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Canadian Aquaculture Styrofoam®-Encasement

Final Report
Bee Islets Growers Corporation
AIMAP 2012-P02

Executive Summary

Styrofoam® has long been used by the Aquaculture Industry to provide lightweight inexpensive flotation. Unfortunately the sun and the brine have been breaking it down into microscopic inorganic particles dispersed by wind and tides. Studies by Captain Charles Moore and the Algalita Foundation found that even in the middle of the Pacific Ocean, plastic nodules have been found to outweigh plankton by a ratio of six to one. Unending amounts of plastic pellets wash onto beaches worldwide, one beach in New Zealand was found to contain over 100,000 pellets per square meter - all of which are contaminating marine life and the human food chain.

Bee Islets Growers (BIG) has a vested interest in solving the industry's Styrofoam® issue. We are located inside scenic Gorge Harbour on Cortes Island BC. The words "Cortes Island" and "quality shellfish" are synonymous in many parts of the world. We are proud of our ability to grow and harvest a superior product from the pristine waters of British Columbia's north-central coast. 

In June of 2012, with the assistance of an AIMAP grant from the DFO, we began an innovative project called Canadian-Aquaculture-Styrofoam®-Encasement (CASE) to encase 300 existing Styrofoam® floats used for 50 rafts containing mussel, scallop, and oysters thereby eliminating float disintegration, protecting water and shellfish quality. 

By encapsulating existing Styrofoam® floats in a shell of rugged seaworthy plastic, refurbishing them via the CASE technique can extend the life of the floats for many more decades of use, plus end the breakdown of foam nodules into the water column and onto the beaches. 

The exciting aspect of this project is the affordability for operations of all sizes: we found that the CASE technique costs between 40% to 60% less (dependent on the condition of the old floats and how much coating it takes) rather than buying new pre-coated floats. 

In addition to these economic advantages, this project achieved both of Bee Islets' Environmental & Social Goals in the following ways: reduced Styrofoam® in water, reduced aquaculture debris, more affordable aquaculture operations, more aquaculture jobs, and improved tourism experience with cleaner BC beaches.

As a result, the DFO's Aquaculture Innovation and Market Access Program (AIMAP) investment combined with our industry investment has resulted in the development of an innovative solution, increasing environmental performance of existing shellfish rafts and providing aquaculture waste control. 

Adoption of this technique by BC shellfish growers will make aquaculture more sustainable by protecting the health of Canada's aquatic ecosystems.


Bee Islets Growers (BIG) CASE project was designed to address the following problem. Styrofoam® (which is expanded polystyrene, also known as EPS) was created by Dow Chemicals in the 1970′s as a lightweight insulation device. Coffee cups, food containers, and construction products were all made out of Styrofoam®. Containing approximately 95% air, it also provides very good floatation properties, and was quickly adopted for use in the aquaculture industry. Unfortunately Styrofoam® breaks down easily and releases chemicals when it gets wet, thus contaminating the water supply and the marine food chain.

“By 1986, styrene was found in 100 percent of all samples of human fat tissue taken as part of a U.S. Environmental Protection Agency (EPA) Human Tissue Survey. Researchers found that Styrofoam® cups lose weight when in use, meaning that styrene is oozing into the foods and drinks we consume. It then ends up stored in our fatty tissue, where it can build up to levels that can cause fatigue, nervousness, difficulty sleeping, blood abnormalities, and even carcinogenic effects.” (source:

The rationale for the CASE project was to meet the following two AIMAP objectives with a new application of technology focused upon: Increasing environmental performance and Waste control, reduction or mitigation.

The Bee Islets Growers Corporation initiated this project with a commitment from our 17 members to contribute cash, plus in-kind time in the form of volunteer labour towards the project. In addition, we received a cash discount on a bulk order of materials from Polysource our coating supplier, and free shipping from West Coast Spray Foam in Campbell River who applied the new technology coating, creating a 40 mil (approximately half a centimeter) thick protective hard shell around our existing Styrofoam® floats. 

The CASE coating we selected after considering various options, is a product called Hydrothane 90A (HT-90A). It is currently being used in the automotive industry for truck bed liners and providing chemical resistant membranes for concrete and steel tanks. The coating is gasoline and chemically resistant, it is an aromatic protective coating that adheres to all substrates, it can be built up to any thickness, and is flexible in low temperatures in addition to being abrasion resistant. It provides a waterproof layer that has NO Volatile Organic Compounds (VOC), which means there are no gases emitted once the coating solidifies (as per the technical specifications the coating is dry to the touch in 10-15 seconds. This coating is also approved for food contact. This means it will protect air quality, water quality, shellfish quality, and providing a new industrial use of this coating for aquaculture applications.

As of February 2013, the BIG CASE pilot project protects 230 floats (also called billets), which currently support 40 rafts (approximately one third) of BIG's total of 150 aquaculture rafts used for oysters, mussels, and scallops.

