PRE2015 4 Groep5

Seaweed farming

Group members

• Aniceta, N.M.F (0876672)
• Boelsums, N.M (0964376)
• Brandts, A (0895917)
• Haenen, S.R.R (0889428)
• Kuijpers, J.J.L (0838617)

Preliminary brainstorm

Benefits

• Enhances natural water ecosystem
  • Various types combats a monoculture
• Cheaper and sustainable food supply
  • For livestock (veevoer)
    • Decreases the need for deforestation
  • For humans
• Descreases the magnitude of waves
• Reduces the CO2/ increases the O2 in the water
• Zee is better than in a basin
  • Natural nutrition supply

Creating an automated robotic seaweed farm would make seaweed farming cheaper, bigger and safer, which would magnify the following benefits of seaweed farming:

-Farming in the seas is a sustainable alternative to farming on land. It does not require cultivation of the area, fertilizing with phosphorus or water.

-Seaweed can be used as livestock feed, which offers an alternative to the soy-based livestock feed. Soy farming is currently the main cause of deforestation and damages the climate. Seaweed based livestock feed would be a sustainable alternative to that.

-Seaweed can be consumed by humans. With the growing world population, seaweed can become an important factor in feeding the planet and preventing famines.

-Seaweed farms that are located nearby the shore break waves and thus increase the safety of the people living at the coasts.

There are currently several "Aquatic dead zones", there is no life to be found in these areas. No plants, plankton or fish. When a seaweed farm is introduced to such an area, it will have a positive impact on the ecosystem. The plants will generate oxygen and attrackt plankton, the plankton will attrackt fish. Image: Aquatic dead zones [1]

The seaweed farm would be collecting data about its surroundings, this data could be used to monitor pollution and the effects of climate change on the oceans. All this data could be used to protect the seas.

Proposals

• Floating robot
  • Solar panel
  • Lowering (anker-style) cutter
  • Hard to position,
    • Drifts
    • “Dijnst[dutch]”
• Rover robot
  • Stable polypoid (crab-style)
  • Hard to cut above his head
• Swimming robot
  • May become struck between the weed
  • Perfect mobility and can cut everywhere

Combination of multiple robot’s for every seafruit a suitable robot.

Mariculture

Representation of a sea farm

Environmental effects

There are several positive and negative aspects regarding seaweed farms. These can be classified in two categories:

• Physical effects: effects on water movement, physical structure of terrestrial and aquatic habitats and aesthetic impacts, etc.
• Ecological effects: water quality, primary and secondary productivity and native fisheries, etc.

These effects tend to be more extreme when farming is more intensive.

• Positive aspects of seaweed farms:
  • Income, employment and foreign exchange (import/export).
  • Pond-farms can make use of otherwise unfertile and underutilised land.
  • Large-scale farms influence coastal water movement, causing enhanced sedimentation and better protection of the coastal areas from erosion.
  • Introduction of seaweed culture rafts, ropes, anchors, etc. can increase the surface area of substrate, which may enhance production of other marine organisms in a similar way to what artificial reefs have been shown to do.
  • Seaweed culture mostly relies on a natural nutrient supply.
  • Seaweed farms offer shelter for other animals, increasing the biodiversity.
  • The area below seaweed farms can be used for invertebrate farming such as sea cucumbers.
  • Seaweed farms may be placed further offshore to better utilize offshore resources.

• Negative aspects of seaweed farms:
  • Conflicts with other users of the coastal zone.
  • Concerns over potential environmental impacts.
  • Large surface area required for viable seaweed culture.
  • Site preparation may involve removal of native animals, plants and destroying the natural environment (e.g. removing rocks) which may damage the local ecosystem.
  • Routine management can result in damage through trampling and accidental damage of the local ecosystem.
  • Physical shading of an area can occur. The effects of this have not been well-studied.
  • Due to the large surface area required, the visual impact can be a strong argument against seaweed farms, especially in coastal areas.
  • Intensive farming may require additional fertilization. This has yet unknown effects on the local ecological system.
  • Large farms and intensive farming may cause deceases to spread more rapidly, causing production loss and other negative effects for the ecology.
  • Intensive farming may reduce the nutrient levels of coastal waters, making it harder for other organisms to survive.

These effects should be considered when deploying seaweed farms to ensure sustainable aquaculture development.

Maritime robotics

Types of maritime robots

• The Sensor Buoy: floats at one spot on the surface. Mainly used for acquiring data.
• The Traveler: like the sensor buoy but moves using solar energy and wave energy(enhances wave movement to accelerate)
• Underwater Airplanes: like an airplane but with tiny wings, uses propellor. Can be tricky because it can not stop and it is unsure what lies ahead.
• Diving Box: often equipped with lots of sensors. Can move in any direction and float in midwater. However, it is very energy inefficient and can only be used for a short moemnt unless you attach a thether.
• Wild cards: weird, specialized and animal like robots.

Buoyancy Mass of water - mass of robot =

• + Robot will return to the surface.
• 0 Gravity free floating :D
• - Make sure the robot can drop some weight or it will never return.

Pressure: Increases 1 bar every 10 meters. Is important to consider in the design of the farm, up to what depth can it function?

Communication & orientation: Above water: iridium SBD

Under water: No wireless communication possible and lasers are very unreliable. So... we must use accoustic waves. It is the best thing we have but still not ideal because the speed of sound in water is slow. It is never really clear what is ahead, expecially when the robot is far away.

Practical tips It's not all that difficult and expensive! Make sure that you can retrieve your robot when it breaks. Keep it small. A lot can already be achieved with just a water proof container with a battery, a phone and some tampons to soak up leaked water. Drinking bottles can be used as as pressure proof containers in shallow waters. Syringes can be usedfor building engines to change the weight of the verhicle and regulate the buoyancy. Sonars are very expensive but "fishfinders" are a good alternative.

Responsibilty The laws of the sea are rather unclear, but here are some general rules:

• Dont go to nature protected areas.
• Beware of materials that can be harmful (also think about paint for example)
• Dont switch a robot between enviroments. It gives certain species a chance to invade an ecosystem whch can be harmful.
• Be aware that salt water is conductive. Especially when touching your circuits!

USE: stakeholders

• Why? => Provide a feasible feedback
• Users: Livestock farmers (veevoer), Foodbuyers
• Enterprise: Seafarmers
• Society: Reduces the shortage of food

Tasks

Logbook

Drive

USE Waterpret

Sources

• The Seas Will Save Us: How an Army of Ocean Farmers are Starting an Economic Revolution
• Handbook Seaweed Cultivation
• Maritime Robotics [32C3] https://www.youtube.com/watch?v=Iouy-vnBYA8
• World map of sea-depth; original image (slow commection), faster image.
• https://motherboard.vice.com/read/the-last-time-our-oceans-got-this-acidic-it-drove-earths-greatest-extinction[ https://motherboard.vice.com/read/the-last-time-our-oceans-got-this-acidic-it-drove-earths-greatest-extinction]
• Tools for the Design Revolution - IDRV Institute of Design Research Vienna
• ENVIRONMENTAL ASPECTS OF SEAWEED CULTURE
• Practical tips can be found in the documentation of the student teams that participated in these competitions: World Robotic Sailing Competition [2], EURathlon [3], RoboBoat & RoboSub [auvsifoundation.org], Singapore AUV competition [4], MATE ROV competition [5]