The Environmental Protection Department (EPD)’s 2015 report, Investigation on the Sources and Fates of Marine Refuse in Hong Kong, categorizes marine debris into eight major types. Shoes are not listed as a distinct category but are grouped with clothing, towels, and hats under “Cloth.” The report notes that of the approximately 15,000 tonnes of marine debris collected annually in Hong Kong, “Cloth” constitutes no more than 2%, or roughly 300 tonnes. This makes it challenging to discern the specific contribution of shoes to the total.

The 2% may seem minor, but it’s far from insignificant. Since 2021, My Nature Diary, a platform dedicated to marine debris issues, has meticulously catalogued sea waste, revealing that “clothing/footwear/bags” number in the thousands annually and have repeatedly ranked among Hong Kong’s top ten marine debris types.

The variety of shoes found in marine debris is vast. Based on nearly a decade of beach cleanups by The Green Earth, flip-flops dominate, followed by sandals, canvas shoes, hiking boots, high heels, pointed-toe shoes, and Crocs. Brand-wise, there’s no shortage of name-brand trainers like Adidas, Nike, and New Balance, alongside counterfeit Gucci sandals. Beaches resemble a miscellaneous shoe stall, with everything imaginable.

Flip-flops, lightweight and buoyant, can float across oceans, so their abundance is unsurprising. However, it’s worth noting that heavier shoes likely sink to the seabed before being noticed, suggesting the total weight of shoe debris far exceeds the 300 tonnes reported for “Cloth” in EPD’s report.

You might wonder: unlike single-use items like plastic bottles, cigarette butts, or food packaging, how do shoes and clothes end up numbering in the thousands? To answer, let’s first explore the sources of marine debris in Hong Kong.

Waterfront and Water-Based Activities: Shoes are often swept away by waves during beach play or lost while kayaking. Operators of speedboats ferrying tourists to outlying island beaches note that passengers wading to board, often juggling beer, children, or distracted by taking photos, frequently lose their shoes, joining the “flip-flop dropout club”.

Vessels: Items are accidentally or deliberately dropped from fishing operations (e.g., fish farms, fishing boats), yachts, cargo ships, or cruise liners. The latter is particularly deplorable.

Runoff from Rivers and Drainage Channels: Household waste, including shoes, is easily washed into rivers, especially during heavy rain or typhoons.

The striking “shoe array” in the image was collected by members of My Nature Diary during a 2021 cleanup at Fan Lau, Lantau Island. A record-breaking 1,645 shoes were gathered in a single day, with over half being flip-flops. The cleanup’s initiator Yeungs, known as “Sheeppoo” remarked, “That day, we were truly shocked by the sheer number of shoes.” Similar scenes have since been observed at other beaches, creating a spectacular sight.

In May 1990, the cargo ship Hansa Carrier, en route from South Korea to the United States, encountered a storm south of the Alaska Peninsula. Twenty-one 40ft containers fell overboard, five of which carried 61,000 pairs of Nike trainers, scattering them across the sea. This incident became known as “The Great Shoe Spill of 1990.”

You might recall a similar cargo ship accident that released tens of thousands of bath toys—yellow ducks, red beavers, and more—into the ocean. However, the outcomes differ. The Nike trainers, each marked with a unique serial number, sparked an idea in oceanographer Curtis Ebbesmeyer. By collecting data on the shoes’ drift and stranding locations, he could enhance understanding of ocean currents and track marine debris movement.

Individual efforts have limits, so Ebbesmeyer launched a citizen science initiative, rallying beachcombers in Washington State, Oregon, and British Columbia, Canada, to participate. This led to the formation of the Beachcombers’ and Oceanographers’ International Association, a non-profit organization that publishes Beachcombers’ Alert, a magazine tracking global marine debris dynamics.

The real experts are among the public. These beachcombers—enthusiasts, amateur collectors, and environmental volunteers—are passionate about ocean flotsam. Beyond aiding scientific research, they organize “swap meets” to pair single shoes into wearable sets for personal use or resale. Some acquired drift shoes for about $20 (a quarter of their original price), which, after cleaning, remained wearable.

