I Do Not Want to Inhale: Finding microplastics in Shonan Beach

 

So, one fine January morning, scientists for Kanagawa Environmental Research Center gathered us, the registered ESD instructors, in a beach where Shonan Bellmare soccer team trained themselves during off-season. It was a beautiful day. The beach volleyball players engaged in their daily training routine while neighbors brought their pooches for morning stroll. A scientist instructed us, “First we situate 40cm*40cm codrato on beach.” “Please aim the collection point along the line where tide reached max, then retreated. They leave the debris on sand.” OK.

We can recognize
how far the tide came at this point with debris.
Nearer to the sea, the tidal flow washed
the fragments several times and
the beach became “seemingly” smooth and clean.

40cm*40cm was like this.

“Next, please scoop the sand within the square for about 3cm deep, and filter the contents in the sieves. We use a combination of two sieves. Above is a tool of coarser mesh with 4.74mm2. Join up a finer sieve with 2mm2 mesh below. Microplastic has, by definition, the size of 5mm less in its longest length which is often the diagonal. 4.75mm mesh could let pass a particle of this size. The lower sieve would release smaller bits, which would be defined as nanoplastics. Collecting nanoparticles is totally different issue, so we skip it today.” Sure. Let’s start sand play!

Two-story sieve system

Ready …

Go!

On the line where the tide reached max, there were lots of fragments of wood, bamboo, hard pampas grasses, and garbage of apparently artificial materials. At the point where I collected the sand not many glasses, beer cans or cigarette butts were found. Maybe, that’s good news. We collected large trash from a codrato before start scooping. In the first sieve, there remained relatively large fragments of wood and shells, and we returned them to the sand. The below is where our target remained. We damped them in a (Ahem) plastic Ziploc and brought it to the lab.

The “above” sieve.

The “below.”
They contain the thing of probably more than 5mm in size.
But they could go through 4.75mm mesh.

You may think the selection for the point of codrato would measure the level of plastic contamination higher than the average of the beach. Scientists for the Center thought the same thing and they did exhaustive study for the same beach before. “We tried several points if there is the optimum point where we can collect the microplastics in the most efficient way. Our conclusion is statistically speaking there is not much difference among locations in one beach and the amount of sand scooped. This means microplastics are scattered evenly and widely without difference in depth. Operationally, it’s good news. To think about the level of contamination, it’s VERY serious finding.” Oh yeah.

Today’s catch.

We brought the scooped materials to the lab and sorted the contents into organic things and plastics by hand, er, by tweezers to be exact. In our bag, there was no apparent porcelain and glass bits or steel wires, so the “artificial” debris was all plastics. At a glance neon green or the like of artificial coloring was not found much. So, the first impression was “Nah, problem is not serious.” Not so fast, please. The problem was, the originally white or transparent plastics absorbed or were smeared by some chemicals during their stay in water, and changed their color into similar to organic woods or the like. Deception. So, we have to identify the thing which was

a) Unnaturally geometrical, and/or

b) Looked a bit strange. 

Category b) is somehow easier to understand, isn’t it? We just trust our gut instincts. 😉

“A bit strange” things are apparent, don’t you think?

The particle in a) category was tricky as the beach was full of tiny rocks polished into something round tiny pebbles. As we know their origin was huge volcanic rocks created by tectonic movements, like andesites and tonalites, in Tanzawa. So, even when they are tiny, they keeps their characteristics of volcanic mineral. We patiently separated such pebbles from the “catch.” The plastic particles remained after this check was once the contents of beads cushions or beloved teddy bears. The main body of them was already trashed, but the staffing = plastic beads came out from the sac, drained into the stream, and ended up in the beach. During this process, they were exposed to sea water and uv-light which turned their color from white/transparent to something “organic-kind” brown. When left as such in the beach, they will be broken into smaller bits and become nanoplastics, or smaller. As they are small and light, when the wave splash kicks up them with sea water into the atmosphere, they can float in the air and end up at the bottom of the lung of mammals, humans included. Anyone cancer? Stroke? Heart attack?

The pebbles from Tanzawa, and a shell.
I plan to make them into an accessory with resin.

