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Bycatch in net fisheries is recognized as a major source of mortality for many marine species, including seabirds. Few mitigation solutions, however, have been identified. In a new study authors assessed the effectiveness of illuminating fishing nets with green light emitting diodes (LEDs) to reduce the incidental capture of seabirds. Experiments were conducted in the demersal, set gillnet fishery of Constante, Peru and compared 114 pairs of control and illuminated nets. Seabird bycatch was higher in control nets than in illuminated nets, representing an 85.1% decline in the guanay cormorant (Phalacrocorax bougainvillii) bycatch rate. 39 cormorants were caught in control nets, while only 6 were caught in illuminated nets. This study showing that net illumination reduces seabird bycatch and previous studies showing reductions in sea turtle bycatch without reducing target catch indicate that net illumination can be an effective multi-taxa bycatch mitigation technique. This finding has broad implications for bycatch mitigation in net fisheries given LED technology’s relatively low cost, the global ubiquity of net fisheries, and the current paucity of bycatch mitigation solutions. More info at: Mangel JC, Wang J, Alfaro-Shigueto J, Pingo S, Jimenez A, Carvalho F, Swimmer Y, Godley BJ (2018) Illuminating gillnets to save seabirds and the potential for multi-taxa bycatch mitigation. Royal Society Open Science 5: 180254.
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For many decades, the spectral composition of lighting was determined by the type of lamp, which also influenced potential effects of outdoor lights on species and ecosystems. Light‐emitting diode (LED) lamps have dramatically increased the range of spectral profiles of light that is economically viable for outdoor lighting. Because of the array of choices, it is necessary to develop methods to predict the effects of different spectral profiles without conducting field studies, especially because older lighting systems are being replaced rapidly. We describe an approach to predict responses of exemplar organisms and groups to lamps of different spectral output by calculating an index based on action spectra from behavioral or visual characteristics of organisms and lamp spectral irradiance. We calculate relative response indices for a range of lamp types and light sources and develop an index that identifies lamps that minimize predicted effects as measured by ecological, physiological, and astronomical indices. Using these assessment metrics, filtered yellow‐green and amber LEDs are predicted to have lower effects on wildlife than high pressure sodium lamps, while blue‐rich lighting (e.g., K ≥ 2200) would have greater effects. The approach can be updated with new information about behavioral or visual responses of organisms and used to test new lighting products based on spectrum (see here). Together with control of intensity, direction, and duration, the approach can be used to predict and then minimize the adverse effects of lighting and can be tailored to individual species or taxonomic groups. More info at Longcore T, Rodríguez A, Witherington B, Penniman JF, Herf L, Herf M (2018) Rapid assessment of lamp spectrum to quantify ecological effects of light at night. Journal of Experimental Zoology A  All of the calculations and visualization of the intersection of light spectrum and human and animal response curves can be viewed at a website that will be updated with new lamp spectra and response curves and will allow users to submit spectra for analysis.  Penguins crossing under the tunnels with red and blue light. Photo: Beneharo Rodríguez. Wildlife watching is an emerging ecotourism activity around the world. In Australia and New Zealand, night viewing of little penguins attracts hundreds of thousands of visitors per year. As penguins start coming ashore after sunset, artificial lighting is essential to allow visitors to view them in the dark. This alteration of the nightscape warrants investigation for any potential effects of artificial lighting on penguin behavior. We experimentally tested how penguins respond to different light wavelengths (colors) and intensities to examine effects on the colony attendance behavior at two sites on Phillip Island, Australia. At one site, nocturnal artificial illumination has been used for penguin viewing for decades, whereas at the other site, the only light is from the natural night sky. Light intensity did not affect colony attendance behaviors of penguins at the artificially lit site, probably due to penguin habituation to lights. At the not previously lit site, penguins preferred lit paths over dark paths to reach their nests. Thus, artificial light might enhance penguin vision at night and consequently it might reduce predation risk and energetic costs of locomotion through obstacle and path detection. Although penguins are faithful to their path, they can be drawn to artificial lights at small spatial scale, so light pollution could attract penguins to undesirable lit areas. When artificial lighting is required, we recommend keeping lighting as dim and time‐restricted as possible to mitigate any negative effects on the behavior of penguins and their natural habitat.
More infot at: Rodríguez A, Holmberg R, Dann P, Chiaradia A (2018) Penguin colony attendance under artificial lights for ecotourism. Journal of Experimental Zoology A, doi: 10.1002/jez.2155  Manx shearwater grounded on a road. Photo: Martyna Syposz. We analysed data collected by a volunteer-based initiative for rescuing grounded birds, in Mallaig, a village in the west of Scotland. The village is 27km away from the Isle of Rum, the second biggest colony of Manx shearwaters in the world. We investigated how moon and meteorological variables affect the number of birds that were recovered on the ground. We found that during full moon fewer birds ground in the village than during new moon; similar to effects discovered in other studies. In addition we found that strong onshore winds cause more groundings suggesting that birds may be blown towards the village and then being affected by the lights. To a lesser extent, visibility conditions also have an effect on grounding probabilities in Mallaig. Our results can improve rescue campaigns of not only Manx Shearwaters but also other species attracted to light pollution, by predicting conditions leading to an increase in the number of groundings.
