Kona Blue Water Farms has applied for a permit to determine whether it would be possible to grow young amberjack to harvest size over 10 months in submerged cages tethered to surface buoys drifting freely on a circular ocean current off the Big Island. See Star Advertiser for more
Kona Blue’s other open ocean fish cage farm off the Big Island has failed to produce. The other operation, Hukilau, which produces moi is in financial difficulties. Hawaii Oceanic Technology also wants to start an open ocean cage farm off the Big Island.
Critics point to the unsustainability of open ocean fish farming and the diseases which are bread by confining the fish and which easily pass to the wild fish.
Kona Blue said in its permit application that allowing cages to float freely in more pristine waters would improve water circulation, reduce fish disease and better disperse waste. Which tends to support those who are saying that this aquaculture model has disease and waste problems.
Oddly, Kona Blue applied for a fishing permit that categorizes the cages as a type of fishing gear.
Food & Water Watch, a Washington, D.C.-based organization and critic of open-ocean aquaculture, fears the test will open the door to commercial fish farms in federal waters through the Fisheries Service, which is part of the National Oceanic and Atmospheric Administration.
“NOAA is putting ocean fish farming cages in the same category as rods and reels and fishing nets, so the agency can claim it has authority to issue a permit for this new ‘gear type,’” Wenonah Hauter, executive director of Food & Water Watch, said in a statement. “It’s outrageous that NOAA is equating this dangerous, large-scale polluting method of farming fish with fishing.”
Closer to home, the group Pono Aquaculture Alliance has this to say about open ocean caged fish farming:
The present situation
At present there are two active sea-cage aquaculture operations in Hawai‘i: Hukilau foods, which cultures moi (threadfin) near Oahu, and Kona Blue Water, which cultures kāhala (yellowtail) near the Big Island. Both are seeking to expand. Indigo Seafoods is applying for a lease to culture moi, and a new company, Hawaii Oceanic Technology Institute, proposes to culture ahi (tuna) in submerged mobile cages. We should understand this industry better because, once they have been granted, leases for sea-cage aquaculture become property and are nearly impossible to take back.
The business model
The business model for sea-cage aquaculture has been the same for fifty years. Land-based hatcheries produce carnivorous salt-water fish for grow-out in ocean cages. Here in Hawai‘i, moi and kāhala are fed pellets containing at least 35% fishmeal made from grinding up fish caught in other parts of the world. Ocean currents bring clean water into the cage and carry wastes away. If the price of fishmeal is low, and the cultured fish is perceived as glamorous, operators can make large profits, but the business is capital intensive. Even for a small farm, over a million dollars must be spent before the first harvest. That is why Hawaii’s two active sea-cage companies are now both owned by large corporations.
Escapes, disease and epidemics
Storms can destroy cages, so escapes are always a risk, and escaped farm fish reduce the fitness of wild fish by interbreeding with them. However, the main risk in sea-cage aquaculture is disease. The cage excludes macro-predators like sharks and seals, but it does not exclude micro-predators, the pathogens that cause disease. Thus a sea-cage is always a pathogen culture facility. Hoping for economies of scale, sea-cage operators expand year by year until epidemics result, causing catastrophic loss of product and jobs. Bankrupted by escapes or disease, the few remaining local operators inevitably sell out to multinational corporations that use antibiotics and chemicals to combat disease. On the coast of British Columbia, Canada, where I grew up the sea-cage farming industry is now entirely controlled by two large Norwegian companies, Marine Harvest and Cermaq. Four times, British Columbians have flown to Norway to plead in vain for removal of farms from the migration routes of wild fish.
Why farmed fish cause wild fish to decline
Wherever fish are cultured in sea-cages, wild fish decline. To understand this, recall that when a wild fish falls ill, it is likely to starve or to be eaten by predators. It doesn’t live long enough to infect many other fish. But sea-cage fish are fed every day and protected from predators by their cage. When they fall ill they live a long time while shedding pathogen into the water. The higher levels of pathogen then cause wild fish to decline. This also happens in land animal culture if farm stock is not separated from wild stock, a fact that has been forgotten in North America where most wild stocks have been extirpated, but not in Africa where African wild cattle have never recovered from rinderpest carried by European cattle. Physical separation of wild and domestic stock is possible in terrestrial animal culture, but it is impossible in sea-cage aquaculture because water flows freely through the cage, carrying pathogens for many miles. Wild stocks have declined with every aquaculture that protects farm stock from predators, even in highly regulated aquacultures such as shrimp farming in Mexico, abalone in Australia, and salmon in Norway. One result is that commercial, subsistence and sport fishermen all lose their fisheries.
