1. Aquaculture: sea Urchins- The spiny hedgehog of the sea
Marlee Hayes

2. Species Green Sea Urchin Purple Sea Urchin
Strongylocentrotus droebachiensis
Purple Sea Urchin
Strongylocentrotus purpuratu
Red Sea Urchin
Mesocentrotus franciscanus
The variegated sea urchin
Lytechinus variegatus
Over fishing has negatively impacted sea urchin populations.
Aquaculture, especially inland, is just beginning.
Sea Urchins have great potential for sustainable aquaculture.
High fecundity
Quick growth rate
Hardiness
The consumable part of the Sea Urchin is the Roe or Uni.

3. Sea Urchin Anatomy

4. Economical/Ecological Importance
Valuable food item in Japan, France, United States, China and other areas.
California exports a large amount of sea urchin to Japan.
Sea Urchins are grazers.
Possible keystone species.
Urchins can decimate kelp beds.
Kelp provides a natural product, algin.
Sea otters, sea stars, wolf eels and triggerfish are predators of urchins
Model organism for scientific research
Market Prices
Catalina Offshore Products, California, AL
1 pound live wild whole red or black sea urchin $13.99
California Gold Uni 80 grams $19.99
California Premium Uni 80 grams $11.99
Santa Barbra Fish Market
$9.95 each Fresh caught by divers
Japan
Approximately $ 8.20-$40.98 per tray (imported from California)
Seasonality
the price of Chilean fresh roe almost triples off-season: from around $12 per kilo roe to around $36 per kilo of roe. 

5. Life Cycle Diecous Broadcast Spawners External Fertilization
Seasonal Conditions
Photoperiod,
Temperature
Salinity
Echinopluteus Larvae(months) → Metamorphosis (~30 min) → Adult (max size ~5years)

6. Reproduction in Captivity
Spawning can be induced by acetylcholine/potassium chloride injection
Eggs or sperm can be collected by placing urchin upside down over beak and gametes will be released from the gonodapore
Sperm needs to be diluted with saltwater to be activated and prevent multiple fertilizations
Temperature changes can also induce spawning
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7. Production Methods Offshore sea farming Stock enhancement
Cages where urchins are raised in open ocean
Stock enhancement
Hatching larvae and growing until small juveniles, then release into wild until harvest

8. Production Methods Land based raceways/Tanks Small Scale Successes UAB
Texas A&M
Gonad enhancement
Seasonality issue remedied

9. Sea Urchin Platter System
Ireland UCC
Stackable, layered

10. Feeding Macroalage (Larvae need single celled algae)
Juveniles (phytoplankton/diatoms)
Seaweed (Kelp)
High-protein, sinking, pelleted food
No commercially-available feed for large scale
Standardized optimal feed is needed

11. Feeding
Research to produce ideal feed to meet nutrition requirements and produce the best marketable product
Enhancement of Gonad
Size
Color
Texture
Taste

12. Feeding

13. Water chemistry and Environmental Conditions
Temperature ° Celsius
Synthetic Sea Water
Salinity 35 mg/L
Recirculating System with mechanical, chemical, and biological filters, UV sterilization and aeration
Feces must be manually siphoned
pH of 7.5
Partial water change 1-3 times weekly
Oxygen Levels and Light Cycles can affect growth and development

14. Advantages High Fecundity Hardy Can be cultured densely
Rapid growth rate
Gonad development can be enhanced
Year round production
Potential for poly culture
Protection from predation

15. Disadvantages Standardized feed Can’t see the product
Land based Tanks/Raceways
Mass spawning event
Larval care/stages
Intensive
Manually siphon system (dense feces)
Eat anything including equipment
Sea based Cages/Ranches
Environmental Impacts
Unpredictable
Pollution
Nutrification
Physical Damage
Burying/ Crushing

16. Sea Urchins are Cool!
Certain species of sea urchins (such as flower urchin) have spikes filled with venom. The flower urchin is extremely venomous and has caused rare fatalities. Toxopneustes pileolus
Sea urchin has special type of mouth, called "Aristotle's lantern". Mouth is equipped with five sharp teeth that are able to drill a hole in the rock. Using its Aristotle’s lantern, the purple sea urchin is capable of biting pieces out of the rock, and the spines slowly erode away at the surface, creating a small pit in which the urchin may remain for long periods of time.
Red sea urchin may have the longest lifespan on Earth. It can potential survive up to 200 years in the wild. In other words, an individual red sea urchin that hatched on the day in 1805 that Lewis and Clark arrived in Oregon may still be thriving – and even breeding.

17. Acknowledgements Dr. Stephen Watts Dr. Hugh Hammer Dr. Mickie Powell
Laura Heflin
Watt’s Lab
SRAC
FAO
Sea Urchins: Biology and Ecology by
John M Lawrence