scholarly journals eOceans dive-logs for science and conservation: a case study of sharks in Thailand

2018 ◽  
Author(s):  
C. A. Ward-Paige ◽  
A. Westell ◽  
B. Sing
Keyword(s):  
Citizen Science ◽  
Anthropogenic Activities ◽  
Tourism Industry ◽  
Conservation Strategies ◽  
Shark Species ◽  
Spatial And Temporal Patterns ◽  
Marine Animals ◽  
Science Management ◽  
Leopard Sharks ◽  
Abundance And Distribution

AbstractMany marine animals around the world are threatened by a variety of anthropogenic activities, yet there is often a paucity of data to monitor patterns in abundance and distribution or to evaluate human interventions. The new citizen science program eOceans helps to fill this gap by gathering observations of various marine animals from worldwide ocean explorers. In 2012, a dedicated Thailand-wide census of sharks, and other animals, began as collaboration between eOceans scientists and the dive tourism industry. Using the observations from 9,524 dives (9,357 hours underwater) logged by >169 divers on 153 sites, we describe the spatial and temporal patterns of sharks in coastal Thailand. A total of 12 shark species were encountered, most commonly (67%) as individuals, and were observed on 11% of all dives, on 59% of sites, in all months and years. The two most frequently encountered species were blacktip reef (Carcharhinus melanopterus) and leopard sharks (Stegostoma fasciatum). Many species had peak encounter rates in summer, but aggregated in various seasons in different years. Mating events and nursery sites were observed rarely, and only for blacktip reef and whitetip reef (Triaenodon obesus) sharks. These results could be of value to species-or region-specific biologists, ecologists and fisheries scientists, as well as to managers and policy makers that could use the findings to monitor future trends and prioritize conservation strategies. Moreover, this study highlights the value that collaborative eOceans citizen science projects could have in support of marine science, management and conservation efforts worldwide.

Predicting changes in distribution of a large coastal shark in the face of the strengthening East Australian Current

2020 ◽  
Vol 642 ◽  
pp. 163-177 ◽  
Author(s):  
Y Niella ◽  
AF Smoothey ◽  
V Peddemors ◽  
R Harcourt
Keyword(s):  
Austral Summer ◽  
Conservation Strategies ◽  
Limiting Factor ◽  
Commercial Fisheries ◽  
East Australian Current ◽  
Spatial And Temporal Patterns ◽  
Marine Animals ◽  
Factors Affecting ◽  
Southeastern Australia ◽  
The Face

In the face of accelerating climate change, conservation strategies will need to consider how marine animals deal with forecast environmental change as well as ongoing threats. We used 10 yr (2009-2018) of data from commercial fisheries and a bather protection program along the coast of New South Wales (NSW), southeastern Australia, to investigate (1) spatial and temporal patterns of occurrence in bull sharks and (2) environmental factors affecting bull shark occurrence along the coast of NSW. Predicted future distribution for this species was modelled for the forecast strengthening East Australian Current. Bull sharks were mostly harvested in small to larger estuaries, with average depth and rainfall responsible for contrasting patterns for each of the fisheries. There was an increase in the occurrence of bull sharks over the last decade, particularly among coastal setline fisheries, associated with seasonal availability of thermal gradients >22°C and both westward and southward coastal currents stronger than 0.15 and 0.60 m s-1, respectively, during the austral summer. Our model predicts a 3 mo increase in the availability of favourable water temperatures along the entire coast of NSW for bull sharks by 2030. This coastline provides a uniquely favourable topography for range expansion in the face of a southerly shift of warmer waters, and habitat is unlikely to be a limiting factor for bull sharks in the future. Such a southerly shift in distribution has implications for the management of bull sharks both in commercial fisheries and for mitigation of shark-human interactions.

scholarly journals Biological Consequences of Marine Energy Development on Marine Animals

Energies ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 8460
Author(s):  
Lenaïg G. Hemery ◽  
Andrea E. Copping ◽  
Dorian M. Overhus
Keyword(s):  
Anthropogenic Activities ◽  
Energy Systems ◽  
Energy Development ◽  
Knowledge Gaps ◽  
Marine Animals ◽  
Natural Habitats ◽  
Holistic View ◽  
Energy Devices ◽  
Marine Energy ◽  
Animal Populations

