Joint Institute for Marine and Atmospheric Research

Hawaii, Hawaii, United States

Joint Institute for Marine and Atmospheric Research

Hawaii, Hawaii, United States
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Baker J.D.,National Oceanic and Atmospheric Administration | Harting A.L.,Harting Biological Consulting | Wurth T.A.,Joint Institute for Marine and Atmospheric Research | Johanos T.C.,National Oceanic and Atmospheric Administration
Marine Mammal Science | Year: 2011

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. Using these rates, a conservative estimate of current MHI abundance and a previously published stochastic simulation model, we estimate the MHI population growth rate and projected abundance trend. Analogous estimates for the NWHI are derived from a much richer data set. Estimated survival from weaning to age 1 yr is 77% in the MHI, much higher than recent NWHI estimates ranging from 42% to 57%. Moreover, MHI females begin reproducing at a younger age and attain higher birth rates than observed in the NWHI. The estimated MHI intrinsic rate of population growth is 1.07 compared to a 0.89-0.96 range in the NWHI. Assuming an initial abundance of 152 animals in the MHI, projections indicate that if current demographic trends continue, abundance in the NWHI and MHI will equalize in approximately 15 yr. These results underscore the imperative to mitigate the NWHI decline while devoting conservation efforts to foster population growth in the MHI, where documented threats including fishery interactions, direct killing, and disease could rapidly undo the current fragile positive trend. 2010 by the Society for Marine Mammalogy Published 2010. This article is a US Government work and is in the public domain in the USA.

Sievanen L.,Joint Institute for Marine and Atmospheric Research | Sievanen L.,Brown University
Maritime Studies | Year: 2014

Many fisheries stocks and the livelihoods of those who make their living from fishing are in decline, and these declines are exacerbated by uncertainties associated with increased climate variability and change. Social scientists have long documented the importance of mobility and diversification in reducing the risk and uncertainty associated with climate variability, particularly in the context of small-scale fishing. However, it is unclear how these traditional mechanisms are buffering fishers against the varied stressors they currently face, including those associated with environmental variability. This paper examines how fishers on the southern gulf coast of the Mexican state of Baja California Sur perceive and respond to stressors associated with normal environmental variability, how their ability to adapt is spatially distributed, and what threats they perceive to their continued ability to adapt. Understanding the adaptation strategies and everyday vulnerabilities that fishers face can elucidate problems associated with current fisheries management and the underlying factors that cause vulnerability, and also help decision makers, including fishers themselves, develop more effective adaptation strategies in the face of climate change. © 2014, Sievanen; licensee Springer.

Nadon M.O.,University of Miami | Nadon M.O.,Joint Institute for Marine and Atmospheric Research | Nadon M.O.,National Oceanic and Atmospheric Administration | Ault J.S.,University of Miami | And 3 more authors.
PLoS ONE | Year: 2015

The coral reef fish community of Hawaii is composed of hundreds of species, supports a multimillion dollar fishing and tourism industry, and is of great cultural importance to the local population. However, a major stock assessment of Hawaiian coral reef fish populations has not yet been conducted. Here we used the robust indicator variable "average length in the exploited phase of the population (L¯)", estimated from size composition data from commercial fisheries trip reports and fishery-independent diver surveys, to evaluate exploitation rates for 19 Hawaiian reef fishes. By and large, the average lengths obtained from diver surveys agreed well with those from commercial data. We used the estimated exploitation rates coupled with life history parameters synthesized from the literature to parameterize a numerical population model and generate stock sustainability metrics such as spawning potential ratios (SPR). We found good agreement between predicted average lengths in an unfished population (from our population model) and those observed from diver surveys in the largely unexploited Northwestern Hawaiian Islands. Of 19 exploited reef fish species assessed in the main Hawaiian Islands, 9 had SPRs close to or below the 30% overfishing threshold. In general, longer-lived species such as surgeonfishes, the redlip parrotfish (Scarus rubroviolaceus), and the gray snapper (Aprion virescens) had the lowest SPRs, while short-lived species such as goatfishes and jacks, as well as two invasive species (Lutjanus kasmira and Cephalopholis argus), had SPRs above the 30% threshold. Copyright: This is an open access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication.

