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Introduction
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Publications
Publications (75)
The Irrawaddy dolphin ( Orcaella brevirostris ) is an endangered cetacean that ranges throughout much of Southeast Asia and lives in coastal, estuarine, and riverine habitats including three river systems: Ayeyarwady, Mekong, and Mahakam. Many populations face risks from human interference, but overall rangewide diversity and connectivity is not we...
River cetaceans are particularly vulnerable to anthropogenic impacts due to their constrained ranges in freshwater systems of China, South Asia, and South America. We undertook an exhaustive review of 280 peer-reviewed papers and grey literature reports (1998−2020) to examine the current status of knowledge regarding these cetaceans and their conse...
We reviewed Coram et al. (Biodivers Conserv 30:2341–2359, 2021, https://doi.org/10. 1007/s10531-021-02196-6), a paper that highlights the use of social media data to under- stand marine litter and marine mammals in Southeast Asia. While we commend its intent, we find that the methodology used and conclusions drawn portray an incomplete and inac- cu...
Ocean acidification along the California Shelf is controlled by the upwelling of deep CO2-rich waters. This coastal upwelling is driven by along-shore winds, which vary seasonally. We report aragonite undersaturation based on proxy values derived from temperature, salinity, and dissolved oxygen data and show the relationship between the spatial ext...
Uncertainties about the magnitude of bycatch in poorly assessed fisheries impede effective conservation management. In northern Peru, small-scale fisheries (SSF) bycatch negatively impacts marine megafauna populations and the livelihoods of fishers which is further elevated by the under-reporting of incidents. Within the last decade, accounts of en...
In recent decades, several studies and reviews have contributed new data on marine mammal composition and distribution in Vietnam, including surveys of whale temples along the coast in the southern part of the country. Whale temples have amassed a sizeable number of specimens that have been used as a valuable source of information concerning marine...
• Mediterranean fin whales aggregating in the Pelagos Sanctuary in summer to feed are exposed to vessel collision risk, particularly from high-speed ferries.
• This study developed models to predict summer fin whale distribution using a generalized additive model (GAM) and MaxEnt, with the aim of providing a tool to identify potential high whale–fe...
We document changes in the number of sightings and timing of humpback (Megaptera novaeangliae), blue (Balaenoptera musculus), and gray (Eschrichtius robustus) whale migratory phases in the vicinity of the Farallon Islands, California. We hypothesized that changes in the timing of migration off central California were driven by local oceanography, r...
• Patterns and changes in the distribution of coastal marine mammals can serve as indicators of environmental change that fill critical information gaps in coastal and marine environments. Coastal habitats are particularly vulnerable to the effects of near‐term sea‐level rise.
• In California, Pacific harbour seals (Phoca vitulina richardii) are a...
There is growing evidence that smaller vessels not required to broadcast data via the Automatic Identification System (AIS) contribute significant noise to urbanized coastal areas. The Marine Monitor (M2), a vessel tracking system that integrates AIS data with data collected via marine radar and high-definition camera, was employed to track all ves...
Marine mammals can play important ecological roles in aquatic ecosystems, and their presence can be key to community structure and function. Consequently, marine mammals are often considered indicators of ecosystem health and flagship species. Yet, historical population declines caused by exploitation, and additional current threats, such as climat...
Habitat prioritization is a powerful tool for identifying critical wildlife areas for conservation. This study evaluates the risk of disturbance from maritime activities to seabirds in order to prioritize critical seabird foraging habitat for conservation thereby providing a much-needed methodological contribution demonstrating how to transparently...
Southern sea otters have been actively managed for their conservation and recovery since listing on the federal Endangered Species Act in 1977. Still, they remain constrained to a geographically small area on the central coast of California relative to their former coast-wide range, with population numbers far below those of the estimated optimal s...
Fisheries bycatch has been identified as the greatest threat to marine mammals worldwide. Characterizing the impacts of bycatch on marine mammals is challenging because it is difficult to both observe and quantify, particularly in small-scale fisheries where data on fishing effort and marine mammal abundance and distribution are often limited. The...