Bee Islets Growers are situated 100 miles north of Vancouver, between Vancouver Island and the mainland coast. The cool, pristine waters of the Salish Sea that lap at the shores of Cortes Island are free of pollution from over-development. Nutrient-rich tidal flows wash our sheltered bays and beaches creating ideal growing conditions for some of the best shellfish to be found anywhere. And, for the most part, Cortes Island shellfish farms are small family operations that take pride in their ability to grow quality products.

Bee Islets Growers are contributing to DFO strategic outcomes of sustainable aquaculture and healthy productive aquatic ecosystems. 

Specifically, the CASE project: 

The BIG Canadian-Aquaculture-Styrofoam®-Encasement (CASE) project has proven the innovative use of this affordable coating when applied to Styrofoam® shellfish floats. This enables industry adoption of new and improved use of technology, processes and products, with direct commercial application.

Option Identification & Analysis:

There is much scientific evidence that Styrofoam® is not healthy for the marine environment, ideally the aquaculture industry would like to move away from its use. However, to date there has been no affordable option to replace it. The only commercially available alternative is to replace them with brand new molded plastic foam-filled floats that have sufficient bouyancy to carry a fully loaded raft. Unfortunately the cost is beyond what most small independent producers can afford:

Option 1/ New Molded Plastic (foam-filled) Float, average cost:

$398.65 per float x 6 floats/raft =  $2,392 per RAFT

 + tax + installation + labour + shipping to do the switch

(Above 2011 quote based on Plastic Plus in Campbell River.)

In addition, any move to replace Styrofoam® floation with the above Option 1 approach, has the unfortunate side-effect of simply moving all the existing foam from floats to land-fills. The problem has only been moved to another location, which is why the CASE project is proposing to encase existing Styrofoam® floats by refurbishing them in a shell of rugged seaworthy plastic. Option 2 will extend the floats useful life, at a fraction of the cost to replace them, and eliminate the break-down of Styrofoam® into the marine environment by effectively “recycling” them.

Option 2/ CASE existing floats, ACTUAL TO-DATE as of DEC 31/12 costs:

(Based upon $29,000 cash spent on the first 20 rafts x 6 floats each = 120 floats completed as of Dec 31/2012 at an average cash cost of $241.66 each.

$241.66 per float x 6 floats/raft = $1449.96 per RAFT

Including tax, installation, labour, and shipping to do the switch with some volunteer labour and donated administrative time to oversee project.

As a result of this analysis, option 2 was selected because it delivers a solution that costs approximately 40% less than Option 1 while offering similar benefits. 

Work Plan:

The following step-by-step activities took place for each of the 50 rafts. Harvest shellfish off raft; then lift raft deck using rental HIAB crane on barge; remove floats and leave wooden rafts still anchored in place with temporary spare floatation for buoyancy; take old floats by boat to dock; load old floats into truck; take floats in groups of 50 for drying to heated warehouse with de-humidifier to speed drying time; when dry then the team from West Coast Spray Foam traveled to Cortes Island where they did the hard shell coating inside a local warehouse (Note that floats can also be transported to/from Campbell River warehouse for drying, storage, and spraying); return refurbished floats to shellfish aquaculture lease from warehouse by truck; load into boats at dock; deliver back to rafts; lift raft deck with HIAB crane barge and replace floats; and restring shellfish spat/cages/lines. 

Technical Challenges:

No major technical issues were encountered, this is mainly a logistics exercise coordinating volunteers, shipping, handling in the midst of an active aquaculture lease. 

Technical expertise for applying the new HT-90A coating to the old Styrofoam® floats was supplied by the West Coast Spray Foam team. They were our sole-source supplier because they are the only certified CUFCA contractor on the BC approved list for Northern Vancouver Island:

Recommendations & Tips:

A/ Coating Thickness Tips: Our initial plan was to apply40 mil (approximately half a millimeter) thick protective hard shell around our existing Styrofoam® floats as per the manufacturer's recommendations. We found the 40 mil thickness ideal for newer smoother floats; however, we found on the most worn & rough surfaces of the oldest floats – a thicker coating was required up to 80 mil (almost 1 millimeter thick) for full waterproof coverage. Note that in the case of Bee Islets, with a lot of older rough floats, where we needed to use 80 mil CASE coating, this reduced our cost savings to 40% (less than the option of buying new hard shelled floats). On newer smoother floats, that only require the 40-mil coating, we believe that costs savings of 60% are achievable by CASING existing floats rather than buying new hard shelled floats.

B/ Hot-wire Trimming Tips: Old rough Styrofoam® floats can sometimes be trimmed using a hot-wire to remove pieces that are too damaged. During the Bee Islets project, we tried using the CASE coating on some of the oldest roughest floats, which had the most damage, but this proved very costly because we had to apply an extremely thick CASE coating (more than 80 mils). We found from experience, that the best options is to use a hotwire to trim off the worst of the rough edges, making the surface smooth before spraying a 40 mil CASE coating. In some cases old floats with too much wear & tear damage, it was decided to replace them with a brand new float that was immediately CASED before being installed on the raft.