Another “unnaturally” plastics we’ve find looked briefly like some shell of seeds. They have a shape after the contents inside were squeezed out. Scientists told us, “It’s plastic.” Originally, they were slow-release fertilizer used massively even in commercial farms. Inside was active ingredients that seeped into the soil and one day they became empty. After reaching this stage, they started to be washed into water stream over ground, to the river, then to the sea. “Ideally, farmers side dressing their crops according to the conditions of their product. But aging problem is serious for the ag community in our prefecture. The grandparents do not have the stamina to tend their field regularly. So, they apply fertilizer contained in the plastic sac to skip regular dressing.” i.e. The problems are in forests, like Yadoriki community, and end up with the sea contamination of microplastics. Hmmmmmmmmm.

For the remnants of slow-release fertilizer,
the bit shown by the arrow is
the most easily identified in this pile of microplastics.
But here, there are roughly 10 such plastic husk.
Could you identify them?

We can analyze such debris for its chemical properties.

The result. It’s acetylcellulose.

According to the scientist of the Center, for Kanagawa Prefecture the level of microplastic contamination is apparently higher along the coast of Sagami Bay compared with the beaches to the direction of Tokyo Bay. Kanagawa’s beach facing to Tokyo Bay is almost at the exit of the Bay. Moreover, there are not many rivers pouring in. In contrast, Sagami Bay has several rivers that run down the large human settlements. Scientists surmised if the origin of the contamination is from open Pacific Ocean, there cannot be such huge difference among locale. Their conclusion is the problem in the sea is coming from the rivers passing through the land. Forests are lovers for sea. So they say. But …

Of course, we now cannot do away with the plastics for our life. We understand senior farmers need any help to continue their farming life. But, there must be some way to prevent inhaling nanoplastics that could cause any serious diseases eventually … Difficult. At least, let’s be careful before throwing away the tattered teddy bear with plastic beads …

If you find environmental issues in Kanagawa Prefecture, especially in cities and coastlines, please make contact with

Kanagawa Environmental Research Center

神奈川県環境科学センター
1-3-39 Shinomiya, Hiratsuka City, 254-0014
〒254-0014　平塚市四ノ宮1-3-39
Phone: 0463-24-3311
FAX: 0463-24-3300 

https://www.pref.kanagawa.jp/docs/b4f/index.html

No syringes, But Microplastics: Beach clean 2026 in Shonan Beach

 

It’s depressing thought, but we have to face the reality before proceeding to the future, right? Our ocean is contaminated by plastic garbage. At least in Japan these days, the direct damping of plastics intentionally to sea is becoming rare. Instead, trash on land, like candy wrappers casually thrown away, is swept by rainwater to a stream nearby, then floating down the river to the sea. Speaking “Forest is a lover of the Sea.” Heck. Yeah, it is true ecologically, but the humans around these two passionate lovers don’t care how the couple nurture their love … Nay, humans are caring. Not many people these days in Japan leave the garbage in forest or on road. If you do this, the city officers and sometimes police will come to see you … Still, many non-biodegradable things drift to the ocean.

Seemingly impeccable beach

And as you know, non-biodegradable does not mean a plastic bag keeps its form as a bag forever. UV light and the other many chemical reactions mutilate the mass of plastic into particles. Microplastics are born. Micro or nano, as substance plastics are plastics and do not decompose into a natural cycle. Moreover, they chemically react with the other toxins especially in ocean where salty water and UV light do a good job for creating another toxic material from trash. Worse, as they are tiny, even if they wash up the beach, they are too small to pick up during the standard beach combing. Period. Facing the reality part is over for this post. The next is, what to do?

Too small to identify them here.

Of course, the best way is to stop supplying the “raw material” for microplastics on land. Yeah. We Lovers of Niiharu engage in weekly forest patrol and collect garbage. The common item we find is PET bottles for drinks and candy wrappers. I don’t say ours is fruitless effort, but probably we need more knowing hands to deal with the problem. Why do I think so? Well, there is an apparent change in “trophies” we can have during the beach combing in Shonan Beach.

Niiharu Lovers are patrolling.

