Eelgrass "Eelgrass" - The Key to the Revival of Clams in Lake Hamana Start of sales of tour experience products and hands-on experience for the press

The Hamamatsu-Hamanako Tourism Bureau and the Bentenjima Cruise Ship Association have planned and launched an experience product that shows the site of the "eelgrass" colony, which is key to the revival of clams in Lake Hamana in Shizuoka Prefecture, as well as a fun way for elementary school students to learn about the SDGs, conduct free research during summer vacation, and create family memories. The content of the program can be enjoyed by elementary school students as part of their free research during summer vacation or as a family memory-making activity.

In addition, we will hold an experience event for the press on Tuesday, May 27, 2025.

Eelgrass" that has begun to grow in colonies in Lake Hamana

1 Background

In the past, Lake Hamana was a popular place for echigo-hatching. However, about 10 years ago, the number of clams began to decline catastrophically, and ebb and flow fishing has been suspended. In order to revive the clams, it is essential to restore eelgrass, which is called the "cradle of the sea" because it is the home of the clams.

Concerned about this situation, Yasunari Mase, head of the Bentenjima Pleasure Boat Association, which has been in charge of the ebb-water clamming business, founded an organization called Hamanako Natures about three years ago, and has continued conservation activities such as sowing and cultivating eelgrass seeds. In April 2025, for the first time in about five years, eelgrass was found growing in colonies along the shores of Bentenjima.

In this experience product, you will see the eelgrass with your own eyes and experience the unique nature and history of Benten Island through the guidance of a local fisherman guide. We hope that this experience will help to increase interest in the current status of eelgrass and conservation activities, and help to ensure that Lake Hamana remains a place where a diverse array of organisms can live for future generations.

2 Overview of the hands-on experience for the press

Date: Tuesday, May 27, 2025, 10:00 a.m. to 12:00 p.m. (tentative)

Location: Bentenjima Seaside Park, near the pier

　　　　　　　　　　 (3775-2 Bentenjima, Maisaka-cho, Chuo-ku, Hamamatsu-shi, Shizuoka, Japan)

Application for the experience: https://forms.gle/Pztn5CK7z2aCLdim8

　　　　　　　　　　 To determine the number of people on board and to be notified in case of inclement weather, etc,

　　　　　　　　　　 Please register by May 25 (Sun.) to ensure the number of participants and to be notified in case of inclement weather.

　　　　　　　　　　 In case of inclement weather, please register by Sunday, May 25.

　　　　　　　　　　　 Scheduled from 10:30 a.m. to 12:30 p.m.

The Bentenjima Boat Association will explain the purpose of the event.

　　　　　　　　　　 The press will be able to experience a 45-minute tour by boat.

　　　　　　　　　　　 (Please be sure to arrive before the start time if you wish to board the boat.)

　　　　　　　　　　 Two Hamamatsu-Hamanako Tourism Ambassadors will also be on board as monitors.

　　　　　　　　　　　 Two Hamamatsu-Hamanako Tourism Ambassadors will also experience the tour at the same time as monitors.

　　　　　　　　　　　 For more information about Hamamatsu Hamanako Tourism Ambassadors, please visit

　　　　　　　　　　　　 https://hamamatsu-daisuki.net/hamanako-ambassador/

3 Outline of Experience Products

Product name: "[Spring and summer only] Tour of Lake Hamana by boat!

　　　　　What is the cradle of the sea, eelgrass?

Period: From August 31, 2025 (Sunday)

Time ：Everyday from 8:00 a.m. to 4:00 p.m. for 45 minutes *Except for July 5 (Sat.) and some other days

Number of persons: 2 to 10 persons (1 group/time)

Fee: Adults 2,000 yen/person, children (4 years old to elementary school students) 1,000 yen/person

　　　　　All prices include tax.

Location: Bentenjima Seaside Park (3775-2, Bentenjima, Maisaka-cho, Chuo-ku, Hamamatsu City, Shizuoka Prefecture)

■Content: (1) After explaining the precautions to be taken on the boat, participants will put on life jackets and board the boat.

　　　　　(2) Explanation of eelgrass while cruising on Lake Hamana,

　　　　　　　(2) Observe and observe the "eelgrass beds" where eelgrass grows in colonies near Bentenjima and Nii-machi, Kosai City.

　　　　　　　Eelgrass beds" near Bentenjima and Nii-machi, Kosai City.

　　　　　(3) Take a commemorative photo in front of the symbolic tower (red torii) of Maizaka Town,

　　　　　　　(4) Return to the pier at Bentenjima Seaside Park.

　　　　　Option: "Rock Play at Ikarise," an uninhabited island (additional 500 yen/person)

　　　　　　(additional 500 yen/person, to be paid locally)

　　　　　　Life jackets, footwear, nets, and buckets are available for rent,

　　　　　　You can come empty-handed and play without worries.

　　　　　　You can also take a commemorative photo right under the symbol tower (red torii) of Maisaka Town.

Reservations: Please make a reservation at least 5 days in advance through the "Hamamatsu Hamanako Yaramaika Tourism" (OTA) website.

　　　　　For more information, please visit

　　　　 https://hamamatsuat.hamamatsu-daisuki.net/experience/1941/

Underwater Observation Glasses

Commemorative photo with the symbol tower of Maisaka Town (red torii gate)

Optional at low tide (extra charge)

4 Other

We are also considering arranging group/educational tours.