Entry — 2026 Ocean Ecosystem Change Contest (video)
Deserts Form in the Sea, Too
One boulder goes from kelp forest to white barren, then back after people replant it: 29 seconds that loop into their own beginning.
People and scenes are AI-generated.
In short
- ImageMade the kelp-forest boulder (A) in Gemini image, then edited it in the same chat into the white boulder (B) and the replanted one (C), keeping the framing
- VideoThree 10 s Veo clips, each starting from A, B or C — the barren spreading, hands replanting, the forest growing back
- NarrationGoogle AI Studio speech · voice Charon · a six-line script with numbers spelled out in Korean
- EditColor matched across the three clips, a loop that melts the last shot into the first frame, narration placed line by line with captions, and the underwater sound kept low — Claude with Python, FFmpeg and OpenCV
- ReviewChecked every fact and figure against the YTN report, and the spelling
Scenes
Scene 1 · Kelp forestDeserts form in the sea, too. It starts with one boulder full of kelp and fish. 
Scene 2 · The barrenKelp disappears and white coralline algae covers the rock: a sea barren. 
Scene 3 · CausesRising water temperature and too many sea urchins are named as the main causes. 
Scene 4 · ReplantingSo people plant seaweed again. 
Scene 5 · The numbers17 sea forests completed in the last four years: seaweed weight up 138%. 
Scene 6 · The loopSea forests grow back. And the video returns to its first frame.
Pipeline
- PlanOne boulder, one framing: forest → barren → replanting → forest, ending where it began
- Generate imageGemini image · 9:16 · edited A → B → C
- Generate videoVeo in the Gemini app · image as first frame · 10 s × 3
- NarrationAI Studio speech · Charon · documentary-narrator tone
- EditPython · FFmpeg · 1080×1920 · color match, loop, captions, sound mix
- Review & exportFacts, sources and spelling checked · 29 s MP4
Prompts
Image A — kelp-forest boulderGemini image · vertical 9:16
Photorealistic underwater photo, vertical 9:16. A rocky reef in the Korean East Sea at about 5 m depth. One large rounded boulder sits in the lower center of the frame, covered with a dense forest of brown kelp swaying upward; a few small rockfish swim between the fronds. Soft sunbeams from the surface, teal-green water with warm golden highlights, fine floating particles. Camera level with the boulder, wide shot, natural documentary look. No people, no text, no logos.Image B — whitened boulderGemini image · edit of A
Edit this image. Keep the exact same camera angle, boulder shape, framing and lighting. Remove all the kelp and all the fish. The boulder is now bare and covered with a chalky white crust of coralline algae, with a few dark spiny sea urchins on it. The water looks emptier and slightly grayer. Photorealistic. No text.Image C — boulder with a seeded ropeGemini image · edit of B
Edit this image. Keep everything exactly the same, including the sea urchins. Add a thick rope tied tightly around the middle of the boulder, lying flat against the rock surface (not arching above it), with small young brown kelp seedlings growing along the rope. Photorealistic. No people, no text.Clip 1 — the barren spreadsVeo in the Gemini app · A as first frame
Use this image as the first frame. Vertical 9:16, 8 seconds. Slow, steady push-in toward the boulder. In a smooth time-lapse, the kelp fronds wither and disappear, the rockfish swim away, and the bare rock gradually turns chalky white as coralline algae spreads over it; dark sea urchins appear. Ends on a white, empty boulder. Photorealistic underwater documentary, natural light. No people, no text. Sound: soft underwater ambience fading to a low, empty hum.Clip 2 — replantingVeo in the Gemini app · B as first frame
Use this image as the first frame. Vertical 9:16, 8 seconds. Same camera angle, almost still. A diver's gloved hands enter from the right edge and carefully tie a short rope with young brown kelp seedlings onto the white boulder, then slowly pull back out of frame. Only hands and forearms are visible, no face. Photorealistic underwater documentary, soft sunbeams. No text. Sound: underwater ambience and gentle regulator bubbles.Clip 3 — the forest returnsVeo in the Gemini app · C as first frame
Use this image as the first frame. Vertical 9:16, 8 seconds. Smooth time-lapse: the young kelp on the rope grows taller and spreads over the whole boulder, the white crust fades back to dark rock, and small rockfish return and swim between the swaying fronds. Slow pull-back to a wide shot with the boulder in the lower center of the frame, warm sunbeams, teal-green water. Photorealistic underwater documentary. No people, no text. Sound: underwater ambience growing brighter and fuller.Narration direction and scriptGoogle AI Studio speech · Gemini 3.8 Flash TTS · Charon
Read aloud in Korean, in a calm, warm nature-documentary narrator voice. Unhurried, with a clear pause (about one second) between each line:
바다에도 사막이 생깁니다.
해조류가 사라진 바위를 하얀 석회조류가 덮는 것, 갯녹음입니다.
수온 상승과 성게의 과도한 증가가 원인으로 꼽힙니다.
그래서 사람들이 해조류를 다시 심습니다.
바다숲 열일곱 곳에서, 해조류 무게는 백삼십팔 퍼센트 늘었습니다.
바다숲은, 다시 자랍니다.Keeping the same boulder
- Edited B and C in the same chat that made image A, so the boulder and framing stay put
- Each image became the first frame of a Veo clip, so all three shots start from the same place
- In the last 1.2 s clip 3 melts into image A, so the video loops back without a cut
Figures and sources
- What a sea barren is and its causes (warming water, too many urchins) — YTN, 2026-08-30
- “17 sea forests completed in the last four years … seaweed weight up 138%” — same report, Minister of Oceans and Fisheries
- Numbers spelled out in Korean in the script so the TTS reads them right
Outside sources
- Font: Pretendard (SIL Open Font License 1.1)
- Sound: Veo’s underwater ambience plus AI Studio TTS narration, no stock audio
- No stock footage, photos, logos or real people (the diver’s hands are AI-generated)