Shellfish and kelp growers are exploring alternatives, from kelp-based ropes and lobster bait bags to oyster cages made only of wood and metal.
Eric Oransky, founding partner of Maine Sea Farms, holds two beech oyster harvest bags.(Image credit: Ocean Farm Supply)
Erin Adams drives a refurbished lobster boat along the Harraseeket River to Casco Bay in southern Maine.As she passes the tiny Pound of Tea Island, where seagulls rest and a lone red Adirondack chair sits seductively by the water, her destination looms: a 10-acre oyster farm.It was a windy day, and the boat was bouncing up and down as Adams slowed down near a row of black oyster cages that floated and undulates in the waves.
Adams was harvesting today with her business partner, Eric Oranski, who worked fast, pulling up the oyster bags and tossing them onto the deck.The contents were dumped on a processing table, and they counted the oysters in groups of 10, occasionally placing two together to make sure they were still alive.Oransky then fed each group of 10 into a chute, and Adams packed them in mesh bags.Voila!They are ready to be delivered fresh from the boat.
However, these mesh bags are not made of ordinary polypropylene mesh.They are woven from ropes made from 100% European beech wood that is sustainably harvested from sparse forests certified by the Forest Stewardship Council or the Forest Certification Endorsement Scheme.They are the only plastic-free, biodegradable, home compostable oyster “harvest” bags on the market.
Maine Ocean Farms uses approximately 1,200 of these bags each season.The packaging is sold by Ocean Farms Supply, a business launched last year by Maine Ocean Farms with Adams at the helm.Although the company sells the material to growers and wholesale distributors of oysters, clams and mussels as far away as Mexico, California and Florida, most of its business is done locally.
Erin Adams and Eric Oransky count oysters.Adams is cutting a mesh bag from a roll of material in the background.(Image credit: Meg Wilcox)
The company’s bags have already replaced 14 miles of polypropylene mesh, according to Adams, who added: “We’re just getting started.”
Demand for non-plastic aquaculture equipment is growing, as evidenced by a crowd of a hundred or so seafood farmers at the Northeast Aquaculture Conference in April to hear Adams and others speak on the subject.
Aquaculture both contributes to and can be harmed by the ocean plastic crisis.Much of the industry’s equipment, from ropes to cages to flotation devices, is made of plastic.Over time, the plastic degrades, producing millimeter-sized particles that can be ingested by shellfish and finfish, potentially damaging their health.While harvest bags are only a fraction of the plastics used in typical oyster farms and in aquaculture more generally, replacing them with non-plastic biodegradable materials is a step in the right direction.
They are just one of a growing number of emerging innovations being developed by mariculture farmers (small-scale shellfish and kelp farmers) to reduce their contribution to the ocean’s plastic crisis.Other new products include kelp-based rope and lobster bait bags, oyster cages made only from wood and metal, and cotton and hemp systems for raising shellfish larvae.While innovators are still grappling with the longevity, durability and cost competitiveness of new materials, this trend shows some promise.
“If you can create a biodegradable material, or something gentler (for farmed shellfish), then you can improve the health of the product, the quality of the product and the environment at the same time. It’s a win-win situation,” said Ocean said Joel Baziuk, deputy director of the Conservation Society’s Global Ghost Gear Initiative.
Every year, 11 million tons of plastic enter the ocean, and an estimated 15 to 50 trillion pieces of plastic do not break down completely, but instead break down into smaller and smaller pieces.About 80 percent of plastic comes from terrestrial sources, including wastewater, said Britta Baechler, senior manager of marine plastics research at the Ocean Conservancy.
Baziuk told Civil Eats that aquaculture contributes to ocean plastic pollution in three main ways.Open water cages, wave action and extreme weather wear plastic ropes, nets and flotation systems that lose gear, and single-use plastics used in day-to-day operations can end up in the ocean, especially in areas with poor waste management systems.
“We know [aquaculture] is a major medium, we just don’t know how much because there isn’t enough research,” Baziuk said.
“People tell us they’ve been looking for 15 years” for a non-plastic packaging material, Oransky said.”Surprisingly, some sailors, carpenters and boat builders have discovered this.”
About 1,300 species of marine animals have been found to ingest marine plastic, Baechler said.Bivalve mollusks filter a lot of water to feed, which means microplastics can get trapped in their gills or guts and cause blockages.Studies have shown that microplastics reduce the ability of clams, oysters and mussels to produce energy; they impede muscle function and impair reproduction and growth.Hormone-disrupting chemicals leached from microplastics, such as bisphenols and phthalates, can also alter the behavior of marine animals or affect their ability to grow, reproduce and eat efficiently.
Little is known about the effects of consuming microfiber-contaminated shellfish in humans, and more research is needed.But that doesn’t mean people shouldn’t eat shellfish, Baechler said.”Our consumption of microplastics is not a good thing for human health, but it’s not a problem specific to shellfish or seafood. It’s all over the human food system.”
Energetic and energetic, Oransky grew up in Freeport, Maine, and sailed Casco Bay in the summers.His passion for water led him to co-found Ocean Farms Maine in 2017 after working as a carpenter.