C/ Equipment & Facility Tips: Recommended preparation for a CASE project includes 2 Trucks for shipping floats to/from warehouse, 1 or 2 boats for towing floats, public dock space at wharf for loading/unloading, warehouse fordrying & coating floats, 1 HIAB crane barge, and huge tarp i.e. 30 square feet minimum to contain any overspray, which simplifies cleanup after CASE coating is applied.

D/ Quantity Tips: Recommended number of individual floats to spray in a “batch” is a minimum of 20 and a maximum of 80. West Coast Spray Foam can complete approximately 40 floats per day with a standard crew of 3 persons.

E/ Coating Coverage: Our experience was that it takes 3 sets of HT-90A (it comes as 2-separate barrels of coating that are mixed prior to spraying) to cover 150 older rough Styrofoam® floats supporting approximately 25 rafts. It is possible that 2 sets of HT-90A would be sufficient for coating 150 new smooth floats.

F/ Project Duration: Approximately one third (40 rafts containing 230 Styrofoam® billet floats) were refurbished with hard-shelled CASE on the BIG lease as of February 2013. The project is completed over a 9-month (July thru February) period time. The ideal time to do a CASE project is in phases that coincide with the annual harvest cycle as part of annual float/raft maintenance ( i.e., winter and spring).

Going Forward:

The grower usually builds shellfish rafts; most have been constructed from wooden decks on top of flotation devices. Rafts must be able to support the weight of planned shellfish capacity at harvest with adequate margins for safety and unplanned events such as postponed harvests. Continued growth of shellfish, combined with fouling has caused rafts to sink, representing heavy losses to growers. Block foam is the standard flotation material either 18″x 24″ or 24″x 24″ in 8′ or 24′ lengths.

Styrofoam® floats are usually wrapped in “bulldog” black plastic sheets, held in place with duct tape. Unfortunately with stormy weather and chafe, the plastic sheeting is easily damaged, punctured, and can break loose releasing foam pellets. Raft users usually clean the fouling off their foam floats at harvest time, which must be done either by a diver or the floatation must be removed, cleaned, and then replaced. All of which adds to the wear and tear on existing Styrofoam® floats.

Another opportunity for going forward is whenever new Styrofoam® floats are being purchased (to build a new raft, or to replace badly worn and damaged floats) – then have those new floats CASED before they are installed into the marine environment. One major supplier of uncoated billet floats on Vancouver Island has already expressed an interest in using this spraying technique.


We the 17 members of Bee Islets Growers, acquired 150 Styrofoam® rafts when we purchased the aquaculture lease from Redonda Seafarms in 1997. This company was closing down operations, which would have resulted in the loss of 200 local jobs.  Our purpose was to protect island jobs so that members of our remote community could continue to make a living from the ocean. 

Over the past 15 years we have done regular maintenance on our rafts, keeping the lease in good repair and we are excited to have made a breakthrough for recycling our old Styrofoam® floats by initiating the CASE project. The main goal achieved by the CASE project was improved waste management from less Styrofoam® nodules being released into the water column and food chain. In conclusion, we have found that the HT-90A casing provides the following results:

Economic Measures: 40% cost savings versus purchasing new hard-shelled floats, reduced maintenance for easier cleaning & de-fouling in future, both of which provide improved economic viability for small and large aquaculture operations.

Environmental Measures: improved water quality, based upon Performance Measurement Methodology and Lab Test Results. Lab results confirm that there are almost un-detectible levels (less than 0.0005 mg/L) of toxins leaching into the water column from the CASE floats. PH Testing of salt water from 4 different sites within Gorge Harbour itself plus outside in the open ocean at Stange's Bay on the west side of the island, confirm that PH remains consistent at 7.70 which is normal for a coastal salt water environment.

Social Measures: direct and indirect jobs saved by making aquaculture operations more cost effective, jobs created during the CASE conversion, positive local community impacts on beach cleanliness for tourism, and positive relationships with upland owners.

According to our local shellfish website there are 30+ growers located in the Cortes Island area. When the Klahoose First Nation adds 90 more rafts into the Gorge, we will reach our capped maximum carrying capacity of 557 rafts as per the Aquaculture Plan for the area. 

BC Shellfish Association has 160 members. We estimate that they have approximately 5000 rafts in the Pacific region that could benefit from using this technology to eliminate Styrofoam® up and down the west coast of Canada. 

In conclusion, we declare the Canadian-Aquaculture-Styrofoam®-Encasement (CASE) Project to be successful. On-going toxicity and PH tests will be done during 2013, additional photographs & durability results will be submitted to the DFO in one year as an update about the longer term stability of the CASE coating.

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