An accelerating trend of global urbanization accompanying population growth makes frequently updated land use and land cover (LULC) maps critical. LULC maps have been widely created through the classification of remotely sensed imagery. Maps of urban areas have been both dichotomous (urban or non-urban) and entailing of discrete urban types. This s...
Marine mammal bycatch poses a particular challenge in developing countries, where data to document bycatch and its effects are often lacking. Using the Bycatch Risk Assessment (ByRA) toolkit, based on InVEST open-source models, we chose 4 field sites in Southeast Asia with varying amounts of data on marine mammals and fishing occurrence: Trat provi...
Aim:
The Irrawaddy dolphin (Orcaella brevirostris) is an endangered cetacean found throughout Southeast Asia. The main threat to this species is human encroachment, led by entanglement in fishing gear. Information on this data-poor species' ecology and habitat use is needed to effectively inform spatial management.
Location:
We investigated the...
Most species of whales are vulnerable to vessel collisions, and the probability of lethality increases logistically with vessel speed. An Automatic Identification System (AIS) can provide valuable vessel activity data, but terrestrial-based AIS has a limited spatial range. As the need for open ocean monitoring increases, AIS broadcasts relayed over...
Vessel traffic management systems can be employed for environmental management where vessel activity may be of concern. One such location is in San Francisco Bay where a variety of vessel types transit a highly developed urban estuary. We analyzed vessel presence and speed across space and time using vessel data from the Marine Monitor, a vessel tr...
Recovering species are often limited to much smaller areas than they historically occupied. Conservation planning for the recovering species is often based on this limited range, which may simply be an artifact of where the surviving population persisted. Southern sea otters (Enhydra lutris nereis) were hunted nearly to extinction but recovered fro...
Irrawaddy dolphins (Orcaella brevirostris) are threatened, little‐known cetaceans primarily jeopardized by fishing gear entanglement. Information regarding life history, foraging ecology, and movement are crucial to determine management units and conservation regions. This is the first analysis of the ontogenetic changes in diet and habitat of Irra...
While harbor porpoises currently enter San Francisco Bay year-round, evidence suggests a disappearance that spanned approximately 65 yr. The range of energetic costs of basal metabolism, locomotion, thermoregulation, and reproduction was estimated for porpoises, using a velocity-dependent bioenergetic model to estimate the potential food requiremen...
Fisheries bycatch is a widespread and serious issue that leads to declines of many important and threatened marine species. However, documenting the distribution, abundance, population trends and threats to sparse populations of marine species is often beyond the capacity of developing countries because such work is complex, time consuming and ofte...
UNEP- CMS Dugong Catch & Bycatch Questionnaire.
(DOC)
Dugong Catch & Bycatch Questionnaire project manual.
(PDF)
Dugong Catch & Bycatch Questionnaire data upload sheet.
(XLSX)
IN THEIR POLICY Forum “U.S. seafood
import restriction presents opportunity and
risk” (16 December, p. 1372), R. Williams
et al. describe some possible effects of the
U.S. National Oceanic and Atmospheric
Administration (NOAA) rule requiring that
seafood imported into the United States
must come from fisheries that comply with
the U.S. Marine Mamma...
Seabird aggregations at sea have been shown to be associated with concentrations of prey. Previous research identified Central California as a highly used foraging area for seabirds, with locally breeding seabirds foraging close to their colonies on Southeast Farallon Island. Herein, we focus on nonresident (i.e. non-locally breeding) seabird speci...
Citizen science projects enlist the public to collect data at an array of locations over time and have been remarkably successful in advancing scientific knowledge; contributions provide a vast amount of data on species occurrence, distribution, and density around the world. Many citizen science projects strive to improve the scientific literacy of...
The identification of tree species can provide a useful and efficient tool for forest managers for planning and monitoring purposes. Hyperspectral data provide sufficient spectral information to classify individual tree species. Two non-parametric classifiers, support vector machines (SVM) and random forest (RF), have resulted in high accuracies in...