Marine energy devices harness power from attributes of ocean water to form a sustainable energy source. Knowledge gaps remain about whether marine energy systems can affect the environment, adding another threat to animal populations and habitats already under pressure from climate change and anthropogenic activities. To date, potential environmental effects have been studied under the scope of stressor–receptor interactions, where moving parts of, or emissions from, a system could harm the animals, habitats, and natural processes. While crucial for understanding effects and identifying knowledge gaps, this approach misses a holistic view of what animals may experience in the presence of marine energy systems. We look at six biological consequences and forces that drive the health of an animal population and the effects expected from marine energy development: success of early life stages; changes in competitive capabilities; growth and survival based on food availability; susceptibility to predators; injury or death; and reproductive success. We use case studies to develop this approach, focusing on a variety of marine animals. An approximate level of risk is assigned for each interaction based on the biological consequences. This work highlights the need to examine the effects of marine energy development on animal populations within their natural habitats.

scholarly journals Coalescence times, life history traits and conservation concerns: an example from four coastal shark species from the Indo-Pacific

2021 ◽  
Author(s):  
Pierre Lesturgie ◽  
Serge Planes ◽  
Stefano Mona
Keyword(s):  
Population Structure ◽  
Life History ◽  
Life History Traits ◽  
New Caledonia ◽  
Demographic History ◽  
Conservation Strategies ◽  
Shark Species ◽  
Effective Population ◽  
Demographic Models ◽  
Mobile Species

Dispersal abilities play a crucial role in shaping the extent of population genetic structure, with more mobile species being panmictic over large geographic ranges and less mobile ones organized in meta-populations exchanging migrants to different degrees. In turn, population structure directly influences the coalescence pattern of the sampled lineages, but the consequences on the estimated variation of the effective population size (Ne) over time obtained by means of unstructured demographic models remain poorly understood. However, this knowledge is crucial for biologically interpreting the observed Ne trajectory and further devising conservation strategies in endangered species. Here we investigated the demographic history of four shark species (Carharhinus melanopterus, Carharhinus limbatus, Carharhinus amblyrhynchos, Galeocerdo cuvier) with different degrees of endangered status and life history traits related to dispersal distributed in the Indo-Pacific and sampled off New Caledonia. We compared several evolutionary scenarios representing both structured (meta-population) and unstructured models and then inferred the Ne variation through time. By performing extensive coalescent simulations, we provided a general framework relating the underlying population structure and the observed Ne dynamics. On this basis, we concluded that the recent decline observed in three out of the four considered species when assuming unstructured demographic models can be explained by the presence of population structure. Furthermore, we also demonstrated the limits of the inferences based on the sole site frequency spectrum and warn that statistics based on linkage disequilibrium will be needed to exclude recent demographic events affecting meta-populations.

scholarly journals Cetacean Research and Citizen Science in Kenya

2021 ◽  
Vol 8 ◽  
Author(s):  
Michael Gilbert Mwango’mbe ◽  
Jane Spilsbury ◽  
Steve Trott ◽  
Judith Nyunja ◽  
Nina Wambiji ◽  
...  
Keyword(s):  
Citizen Science ◽  
Marine Mammal ◽  
Marine Mammals ◽  
Bottlenose Dolphins ◽  
Conservation Strategies ◽  
Science Data ◽  
Pilot Whale ◽  
Area Of Interest ◽  
Mammal Conservation ◽  
Kenyan Coast