About 20 years ago, I helped beach clean to hold the Shonan Open Water Swim Race. At that time Shichiri-ga-hama 七里ガ浜 (; my post for March 9, 2025) had still certain amount of sand beach. We could set up the starting-point for swimmers of 5km race to Katase Higashi-hama 片瀬東浜 in front of Enoshima Island 江の島 (; my post for June 30, 2017). That Friday morning, a day before the race, we collected trash, like pieces of wood came down from Tanzawa Mountains 丹沢, debris of handheld fireworks (they are dangerous for barefoot swimmers), plastic wrappers for sweets and lunch packs, PET bottles, AND old TV, tyres, used syringe needles. We’re astonished to find a corner with needles, tyres, broken TVs, and called the City of Kamakura 鎌倉市 for help. Of course, we lamented the shameful morale of somebody who damped such things there. Now that I look back, it was good old simple days. Nowadays, when we beach clean, it is difficult to find old TV et al. Actually, finding PET bottles for drinks is not so frequent. The large “catch” could be some stray fishing tools probably fishermen gave up somewhere in the waters off. Hurrah for clean beach!? Nope. Instead, we meet sand with particles of strangely vivid pink, neon blue, and plastic green. The beach is covered with microplastics. Collecting these with tongs? You must be joking.

Strange colors here and there.

One sunny day this month, Kanagawa Environmental Research Centre organized a study session on how to scientifically monitor the microplastics contamination in our beach. The idea is simple. We gather plastic particles in a unit quadrant, 40cm*40cm, of sandy beach using trowels and sieves. We then count how many MP we find in that unit, measure a probably representative specimen, then analyze chemical characteristics of it with machines. Just gathering micro plastics is simply fun. These days kids, especially in elementary schools along the Shonan Beach, engage in the activity to experience the problem in their playing ground. Good. Knowing is the first step to solve the problem. We adults are required to think about it more. Let me continue about it next week.

If you find environmental issues in Kanagawa Prefecture, especially in cities and coastlines, please make contact with

Kanagawa Environmental Research Center 神奈川県環境科学センター

1-3-39 Shinomiya, Hiratsuka City, 254-0014
〒254-0014　平塚市四ノ宮1-3-39

Phone: 0463-24-3311
FAX: 0463-24-3300

https://www.pref.kanagawa.jp/docs/b4f/index.html

Whatever Happens, Babies Are Coming: seedlings in dry river beds for winter Tanzawa

It is still at the proposal stage for a possible new project for forests in rural Kanagawa about which I said a bit last week. The theme is to assess the effects from frequent storms et al, probably due to climate change. A sudden torrential rain for a short period of time has become common these days, which could have effects on environment. Landslides and debris flows could often occur to destroy communities downstream. Especially afforested cedars where the network of root system is somehow simple and its forest floor has lesser biodiversity, the new disaster risks many be materializing easily … Such questions are certainly worth looking at. Let us see how the theme evolves in 2026 and beyond. Having said that, mini floods are habitual for rivers running down from Tanzawa Mountains even before the climate change days.

Once it collapsed, it was like this.

There is a theory the name Tanzawa 丹沢 is from classic Korean circa 1AD. According to this story, the name of the place means “many small streams.” Apt. Then, once the storm comes, these not so long but rapid flows frequently change the course. It has created wide riverbeds in deep mountains. The feature is due to the fragile soil of the area thanks to the continuing crash of Philippine, North American and Eurasian Plates. In such wide dry gravel bars, there come pioneer plants, such as Euptelea or cat’s claw, which do not care about the crumbly stone filled soil. These species should be gone once the soil becomes stable and the dominant species for the climate of the area, such as ring-cup oak, will conquer the pioneers. Alas, such transition has not happened in Tanzawa’s riverbeds.

I think this is Japanese hornbeam in winter.
Yeah, it’s another pioneer plant along mountainous streams,
but I think even this one has some limit …

Very wide dry riverbed

Euptelea in bloom

Still, it does not mean we can find only pioneer plants in Tanzawa’s riverbeds. At least baby trees sprout in a gravel-filled space, even if they will be wiped away once a storm comes. From late autumn to early spring when Kanto Region is in a dry season and Tanzawa Mountains are ‘sleeping,’ we can leisurely find variety of seedlings and rosettes there. Thinking whose babies they are is like a treasure hunt in deep mountain. For example, these are the kids I found the other day in Yadoriki stream.

