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Abd Mutalib, A. H., Fadzly, N., Ahmad, A., & Nasir, N. (2014). Understanding nesting ecology and behaviour of green marine turtles at Setiu, Terengganu, Malaysia. Mar Ecol, 36(4), 1003–1012.
Abstract: In this paper, we emphasize the importance of understanding the nesting ecology and nesting behaviour of green marine turtles (Chelonia mydas). Data were collected from 2007 until 2012 from nesting beaches at Setiu Terengganu, Malaysia. We focused on one of the beaches, Telaga Papan, based on data collected in 2012. We recorded the distribution of nesting areas, the emergence hour and the correlation between successful nesting attempts and false crawls. Telaga Papan had a significantly higher distribution of green marine turtle nesting compared with the other five beaches (ANOVA, F5,42 = 8.874, P < 0.01, mean = 36.750 ± 3.727). The highest number of successful nesting attempts was recorded in 2012 (mean = 28.714). A majority of the species landed between 22:00 and 23:59 h (25%). There was a strong correlation between successful nesting attempts and false crawls (rs = 0.883, P = 0.02). Based on these findings on the nesting ecology and nesting behaviour of green marine turtles, we suggest that scientific research, strict monitoring, awareness programs and policy implementation should be carried out proactively. Such activities are necessary to reduce the anthropogenic pressures at the nesting beaches as well as to ensure more successful nesting attempts of green marine turtles in Setiu.
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Mazor, T., Levin, N., Possingham, H. P., Levy, Y., Rocchini, D., Richardson, A. J., et al. (2013). Can satellite-based night lights be used for conservation? The case of nesting sea turtles in the Mediterranean. Biological Conservation, 159, 63–72.
Abstract: Artificial night lights pose a major threat to multiple species. However, this threat is often disregarded in conservation management and action because it is difficult to quantify its effect. Increasing availability of high spatial-resolution satellite images may enable us to better incorporate this threat into future work, particularly in highly modified ecosystems such as the coastal zone. In this study we examine the potential of satellite night light imagery to predict the distribution of the endangered loggerhead (Caretta caretta) and green (Chelonia mydas) sea turtle nests in the eastern Mediterranean coastline. Using remote sensing tools and high resolution data derived from the SAC-C satellite and the International Space Station, we examined the relationship between the long term spatial patterns of sea turtle nests and the intensity of night lights along Israel’s entire Mediterranean coastline. We found that sea turtles nests are negatively related to night light intensity and are concentrated in darker sections along the coast. Our resulting GLMs showed that night lights were a significant factor for explaining the distribution of sea turtle nests. Other significant variables included: cliff presence, human population density and infrastructure. This study is one of the first to show that night lights estimated with satellite-based imagery can be used to help explain sea turtle nesting activity at a detailed resolution over large areas. This approach can facilitate the management of species affected by night lights, and will be particularly useful in areas that are inaccessible or where broad-scale prioritization of conservation action is required.
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Sella, K. N., Salmon, M., & Witherington, B. E. (2006). Filtered Streetlights Attract Hatchling Marine Turtles. Chelonian Conservation and Biology, 5(2), 255–261.
Abstract: On many nesting beaches, hatchling marine turtles are exposed to poled street lighting that disrupts their ability to crawl to the sea. Experiments were done to determine how hatchlings responded to street lighting transmitted through 2 filters that excluded the most disruptive wavelengths (those < 530 nm; those < 570 nm). Filtered lighting, however, also attracted the turtles though not as strongly as an unfiltered (high-pressure sodium vapor) lighting. Filtering is therefore of limited utility for light management, especially since other alternatives (such as lowering, shielding, or turning off unnecessary lighting; use of dimmer lights embedded in roadways) are more effective.
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Thums, M., Whiting, S. D., Reisser, J., Pendoley, K. L., Pattiaratchi, C. B., Proietti, M., et al. (2016). Artificial light on water attracts turtle hatchlings during their near shore transit. R. Soc. open sci., 3(5), 160142.
Abstract: We examined the effect of artificial light on the near shore trajectories of turtle hatchlings dispersing from natal beaches. Green turtle (Chelonia mydas) hatchlings were tagged with miniature acoustic transmitters and their movements tracked within an underwater array of 36 acoustic receivers placed in the near shore zone. A total of 40 hatchlings were tracked, 20 of which were subjected to artificial light during their transit of the array. At the same time, we measured current speed and direction, which were highly variable within and between experimental nights and treatments. Artificial lighting affected hatchling behaviour, with 88% of individual trajectories oriented towards the light and spending, on average, 23% more time in the 2.25 ha tracking array (19.5 ± 5 min) than under ambient light conditions (15.8 ± 5 min). Current speed had little to no effect on the bearing (angular direction) of the hatchling tracks when artificial light was present, but under ambient conditions it influenced the bearing of the tracks when current direction was offshore and above speeds of approximately 32.5 cm s−1. This is the first experimental evidence that wild turtle hatchlings are attracted to artificial light after entering the ocean, a behaviour that is likely to subject them to greater risk of predation. The experimental protocol described in this study can be used to assess the effect of anthropogenic (light pollution, noise, etc.) and natural (wave action, current, wind, moonlight) influences on the in-water movements of sea turtle hatchlings during the early phase of dispersal.
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Weishampel, Z. A., Cheng, W. - H., & Weishampel, J. F. (2016). Sea turtle nesting patterns in Florida vis-Ã -vis satellite-derived measures of artificial lighting. Remote Sens Ecol Conserv, 2(1), 59–72.
Abstract: Light pollution contributes to the degradation and reduction of habitat for wildlife. Nocturnally nesting and hatching sea turtle species are particularly sensitive to artificial light near nesting beaches. At local scales (0.01–0.1 km), artificial light has been experimentally shown to deter nesting females and disorient hatchlings. This study used satellite-based remote sensing to assess broad scale (~1–100s km) effects of artificial light on nesting patterns of loggerhead (Caretta caretta), leatherback (Dermochelys coriacea) and green turtles (Chelonia mydas) along the Florida coastline. Annual artificial nightlight data from 1992 to 2012 acquired by the Defense Meteorological Satellite Program (DMSP) were compared to an extensive nesting dataset for 368, ~1 km beach segments from this same 21-year period. Relationships between nest densities and artificial lighting were derived using simultaneous autoregressive models to adjust for the presence of spatial autocorrelation. Though coastal urbanization increased in Florida during this period, nearly two-thirds of the surveyed beaches exhibited decreasing light levels (N = 249); only a small fraction of the beaches showed significant increases (N = 52). Nest densities for all three sea turtle species were negatively influenced by artificial light at neighborhood scales (<100 km); however, only loggerhead and green turtle nest densities were influenced by artificial light levels at the individual beach scale (~1 km). Satellite monitoring shows promise for light management of extensive or remote areas. As the spectral, spatial, and temporal resolutions of the satellite data are coarse, ground measurements are suggested to confirm that artificial light levels on beaches during the nesting season correspond to the annual nightlight measures.
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