Studies conducted in the past didn’t intend to show the effects of radiotracking upon organisms. However, a mounting body of research examining the effects of radio telemetry on wildlife suggests that our conservation efforts may inadvertently impose an unwanted toll on the organisms tracked.
Research has
revealed that radio-tracking devices can cause
benign tumors, tissue
irritation, infection, sarcomas, malignant cancers, metabolic changes, biased
sex ratios, skin irritations, behavioral changes, and increased vulnerability
to predators, among other issues. While
factors like the weight and attachment method of tracking gears are often
blamed for these effects, another factor that hasn’t been discussed much is the interaction of the
electromagnetic field produced by the tracking gears.
Radiotelemetry serves as the eyes and ears of conservationists, offering a window into the secret lives of wildlife. It enables researchers to track and monitor wildlife, understand their behaviors, and protect their habitats with precision and insight. The method utilizes radio waves to remotely track animals and gather critical data about their movements and habitats. By analyzing the data collected, researchers can pinpoint crucial habitats, migration routes, and breeding grounds vital for a species' survival. Researchers even argue that the present state of fish and wildlife conservation/management, as well as our growing understanding of the needs of specific fish and wildlife populations, would not exist for many species without the use of radio tracking, data logger, and micro-chip devices.
Radio transmitters emit electromagnetic fields (EMFs) primarily in the non-ionizing radio frequency range spanning from 3 KHz to 300 GHz, potentially affecting wildlife in various ways. Despite being generally considered safe at typical exposure levels due to its low energy, prolonged exposure to these EMFs can still impact wildlife. Radiofrequency Radiation (RFR), emitted by radio transmitters, can interfere with biological processes, affecting the nervous, reproductive, endocrine, and immune systems of animals. It may disrupt migration patterns, alter behavior, and affect breeding success. Some advanced tracking systems emit microwaves, penetrating deeper into tissues and potentially causing similar impacts as RFR, albeit with greater intensity. Additionally, low-frequency magnetic fields emitted by transmission gears, alongside pulse-modulated signals common in modern tracking devices, can disrupt navigation and foraging behaviors in certain species.
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| Using radiotelemetry to track bat movements and behavior in the wild. Picture Credit: via Flickr |
EMFs (electromagnetic fields) or radiation are invisible energy fields linked to
the utilization of electrical power and different types of natural and
artificial lighting. These fields are typically divided into two categories
based on their frequency: non-ionizing radiation, which is generally regarded
as safe for humans due to its low intensity, and ionizing radiation, marked by
higher levels that pose a risk of damaging cells and DNA.
While the world is keenly aware of the adverse effects of ionizing radiation, there has been limited research
conducted on the potential impacts of non-ionizing radiation on both human
health and the environment. Non-ionizing electromagnetic fields (EMF) have been
traditionally viewed as posing
minimal risk due to their
inability to dislodge electrons from atoms or cause significant biological
damage. While ionizing bands like X-rays and gamma-rays are known for their
ability to disrupt DNA through electron displacement, non-ionizing radiation,
was believed to lack sufficient energy for such efforts, with only electric
shock within the Extremely Low Frequency (ELF-EMF) range and tissue heating at
high intensities in the Radiofrequency (RFR) bands being considered as
potential damage.
However, recent
research suggests that non-ionizing EMF might still trigger harmful biological
effects below recognized thresholds. These effects could include indirect DNA
damage induced by free radical production, pointing to a nuanced understanding
of the potential risks associated with non-ionizing radiation. Research suggests that some EMFs, like extremely low frequency (ELF) and
radiofrequency (RFR) bands, may be potential human carcinogens according to the
International Agency for Research on Cancer (IARC) at the World Health
Organization. This means they could have similar negative effects as substances
like lead and formaldehyde.
Research on the effects of RFR on living organisms has documented various
effects such as oxidative damage, stress proteins, calcium channel
modification, and immune system effects across various mammal, bird, and human
cell types. Moreover, effects include lower annual survival rates in birds,
nervous system and behavioral effects in birds and mammals, genotoxic effects
and potential carcinogenicity in mammals and humans, and fertility,
reproduction, offspring viability, and sex-ratio effects in mammals and humans.
These effects include altered reproductive rates biased sex ratios in birds and
mammals, and navigational disruption leading to the loss of orientation of
birds and mammals such as mice and bats. Additionally, there are changes in
movement patterns in birds.
Alfonso
Balmori, a Spanish researcher, highlights in his 2016 paper the absence of studies on the effects of non-ionizing
electromagnetic radiation (radiofrequency radiation, RFR) emitted by active
radio transmitters. Balmori further
states that while a single reference in the extensive literature discusses the
potential negative effects of radio signals on animals, it suggests that the
low radiated power (10 mW) from VHF transmitters makes this possibility highly
unlikely (Mech and Barber, 2002). Despite the considerably higher radiated
power of PTTs used in advanced satellite telemetry systems (ranging from about
250 mW to 2W), no detrimental effects on animals had been reported (Mech and
Barber, 2002).