More info at: Syposz M, Gonçalves F, Carty M, Hoppitt W, Manco F (2018) Factors influencing location and number of Manx Shearwater grounding in west Scotland. Ibis, doi.org/10.1111/ibi.12594  Scopoli's shearwater at night. Photo: Paolo Becciu. Several studies on petrels and shearwaters have shown that light pollution can be harmful for both fledglings and adults, but little is known of the way such anthropogenic elements affect the quality of parental care at the nest. Chick provisioning in petrels and shearwaters occurs exclusively at night and is also negatively correlated with the intensity of moonlight. Thus, we tested the effect of two outdoor disco events, organized during the touristic season, on overnight weight gain in 26 chicks of Scopoli’s shearwaters (Calonectris diomedea) from Linosa Island. The two disco events occurred under contrasting moonlight conditions (moonless vs moonlight). We observed a weight loss in chicks situated closer to disco compared with the control nests located further away. Therefore, this effect was only evident on the moonless night and all the chicks fledged successfully at the end of the breeding season. These results suggest that light disturbances can have a negative effect on parental care, but moonlight might musk the bird’s perception and thus the magnitude of the disturbance. However, it remains crucial to further our understanding of the impact, which touristic anthropogenic activities have on breeding birds, and to identify and effectively manage human activities in important breeding grounds such as Linosa Island, the biggest colony of Scopoli’s shearwater in Europe.
More info at: Cianchetti-Benedetti M, Becciu P, Massa B, Dell’Omo G. (2018) Conflicts between touristic recreational activities and breeding shearwaters: short-term effect of artificial light and sound on chick weight. Eur J Wildl Res 64: 19 New publication on light attraction of the threatened Hutton's shearwaters on New Zealand12/12/2017  Hutton's shearwater grounded by artificial lights. Photo: A. Howard. Using data from community-based rescue campaigns and systematic research, we assessed the characteristics of fallout events observed in fledglings of the threatened New Zealand endemic Hutton’s shearwater (Puffinus huttoni) or Kaikōura tītī. Despite strong annual variation in observed fallout numbers, the proportion of annually produced fledglings collected as ‘fallout birds’ remained below 1% each year. Among those, more than 80% survived due to community rescue efforts. Fallout was found to increase significantly during new moon, while weather effects remained inconclusive. Most fallout occurred within brightly lit areas of Kaikōura township, particularly along its coastal roads. High light source densities and high wattage lights appeared to be influential in some areas but could only partly explain the spatial distribution of fallout at this small scale.
More info at: Deppe, L., Rowley, O., Rowe, L. K., Shi, N., McArthur, N., Gooday, O., & Goldstien, S. J. (2017) Investigation of fallout events in Hutton's shearwaters (Puffinus huttoni) associated with artificial lighting. Notornis 64: 181-191.  After 20 years of outreach activities, the Concejalía Delegada de Medio Ambiente of La Orotava, through its Centro de Educación Ambiental Municipal, organizes the XX Jornadas de Formación Telesforo Bravo from 23 to 27 October 2017. There are a lot of activities (seminars, talks, films and field excursions) with the best naturalists of the Canary Islands. We invite you to assist and we hope you enjoy! All the details at: XX Jornadas Telesforo Bravo  Short-tailed shearwater fledgling. Photo: Airam Rodriguez. Studies testing the effect of artificial light characteristics on attractiveness to seabirds have not provided conclusive results and there is some urgency as some endangered petrel species experience high light-induced mortality. We designed a field experiment to test the effect of three common outdoor lighting systems with different light spectra (high pressure sodium, metal halide and white light emitting diode) on the number and the body condition of grounded fledglings of the short-tailed shearwater Ardenna tenuirostris. A total of 235 birds was grounded during 99 experimental hours. 47% of birds was grounded when metal halide lights were on, while light emitting diode and high pressure sodium lights showed lower percentages of attraction (29% and 24%). No differences in body condition were detected among the birds grounded by the different lighting systems. We recommend the adoption of high pressure sodium lights (or with similar spectra) into petrel-friendly lighting designs together with other light mitigation measures such as light attenuation, lateral shielding to reduce spill and appropriate orientation.
Rodríguez A, Dann P, Chiaradia A (2017) Reducing light-induced mortality of seabirds: high pressure sodium lights decrease the fatal attraction of shearwaters. Journal for Nature Conservation 39: 68-72.
  Locations where attraction of seabird fledglings to lights has been reported. Numbers indicate the number of species affected. Circle size represents the number of grounded birds, while color represents the IUCN category of the most endangered species at each location. Artificial lights at night cause high mortality of seabirds, one of the most endangered groups of birds globally. Fledglings of burrow-nesting seabirds, and to a lesser extent adults, are grounded by lights when they fly at night. We review the current state of knowledge of light attraction, identify information gaps and propose measures to address the problem. Although other avian families such as Alcidae and Anatidae can be involved, the most affected seabirds are petrels and shearwaters: at least 56 species, more than one-third of them (24) threatened, are grounded by lights. Grounded seabirds have been found worldwide, mainly on oceanic islands but also at some continental locations. Petrel breeding grounds confined to formerly uninhabited islands are particularly at risk from ever-growing levels of light pollution due to tourism and urban sprawl. Where it is impractical to ban external lights, rescue programs of grounded birds offer the most immediate and extended mitigation measures to reduce light-induced mortality, saving thousands of birds every year. These programs also provide useful information for seabird management. However, the data typically are fragmentary and often strongly biased so the phenomenon is poorly understood, leading to inaccurate impact estimates. We identified as the most urgent priority actions: 1) estimation of mortality and impact on populations; 2) assessment of threshold light levels and safe distances from light sources; 3) documenting the fate of rescued birds; 4) improvement of rescue campaigns, particularly in terms of increasing recovery rates and level of care; and 5) research on seabird-friendly lights to reduce attraction. More research is necessary to improve our understanding of this human-wildlife conflict and to design effective management and mitigation measures.
Rodríguez A, Holmes ND, Ryan PG, et al. 2017. A global review of seabird mortality caused by land-based artificial lights. Conservation Biology. DOI: 10.1111/cobi.12900 |
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June 2018
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