Like many in Maine’s mariculture community, Oranski is young, innovative and environmentally conscious.”These are people who are driving interest in reducing plastic and coming up with technologies based on non-fossil fuels,” Sebastian Bell, executive director of the Maine Aquaculture Association, told Civil Eats.
Oransky searched the market extensively for alternatives to plastic bags, testing bioplastics made from corn, soy and other materials, before turning to beech-wood bags made by Austrian company Packnatur.Then it took a few months to perfect the shellfish bags, because Pronatur’s original bags were designed for fruit and vegetables, not heavy, sharp objects like oysters.
“Let’s start using the product. Let’s get rid of this plastic waste stream and take the next step and focus on the future.”
When the pandemic hit and oyster sales dipped, Oransky decided to pivot and make a bag project about “Not Just Us.”He hired Adams to lead the effort and Ocean Farm supplies.
“People tell us they’ve been looking for 15 years” for a non-plastic packaging material, Oransky said.”Surprisingly, some sailors, carpenters and boat builders have discovered this.”
The material for the bags is made in Austria because it is cheaper to produce there, but Adams has started talks with the University of Maine to explore producing them locally.”It just depends on getting the right [tree] species to grow here,” she said.The tree also cannot compete with trees used in the lumber and pulp industries.
For now, Adams said they are focused on building the market.”Let’s put the product to work, let’s get rid of this plastic waste stream, and then take the next step and focus on the future.”
In addition to Harvest bags, Maine Sea Farms uses black floating bags made of high-density polyethylene (HDPE) to grow oysters.HDPE bags are widely used because they are cheap, but even the metal cages that some oyster farmers use to secure the bottom of tidal zones are coated with PVC plastic and contain plastic components.
Cages may also be a source of microplastics ingested by shellfish growing in them.There are few studies on this issue, but one study found that exposure to microplastics in aquaculture farming materials reduced colonization success and delayed growth of oyster larvae.
Ocean plastic researcher and oyster farmer Abby Barrows is on a mission to replace this plastic.She is developing experimental oyster bags made from cork and cedar trees with fine stainless steel or aluminum mesh on the top and bottom.She is also developing ropes made from Manila hemp.
Abby Barrows pulls up one of her experimental metal and wood oyster bags at Long Cove Sea Farm.(Image credit: Greta Rebs)
“Oysters are touted as the most sustainable fishery, and I do believe [this is true], but we need to look at how we farm oysters and how we can further make it a sustainable system,” she told Civil Eats.
This summer, Barrows is conducting side-by-side experiments on several farms, including her own Long Cove Sea Farm, to compare the development of baby oysters in wooden and metal cages versus plastic cages.She is working with scientists in Nova Scotia who will measure microplastic levels in oysters.
“It’s ironic that we’re going back to some of the gear that was originally used,” Bell said.”35 to 40 years ago, our oyster growers used bags made of wood and wire mesh.”
One of the challenges of eliminating plastics from aquaculture is that they “do well in marine environments,” Belle said.”They are not corroded and are very strong, especially in winter. It is always a balancing act between developing a product with a sufficiently long life and economical use.”
Striking a balance between the longevity and biodegradability of non-plastic materials is one reason why, with the exception of Barrows, most efforts have focused on replacing single-use plastics such as harvest bags or bait bags.It’s easier to develop truly biodegradable products that don’t require prolonged use.
For example, Katie Weiler, whose startup Viable Gear makes kelp-based aquaculture equipment, hopes to solve the mussel socks used to farm mussels before they get big enough to be attached to a production line, but the product needs to be used for more than a year .Instead, she decided to prototype a kelp-based seeding line to replace the nylon that kelp growers currently use.The twine needs to last five months to give the kelp plants enough time to take root on the long ropes in the ocean, Wheeler said.
Weiler is also developing bait bags for the lobster and crab industries and is interested in kelp wrap to replace the plastic used to wrap boats in winter.Currently, her startup is targeting easier-to-replace plastics used in aquaculture, she told Civil Eats.”Eventually, it would be great if we could come up with something more durable that doesn’t release toxic microplastics in shellfish.”
Cost is another big issue.Ocean Farm Supply’s bags cost 20 cents more per bag, but they “send a message to customers that oyster farmers care about sustainability,” Oransky said.”Ten years ago, it would have been a tough sale,” he added, but today, customer needs are changing.
Barrows is too early to know how much her wood and metal cages will cost, but she hopes to make them cost-competitive through longevity.They’re designed to last 20 to 30 years, longer than their plastic counterparts, so they’ll be “an asset to your farm,” she said.
These efforts are just the beginning of addressing aquaculture’s contribution to the plastic crisis.”Every step in the right direction is a worthwhile step,” Baziuk said, “even if it doesn’t solve the problem overnight.”
Meg Wilcox is a Boston-based freelance writer focused on solutions-driven stories about how people are fighting climate change, protecting the environment and making our agricultural systems more sustainable, including addressing poverty.Read more >
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Post time: Jun-29-2022