Whereas, a recent paper titled "Health and
environmental effects to wildlife from radio telemetry and tracking
devices—state of the science and best management practices," published in
Frontiers in Veterinary Sciences suggests that while the radiation emitted by
many tagging devices is relatively minimal, it can still induce biological
effects due to their proximity to body tissues with high local energy
absorption. Many investigations regarding the impacts of
electromagnetic radiofrequency (RFR) on living organisms caution about the
potential dangers of this radiation. It can notably disrupt the nervous system,
reproductive, endocrine, and immune systems, and it plays a role in various
biological processes.
According to
Steenhof and colleagues (2006), when studying animals for scientific purposes,
it is essential to ensure that the techniques employed do not compromise the
welfare or behavior of the subjects and that the results obtained remain unbiased
in terms of scientific quality. Hence, researchers must integrate the assessment
of potential impacts from research methods into their study design, taking
careful consideration of any biases that may be present. Radio-tracking can
even lead to transmitters influencing the survival, behavior, or health of
subjects, thereby resulting in skewed and inaccurate interpretations of the
research findings. While some aspects of behavior and ecology may be minimally
impacted, the cumulative effect could be significant due to the long-term
nature of these effects.
Exposure standards for nonhuman species to ELF-EMF/RFR
are lacking, and the absence of post-radio-tagging surveillance for health
effects suggests potential risks, as radio-tagging technology, often in
constant communication with distant receivers, may subject wildlife to strong
chronic exposures, which could contribute to animal mortality from various
causes. Understanding the diverse effects of EMFs on wildlife requires further
research considering factors like frequency, intensity, duration of exposure,
and species sensitivity, aiding in the development of mitigation strategies to
protect wildlife populations.
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| A salt-water crocodile with a GPS-based satellite transmitter attached to its head. Image via Wikipedia |
Perhaps, it would be better if conservationists, ecologists, researchers, and others involved in wildlife monitoring explored alternatives to traditional radio gear, as doing so could minimize the adverse effects of electromagnetic field (EMF) exposure, ensuring more sustainable and ethically sound wildlife monitoring practices. Non-invasive approaches and non-electromagnetic field technologies present viable options, albeit with accompanying pros and cons. Artificial intelligence (AI) shows potential but is still in its early stages, while tried-and-trued methods involve labor-intensive field techniques and advanced photographic equipment. Although access to some non-invasive technologies may be limited by cost or availability, such as satellite imagery, methods like eBird and radar tracking offer valuable trend-mapping capabilities, although radar use presents challenges in detecting individual targets. Satellite photography can reveal critical information, but its precision may be limited, and costs can be prohibitive. Camera traps offer non-invasive wildlife assessment, though they are labor-intensive and site-specific. Mark-recapture techniques provide population estimates but require significant resources and expertise. Hair/scent/scat analysis and computer modeling/AI offer innovative approaches but may be specialized and costly. As AI evolves, it holds promise for wildlife monitoring, potentially reducing reliance on radio telemetry, but further validation is necessary. Integrating AI with existing tracking methods could revolutionize wildlife research, though continued study is essential.
Beyond tracking individual animals, radio telemetry informs broader conservation efforts by shedding light on population dynamics, helping scientists assess the health of wildlife populations, and detecting shifts that may signal environmental changes or threats. By understanding where and how animals move, conservationists can mitigate human-wildlife conflicts, safeguarding both livelihoods and ecosystems. Through radiotelemetry, bridges are built between conservation interventions and their real-world impact, ensuring that efforts to protect our planet are grounded in data and results.
However,
researchers express concern that significant physiological impacts on various
wildlife species, pets, and domestic animals may be disregarded due to outdated
assumptions that low-level EMFs are harmless to living tissues. Alternatively,
any potential effects might be deemed insignificant, prioritizing our curiosity
about other species over their fundamental need for undisturbed survival.
The utilization of radio-tracking devices has been steadily growing over time, with numerous designs and applications adapted for various research purposes. Despite the widespread use of radio-telemetry in wildlife research, comprehensive data on the total number and types of devices in the field are lacking due to proprietary information held by manufacturers. Moreover, there has been relatively little research conducted by wildlife biologists on the potential impacts of electromagnetic fields (EMF) from radio telemetry equipment on wildlife. Recent studies show that even low levels of EMF exposure can have detrimental effects on various species, including DNA damage, cancers, and behavioral abnormalities.
This is a call for more
research to understand the cumulative effects of EMF exposure on wildlife, especially
as it pertains to species decline and potential contributions to the ongoing
global species extinction event. Wildlife professionals have an ethical responsibility
to consider the impacts of tracking technologies on species and to question
whether the benefits outweigh the potential harm, particularly for endangered populations.