Cahoon M.K.,Joint Institute for Marine and Atmospheric Research | Littnan C.L.,National Oceanic and Atmospheric Administration | Longenecker K.,Bishop Museum | Carpenter J.R.,University of Hawaii at Manoa
Endangered Species Research | Year: 2013

Divergent trends in population abundance of Endangered Hawaiian monk seals Monachus schauinslandi are apparent between the northwestern Hawaiian Islands (NWHI) and the main Hawaiian Islands (MHI). The smaller, recently established MHI seal population is increasing, exhibits higher juvenile survival, and seals appear to be in better condition overall relative to seals in the NWHI. Using traditional dietary analysis we characterize the diet of MHI monk seals for the first time and examine the hypothesis that diet and prey availability may be driving these regional trends. Prey remains from feces and regurgitates (n = 120) were identified to the lowest possible taxonomic level and compared with results from NWHI historical data. The most common prey taxa, by percent frequency of occurrence, were Balistidae (48.3%), Crusta cea (37.5%), Acanthuridae (32.5%), Muraenidae (30.8%), Serranidae (20.8%), Cephalopoda (18.3%), Holocentridae (17.5%), Labridae (16.7%), and Scaridae (10.8%). Results indicate that MHI and NWHI seals eat similar diets; however, an incongruity in body conditions of seals between regions indicates a possible difference in intra- or inter-specific competition, prey availability, and quality. Further research assessing foraging behavior and habitat use would aid in identifying the regional differences observed. © Inter-Research 2013.

Baker J.D.,National Oceanic and Atmospheric Administration | Johanos T.C.,National Oceanic and Atmospheric Administration | Wurth T.A.,Joint Institute for Marine and Atmospheric Research | Littnan C.L.,National Oceanic and Atmospheric Administration
Marine Mammal Science | Year: 2014

Body length and axillary girth measurements of more than 600 free-ranging Hawaiian monk seals from 1 to 20 yr old were analyzed. Comparison of fitted von Bertalanffy growth models confirmed there is no evidence of sexual dimorphism in this species. Substantial differences in growth patterns were detected among seven subpopulations representing the species entire geographic range. The age at which seals would be expected to attain a reference length of 180 cm ranged from just over 3 yr up to almost 7 yr at the various sites. Subpopulations exhibiting slower growth have previously been found to also exhibit lower age-specific reproductive rates. Differences in growth of seals among sites likely indicate varying environmental conditions determining growth during the time periods represented in the sampled data. © 2014 Society for Marine Mammalogy.

Brown E.,Kalaupapa National Historical Park | Hughes G.,Kalaupapa National Historical Park | Watanuki R.,Kalaupapa National Historical Park | Johanos C.T.,National Oceanic and Atmospheric Administration | Wurth T.,Joint Institute for Marine and Atmospheric Research
Aquatic Mammals | Year: 2011

The Hawaiian monk seal (Monachus schauin-slandi) is one of the most endangered marine mammals on earth, with the majority (90%) of the population found in the relatively uninhabited Northwestern Hawaiian Islands (NWHI) and the remaining 10% in the heavily developed main Hawaiian Islands (MHI). Since 1998, the total population has declined 4%/y to ~1,100 animals. Despite this trend, the population in the MHI is increasing, with monk seals pupping at Kalaupapa National Historical Park on the island of Moloka'i. Long-time human residents in Kalaupapa indi-cated that monk seals rarely used the beaches prior to 1997, and no births had been observed since at least 1941. Since 1997, a total of 53 pups have been born, with births increasing at an aver-age annual rate of 26.6%. Reproductively active females born at Kalaupapa exhibited a 55.6% site fidelity. Spatially, monk seal density was higher on sandy beaches (2.0 monk seals km -1) than basalt (0.3 monk seals km -1) habitat. Temporally, monk seal density was highest during the late spring and early summer due to the presence of mother-pup pairs. After weaning, monk seals also used adja-cent basalt habitat and typically moved away from Kalaupapa at the onset of winter; since 2009, monk seal sightings have increased throughout the year. Explanations for the emergence of the pupping area include suitable habitat characteristics (e.g., protected shallow water habitat, high prey abun-dance, and low predator/competitor abundance), reduction of human activities (e.g., elimination of cattle in 1985, sparse [3.4 people km -2] and declin-ing [90% since 1900] human population, and low public visitation [8,494 people y -1]), and a sup-portive community. Current management actions include habitat-use surveys, population studies, community presentations, and law enforcement patrols. Kalaupapa has become a productive pupping area for monk seals in the MHI, and the establishment of a birthing area provides hope for the survival of this endangered species.

Fautin D.,University of Kansas | Dalton P.,University of Washington | Incze L.S.,University of Southern Maine | Leong J.-A.C.,Hawaii Institute of Marine Biology | And 14 more authors.
PLoS ONE | Year: 2010

Marine biodiversity of the United States (U.S.) is extensively documented, but data assembled by the United States National Committee for the Census of Marine Life demonstrate that even the most complete taxonomic inventories are based on records scattered in space and time. The best-known taxa are those of commercial importance. Body size is directly correlated with knowledge of a species, and knowledge also diminishes with distance from shore and depth. Measures of biodiversity other than species diversity, such as ecosystem and genetic diversity, are poorly documented. Threats to marine biodiversity in the U.S. are the same as those for most of the world: overexploitation of living resources; reduced water quality; coastal development; shipping; invasive species; rising temperature and concentrations of carbon dioxide in the surface ocean, and other changes that may be consequences of global change, including shifting currents; increased number and size of hypoxic or anoxic areas; and increased number and duration of harmful algal blooms. More information must be obtained through field and laboratory research and monitoring that involve innovative sampling techniques (such as genetics and acoustics), but data that already exist must be made accessible. And all data must have a temporal component so trends can be identified. As data are compiled, techniques must be developed to make certain that scales are compatible, to combine and reconcile data collected for various purposes with disparate gear, and to automate taxonomic changes. Information on biotic and abiotic elements of the environment must be interactively linked. Impediments to assembling existing data and collecting new data on marine biodiversity include logistical problems as well as shortages in finances and taxonomic expertise. © 2010 Fautin et al.

