenter, James T. Case, Dyanna M. Lambourn, Jim Rice, John Calambokidis, Joseph K. Gaydos, M. Bradley Hanson, Deborah A. Duffield, Sandra Dubpernell, Susan Berta, Matt Klope

United States Department of Commerce: Staff Publications

In 2006–2007, an unusually high number of harbor porpoises (Phocoena phocoena) stranded along the Washington and Oregon coastlines. Spatiotemporal analyses were used to examine their ability to detect clusters of porpoise strandings during an unusualmortality event (UME) in the Pacific Northwest using stranding location data. Strandings were evaluated as two separate populations, outer coast and inland waters. The presence of global clustering was evaluated using the Knox spatiotemporal test, and the presence of local clusters was investigated using a spatiotemporal scan statistic (space–time permutation). There was evidence of global clustering, but no local clustering, supporting the hypothesis that …

Common Bottlenose Dolphins (Tursiops Truncatus) In California Waters: Cranial Differentiation Of Coastal And Offshore Ecotypes, William F. Perrin, Janet L. Thieleking, William A. Walker, Frederick I. Archer, Kelly M. Robertson

United States Department of Commerce: Staff Publications

Coastal and offshore bottlenose dolphins in California waters are currently assessed and managed as separate stocks. Recent molecular studies (of mtDNA haplotypes and microsatellites) have shown the two populations to be genetically differentiated. This study investigated cranial osteological differentiation of the forms. The sample analyzed included 139 skulls from live captures, direct takes, fishery bycatch, and strandings; the skulls were assigned to form based on collection locality or mtDNA haplotype. The coastal form differs from the offshore form mainly in features associated with feeding: larger and fewer teeth, more robust rostrum, larger mandibular condyle, and larger temporal fossa. This suggests …

Recreational Fishing Depredation And Associated Behaviors Involving Common Bottlenose Dolphins (Tursiops Truncatus) In Sarasota Bay, Florida, Jessica R. Powell, Randall S. Wells

United States Department of Commerce: Staff Publications

Odontocete depredation involves stealing or damaging bait or prey already captured by fishing gear. The increase in depredation is of concern for small stocks of cetaceans because interactions with fishing gear can lead to serious injury or mortality through entanglement or ingestion. Using long-term data sets available for the bottlenose dolphin (Tursiops truncatus) community in Sarasota Bay, Florida, we investigated recreational fishing gear interactions by (1) examining temporal patterns in depredation and associated behaviors from 2000 to 2007; (2) quantifying the behavior of dolphins that depredate or engage in associated behaviors; and (3) identifying factors associated with the …

A Model Of Chinook Salmon Population Dynamics Incorporating Size-Selective Exploitation And Inheritance Of Polygenic Correlated Traits, Jeffrey F. Bromaghin, Ryan M. Nielson, Jeffrey J. Hard

United States Department of Commerce: Staff Publications

Concern regarding the potential for selective fisheries to degrade desirable characteristics of exploited fish populations is growing worldwide. Although the occurrence of fishery-induced evolution in a wild population has not been irrefutably documented, considerable theoretical and empirical evidence for that possibility exists. Environmental conditions influence survival and growth in many species and may mask comparatively subtle trends induced by selective exploitation, especially given the evolutionarily short time series of data available from many fisheries. Modeling may be the most efficient investigative tool under such conditions. Motivated by public concern that large-mesh gillnet fisheries may be altering Chinook salmon in western …

From Observations To Forecasts – Part 8: The Use Of Satellite Observations In Numerical Weather Prediction, Andrew Collard, Fiona Hilton, Mary Forsythe, Brett Candy

United States Department of Commerce: Staff Publications

The use of satellites in weather prediction was introduced in an earlier article in this series (Kidd, 2010) which focused on satellite imagery, used primarily by forecasters and researchers to observe and understand synoptic scale weather patterns and their development. Many types of satellite observation are also used directly in numerical weather prediction (NWP) models. Observations from up to 50 individual satellite instruments are routinely assimilated at many centres. This article reviews the main types of satellite observations used in NWP, how they are used and why they are important.

As is often the case in this field, this article …

Cooperative Hunting Behavior, Prey Selectivity And Prey Handling By Pack Ice Killer Whales (Orcinus Orca), Type B, In Antarctic Peninsula Waters, Robert L. Pitman, John W. Durban

United States Department of Commerce: Staff Publications

Currently, there are three recognized ecotypes (or species) of killer whales (Orcinus orca) in Antarctic waters, including type B, a putative prey specialist on seals, which we refer to as “pack ice killer whale” (PI killer whale). During January 2009, we spent a total of 75.4 h observing three different groups of PI killer whales hunting off the western Antarctic Peninsula. Observed prey taken included 16 seals and 1 Antarctic minke whale (Balaenoptera bonaerensis). Weddell seals (Leptonychotes weddellii) were taken almost exclusively (14/15 identified seal kills), despite the fact that they represented only 15% …

State Of The Climate In 2010, Jessica Blunden, Derek S. Arndt, Molly O. Baringer

United States Department of Commerce: Staff Publications

Several large-scale climate patterns influenced climate conditions and weather patterns across the globe during 2010. The transition from a warm El Niño phase at the beginning of the year to a cool La Niña phase by July contributed to many notable events, ranging from record wetness across much of Australia to historically low Eastern Pacific basin and near-record high North Atlantic basin hurricane activity. The remaining five main hurricane basins experienced below- to well-below-normal tropical cyclone activity. The negative phase of the Arctic Oscillation was a major driver of Northern Hemisphere temperature patterns during 2009/10 winter and again in late …

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. …