In 2011, several non-governmental and government agencies established the Kenya Marine Mammal Network (KMMN) to provide a platform for the consistent collection of data on marine mammals along the Kenyan coast, identify areas of importance and engage marine users and the general public in marine mammal conservation. Prior to the KMMN, relatively little was known about marine mammals in Kenya, limiting conservation strategies. The KMMN collects data nationwide through dedicated surveys, opportunistic sightings and participative citizen science, currently involving more than 100 contributors. This paper reviews data on sightings and strandings for small cetaceans in Kenya collated by the KMMN. From 2011 to 2019, 792 records of 11 species of small cetaceans were documented. The most frequently reported inshore species were the Indo-Pacific bottlenose dolphin and Indian Ocean humpback dolphin. Offshore species, included killer whales, short-finned pilot whale and long-snouted spinner dolphin. Indo-Pacific bottlenose dolphins, long-snouted spinner dolphins, striped dolphins and Risso’s dolphins were recorded through stranding reports. The efforts of the KMMN were disseminated through international meetings (International Whaling Commission, World Marine Mammal Conference), national status reports, outreach and social media. Data has also supported the identification of three IUCN Important Marine Mammal Areas and one Area of Interest in Kenya. Further research is needed to improve estimates of cetacean abundance and distribution, particularly in unstudied coastal areas, and to assess the extent of anthropogenic threats associated with fisheries, coastal and port development, seismic exercises and unregulated tourism. The expansion of the network should benefit from the participation of remote coastal fishing communities, government research agencies, tourism and seismic operations, among others. The KMMN demonstrated the value of dedicated and citizen science data to enhance marine mammal conservation strategies to boost awareness and eco-tourism and to bring the public and science closer together, promoting research and effective conservation efforts.

scholarly journals A Portable Device for Methane Measurement Using a Low-Cost Semiconductor Sensor: Development, Calibration and Environmental Applications

Sensors ◽  
2021 ◽  
Vol 21 (22) ◽  
pp. 7456
Author(s):  
Leonardo Furst ◽  
Manuel Feliciano ◽  
Laercio Frare ◽  
Getúlio Igrejas
Keyword(s):  
Tin Dioxide ◽  
Anthropogenic Activities ◽  
Low Cost ◽  
Ventilation System ◽  
Treatment Plant ◽  
Good Alternative ◽  
Oxide Semiconductor ◽  
Spatial And Temporal Patterns ◽  
Cost System ◽  
Methane Concentrations

Methane is a major greenhouse gas and a precursor of tropospheric ozone, and most of its sources are linked to anthropogenic activities. The sources of methane are well known and its monitoring generally involves the use of expensive gas analyzers with high operating costs. Many studies have investigated the use of low-cost gas sensors as an alternative for measuring methane concentrations; however, it is still an area that needs further development to ensure reliable measurements. In this work a low-cost platform for measuring methane within a low concentration range was developed and used in two distinct environments to continuously assess and improve its performance. The methane sensor was the Figaro TGS2600, a metal oxide semiconductor (MOS) based on tin dioxide (SnO2). In a first stage, the monitoring platform was applied in a small ruminant barn after undergoing a multi-point calibration. In a second stage, the system was used in a wastewater treatment plant together with a multi-gas analyzer (Gasera One Pulse). The calibration of low-cost sensor was based on the relation of the readings of the two devices. Temperature and relative humidity were also measured to perform corrections to minimize the effects of these variables on the sensor signal and an active ventilation system was used to improve the performance of the sensor. The system proved to be able to measure low methane concentrations following reliable spatial and temporal patterns in both places. A very similar behavior between both measuring systems was also well noticeable at WWTP. In general, the low-cost system presented good performance under several environmental conditions, showing itself to be a good alternative, at least as a screening monitoring system.

scholarly journals Mining citizen science data to explore stopover sites and spatiotemporal variation in migration patterns of the red-footed falcon

2020 ◽  
Vol 66 (5) ◽  
pp. 467-475 ◽  
Author(s):  
Anastasios Bounas ◽  
Maria Solanou ◽  
Michele Panuccio ◽  
Sanja Barišić ◽  
Taulant Bino ◽  
...  
Keyword(s):  
Citizen Science ◽  
Conservation Strategies ◽  
Migration Routes ◽  
Central Mediterranean ◽  
Science Data ◽  
Yearly Variation ◽  
Migration Patterns ◽  
Species Migration ◽  
Stopover Sites ◽  
The Mediterranean

