Despite the obvious power and advantages of the Argos system to track animals by satellite, the data generated are difficult for many biologists to exploit. A broad range of skills is required to ...efficiently download, collate, filter and interpret Argos data. Integration of animal movements with other physical (e.g. remote sensing imagery) and anthropogenic (e.g. fishery distributions) datasets presents additional technical and computing challenges. The Satellite Tracking and Analysis Tool (STAT) is a freely available system designed for biologists who work on animal tracking; it includes a set of standardized tools and techniques for data management, analysis, and integration with environmental data. STAT logs in to the Argos computer network each day and downloads all available locations and associated data for each user. These data are parsed and stored in a relational database and automatically backed up to an offsite location. A number of data filtering options are available, including setting maximum speed, time or distance between consecutive points, Argos location class, and turning angle. A variety of environmental data layers, including bathymetry, sea surface temperature, sea surface height, ocean currents and chlorophyll, can be sampled for all locations in the STAT database and can be downloaded and incorporated into tracking maps and animations. STAT also facilitates collaboration and the sharing of animal tracking information with the wider public and funding organizations. We hope that STAT will act as a catalytic foundation, fostering collaboration among users of satellite telemetry, and ensuring maximum value from these studies.
Over the past 3 decades, the status of sea turtles and the need for their protection to aid population recovery have increasingly captured the interest of government agencies, non-governmental ...organisations (NGOs) and the general public worldwide. This interest has been matched by increased research attention, focusing on a wide variety of topics relating to sea turtle biology and ecology, together with the interrelations of sea turtles with the physical and natural environments. Although sea turtles have been better studied than most other marine fauna, management actions and their evaluation are often hindered by the lack of data on turtle biology, human-turtle interactions, turtle population status and threats. In an effort to inform effective sea turtle conservation a list of priority research questions was assembled based on the opinions of 35 sea turtle researchers from 13 nations working in fields related to turtle biology and/or conservation. The combined experience of the contributing researchers spanned the globe as well as many relevant disciplines involved in conservation research. An initial list of more than 200 questions gathered from respondents was condensed into 20 metaquestions and classified under 5 categories: reproductive biology, biogeography, population ecology, threats and conservation strategies.
We used satellite telemetry to study postnesting migrations of 42 loggerhead sea turtles Caretta caretta from 3 Florida rookeries. Postnesting migrations ended in neritic (<200 m) waters of Florida, ...Alabama, Texas (USA), and of Mexico and the Bahamas. Most postnesting migrations were restricted to the continental shelf and were relatively direct. Migrations through oceanic areas (>200 m) tended to be less direct, largely due to apparent influences of the Florida Current in the Atlantic and to looping travel paths (often along edges of mesoscalc eddies of the Loop Current) in the Gulf of Mexico. The largest loggerheads tended to migrate to foraging grounds that were farthest from the nesting beach. Turtles spent more time near the surface (<3 m) when migrating than they did during residency at foraging sites, and were Likely swimming just below the surface. The substantial amount of time spent near the bottom in neritic areas and the looping travel paths in oceanic areas indicate that migrating loggerheads may have been foraging. We identified 4 migratory corridors. Two were on the continental shelf of the Florida Panhandle, 1 was along the northern coast of Cuba, and 1 was along the southeastern coast of Florida. Migrating loggerheads may be uniquely vulnerable to mortality factors because of where they travel and how they behave, particularly if they are concentrated in narrow (perhaps <10 km wide) migratory corridors. Characterizing the behavior and identifying the travel paths of loggerheads during postnesting migrations are necessary steps for implementing successful recovery efforts.
Marine turtles undergo dramatic ontogenic changes in body size and behavior, with the loggerhead sea turtle, Caretta caretta, typically switching from an initial oceanic juvenile stage to one in the ...neritic, where maturation is reached and breeding migrations are subsequently undertaken every 2–3 years 1–3. Using satellite tracking, we investigated the migratory movements of adult females from one of the world's largest nesting aggregations at Cape Verde, West Africa. In direct contrast with the accepted life-history model for this species 4, results reveal two distinct adult foraging strategies that appear to be linked to body size. The larger turtles (n = 3) foraged in coastal waters, whereas smaller individuals (n = 7) foraged oceanically. The conservation implications of these findings are profound, with the population compartmentalized into habitats that may be differentially impacted by fishery threats in what is a global fishing hotspot 5. Although the protection of discrete areas containing coastal individuals may be attainable, the more numerous pelagic individuals are widely dispersed with individuals roaming over more than half a million square kilometers. Therefore, mitigation of fisheries by-catch for sea turtles in the east Atlantic will likely require complex and regionally tailored actions to account for this dichotomous behavior.