People buy shoes for many reasons — or sometimes for no reason at all. When your shoe cabinet is overflowing, styles become outdated, shoes develop an odor, or they “fall apart” from disuse, what do you do? Do you give them away, clean them, repair them, recycle them, or simply discard them? In recent years, some organizations have claimed they can dismantle and sort recycled shoes, giving them a new life. Recycling has become a potential solution, but it still requires careful consideration.

The rise of “fast fashion” fuels a “replace with newer” consumption model. To enable rapid turnover and low prices, product quality is often sacrificed. Many garments and accessories are discarded after minimal use. However, when vast quantities of low-quality clothing and footwear flood recycling bins, even distribution to underserved communities cannot absorb them. Recycling is costly and economically unviable, potentially overwhelming the entire recycling system.

People often delude themselves into thinking others can handle what they cannot, shipping discarded clothing and shoes to developing regions under the guise of “textiles” or “used clothes” to clear their conscience.

This is a problem for old clothes and a challenge for shoes, which are similarly labeled as “textiles” and shipped overseas. In 2021, Australia’s High Commissioner to Ghana joined a local beach cleanup and was shocked to collect over 30 kilograms of shoes in under two hours, with more left behind. According to beach cleanup data provided by Ocean Conservancy to The Green Earth, shoes stood out in 2022 as the fifth most common marine debris item in Africa, totaling 50,781 pairs. Ghana led African nations, accounting for over 75% of the shoes collected¹.

1. The Ocean Conservancy notes that the number of shoes collected across countries is influenced by factors such as the number of participants, frequency of cleanups, and the precision of data recording. Consequently, the actual number of shoes in Africa is estimated to be far greater than the reported 50,781 pairs.

Ghana hosts the world’s second-largest second-hand goods market. Greenpeace’s 2024 report, Fast Fashion, Slow Poison: The Toxic Textile Crisis In Ghana, reveals that the country receives an average of 15 million imported second-hand clothing items weekly. This means that in less than three weeks, the import volume is sufficient to provide one item per person nationwide. The issue is that approximately half of these items, due to poor quality (often plastic-based synthetic fibers), damage, or unsuitability for the local climate, cannot be resold or recycled. With inadequate disposal facilities, they end up in illegal landfills, are burned unlawfully, or are abandoned in rural areas and along coastlines.

Although Greenpeace’s report does not focus on shoes, its author, Sam Quashie-Idun, notes that textile marine debris includes shoes mixed with exported second-hand clothing, often without thorough sorting. Due to their poor quality, many of these shoes are ultimately discarded into the natural environment, gradually breaking down into microplastics with long-term ecological impacts.

Sam, born in Ghana, serves as the Head of Investigations at Greenpeace Africa. He is uncertain about when the surge in shoe debris began, but suggests it may be linked to recent restrictions on waste plastic imports in Asia and Southeast Asia, redirecting waste to Africa. He adds that Greenpeace has focused on Ghana, Kenya, and Tanzania for years, but countries like Nigeria, South Africa, and Uganda are similarly affected by imported second-hand clothing and shoes.

Keep Shoes Sparkling Clean

Trainers: Avoid washing machines or soaking overnight, as prolonged exposure can damage stitching and adhesive soles, or cause the shoe to soften and deform.

Hiking Boots: Don’t sun-dry after cleaning, as this can harm the surface and increase the risk of sole detachment due to thermal expansion and contraction. Air-dry instead, remove insoles, and stuff with newspaper to maintain shape.

Leather Shoes: Gently wipe with a leather-specific cleaner or damp cloth; never soak in water.

Canvas Shoes: Lightly brush with a neutral detergent; avoid vigorous scrubbing.

Shoes Need Skincare Too

Ventilation and Dryness: Store in a cool, well-ventilated area to prevent mould from dampness.

Avoid Direct Sunlight: Strong sunlight can cause leather to crack or fade.

Keep Shoes in Shape

Use shoe trees to maintain the shape, especially for leather shoes.

Shoes Need Exercise

Shoes left unworn for too long can harden, causing soles and adhesive to deteriorate and detach. Wear them at least every few months to keep the materials flexible.

Shoes Need Rest

Rotate your shoes to allow them to breathe and recover.