Since 2007, Kanagawa Prefecture mobilizes citizen volunteers to monitor water source rivers of Sagami 相模川 and Sakawa 酒匂川 Rivers (; my post on October 28, 2022). Every February, the researchers for the Prefecture at Kanagawa Environmental Research Centre 神奈川県環境科学センター preside two report sessions that tell us the collected results from volunteers’ studies during a fiscal year. According to this year’s session, we are 156 citizen monitors, the biggest number in 18 years of the project. We checked 48 points on Sagami and Sakawa Rivers. Unfortunately (or not), we did not find critically endangered species this fiscal year. Among the findings, Mr. Hasebe of the Environmental Research Center said the checking of Japanese fluvial sculpin is probably increasing. The fish lives only in the purest water. So, we in Kanagawa Prefecture procure water of improving quality seeping out from our forest. The other day, I’ve heard we in Kanagawa Prefecture pays the lowest tariff for tap of water thanks to these within-prefecture water sources. We must be grateful of it.
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| We’re collecting our specimen. |
Kanagawa Prefecture gives scores for several indicator families of aquatic creatures, which shows the water quality where the animal lives. The numbers are adjusted to Kanagawa’s river from the Japanese Biological Monitoring Working Party (BMWP) published in 2017 from the Ministry of Environment. Japanese BMWP itself is modified for Japan based on English version started in 1976. We identified our catch under microscopes, and if it has a defined point, we record it in the report. The observations’ numbers are summed up, then we divide the total by the number of species we’ve recorded. We do the math like
(Kamimuria quadrata’s score + Perissoneura Paradoxa’s score + Oyamia gibba’s score + Epeorus latifolium’s score) / (Number of species in this equation, i.e. 4)
= (9+9+9+9) / 4
= 9
Perfect score is 10, which says the stream has impeccable quality. 9 is the second highest grade. For fiscal 2023, the best scored point, 8.15, was at ASL950m confluence of Mizuhi Stream ミズヒ沢 and Shijuhasse River 四十八瀬川 on the slope of Mt Nabewari 鍋割山 (ASL 1272m). Our study in Yadoriki Stream 寄沢 earned the 2024 second position with score 8.11 at ASL425m confluence of Yadoriki and Takigoh 滝郷沢 Streams. Not bad.
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| The score 8.11 |
I’ve found a sort of “???” in the score calculation. Because of the math, a place, where we have found only a small number of creatures but each of them had a higher score, earns good evaluation. Let’s call this place A. Take another place, call it B which records more species including all the animals found in Place A + the other insects et al of lower score. Then, the evaluation of Place B can be lower than Place A … I also noticed compared with the last year’s expedition I did alone in Yadoriki Stream, in FY 2023 adventure with tons of help from the fellow Forest Instructors, we’ve recorded more families of aquatic animals. Power of number in this regard. OK, but the final score becomes lower. Let’s be philosophical, and read the earned grade with a pinch of salt. The pros in Kanagawa Environmental Research Centre said the computed score can be a rough indication unless the numbers are widely apart. Roughly, roughly, if the score is higher than 7, we can regard the water quality good for tap of water. Oh, caution. Yeah, we can drink them in mountains if you like. But we can find such several tiny water animals that can be identifiable only with microscopes and their DNAs are floating freely. Moreover, there are lots of wild animals roaming in the forest of Kanagawa. They don’t hesitate pee and poop near the streams. Your cup of water procured from the stream in deep mountain surely has such ingredients. Allow them going down to your stomach? It’s your choice!
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| A bit
of photo gallery I’ve taken from the specimen. It’s stonefly. I always think the pattern of their back is so artistic. |
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| Caddisfly.
Don’t you think it’s cute? The thing next to the bug is its home. I tell you it’s so difficult to destroy. |
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| Hexatoma
sp. When it becomes adult, it is like a large mosquito (but doesn’t bite). I personally think it is also very cute, like a fluffy doll. 😍 |
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| Leuctridae. By the way, I took all these phots with Google Pixel. Though it does not have macros camera, it does this good job. 😉 |
The result from environmental DNA is also very interesting. There are several mismatches. Some families of animals have been catalogued as specimen, but no e-DNA result, or vice versa. Yeah. We made specimen roughly 100m long area of stream, but DNA was collected from just one pin-point place. That could make a difference for sure. Also, there are lots of DNAs found for non-aquatic insects. Mr. Hasebe said “If an ant fall in the stream, and madly swam for survival, its DNA can be found, right?” Hm. Yeah, it’s a likely scenario. Mammalian DNAs are also found. Boar and Masked palm civet. DNA keeps its form in non-refreg aquatic environment for about an hour or so. Maybe, their pee and/or poop is constantly dissolving in stream … or, their hair? Carcass floating? Actually, the scholars are trying to collect environmental DNA for non-aquatic animals as well. A group tried to gather DNA from morning dews on leaves. Another tried adhesive handy cleaner on soil. Who knows same time next year, we may be given a new tool to collect DNA from another place? Let us see …
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| Stabilizing the collected DNA in a filter with chemical. |
Oh, recently, I’ve learned one way of calculating opening of cherry blossoms in higher altitudes. It’s like
A day of beginning cherry blossoms in a place ASL X m
= A day of beginning blossoms in a nearby seaside + X*(2 or 3)/100
i.e. a place of 100m higher altitude will have 2 to 3 days delay in opening flowers. I’ll try this formula to plan this year’s cherry blossom hiking. 😊
1-3-39 Shinomiya, Hiratsuka City, 254-0014
〒254-0014平塚市四之宮1-3-39
Phone: 0463-24-3311
FAX: 0463-24-3300
k-center@k-erc.pref.kanagawa.jp
https://www.pref.kanagawa.jp/docs/b4f/index.html
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