Integrated Tidal Current Demonstration Project at:

Race Rocks, British Columbia, Canada

Gouri Bhuyan, Powertech Labs Inc

Glen Darou – Clean Current Power Systems Inc.

Christian Blondeau, Lester B. Pearson College

Mark Edmunds,- Xantrex Technology

Max Larson- Triton Consulting

Gary Bouwman- AMEC

European Commission Coordinated Action on Ocean Energy (CA-OE)

Workshop on Environmental, Economics, Development Policy, and Promotion of

Opportunities, Copenhagen, Denmark 26-27 April 2007

6 month fouling records

Posted on Sunday,April 15, 2007 by Garry Fletcher

A week before raising the turbine in April 2007, the outer Nereocystis growth was removed by the Pearson College Divers. Since the top of the turbine is in a water depth averaging 10 metres it is shallow enough for the brown Macroalgae to take foothold and within a few weeks it would have reached the surface. This algae can atttach to a solid substrate within the top 12 metres of water at Race Rocks.

: In April, 2007, the turbine was pulled up for inspection and possible refit of bearings.

: Growth of this macroalgae starts in March and had already reached several metres in height

: The kelp holdfasts were attached to the outer cowling on irregularities on the surface.

: A felt-like growth of algae and hydroids has already covered the flange below the turbine.

: It gave us an opportunity to examine the distribution of the species and level of growth of the fouling organisms.

: It also provided evidence of which materials are best in repelling growth

: . Many areas were completely covered with encrustations of diatoms or hydroids. This is one of the blades of the turbine.

: A scrape on the blade shows the thickness of the diatoms.

: These hydroids are likely the species Plumularia lagenifera

: All hydroids were of the order Leptothecatae with no Anthoathecatae observable.

: As in other instances we have experienced when there was long term deployment of instruments at Race Rocks, colonies of skeleton shrimp, shown here, cover some surfaces, and cling to the hydroid colonies.

: Skeleton shrimp (Caprella laeviuscula) hang from their rear appendages in this enlarged photo of a bolt head.

: Various species of red and brown algae ( Laminaria sp ) starting to grow, with more skeleton shrimp scattered throughout

: The turbine was too deep for the growth of green algae. These brown algae, Desmarestia sp. were attached to a blade. They appear green since they have been drying out for some time and the acids in the lamina tend to speed deterioration of pigment

: A few small bull kelp, (Nereocystis leutkeana) have anchored to the structure. This could provide problems for future entanglement if these kelp thrive on the structure.

: A mixed population of some red and brown algaes.

: In the areas underneath the structure where the cables attach, a good amount of protection is available thus encouraging the attachment of the fouling species.

: A 1 cm diameter barnacle has attached to this part of the structure. Note also skeleton shrimp.

: It demonstrated the problem of having any small crevice or location where organisms could establish a foothold on the structure.

: Hydroid clump on the underside of the cowling.

: Colonial Tunicates, the gelatinous yellow mass along one seam, have started to colonize in this area.

: Diatoms coat many of the exposed surfaces. They are usually the precursor to futire invertebrate growth..

Thanks to Russell Stothers of Clean Current and the Pearson College Divers for these images.

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Posted on Sunday,April 15, 2007 by Garry Fletcher

6-Month Fouling Records on Tidal Energy Turbine

Posted on Thursday,April 5, 2007 by Garry Fletcher

A week before raising the turbine in April 2007, the outer Nereocystis, or Bull kelp growth was removed by the Pearson College Divers. Since the top of the turbine is in a water depth averaging 10 metres it is shallow enough for the brown Macroalgae to take foothold and within a few weeks it would have reached the surface. This algae can atttach to a solid substrate within the top 12 metres of water at Race Rocks.

: Unicode

: The kelp holdfasts were attached to the outer cowling on irregularities on the surface.Unicode

: A felt-like growth of algae and hydroids has already covered the flange below the turbine.

: It gave us an opportunity to examine the distribution of the species and level of growth of the fouling organisms.

: In April, 2007, the turbine was pulled up for inspection and possible refit of bearings.

: It also provided evidence of which materials are best in repelling growth

: Many areas were completely covered with encrustations of diatoms or hydroids. This is one of the blades of the turbine.

: encrustations of diatoms or hydroids. This is one of the blades of the turbine. A scrape on the blade shows the thickness of the diatoms

: These hydroids are likely the species Plumularia lagenifera

: All hydroids were of the order Leptothecatae with no Anthoathecatae observable.

: As in other instances we have experienced when there was long term deployment of instruments at Race Rocks, colonies of skeleton shrimp, shown here, cover some surfaces, and cling to the hydroid colonies.

: deployment of instruments at Race Rocks, colonies of skeleton shrimp, shown here, cover some surfaces, and cling to the hydroid colonies. Skeleton shrimp (Caprella laeviuscula) hang from their rear appendages in this enlarged photo of a bolt head.

: Various species of red and brown algae ( Laminaria sp ) starting to grow, with more skeleton shrimp scattered throughout

: The turbine was too deep for the growth of green algae. These brown algae, Desmarestia sp. were attached to a blade. They appear green since they have been drying out for some time and the acids in the lamina tend to speed deterioration of pigments.

: .A few small bull kelp, (Nereocystis leutkeana) have anchored to the structure. This could provide problems for future entanglement if these kelp thrive on the structure.

: A mixed population of some red and brown algaes.

: In the areas underneath the structure where the cables attach, a good amount of protection is available thus encouraging the attachment of the fouling species.

: A 1 cm diameter barnacle has attached to this part of the structure. Note also skeleton shrimp.

: A 1 cm diameter barnacle has attached to this part of the structure. Note also skeleton shrimp. It demonstrated the problem of having any small crevice or location where organisms could establish a foothold on the structure.

: Hydroid clump on the underside of the cowling.

: Colonial Tunicates, the gelatinous yellow mass along one seam, have started to colonize in this area.

: Diatoms coat many of the exposed surfaces. They are usually the precursor to futire invertebrate growth.

asasa

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Race Rocks Ecological Reserve-

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Monthly Archives: April 2007

Integrated Tidal Current Demonstration Project at Race Rocks

6 month fouling records

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6-Month Fouling Records on Tidal Energy Turbine