Rosette for Philadelphia fleabane.
It is a naturalized plant from the US.
I noticed there are several such plants of
 foreign origin in the riverbed.
For example, maybe,

Lysimachia? also from the US, and

Sonerila dongnathamensis?
If so, it is from Thailand.

Oriental false hawksbeard. It’s Japanese native.

Plume poppy. ditto

Hydrangea macrophylla. ditto

Stephanandra incisa

Deutzia crenata.
Come to think of it,
they all love forest edge with full-sunshine.
Typical feature of ecotone, maybe …

Trachelospermum asiaticum

I think it is winged spindle.
Though now it is familiar as a garden plant,
we can commonly find it in mountains.
Our ancestors used it for painkiller.
For such usage,
the tree must have been on a stabler soil ...

Japanese Spiraea.
It also loves rocky soil, and is loved by gardeners.

I know they will be crashed by rocky debris tumbling down from the upstream, when the rainy season comes. Still, some baby maples turned their color into vivid red in dry rocks. Hmmmmmmm … this may could be an inspiration for Bonsai art. If you have a chance to visit upstream rivers in Tanzawa, just look down on your feet. Those babies are betting on the chance of their survival in this very harsh condition. Impressive.

Crashed …

Japanese maple baby

If you find environmental issues in Kanagawa Prefecture, please make a contact with

Kanagawa Natural Environment Conservation Center

神奈川県自然環境保全センター

657 Nanasawa, Atsugi City, 243-0121
〒243－0121　厚木市七沢657

Phone: 046-248-0323

You can send an enquiry to them by clicking the bottom line of their homepage at 

http://www.pref.kanagawa.jp/div/1644/

Every New Beginning Comes from Other Beginning's End: Kanagawa’s forests and aging society

 

And so, Yokohama’s problem of aging population for environmental management is tackled in this way (; my post last week). In numbers as of January 1, 2026, Yokohama has 3,769,748 population which has been increasing in this post-COVID era. Especially, younger generations have moved into our city. They are nullifying the decrease from elderly passing-away. In addition, our city will host International Horticultural Expo in 2027, “Green×Expo” held near Citizen Forests of Northan Yokohama, i.e. Seya, Oiwake, Yasashi, Kamikawai, Miho, and Niiharu (; my posts during 2015). The momentum is building up in our neighborhood greenery. Yokohama can, at least for now, think a way to deal with the greying population as a public relation matter. It should be fortunate. Kanagawa Prefecture has a different problem.

A neighborhood stroll path in Yokohama

Yokohama has 437.4km2, roughly 18% of Kanagawa Prefecture with 2416.55km2. In this limited area we have approx. 41% of Kanagawa’s population with 9,217,647 (as of September 1, 2025). People live in Yokohama is relatively young and increasing. In contrast, for some time Kanagawa Prefecture in total is observing the decrease in population and rapid aging especially in rural areas. Even before the greying problem became obvious, a guy for financial affairs of the Prefectural Office once told me money-wise Kanagawa Prefecture was depending heavily on taxpayers of Yokohama. Well, we Yokohama people are generous. We’re paying 3 different taxes for environmental issues. One is the national tax, Forest Environment Tax. Another is the prefectural tax, Water Source Environmental Protection Tax. And finally Green Tax for the City of Yokohama. Among these three, national tax is returned to the city as a subsidy for “Using Japanese forestry products among citizens.” E.g. Building your home in Yokohama with Japanese timbers will receive municipal support pecuniary. Green tax is for maintaining and expanding your neighborhoods forests of Yokohama. Your family can enjoy your Saturday lunch there easily. Then, Water Source Tax? Er …

This fall, we’ve enjoyed beautiful autumn leaves
in Yokohama’s forests.

Water source forests for Kanagawa Prefecture are in the eastern slopes of Hakone National Park, Tanzawa Mountains and Takao Mountains which are Quasi-national Parks. When the tax was introduced in 2007, the forests of the area were indeed suffering neglect due to already aging and decreasing population of mountain villages. But thanks to the nature of forestry, once the maintenance jobs are done with the tax base, the next job-cycle for such areas begins 20 or more years later. This means, taxing 2026 people for 30-years-later-jobs has a little persuasive power. In addition, for the majority of city rats, i.e. we the people of Yokohama, National Parks are recreational areas, i.e. luxury, and do not have much familiarity with our daily lives. Paying tax for this now? No way.