Howell E.A.,National Oceanic and Atmospheric Administration | Hoover A.,Joint Institute for Marine and Atmospheric Research | Hoover A.,University of Maryland Center for Environmental Science | Benson S.R.,Southwest Fisheries Science Center | And 4 more authors.
Fisheries Oceanography | Year: 2015

Fishery management measures to reduce interactions between fisheries and endangered or threatened species have typically relied on static time-area closures. While these efforts have reduced interactions, they can be costly and inefficient for managing highly migratory species such as sea turtles. The NOAA TurtleWatch product was created in 2006 as a tool to reduce the rates of interactions of loggerhead sea turtles with shallow-set longline gear deployed by the Hawaii-based pelagic longline fishery targeting swordfish. TurtleWatch provides information on loggerhead habitat and can be used by managers and industry to make dynamic management decisions to potentially reduce incidentally capturing turtles during fishing operations. TurtleWatch is expanded here to include information on endangered leatherback turtles to help reduce incidental capture rates in the central North Pacific. Fishery-dependent data were combined with fishing effort, bycatch and satellite tracking data of leatherbacks to characterize sea surface temperature (SST) relationships that identify habitat or interaction 'hotspots'. Analysis of SST identified two zones, centered at 17.2° and 22.9°C, occupied by leatherbacks on fishing grounds of the Hawaii-based swordfish fishery. This new information was used to expand the TurtleWatch product to provide managers and industry near real-time habitat information for both loggerheads and leatherbacks. The updated TurtleWatch product provides a tool for dynamic management of the Hawaii-based shallow-set fishery to aid in the bycatch reduction of both species. Updating the management strategy to dynamically adapt to shifts in multi-species habitat use through time is a step towards an ecosystem-based approach to fisheries management in pelagic ecosystems. © 2015 John Wiley & Sons Ltd.

Baker J.D.,National Oceanic and Atmospheric Administration | Becker B.L.,National Oceanic and Atmospheric Administration | Wurth T.A.,Joint Institute for Marine and Atmospheric Research | Johanos T.C.,National Oceanic and Atmospheric Administration | And 2 more authors.
Biological Conservation | Year: 2011

The deteriorating demographic status of the endangered Hawaiian monk seal has motivated renewed and expanded proposals for conservation action, including translocation of seals to improve survival. Over the past three decades, numerous monk seal translocations have been conducted with a variety of objectives, including mitigating shark predation and conspecific male aggression, reducing human-seal interactions, and taking advantage of favorable foraging habitats to improve survival. Here, we analyze our cumulative experience with translocation of Hawaiian monk seals. We found a strong correlation between the time seals remained in the vicinity of the release site and their age. Recently weaned pups (with little or no at-sea foraging experience) exhibited high fidelity to release sites commensurate with that shown by untranslocated pups to their birth location. In contrast, juvenile and adult seals tended to stray from their release locations farther and sooner. Nevertheless, when 21 adult male seals were moved more than 1000. km from Laysan Island in the Northwestern Hawaiian Islands (NWHI), to the main Hawaiian Islands (MHI), they subsequently dispersed among the MHI; however, only one was observed to return to the NWHI. Translocated seals appeared to survive at rates comparable to seals native to the release site. Outcomes suggest that in most cases the intended objectives of translocations were achieved. Except for one notable case, translocations within the MHI to arrest human-seal interactions were mostly unsuccessful. These findings will be essential for informing successful large-scale translocation plans in the future. © 2011 Elsevier Ltd.

PubMed | 9 741 Amaumau Place, Joint Institute for Marine and Atmospheric Research, Hawaii Institute of Marine Biology and National Oceanic and Atmospheric Administration
Type: | Journal: Advances in experimental medicine and biology | Year: 2015

Chlorophyll is the basis for ecosystem productivity in most marine environments. We report on an ongoing effort to examine whether ambient sounds are tied to chlorophyll levels. We hypothesized that an increase in food-web available energy will be distributed across trophic levels, eventually reaching sound-producing animals and increasing acoustic levels. To test our hypothesis, we compared reef environments to explore links between soundscapes and chlorophyll a concentrations. The study sites resided in disparate oceanographic regimes that experienced substantially different oceanographic conditions. We anticipated that the results would show differing patterns of primary productivity between sites and therefore would be reflected in the soundscapes.

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