Why are the fish gasping at the surface? Students join Detective Kee at a fish farm to read an illustrated case, build key vocabulary and analyse dissolved oxygen data to work out what went wrong and what the farm should do next. Now includes a short editable PowerPoint for whole-class introduction.

At Bluewater Fish Farm, the fish are crowding at the surface and gasping. The farmer thinks they are hungry, but Kee notices cloudy water, algae, uneaten feed and an aerator that stopped overnight. A dissolved oxygen reading of just 2.1 mg/L raises even more questions. Students follow the evidence, interpret fictional water-quality data and recommend practical management actions.

The science is handled carefully: students separate observations, measurements and inferences, and the resource avoids treating any single dissolved oxygen value as a universal lethal limit.

What is included

• 5 printable A4 student pages: illustrated mystery, comprehension questions, prediction task, science word search, vocabulary challenge, data analysis and scientific conclusion
• 2-page answer key with acceptable alternative answers and solved word search
• 1-page teacher guide with objectives, timing, lesson flow, support, extension ideas and science notes
• 1-page terms of use
• Editable classroom-introduction PowerPoint (5 slides, 16:9): a quick whole-class lesson starter that sets the scene, introduces observation, measurement and inference, previews the ten key words and walks students through the mission. It is not a complete lesson and does not replace the printable pages. Teacher notes are included and no answers are shown.

Students will learn to

• Recognise common signs of oxygen stress in fish
• Explain why dissolved oxygen matters in aquatic environments
• Interpret water-quality observations and measurements
• Identify possible causes of reduced dissolved oxygen
• Recommend practical fish-farm management actions
• Separate observations, measurements and scientific inferences

Suitable for KS3 and KS4 Biology, environmental science and introductory aquaculture or land-based courses. Use it as a full 40–60 minute lesson, two shorter sessions, a cover lesson or homework. Materials: printed student pages and a projector for the optional slides. No laboratory equipment is required.

PowerPoint compatibility: the slides use Fredoka and Nunito Sans. Google Slides includes both fonts; PowerPoint or Keynote may substitute fonts if they are not installed.

All data are fictional and provided for classroom investigation. Kee’s Aquatic Science Mysteries is an illustrated case-based series from The Blissful Meow.

New to the series? Try the free Can You Spot the Sick Fish? observation challenge.

Continue with Case No. 002: The Mystery of the Invisible Poison.

A little science, a little detective work and one curious black cat! (=^ェ^=)