Wild fish fight jellification
The decline of wild fish also promotes algal blooms—and jellyfish, because plankton-eating wild fish compete with jellyfish for food. All juvenile wild fish consume plankton. If wild fish are allowed to decline, jellyfish are released from competition for that plankton. We have seen the results of this already in Hawaii, where poisonous jellyfish have increased as wild fish stocks have been over-harvested. Science cannot prove beyond a doubt that loss of wild fish in Hawaii has promoted jellyfish, but that is how it has worked in other parts of the world, and there is no biological or oceanographic reason to suppose that Hawaii is different.
Sea-cage farming depletes the distant ocean
The use of fish meal and fish oil in sea-cage aquaculture is both a business risk, due to continuing increases in price, and an environmental risk because of the ecological importance of the fish ground up to make those products. The fish meal and oil needed to produce 1 pound of kāhala require 4.2–5.4 pounds of wild fish. Ahi can’t be raised on pellets; they require actual fish flesh as food, and ahi farms in Australia consume 12–20 pounds of wild fish to produce one pound of ahi. Fish meal and fish oil are made mainly from forage fish such as anchovies, menhaden, sardines and herring. Herring is the principal diet item of the humpback whales that come to Hawaii each winter to breed. Anchovy was an important diet item of the rural poor in South America until its use for fishmeal caused a rise in price—the United Nations Food and Agriculture Organization deplores the diversion of fish edible by humans to fishmeal production. Menhaden are the food of sea bass and blue fish on the Atlantic coast of the US, and of endangered brown pelicans in the Gulf of Mexico. Herring, sardines, anchovies and menhaden are also important consumers of plankton, competing directly with jellyfish. For example, over-fishing of sardines and anchovies in the northern Benguela of Africa has caused them to be replaced by jellyfish in a ratio of 4 to 1 by weight. The menhaden fishery has been banned in most Atlantic states, and is likely to eventually be banned in the Gulf of Mexico so that menhaden can help control the excess plankton that results from agricultural fertilizer carried into the Gulf by the Mississippi River. Farmers of poultry and hogs can substitute soymeal for fishmeal in their operations, but there is no substitute for fishmeal in the culture of carnivorous fish.
Bycatch, trimmings and toxins
Two other important components of fishmeal are bycatch (non-target fish from capture fisheries) and the trimmings from fish sold to humans. Bycatch and trimmings are high trophic-level fish in which persistent organic pollutants are more concentrated than in forage fish. When fishmeal made from such fish is fed to farm fish, toxins are concentrated yet again by passage through the farm fish. Farm fish may also contain more toxins than wild fish because of the medications they are given to control disease. For example, farmed fish are often treated for ectoparasites by putting toxic chemicals in their feed, chemicals such as malachite green (banned in the UK since 2002, but still used in many other countries), dichlorvos (an organophosphate that is carcinogenic, mutagenic and an endocrine disrupter), azamethiphos (an organophosphate toxic to shellfish) cypermethin (a pyrethroid more toxic than most organophosphates, also a hormone disrupter), deltamethrin (a pyrethroid neurotoxin), teflubenzuron (a benzoylphenyl urea insecticide), ivermectin (a neurotoxin and bioaccumulant), and emamectin benzoate (toxic to fish, mammals and invertebrates). These chemicals can damage the fish as well as the parasite. For example, the side effects of emamectin benzoate, the current chemical of choice that farmers put in their food to treat their fish for sea lice, include corneal edema, cataracts, skin lesions, inappetance, scale loss, peritoneal adhesions, visceral melaniation, ceroid accumulations in spleen, melanin accumulation in kidneys, and loss of equilibrium. Most sea-cage fish are not tested, but tests of sea-cage salmon, for example, showed levels of at least thirteen organic pollutants that were ten times higher than those in wild salmon. How far is Hawaii down this chemical road? Locally, in 2005–2006 Kona Blue Water Farms (KBW) began suffering damaging infestations of skin flukes on its kāhala, and each of its 5–8 cages is now treated about once a month with 1800–2000 liters of 35% hydrogen peroxide, later released to the ocean. Sometime in 2010 it will replace the peroxide treatment with praziquantel (a drug used to treat schistosomiasis in humans) in its fish feed.
Eutrophication and jellification
What of the feces and uneaten feed carried out of the sea-cage by currents? Sea-cage operators in regions of strong current boast that their wastes do not affect the floor beneath their cages, but waste spread thinly through the water may do more harm than waste spread thickly on the bottom. Wastes in the water promote plankton growth, which promotes the growth of jellyfish. Scientists who study this phenomenon refer to it informally as “the rise of slime.” Sea-cage farming of fish thus promotes jellyfish directly by feeding the bottom of the food chain, and indirectly by reducing the numbers of wild fish that consume jellyfish.