Few studies have investigated nitrogen (N) fertilizer management in no-tillage (NT) tobacco (Nicotiana tobacum L.) production systems, even though N fertilization is known to influence tobacco cured ...leaf yield and quality. The present study evaluated how tillage practice and N fertilizer rate affected burley tobacco agronomic performance, plant available nitrogen (PAN) supply, and leaf chemical constituents. In 2012 and 2013, three N fertilizer rates (0, 140 and 280 kg N/ha) were introduced as split-plots within a long-term NT and conventional tillage (CT) (mouldboard plough) comparison study. Results (2007–2013) showed that the effect of tillage on tobacco yield depended on seasonal weather; NT tobacco appeared to have lower yield than CT tobacco in seasons with <450 mm growing season rainfall, but similar yields when rainfall was >500 mm. In 2012 (432 mm rainfall; 84% of the long-term seasonal mean), leaf SPAD reading, leaf nitrate concentration, total nitrogen concentration at the topping day (i.e. removal of flowers/buds at the tops of the plants) and cured leaf nicotine and alkaloid content suggested that N deficiency was more pronounced in NT than CT at the lowest N fertilizer rate. The PAN supply, as measured by a modified in situ resin core method, was similar in 2012 between NT and CT, suggesting that plant factors may have had a role in N uptake efficiency. This scenario did not repeat in 2013 (706 mm rainfall; 137% of the long-term seasonal mean). Even though N fertilization rates were identical for both tillage practices in 2012 and 2013, PAN was lower, on average, in 2012. Because N uptake is largely the result of mass flow, the impact of reduced root density in NT tobacco would be expected to be more pronounced in a season such as 2012, when water was limited. Banding N close to the tobacco root system and/or side-dressing some portion of N may be recommended strategies to improve N use efficiency in NT burley tobacco production.
To aid management and conservation of widely distributed marine vertebrate species, it is necessary to have a knowledge and understanding of their spatial ecology. We tracked 10 adult female ...loggerhead turtles Caretta caretta from Masirah Island, Sultanate of Oman, which hosts one of the world's largest breeding aggregations. Transmitters were specifically deployed early in the nesting season to enable tracking throughout the internesting and post-nesting habitats. Turtles displayed a dichotomy in behaviour during the internesting period, with 6 remaining close to Masirah Island and the others undertaking circuitous oceanic loops, hundreds of kilometres in length. This behaviour did not appear to be related to body size. Tracking-derived minimum clutch frequency was on average (+/- SD) 4.8 +/- 1.2 nests (n = 8 ind.). Post-nesting migrations revealed a propensity towards long-term utilisation of oceanic habitats in the region between Socotra Island (Yemen) and the mainland of Yemen/Oman, with 76 +/- 15.4% of time spent in oceanic habitat (n = 8 ind.). The spatial footprint of our tracked turtles was found to be far less than that of a similar number of turtles that were tagged later in the same season (from a separate unpublished study) and from long-distance returns of flipper tags. The spatial and temporal sub-structuring of the population highlights the need for more comprehensive tracking projects, with deployments across the breeding season in multiple years, in order to obtain reliable estimations of high-use foraging habitats of widely dispersed marine vertebrates. Variation in behaviour patterns suggests the need for diverse conservation measures.
The use of satellite tracking for the fundamental and applied study of marine turtles began in the 1980s but has undergone rapid growth in recent years. To provide a background against which to judge ...the past success and future directions of these research efforts we carried out a comprehensive review of over 130 scientific papers on the use of this technique in this taxon. We show how satellite tracking has changed over time as well as outlining biases in spatial, species and life-stage coverage. Descriptions of migration routes and other habitats have offered novel insights into the basic life history patterns of some species, highlighted focal areas for conservation and reinforced the multi-national nature of the stakeholders of many populations. In foraging areas, knowledge is growing as to how animals move within dynamic seascapes, thus facilitating our understanding of 3-dimensional habitat use and seasonal patterns of behaviour. More experimental approaches have elucidated navigational capabilities and post-release survival following fisheries interaction and long-term captivity. In addition, through the Internet and other media, satellite tracking appears to have been effective in engaging public attention in many countries. Finally, we discuss why the use of the technique has increased so markedly over time and point out key areas of concern that we feel should be addressed by the community of researchers and donors who focus on sea turtles.