Shipping traffic poses a worldwide threat to many large whale species. Spatially explicit risk assessments are increasingly being used as a tool to minimize ship-strike risk. These assessments often use static representations of shipping patterns. We used Automatic Identification System data to quantify variability in cargo shipping traffic enterin...
Effective conservation of coastal marine mammals is largely dependent on reliable knowledge of their abundance, as well as the ecological and human factors driving their distribution. In developing countries, lack of resources and capacity frequently impedes research needed to estimate abundance and to determine the ecological requirements of coast...
Place-based management in the open ocean faces unique challenges in delineating boundaries around temporally and spatially dynamic systems that span broad geographic scales and multiple management jurisdictions, especially in the 'high seas'. Geospatial technologies are critical for the successful design of pelagic conservation areas, because they...
Understanding habitat preferences for endangered species is a high priority for management
strategies to ensure minimum conflict between human uses and wildlife conservation.
The purpose of this study was to identify oceanographic variables that predict occurrences of
humpback whales Megaptera novaeangliae within the Cordell Bank and Gulf of the Fa...
Background/Question/Methods
Conditions in coastal zones worldwide are deteriorating rapidly, barraged by multiple stressors. Lack of integration across human and natural sciences has limited understanding and the ability to solve resilience-related problems, despite the importance of these systems in supporting human populations and biodiversity....
ABSTRACT: Bycatch of marine megafauna in fishing gear is a problem with global implications. Bycatch rates can be difficult to quantify, especially in countries where there are limited data on the abundance and distribution of coastal marine mammals, the distribution and intensity of fishing effort, and coincident interactions, and limited bycatch...
Belize in Central America supports one of the largest populations of endangered Antillean manatees in the Caribbean. In 2012, a country–wide survey resulted in the highest count ever recorded (507 manatees). Manatee use of atolls has only been documented at Turneffe Atoll in Belize. Manatees in Belize, including those that use Turneffe, have been s...
The Irrawaddy dolphin (Orcaella brevirostris) is found in Southeast Asia in nearshore coastal, estua-rine habitats, in three freshwater riverine habitats of the Mahakam, Mekong, and Ayeyarwady Rivers, and in brackish water lakes in Chilika, India, and Songkhla, Thailand (Reeves et al., 2008). Throughout its range, the Irrawaddy dolphin has been stu...
Understanding seabird habitat preferences is critical to future wildlife conservation and threat mitigation in California. The objective of this study was to investigate drivers of seabird habitat selection within the Gulf of the Farallones and Cordell Bank National Marine Sanctuaries to identify areas for targeted conservation planning. We used se...
Northern elephant seals ( Mirounga angustirostris ) historically experienced a significant population decrease to the brink of extinction owing to human exploitation, but have since recovered and recolonized former breeding/haul‐out sites. Point Reyes Peninsula, California, is one location where population increase has resulted in colony expansion....
Turneffe Atoll (TA), located approximately 35km from mainland Belize, is the only atoll in the world where manatees have been reported. We summarized manatee observation data from TA (2001 to 2013), to document distribution patterns and habitat use. The atoll was divided into 21 imaginary zones. One-hundred and sixteen manatee sightings were record...
Accurate monitoring is a critical step in evaluating the conservation and management needs of endangered species. We evaluated a low cost, effective survey method for monitoring West Indian manatees (Trichechus manatus manatus) in Belize, Central America. The objectives for this paper are (1) to evaluate a count-based population index derived from...
Spatially-explicit habitat models can impart a scientific basis for delineating critical habitats that relate species' distributions to physical and biological conditions, even in marine environments with vague and dynamic boundaries. We developed a habitat model of the relationship between the winter distribution of North Atlantic right whales Eub...
A crucial step in any research on endangered species is to obtain baseline information about their geographic range, present population status, and relevant conservation issues. As sirenians are routinely found in coastal, riverine, and lagoon systems, they are often in such close proximity to human settlements that their lives and behavior are sig...