Effects on tourism
Is sea-cage aquaculture compatible with tourism? In the Broughton Archipelago of British Columbia, tourism includes boat tours to view whales, seals and sea lions, as well as sportfishing, and kayaking. Tourists come from all over the world to watch grizzly bears feast on wild salmon in the Glendale River. Local indigenous peoples harvest wild salmon and clams for cultural and commercial purposes. When sea-cage salmon aquaculture began in the 1980s, we welcomed it because we thought it would provide more jobs. Sea-cage operators first shot seals and sea lions (one farmer I interviewed called them “furry hoodlums”), and when shooting became unacceptable they installed underwater noise-makers. Orcas (killer whales) deserted waters in which they had once routinely foraged. Wild salmon, the main food of orcas, are rapidly declining due to disease from farmed salmon, and the clam beds of indigenous peoples are slimy with microorganisms promoted by salmon farm wastes. Other species of wild fish are also in decline, and anglers who catch them report high levels of parasites never seen before in this area. What about jobs? Initially there were jobs setting up the farms, but now the feed comes in by boat, the fish go out by boat or truck, and what is left is the sewage. Green seaweeds are replacing naturally occurring brown seaweeds, a clear sign of excess nutrient in the water. The BC government is powerless to take back leases, so it pretends that nothing is wrong. Apart from details, the story is similar elsewhere, and it is similar in shrimp farming.
Are there good kinds of aquaculture? Yes. Land-based aquaculture in which wastes are recycled is very good. In the ocean, aquacultures based on filter feeders such as mussels and scallops can clean degraded ocean waters, and aquacultures based on seaweed-eating fish do not destroy the forage fish that clean our oceans. One of the best forms of aquaculture is traditional Hawaiian fishpond aquaculture, which was diversified and ecologically advanced. For example, large ocean ponds called loko kuapā were built in areas of submarine fresh water discharge. ‘Ama‘ama (mullet) and awa (milkfish) ate seaweed that grew naturally in the brackish portion of the ponds. To rid themselves of sea lice they swam into the upwelling fresh water. Each pond had a few predators, such as kākū (barracuda), that prevented epidemics by eating sick fish. Turtles aided ponds by eating seaweeds that fish did not eat. Since fishponds did not use hatcheries they did not degrade the genetic fitness of wild fish.
Modern technology and ancient ecology
We should not be surprised by the success of fishponds—pre-contact Hawaiians had many centuries of trial and error to get it right. In order to recover and build on their wisdom it would be useful to restore local fishponds to their pre-contact condition and study them. Even more important, we should make sure that the ecological principles that allowed traditional Hawaiian aquaculture to be so successful are incorporated into modern aquaculture in Hawaii. For example, it may not be necessary to use stone walls, but it is almost certainly necessary to locate pens in areas with submarine groundwater discharge, to culture mainly herbivorous fish, and—perhaps most important of all—to include a few predators for disease control.
Making capture fisheries into effective aquaculture
In any consideration of aquaculture it should not be forgotten that well-maintained capture fisheries are also a form of aquaculture. Capture fisheries have many advantages over cage aquaculture, one of which is that they are highly compatible with tourism. Moreover, past mistakes in capture fisheries are now well understood by science. In order for a capture fishery to be sustainable three things are necessary: (1) fishermen must know that the fish they do not catch today will be there for them tomorrow; (2) fishermen must be confident that cheaters and poachers will be punished; and (3) fishermen must pay a royalty to the state for the fish they catch. Requirement (1) is satisfied by giving fishermen property rights in the form of percentages of the total allowable catch (TAC); such percentages are sometimes referred to as individual transferable quotas (ITQ). Requirement (2) is satisfied by allowing fishermen to organize in self-policing guilds that make their own rules for vessels and gears. The importance of requirement (3) is that fishermen do not stop fishing until their marginal cost exceeds their marginal return. Royalties reduce that marginal return to the point where fishermen stop fishing when fish populations are still large enough to recover from unpredictable environmental variations in local oceanographic conditions. Royalties also pay for policing, the costs of which would otherwise come from general funds. I suggest that in order to restore and sustain Hawaii’s inshore capture fisheries, we should make, say, 40% of our inshore waters into marine protected areas (MPA) and reserve the other 60% for management by self-regulating fishermen’s guilds organized on traditional local principles.