The Problem with Ocean Fouling/succession-

Posted on Saturday,December 5, 2020 by Garry Fletcher

When installing equipment underwater in a high current zone where the water is laden with nutrients from upwelling as it is at Race Rocks, it becomes obvious very soon that any new substrate placed underwater becomes an instant habitat for the settlement of many invertebrate and algal species. For this page I have brought together different examples from the work we did over the years at Race Rocks. . It should be noted that the word “fouling”is a rather perjorative term, seen from the point of view of a natural process interfering with human wishes. However, it simply represents ecological succession, a perfectly natural event in a highly productive environment, and too bad that it inconvieniences us!

This video from 2001 shows what the condition of the growth of life was on a sensor bar that we installed in water at 8 meters depth just off the Jetty at Race Rocks: The sensors were for monitoring Oxygen, salinity, ph, and turbidity. Without constant attention by our divers getting accurate data from sensors like these over a long term would not be possible. This video was taken after three months in the water .

In September of 2011 we ended the experimental Tidal energy Project at Race Rocks. This file has images of the turbine covered in fouling organisms when it was raised for the final time:

Examination of the tidal energy installation after being installed for 6 months

The engineers concern for the kind of materials they were going to use in constructing the turbine were addressed by having the Pearson College Divers install a series of succession plates that could be monitored for growth over several months.

Video inspection done by Chris Blondeau on turbine inspection before removal, June, 2011 The growth of Invertebrtates is quite incredible. Since ther is little opportunity for predators like starfish to browse on this column, growth is unimpeded. This led us to decid that the i meter wide .. 15 metre high column should remain in place after the turbine was removed as such it has turned out to be such a unique habitat.

Another example of succession is evident in the way that kelp attaches to a solid substrate and can end up in modifying the environment. In this case moving rocks from ocean to shore.

Underwater Materials Performance Testing-Succession/Fouling

Posted on Monday,June 9, 2008 by Garry Fletcher

In December of 2007,The Pearson College Divers installed a set of junction boxes as part of a materials testing experiment for the tidal energy project

*Procedure 1*	*Dec 7, 2007– Purpose: To test performance and resistance to fouling of PVC junction boxes and sealant compounds*
*Procedure 2*	*Jan 10, 2008– Purpose: to test resistance to fouling and corrosion of different alloys of Stainless Steel as well as various types of fasteners.*
*Procedure 3*	*Purpose: to protect submarine cables from chafing on sharp rocky edges*
*Procedure 4*	*Purpose: To prevent corrosion of steel Ibeam supporting and holding power and control cables through intertidal zone.*
*Procedure 5*	*Purpose: To provide ballast to steel Ibeam carrying power cables in intertidal zone preventing movement during heavy surge.*

: February 23, 2008e

: PVC boxes side

: PVC boxes top view

: Stainless steel alloys on block- no light

: Stainless steel alloys- illuminated

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.

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.

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Underwater testing of materials to be used in the Tidal current energy project

Posted on Friday,July 8, 2005 by Garry Fletcher

Below: Installation of the Fouling Plates by Chris Blondeau and Pearson College Diving Students in July, 2005. This video shows the installation process for the research project carried out to determine which surfaces discouraged growth in the waters at Race Rocks.

In the spring of 2005, a set of plates made up of 5 different materials and coatings was deployed in the centre of the main channel, straight out from the docks at Race Rocks. This is the result on Nov 2005 results- (qualitative)

: This is one of the replicates, removed for scraped samples on Nov. 9,2005. Plate numbers are on linked enlargement. The make up of the coatings will be supplied separately.

: Plate1

: Plate1

: Filamentous algae and grazed diatoms on plate 1. microscopic images were taken at 100X

: Plate2

: Plate2

: A mix of diatoms and red algae on Plate 2. The small black dot is a baby chiton which is one of many small invertebrates that graze diatoms

: Plate3

: Plate 3

: Plate 4

: Plate 4

: Plate5

: Plate 5

: Red filamentous algae growing among diatoms on plate 5.

ONE YEAR LATER June 09, 2006

: This is one set of the replicates, removed one year later on June 09, 2006..

: Red filamentous algae growing on the aluminum surface at the base of the stand.

: Severe pitting and build up of white crusty mounds of Aluminum oxide on the stand.

: Early succession of Lithothamnion and other algaes

: Plastic bolts

: Stainles steel bolts

: Plate 1 Stainless Steel, After the year of submersion, both this stainless plate and the titanium plate have minimum fouling.

: Stainless Steel. Grazing by small snails and chitons is evident by tracks on the plates.

: Plate 2 Titanium

: Plate 4 Titanium

: Plate 3: a plastic coating

: Plate 3 Plastic

: Plate 3-Plastic

: Plate 4 ICI Coating

: Plate4 ICI

: Plate5 Interguard coating

: Si Coat on the white side

: Plate 5 Interguard coating: Showing 1cm barnacle growing on base after coating is eroded. Interguard coating.

: Plate 5 Interguard

Fouling on Sensor bar

Posted on Thursday,March 15, 2001 by Garry Fletcher

Already by March, the growth of algae on the environmental sensors and the aluminum bar has been prolific. Regular dives have to be made to keep the sensors free of algae. The predominant Genus here is Laminaria.

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Race Rocks Ecological Reserve-

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Tag Archives: fouling