This important scientific volume comprehensively explores the biology and ecological status of manatees and dugongs in all of the geographic regions where they can be found today, from the Caribbean to Eastern Africa, from Arabia to the Amazon, and from Japan through the South Pacific to Australia. Many of these dwindling populations are situated i...
The Sierra Nevada red fox Vulpes vulpes necator is listed as a threatened species under the California Endangered Species Act. It originally occurred throughout California's Cascade and Sierra Nevada mountain regions. Its current distribution is unknown but should be determined in order to guide management actions. We used occurrence data from the...
Reliable abundance estimates are critical for management and conservation of coastal small cetaceans. This is particularly important in developing countries where coastal human populations are increasing, the impacts of anthropogenic activities are often unknown, and the resources necessary to assess coastal cetaceans are limited. We adapted ship-b...
Estuaries are ecologically and economically valuable and have been highly degraded from both land and sea. Estuarine habitats in the coastal zone are under pressure from a range of human activities. In the United States and elsewhere, very few conservation plans focused on estuaries are regional in scope; fewer still address threats to estuary long...
The symposium took place in Bangkok, Thailand on March 5 and 6, 2009. Dugongs (Dugong dugon) are seen in limited areas along both coastlines of Thailand, the Andaman Sea and the Gulf of Thailand. Thai researchers have been studying the dugong since 1979. Information on the history of dugongs, beliefs, and the previous use of dugong body parts in Th...
In a survey of the Myeik Archipelago, we documented seven seagrass species in the southern region. Three seagrass species (Cymodocea rotundata, Enhalus acoroides, and Halophila ovalis) have previously been reported in the Myeik Archipelago; three species (Halodule pinifolia, Halodule uninervis, Syringodium isoetifolium) are new reports for the arch...
A number of international treaties address the conservation of marine resources. The declining state of the world's oceans suggests that these treaties are not succeeding and could use improvement. The Convention on International Trade in Endangered Species (CITES) is increasingly embracing the conservation of marine species. We examine the evoluti...
This research was conducted to assess the location of population groups and conservation issues affecting dugongs Dugong dugon along the eastern Gulf of Thailand off Cambodia and Phu Quoc Island, Vietnam. Interviews in fishing communities in 2002 and 2004 along the Cambodian coast revealed that dugongs are sporadically found in fishing nets and the...
The dugong is classified as vulnerable to extinction by the World Conservation Union on the basis of declines in area or extent of occupancy, habitat quality, and actual or potential levels of exploitation. In Thailand, the largest groups of dugongs are found near islands off the Andaman coast. The authors conducted a 2-year project that included d...
Abstract The reliability of habitat maps that have been generated using Geographic Information Systems (GIS) and image processing of remotely sensed data can be overestimated. Habitat suitability and spatially explicit population viability models are often based on these products without explicit knowledge of the effects of these mapping errors on...
A bstract
In 2000 and 2001, dugong abundance was estimated using aerial surveys in three provinces along the Andaman coast of Thailand. A microlite aircraft was used to fly aerial transects over seagrass areas. All surveys were done during rising tides as the dugongs came to the seagrass beds to feed. The largest population was found in Trang provi...
Interview surveys (131 interviews in 44 villages) were carried out in 2004 to assess the present status of the dugong population inhabiting the Gulf of Mannar between India and Sri Lanka. The area has been an important dugong habitat in the past but there is little recent data. The Gulf is highly productive and intensively fished by both countries...
Using a Geographic Infor mation System (GIS), a sensitivity analysis was performed on estimated mapping err ors in vegetation type, forest canopy cover per centage, and tr ee crown size to determine the possible ef fects error in these data might have on delineating suitable habitat for the Califor nia Spotted Owl ( Strix occidentalis occidentalis)...
Once commonly seen along tropical coasts from East Africa to Australia, dugongs (Dugong dugon) are currently considered rare over most of this range. The IUCN classifies the dugong as vulnerable on a global scale based on declines in occurrence and quality of habitat, and human exploitation. In Thailand, dugongs used to be seen regularly along both...