Abstract Citizen science data have already been used to effectively address questions regarding migration, a fundamental stage in the life history of birds. In this study, we use data from eBird and from 3 additional regional citizen science databases to describe the migration routes and timing of the red-footed falcon Falco vespertinus in the Mediterranean region across 8 years (2010–2017). We further examine the seasonal and yearly variation in migration patterns and explore sites used during the species migration. Our results suggest that the autumn passage is spatially less variable and temporally more consistent among years than in spring and that birds migrate faster in spring than in autumn. The species seems to be more prevalent along the Central Mediterranean during spring migration, probably as a result of the clockwise loop migration that red-footed falcons perform. There was a high variation in annual median migration dates for both seasons as well as in migration routes across years and seasons. Higher variation was exhibited in the longitudinal component thus indicating flexibility in migration routes. In addition, our results showed the species’ preference for lowlands covered with cropland and mosaics of cropland and natural vegetation as stopover sites during migration. Stopover areas predicted from our distribution modeling highlight the importance of the Mediterranean islands as stopover sites for sea-crossing raptors, such as the red-footed falcon. This study is the first to provide a broad-scale spatiotemporal perspective on the species migration across seasons, years and flyways and demonstrates how citizen science data can inform future monitoring and conservation strategies.

scholarly journals Maintaining standing stones benefits biodiversity in lowland heathland

Oryx ◽  
2018 ◽  
Vol 52 (2) ◽  
pp. 240-249 ◽  
Author(s):  
Emma Shepheard-Walwyn ◽  
Shonil A. Bhagwat
Keyword(s):  
Biodiversity Conservation ◽  
Cultural Landscapes ◽  
Anthropogenic Activities ◽  
Integrated Management ◽  
Conservation Strategies ◽  
Management Approach ◽  
Landscape Matrix ◽  
Sacred Sites ◽  
Cultural Aspects ◽  
The Uk

AbstractThe exploitation of natural resources by people generally has detrimental effects on nature but in some cases anthropogenic activities can result in changes to the natural environment that produce new habitats and increase biodiversity. Understanding and supporting such cultural aspects of land use is an important part of effective conservation strategies. The UK has a range of cultural landscapes that contribute to the landscape matrix and are often important for biodiversity. However, little research has been conducted on the relationship between various types of cultural landscapes or their effects on biodiversity. We examined the interaction between semi-natural sacred sites and lowland heathland in Cornwall, and the contribution these sites make to the overall biodiversity within the habitat. We found that semi-natural sacred sites had significantly higher levels of biodiversity compared to surrounding heathland; the existence and use of the sites created new and important habitats for rare and threatened heathland species; and the spiritual and cultural use of the sites aids the management of heathland. Promoting the use of semi-natural sacred sites could therefore contribute to biodiversity conservation. Furthermore, the cultural and spiritual importance of such sites potentially increases the availability of volunteer resources for their management. We highlight the importance of an integrated management approach for achieving effective biodiversity conservation in areas containing multiple types of cultural landscapes.

scholarly journals The Relative Importance of Agricultural and Wetland Habitats to Waterbirds in the Sacramento–San Joaquin River Delta of California

2019 ◽  
Vol 17 (1) ◽  
Author(s):  
W. David Shuford ◽  
Matthew Reiter ◽  
Kristin Sesser ◽  
Catherine Hickey ◽  
Gregory Golet
Keyword(s):  
Central Valley ◽  
Positive Association ◽  
Open Water ◽  
Biodiversity Loss ◽  
Habitat Associations ◽  
Conservation Strategies ◽  
San Joaquin River ◽  
Conservation Actions ◽  
Surrounding Landscape ◽  
Abundance And Distribution

Biodiversity loss from agricultural intensification underscores the urgent need for science-based conservation strategies to enhance the value of agro-ecosystems for birds and other wildlife. California’s Central Valley, which has lost over 90% of its historical wetlands and currently is dominated by agriculture, still supports waterbird populations of continental importance. A better understanding of how waterbirds use available habitat is particularly needed in the Sacramento–San Joaquin Delta, an ecosystem under threat. From 2013 to 2015, we studied waterbird habitat associations in the Delta during fall migration and winter by conducting diurnal counts at random locations in key waterbird habitats throughout the Delta. Waterbird use of cover types (agricultural crops and managed wetlands) varied substantially among waterbird groups, by season, and among geographic sub-regions of the Delta. Overall, wetlands were particularly important to waterbirds in fall. In winter, wetlands and flooded rice and corn were important to many waterbird groups, and non-flooded corn and irrigated pasture to geese and cranes. The factors that influenced waterbird abundance and distribution also varied substantially among groups and differed at various geographic scales. In both seasons, most groups had a positive association at the field level with flooded ground and open water, and a negative association with vegetation. Given the great uncertainty in the future extent and pace of habitat loss and degradation in the Delta, prioritizing the conservation actions needed to maintain robust waterbird populations in this region is urgent. For the Delta to retain its importance to waterbirds, a mosaic of wetlands and wildlife-friendly crops that accounts for the value of the surrounding landscape must be maintained. This includes restoring additional wetlands and maintaining corn, rice, alfalfa, and irrigated pasture, and ensuring that a substantial portion of corn and rice is flooded in winter.