Constructed wetlands have emerged as a viable alternative for secondary treatment of domestic wastewater in areas with landscape limitations, poor soil conditions, and high water tables, which limit ...installation of full-scale adsorption fields. Existing information on the effects of macrophytes on treatment performance is contradictory and mostly derived from greenhouse mesocosm experiments. This study investigated the removal efficiency of fecal bacteria, biological oxygen demand (BOD), and total suspended solids (TSS) in 12 constructed wetlands treating secondary effluent from single household domestic wastewater in Kentucky. The wetlands were monoculture systems planted to cattails (
Typha latifolia L.) or fescue (
Festuca arundinacea Schreb.), polyculture systems planted with a variety of flowering plants, and unplanted systems. Influent and effluent samples were taken on a monthly basis over a period of 1 year and analyzed for fecal coliforms (FC), fecal streptococci (FS), BOD and TSS. The findings suggested no significant differences (
P<0.05) in the average yearly removal of fecal bacteria (>93%) between systems, with the vegetated systems performing best during warmer months and the unplanted systems performing best during the winter. The vegetated systems showed significantly greater (
P<0.05) removal efficiencies for BOD (>75%) and TSS (>88%) than the unplanted systems (63 and 46%, respectively) throughout the year. Overall, the polyculture systems seemed to provide the best and most consistent treatment for all wastewater parameters, while being least susceptible to seasonal variations. The performance of the cattail systems may improve by harvesting the plants at the end of the growing season, thus reducing additional BOD and TSS inputs from decaying biomass litter. The fescue systems were generally inferior to the polyculture and cattail systems because of their shallow rooting zone and limited biofilm surface area, while the unplanted systems were completely inefficient for BOD and TSS removal and should not be recommended.
Conversion of deforested areas into oil palm plantation has been suggested as a means to improve soil quality and carbon sequestration capacity in forest margin areas. Soil organic carbon fractions, ...such as particulate organic carbon is the most sensitive indicator in improving soil organic matter and soil quality. We determined particulate organic matter - carbon (POM-C) and mineral associated carbon (MAC) in Bengkulu and West Java Provinces Indonesia. The study areas were grain crop fields, secondary forest, 5 yr-oil palm plantation, 10 yr-oil palm plantation, 15 yr-oil palm plantation and 25 yr-oil palm plantation. Soil organic carbon fraction magnitudes varied in the surface of 0 to 30 cm of grain crop fields, secondary forest and oil palm plantations. Twenty five year-oil palm plantation provided the largest total organic carbon, while 5 yr-oil palm plantation and grain crop fields contained similar amount of total organic C. Both POM-C and MAC fractions were increased in the plantation sites with oil palm trees and secondary forest compared to the grain crop fields. The plantation sites had a larger POM-C content than grain crop fields, but the increase of POM-C was limited to the surface of 0 to 10 cm of soil. Carbon stock in 0-30 cm under oil palm plantations were reduced up to 20% compared to secondary forests and 28% compared to rubber plantations in Bengkulu and West Java Provinces. On average, converting forest to plantations led to a loss of 10 Mg C/ha after about 10 years of conversion. However, the C stock in the subsoil was similar under the forest and the plantations in Bengkulu. Further, limited C input from litter would eventually cause more losses of SOC in oil palm plantations compared to rubber plantations. In conclusion, investigating the deeper profiles and soil erosion may be an important tool to unfold the trends of soil organic carbon fraction dynamics and magnitudes after the conversion of natural ecosystems to intensive plantations.
Certain organic compounds, including biphenyl and salicylic acid, stimulate polychlorinated biphenyl (PCB) degradation by microorganisms in some environments. However, the usefulness of these ...amendments for improving PCB removal by microorganisms from diverse habitats has not been extensively explored. This study evaluated the effects of biphenyl, salicylic acid, and glucose on changes in aerobic PCB removal and bacterial communities from an agricultural soil, a wetland peat soil, a river sediment, and a mixture of these samples. PCB removal patterns were significantly different between soils and sediments amended with carbon compounds: (i) terrestrial soil microorganisms removed more PCBs than river sediment microorganisms, particularly with regard to PCBs with >4 chlorine substituents, (ii) glucose-supplemented, agricultural soil microorganisms removed more hexachlorobiphenyl than unsupplemented samples, (iii) biphenyl-supplemented, river sediment microorganisms removed more di- and tri-chlorobiphenyls than unamended samples. Carbon amendments also caused unique shifts in soil and sediment bacterial communities, as determined by specific changes in bacterial 16S rRNA denaturing gradient gel electrophoresis banding patterns. These results indicate that organic carbon amendments had site-specific effects on bacterial populations and PCB removal. Further work is needed to more accurately characterize PCB degrading communities and functional gene expression in diverse types of environments to better understand how they respond to bioremediation treatments.
PDF
