Adventure World has been working since 2022 to create a place for blue squids to lay their eggs by utilizing bamboo left uneaten by pandas, with the aim of restoring coastal ecosystems. In 2024, a total of 64 bamboo spawning beds were installed in "Ikogi Fishing Port" in the Hiokigawa area of Shirahama Town. The majority of these spawning beds were confirmed to be spawned by bluefin reef squid. In addition, seaweed and small animals adhered to the surface of the bamboo, indicating its potential as a substrate for increased organisms. We will report on the results of this activity and future prospects.

Background of the activity]
In recent years, the ecosystem of the sea in Shirahama has changed due to the rise in sea water temperature and the expansion of the distribution of organisms that eat algae, and the seaweed that serves as a spawning ground for the bluefin reef squid has been decreasing. Meanwhile, the increase in abandoned bamboo forests in satoyama has become a problem, and appropriate management is required. Adventure World has been cutting down these bamboos and using them as food for pandas, but the pandas eat only some of the fresh branches and leaves of the bamboos, leaving a large amount of the trunks and branches after feeding. Therefore, in 2022, we started an initiative to bundle the uneaten bamboo and sink it to the seafloor to be used as spawning beds for bluefin reef squid and as a base for small creatures to grow. This activity is an ongoing project to conserve the natural environment and strengthen cooperation among local communities.

Outline of activities for the 2024 season】
Installation period: June 26-November 9, 2024
Location: "Ikogi Fishing Port", Hiokigawa area, Shirahama Town
Number of units installed: 64 in total
Co-sponsored by: Shirahama Town
Cooperation: Kyoto University Seto Coastal Laboratory and Shirahama Aquarium, Koide Watership, diving center "Elmar", Wakayama Minami Fishing Cooperative Association, etc.
Main efforts:
① Installation of spawning beds for bluefin reef squid using bamboo left uneaten by pandas (moso bamboo and arrow bamboo)
・In Shirahama sea where seaweed has decreased, 64 spawning sites for bluefin reef squid using bamboo were installed
・After installation, diving surveys and bamboo sampling were conducted periodically from July to November

② Environmental study with local junior high school students participating

21 students from Hioki Junior High School participated in the creation and installation of spawning beds and learned about the marine environment

③ Exhibit of bluefin reef squid eggs at Kyoto University Shirahama Aquarium and public showing of hatching process
④ Survey of organisms attached to bamboo leaves and branches

④ Survey of organisms attached to bamboo leaves and branches Survey of organisms attached to bamboo leaves and branches
・Record the types and numbers of algae and small organisms attached to bamboo and analyze their impact on the ecosystem


【Activity Results
Successful spawning and hatching of bluefin reef squid
The majority of the 64 bamboo groves were confirmed to be spawning bluefin reef squid.
・ 2,641 juvenile squid hatched from eggs exhibited at the Kyoto University Shirahama Aquarium, and were released into the sea.

(2) Contribution to coastal ecosystems
Seaweeds attached to bamboos
Seaweeds, such as Siwaiyahadu and Tamaitadaki, were confirmed to be the base for seaweed growth
- Attached organisms
Crustaceans (Walleye pollack, barnacles), gokaye, egg masses of mollusks, etc. were confirmed to be attached to bamboos
- Signs of ecosystem recovery
Increased seaweed → increased number of small organisms → increased biodiversity Expected to improve biodiversity

(3) Results of dissemination activities
・19,281 people visited the Kyoto University Shirahama Aquarium during the exhibition period, providing an opportunity for many people to experience our activities.
・Pupils from Hioki Junior High School participated, providing an opportunity to deepen their understanding of the coastal environment .

[Future Outlook]
Recent studies have reported that bluefin squid prey on juvenile algae-eating fish, which are believed to cause rocky shore burn. With the confirmation of spawning by the bluefin squid, it is possible that this ecological linkage may act in the future to help reduce the decline of seaweed. It was also observed that as the bamboo gradually decomposes in the sea, it attracts mollusks that feed on the sediment. This suggests that bamboo may not only function as a temporary habitat for small organisms, but that the decomposed organic matter may also affect the nutrient cycle of the sea. We will continue our research to further explore the possibility of using bamboo to restore the ecosystem. We will also deepen our cooperation with local residents and fishermen, aiming to establish a new model for environmental conservation that links satoyama and satoumi.



About the Panda Bamboo Project 】
This project aims to protect the satoyama environment by cutting down bamboos that devastate satoyama and using them as food for giant pandas, and to promote upcycling of bamboo trunks, uneaten bamboo and feces that giant pandas do not eat, which have been disposed of so far, as effective resources. This is a project to promote upcycling of bamboo trunks, uneaten bamboo, and dung, which were previously discarded.