Demography of the central california population of the Leopard Shark (Triakis semifasciata)

1992 ◽  
Vol 43 (1) ◽  
pp. 183 ◽  
Author(s):  
GM Cailliet
Keyword(s):  
Population Growth ◽  
Reproductive Rate ◽  
Shark Species ◽  
Sandbar Shark ◽  
Lemon Shark ◽  
Carcharhinus Plumbeus ◽  
Net Reproductive Rate ◽  
Leopard Shark ◽  
Triakis Semifasciata ◽  
Leopard Sharks

Demographic analyses can be quite useful for effectively managing elasmobranch fisheries. However, they require valid estimates of age-specific mortality and natality rates, in addition to information on the distribution, abundance, habits and reproduction of the population, to produce reliable estimates of population growth. Because such detailed ecological information is usually unavailable, complete demographic analyses have been completed for only four shark species: the spiny dogfish, Squalus acanthias; the soupfin shark, Galeorhinus australis; the lemon shark, Negaprion brevirostris; and most recently the sandbar shark, Carcharhinus plumbeus. In California, reliable estimates of age, growth, mortality, age at maturity, and fecundity are available only for the leopard shark, Triakis semifasciata. A demographic analysis of this species yielded a net reproductive rate (Ro) of 4.467, a generation time (G) of 22.35 years, and an estimate of the instantaneous population growth coefficient (r) of 0.067. If the mean fishing pressure over 10 years (F= 0.084) is included in the survivorship function, Ro and r are reduced considerably, especially if leopard sharks first enter the fishery at early ages. A size limit of 120 cm TL (estimated age 13 years), especially for female sharks, is tentatively proposed for the leopard shark fishery.

scholarly journals Spatial patterns of primate hunting in riverine communities in Central Amazonia

Oryx ◽  
2017 ◽  
Vol 53 (1) ◽  
pp. 165-173 ◽  
Author(s):  
Priscila Maria Pereira ◽  
João Valsecchi ◽  
Helder Queiroz
Keyword(s):  
Spatial Dynamics ◽  
Indigenous Communities ◽  
Conservation Strategies ◽  
Human Populations ◽  
Spatial And Temporal Patterns ◽  
Local Fauna ◽  
Depositional Processes ◽  
Central Amazonia ◽  
Seasonally Flooded ◽  
Support Decision Making

AbstractIn many regions primates are an important dietary resource for isolated human populations, and they are among the most hunted species by traditional and indigenous communities in the Neotropics. Little is known about the characteristics or the spatial and temporal patterns of hunting, which limits a more detailed evaluation of its impact. We describe, quantify and analyse the spatial dynamics of primate hunting in the várzea (seasonally flooded forest) and paleovárzea (characterized by a series of low-lying ridges interspersed with flooded depressions, which result from cyclical depositional processes) environments of Central Amazonia, based on the monitoring of riverine communities at the Amanã and Mamirauá Sustainable Development Reserves over an 11-year period. During this time 402 primate hunting events were recorded, involving the harvesting of 541 individuals of nine species: Alouatta juara, Aotus cf. vociferans, Ateles chamek, Cacajao ouakary, Callicebus lucifer, Cebus albifrons, Saguinus inustus, Saimiri cassiquiarensis and Sapajus macrocephalus. Two hundred and forty of these hunts occurred in the paleovárzea and 162 in the várzea. The distances travelled by the hunters from their communities to the kill sites were significantly different between the environments, with longer distances being covered in the paleovárzea. Hunters in the paleovárzea also hunted across significantly larger areas than those in the várzea. The continuous monitoring of hunting areas and the gathering of data on the exploitation of species are necessary to understand the effects of hunting, as well as to support decision making in the management of the local fauna by traditional communities, and the development of effective conservation strategies for the local game species.

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