In Tanzawa, autumn leaves were also splendid this fall.

Of course, the people living in mountain villages must have different opinions. The public works using the income from Water Source Tax has been VERY important income for rural areas. But, that’s that. For example, Yadoriki Community is observing rapidly decreasing population, and the remaining people are more and more aging. Since last year, there is no commercial farmer in Yadoriki Community. Yes, people are tending their veggie fields for home consumption, but no more tea or citrus growing for business. Reason? Ag works on steep slopes are too much for grandpas and grandmas. Younger people have taken city jobs for better pay, commuting to nearby cities which is really near in Kanagawa Prefecture. A familiar story for all over the world, I guess. The issue of Water Source Tax is now not for environment, but for welfare of aging populations. It’s difficult for the Prefectural Office to sustain the argument for the scheme now. Water Source Tax will be abolished in 2027. Soon.

Er … this openness was really something.
But once we realize this is a commuter road
 within Yadoriki community which is
 half an hour car ride from Odakyu Shin-Matsuda Station,
can we simply praise the atmosphere?
Isn’t it desolation?

Last fall, a new honcho has been assigned to the Prefectural division that is in charge of the matters of rural areas in the west of Kanagawa. That person may have been given the mission from the HDQ in Yokohama to rationalize prefectural works for the area. The closure of the visitors’ service for Yadoriki Water Source Forest was announced last month. The deadline was not clarified but the Forest Instructors’ Association was notified to evacuate the buildings rather sooner. The demolition of the admin house at the entrance is said to be started within months. Yeah. Since last summer, those facilities could not have electricity. The Prefecture surveyed the wiring and found several points where the connection was directly eroded by wet soil (; this is water source!). Moreover, the foundations of the log houses are more and more fragile thanks to the decays from high moisture (; this is water source!). For restoration of such structures the Office needs money of certain amount. When there is no solid reasoning to maintain the service and financial arrangement, closure shall be inevitable.

Yadoriki’s toilets are closed.

Instead, portable toilets are situated.
We don’t know how long this service is provided.

It is said that the offices for the Forest of the 21st Century (; my post for July 28, 2017) will also be closed, or the service there will be reduced to the minimum. For both Yadoriki and the 21st C Forests, I know the number of visitors is really small. The rationalization in fiscal expenditure for them is unavoidable. But I think the real difficult part will start after closure. OK. Stop taking care of the places perhaps would not cause serious problems for now to the environment. The thinning and mowing have been completed in the area thanks to these 20 years of the tax base. But, then, is there a reliable prospect for another policy when the time comes and the forests need help again? I don’t say there is nothing in store for the policies of the Prefectural government … I’m now collecting information which includes interesting projects with top-notch technologies. I’m also hearing the stories when the frozen approach to the forests causes problems. I’ll tell you these when they are ready. Meanwhile, in 2026 we’re starting the new era for our neighborhood forests.

If you find environmental issues in Kanagawa Prefecture, please make a contact with

Kanagawa Natural Environment Conservation Center

神奈川県自然環境保全センター

657 Nanasawa, Atsugi City, 243-0121
〒243－0121　厚木市七沢657

 

Phone: 046-248-0323

You can send an enquiry to them by clicking the bottom line of their homepage at 

http://www.pref.kanagawa.jp/div/1644/

Time Goes By: our neighbourhood forests and humans, 2026

Well, 2026 has begun. I’ve been posting this blog for quite some time. Inevitably, there are changes in the forests. As in the forest of Tsukuba (: my post on December 21, 2025), the forests themselves transform at their own pace, which could be obvious after 40 years. My posts are not that old yet. Unless some huge havoc occurs, like mega typhoon or bulldozing for shopping centres, forests take their time in a slow, steady, and calmful way for transformation. In contrast, changes in humans are much faster.

For one thing, when I started this series in 2015, the main keepers of, say, Niiharu Citizen Forest were retired 60 or 70 somethings. In Japanese demography, this cohort is the typical baby boomers born by 1949 – 1950. They spent their prime days as a locomotive of Japanese economic development without experiencing starvation as their predecessors during war years. In 2015, they have been healthy grandpas and grandmas with stamina and money of generous pension. In addition, they are MANY. In this country of rapidly shrinking population, they are still the most numerous people contributing to the upside-down pyramid of demography. The management system of suburban forests in Megalopolis Tokyo utilized such very distinctive generation. It means, they are more than 75 years old in 2025. Even those mighty seniors are now “75 years old and up,” and often too old to operate chainsaws for 3 hours.

