一度は見たいジャイアントケルプ、でも実はピンチです。(Giant kelp you want to see once, but it's actually a pinch.)

2020/12/21 ブログ





















 最近、海水温はより正常なレベルに戻っているようです。また、ヒトデの個体数は回復している可能性も出てきました。 新しいヒトデは、数年前に殺された消耗病に耐性があり、紫ウニの捕食者としての役割を再開するでしょう。ケルプの森を壊滅させた要因が無くなれば、ジャイアントケルプの再生が行われ、数も元に戻ることでしょう。その時に、アメリカ西海岸に渡って、水中ドローンで上から下まで観察したいと思います。海底から海面まで約50mに渡るジャイアントケルプは、水中ドローンで観察する良いターゲットだと思います。

#水中ドローン #ジャイアントケルプ #オオウキモ #ケルプの森

 It is difficult to go abroad due to the spread of the new coronavirus infection. However, when the pandemic of the new coronavirus is over, there is something I would like to see with an underwater drone. One of them is a huge kelp called Giant Kelp. The Japanese name is Giant kelp. The place where giant kelps are concentrated is called the kelp forest, and it is said that giant kelps continue from the seabed to the surface of the sea. Many shrimp, crabs, fish, seals and sea otters also live in the kelp forest, forming a kind of ecosystem. By all means, I would like to observe many creatures living in the kelp forest with an underwater drone. This kelp forest is naturally distributed from off the Alaska Peninsula to the Gulf of California. To observe the kelp forest, you have to go to the west coast of the United States.


Recently, the kelp forest seems to be in crisis.


 The kelp forest grows 2 feet a day and seems invincible at first glance. However, it seems that about 90% has been lost in the last 5 years. There are two causes. I want you to stay until I go see it.


Cause 1 Sea urchin feeding damage


 One of the causes is that sea urchins, the inhabitants of the Kelp forest, are proliferating and devouring kelp. Originally, sea urchins are eaten by sea stars, who live in the same area, and do not proliferate. However, in recent years, the number of sea stars has decreased sharply due to debilitating diseases. As a result, it led to the outbreak of purple sea urchins, causing catastrophic feeding damage to the kelp forest. Unlike red sea urchins, which are caught in northern California and exported to Japan as high-end foodstuffs, the grown purple sea urchins are small and have no commercial value.


Cause 2 Rise in seawater temperature


 Since 2014, the kelp forest devoured by purple sea urchins has not been able to regenerate. The reason is the rise in seawater temperature. Cold seawater is also required for the growth of the kelp that makes up the kelp forest. Due to the rise in seawater temperature, cold water was not supplied and the growth of kelp stagnated. Coupled with the feeding damage of purple sea urchins, the kelp forest disappeared one by one.


Efforts to revitalize the kelp forest


 In this way, the kelp forest is on the verge of annihilation. Among them, attempts are being made to regenerate the kelp forest. Divers are diving into the sea and collecting purple sea urchins attached to the kelp. Some divers use a device like a vacuum cleaner to suck up. Furthermore, it seems that the removal of sea urchins has become more efficient, instead of simply destroying the sea urchin shells and turning around. In fact, the giant kelp with the sea urchins removed seems to have begun to regenerate.


Is Giant Kelp Renewable?


 Recently, seawater temperature seems to have returned to more normal levels. It is also possible that the number of sea stars is recovering. The new sea star will be resistant to the wasting disease killed a few years ago and will resume its role as a predator for purple sea urchins. If the factors that destroyed the kelp forest disappear, the giant kelp will be regenerated and the number will be restored. At that time, I would like to cross the west coast of the United States and observe from top to bottom with an underwater drone. Giant kelp, which stretches about 50m from the seabed to the surface of the sea, is a good target for observing with an underwater drone.

#UnderwaterDrone #GiantKelp #KelpForest