The Silent Threat: How Microplastics Destroy Honeybee Colonies
"Bees are buzzing around in confusion ,they’re having trouble recognizing flowers, forgetting scents and even struggling to navigate back to their hives.
What’s causing this disorientation? Alongside well-known threats such as pesticides and parasites, a new and unsettling risk to bees is emerging … Microplastics."
In the past decades, the globe has increasingly become acutely aware of the ubiquitous prevalence of microplastics ,small plastic particles smaller than 5 millimeters in diameter that contaminate our planet. From sea floors to mountain peaks, microplastics are omnipresent. But perhaps one of the more intangible yet extremely more important areas affected by this type of contamination is honeybee colony wellness. These are important pollinators of many types of crops and wild flowers, and loss of them has far-reaching implications for biodiversity, food supply, and ecosystem resilience.
"Microplastics are everywhere and are pervasive pollutants of soil,
water, and air. They mainly comprise polyethylene, polypropylene, and
polyacrylamide polymers. Worryingly, humans consume as many as 52,000
particles a year and probably inhale as many as 74,000 in a year. The
particles are divided into groups according to size.
Microplastics have their sources in the diverse range of sources including plastic trash breaking down into smaller pieces, cosmetic microbeads, fibers from synthetic garments released from clothing, and industrial manufacturing operations. Secondary microplastics (MPs) form from the degradation of plastics
where they break down in the atmosphere and water by natural weathering
from things like discarded plastic litter.
Wear and tear of motor
vehicle tyres sends MP fragments up into the atmosphere. They enter the environment through rivers, winds, and on-site disposal, contaminating soils, water sources, and even the air. Honeybees, during their foraging process, are also most vulnerable. Bees collect nectar, pollen, water, and plant resin, typically from contaminated sources, carrying microplastics back to their colony by accident. Once inside the hive, the particles can sediment and pose multiple threats to the colony."
Microplastics are not just inert particles they have a cocktail of harmful chemicals on them that can have severe health implications for honeybees. Plastics contain a variety of additives, such as plasticizers (e.g., phthalates), stabilizers, flame retardants, and colorants, that will leach into the environment if the particles degrade or are ingested. Most of them are recognized endocrine disruptors, which can interfere with the endocrine systems necessary for insect development, behavior, and reproduction. Phthalates, for instance, have been associated with reproductive problems and developmental abnormality in several animals, and their occurrence in microplastics is expected to have the same impact on bees.
Heavy metals like lead, cadmium, and mercury can adhere to plastic surfaces or be incorporated during production, further complicating the toxicity profile. Microplastics can also act as carriers for persistent organic pollutants (POPs) like pesticides, polychlorinated biphenyls (PCBs), and dioxins that are highly toxic and have the ability to accumulate in bee tissues. When bees ingest contaminated microplastics, these chemicals can disrupt normal physiological processes, impair immune function, and increase disease vulnerability. In honeybees, these disruptions can reduce their lifespan, influence foraging habits, and reduce their ability to perform vital functions like maintaining the hive and caring for brood.
This burden of chemicals not only affects individual bees but can be devastating for entire colonies by reducing their ability to survive.
Microplastics enter flowers and other vegetation through many routes in the environment, primarily controlled by wind, and rain. The particles are very small and can become airborne, especially if plastic litter is broken down by sunlight, mechanical processes, or weathering, propelling microplastics into the atmosphere. Wind can carry them far away .Rain also plays a crucial role in this dispersal because suspended or surface microplastics can be washed into soil and bodies of water, in which case they could be adhere to the surface of plants potentially transporting microplastics to the plant stem and roots, and onto flowers.
Microplastics are also apt to adhere to petal, and pollen grain surfaces, subjecting them to foraging insects like honeybees. Once microplastics have settled on flowers, bees necessarily come into contact with these dirty surfaces when harvesting nectar and pollen. Such contact not only introduces microplastics directly into their bodies but also the risk of ingestion of contaminated plant material, starting a pollution cycle in the hive ecosystem and hive products as well.
One of the primary problems is that microplastics are consumed by bees and lead to physical and physiological harm. When bees collect contaminated pollen and nectar, they inadvertently consume microplastics. Microplastics may clog their digestive tract or lead to tissue damage.
The second significant threat is the impact of microplastics on bee larvae and young bees. Larvae are especially vulnerable since they are supplied with pollen and nectar collected by adult bees, which are now possibly microplastic-laden. Microplastics ingested at the sensitive developmental stages have the potential to lead to developmental aberrations, lowered survival, and impaired colony resistance. Studies have found that microplastic particles cause abnormal growth patterns and even physical deformity of bee larvae, and further studies are still attempting to explain such effects in detail.
Microplastics indirectly affect honeybee colonies by affecting their habitat. Contaminated water sources and floral material lead to entire ecosystems being damaged. When bees consume microplastics via the soil or air, the microplastic particles may be contained within the nectar and pollen, creating a method of contamination. This not only harms individual bees but also threatens the larger plant-pollinator webs that contribute to ecosystems . As microplastics accumulate in the environment, there is a chance for long-term, chronic exposure, which may lead to declines in bee populations over time.
The health of honeybee colonies is also defined by microplastics in the sense of their influence on hive health and pathogen balance. Microplastics can compromise the immune systems of bees, potentially making them vulnerable to diseases such as varroosis, Nosema infection, or bacterial or viral pathogens. Compromised immune systems might result in high mortality and colony collapse. In addition, microplastics can interfere with the natural microbial communities within the hive, which are vital to maintaining hive health and resistance to disease.
" As honeybees make their way through the world, they are ideally suited to pick up bits and pieces of microplastics along the way. Bees are covered with hairs that have evolved to hold tiny particles that the bee collects intentionally or simply encounters in its daily travels. These hairs become electrostatically charged in flight, which helps attract the particles."
Microplastics and honeybees are a complicated problem, intertwined with other environmental stresses like exposure to pesticides, habitat loss, and climate change. However, this new threat of microplastics adds further danger. As microplastic contamination increases, so does the risk to honeybee populations already on multiple fronts. To rescue bees from this insidious danger requires action on many fronts, ranging from reducing plastic waste through more sustainable disposal and recycling methods .
Public awareness and policy change are integral solutions to this problem. Encouraging the phase-out of single-use plastics, improving waste management, and investment in zero waste practices can help limit the proliferation of microplastics into the ecosystem.
In addition, more research and investigation is needed to best understand the extent of bee habitat microplastic pollution and its biological effects.
In conclusion, microplastics, as small as they are, have colossal danger for honeybee colonies. Microplastic ingestion, their chemical toxicity, and persistence in the environment are under threat to bees' well-being, lifespan, and fertility.
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