Yet, we’re fine. Thank you.

Moreover, in 2026, 65 years olds are not as those baby boomers. Their prime age was spent during the lost 30 or so years of deflation. New retirees do not expect luxurious pension. Those mandarins for public pension system seriously talk about a “life without retirement: please keep on working until 100 years old.” It’s difficult expecting the same kind of dedication to neighbouring forests from them as those grandpas in 2015.

Even though we’re doing our best.

Yeah. Grandpas and grandmas are still going strong for forest management in Yokohama and Kanagawa. But, death notices are to some extent regular announcement these days for morning assembly of Lovers Associations in Citizen Forest. Forestry sessions we forest instructors support in Kanagawa’s forest welcomes veterans whose average age is 75+. The amount of job gets done in a day is decreasing. The donation to Kanagawa Green Trust from non-corporate entities (i.e. often senior individuals) has nearly halved compared with the amount for 2015. Then, during the last mayoral election in August 2025, two candidates (Mr. Tanaka and Mr. Koyama) ran for office with the agenda to abolish Yokohama’s Green Tax and to shrink municipal projects for greenery, including the system of Citizen Forest. They lost the election but gathered 23% of votes. The incident becomes a wake-up call. Many people involved in Yokohama’s greenery are getting alarmed.

Actually, for more than 20 years the City Office for Yokohama has asked research firms to conduct opinion polls concerning City’s greenery. (The latest result is from here.) Interestingly, the result has not changed for at least 20 years. Everybody thinks maintaining greenery is important to keep the city’s environment nice. But those who actually act for the forests or city gardens are mainly 55 years or up. The majority of such people is 60 to 70 somethings. On the other hand, those who bear the large portion of city tax are working population, i.e. 30 to 40 somethings with kids in schools. The cohort has been answering healthy natural environment in neighbourhood is important for their family life, but “we don’t know what the city office is practically doing for this.” i.e. They do not know Yokohama Green Up Plan for environmental management (; my post for January 26, 2016). But they are contributing to a large share of Green Tax income without knowing the purpose of it. And there is materializing, rather urgently, a serious problem of aging population for greenery management in Yokohama.

Telling you the truth, the awareness of the issue has been shared within the committee members for Yokohama Midori-up (Green-Up) Plan Citizen’s Promotion Council. The former council members recapitulated the problem in their report, and left homework for the next members of the Council to tackle the issue, i.e. do something for public relation to Yokohama’s environment plan. True, Yokohama needs more money for school meals, nursery schools, medical systems, etc. etc. But it’s a different matter nullifying the Green Up Plan and its tax base for covering the cost of another issues. Yokohama’s plan is really unique in Japan for managing the greenery of our city and has been run well for the wellbeing of citizens since 2008. Two years ago, the people of the City Office for Osaka came to see how Yokohama was doing with the Green-Up Plan, and said “Wow, Yokohama is serious for the issue, isn’t it?” Oh yeah. But how to communicate with the people about this important issue? Those parenting generation is more and more familiar with SNS and short messages but not at all with the bureaucratic annual reports, aren’t they?

Anyway, the Council and the City launched last August the official page for Yokohama Midori-Up Action and hopes the information cycle of the forest to the people becomes shorter, more adjusted to busy parents. We’ll see if it is an effective tool for the child-rearing generation to be aware of Yokohama’s environmental policies. I personally think we should be proud of ourselves having a healthy community where some politicians can run for the office peacefully on the platform of controversial issue. But it would be definitely better to have discussions while sharing widely the reliable information about the topic regardless of the political stance. Difficult …

If you have any questions about Yokohama’s Green Tax and Green Up Plan, please make a contact with

Strategic Planning Division, Green Environment Bureau, City of Yokohama
横浜市みどり環境局戦略企画課

Phone: 045-671-2712
FAX: 045-550-4093

Email: mk-kikaku@city.yokohama.lg.jp