Hybrid Striped Bass

March 2022

School of striped bass fishOverview

The term hybrid striped bass refers to crosses between striped bass (Morone saxatilis) and the closely related white bass (M. chrysops). The striped bass is native to the Atlantic and Gulf coasts, although the Gulf populations have largely been extirpated, while the white bass was originally found throughout the Mississippi River watershed. Both fish have been widely introduced beyond their natural ranges. Striped bass were first introduced from New Jersey to California in 1879.

The hybrid combines the growth potential of the striped bass with the hardiness of the white bass. These fish must be produced artificially in hatcheries, and the hybrids cannot be used as breeding stock under normal circumstances so fingerlings must be produced on an ongoing basis year after year. The first documented hybrid striped bass were produced in the 1960’s by various Fish and Game agencies for stocking in reservoirs.

Originally, female striped bass were crossed with male white bass (with the resulting offspring referred to as Palmetto bass), but the reciprocal cross (Sunshine bass) has become increasingly popular over the years. By the late 1970’s research was underway to evaluate the hybrids’ potential for aquaculture production, and commercial production of hybrid striped bass began in the late 1980’s. Hybrid striped bass are now raised in a number of states for food fish markets and for recreational fishing. Some operations focus on fingerling production, others on grow-out, and some facilities may produce both fingerlings and food size fish. Food size fish typically go to market as live product or fresh on ice in the round.

Production

Hybrid striped bass fingerling production involves artificially spawning the parental species under hatchery conditions. Although other methods have been developed with mixed success, the most common approach to artificial spawning involves hormone injection of mature fish that are already near spawning, with subsequent stripping of gametes. Eggs are fertilized manually, treated to remove adhesiveness, and incubated until hatching.

The only economically practical method to culture newly hatched fry is by using fertilized, newly flooded freshwater ponds. Timing of filling and fertilizing these ponds must correspond to the anticipated stocking date in order to have suitable microscopic prey available when larvae begin feeding. These critical activities are generally a combination of art and science. If ponds are filled too early, zooplankton will already be too large for the fry to consume when they are stocked, and if ponds are not filled with sufficient lead time insufficient numbers of food organisms will be available.

Fingerling producers typically feed their fry ponds at a rate of 10 to 12 lb. per acre daily (divided over 3 or more feedings) following stocking. Some growers begin feeding the day after stocking, while others may wait as long as three weeks. Feed must be spread along the water’s edge all the way around the pond, and several feeding per day are necessary to get the fry accustomed to taking an artificial diet. Although the timing details will vary somewhat with differing temperatures, original cross hybrids should typically be consuming feed within two weeks, but reciprocal cross fry may require up to twice as long. At 45 to 50 days after stocking, 1 – 2 inch fingerlings should be ready to transfer for the next phase of production. Some operations hold these fish in tanks for one to two weeks to ensure they are fully trained on artificial feed.  

These 1 – 2 inch fingerlings are graded and stocked into ponds at 8,000 to 12,000 per acre and raised with the goal of reaching about 4 oz. average weight by the onset of winter. These “stocker” size fish are graded once again and stocked into ponds at 3,000 to 5,000 fish per acre for grow-out to marketable size, with feeding beginning as soon as waters warm enough in the spring to elicit a feed response. Depending on stocking rates and aeration capacity, fish should reach 1.5 – 2.5 lb. by the end of the second growing season.

Grow-out has also been successful in raceways and recirculating systems, but each of these approaches has distinct challenges, ranging from nutritional deficiencies to bacterial outbreaks. Bacterial problems are especially serious in recirculating systems, but they are also reported in ponds and raceways. External protozoan parasites and internal grubs are frequent pathogens in pond production.

The 2018 USDA Census of Aquaculture reported a total of 62 farms producing hybrid striped bass in the U.S. Of these, 43 indicated they marketed food size fish, 11 sold stockers and 8 sold fingerlings or fry. Total farm-gate value of these products was $34,878,000, of which 94% was attributed to food size fish. Hybrid striped bass tolerate a wide range of temperatures (39o to 91o F), and production was reported in 19 states. North Carolina led the nation with 14 farms, followed by Illinois with seven, Ohio with six, Florida with five and Arkansas, California, Pennsylvania and Virginia, each with four. Fifteen operations also reported producing hybrid striped bass for conservation, recreation, enhancement or restoration purposes.

Marketing considerations

Fingerling availability is crucial to economic survival and success in any finfish aquaculture operation. In-house fingerling production of hybrid striped bass is not practical except for very large farms because it requires capturing, transporting, holding and spawning wild broodstock (both striped and white bass), which may require significant transport times, not to mention regulatory constraints. These collections must take place at a specific time of the year to coincide with spawning runs in natural habitats. There are very few locations in the U.S. where this is feasible. Some operations purchase newly hatched larvae from established hatcheries and raise them to fingerlings on-site, while others may opt to acquire 1 – 2 inch fingerlings already trained on feed.

Input costs are high in hybrid striped bass production. These fish require comparatively high protein diets, and although research is underway to reduce the animal proteins included in these diets, progress has been limited. Hybrid striped bass also require more aeration than species such as catfish, and are less tolerant of ammonia. Specific management practices are required to suppress snails in culture ponds, since these are vectors for grub parasites that can reduce both survival and marketability. These high input costs require careful planning for production and marketing in order to avoid cash flow problems prior to harvest.  

Historical markets for wild striped bass are found in many regions along the Atlantic seaboard, and these have become the primary outlets for many hybrid striped bass food fish producers. Nonetheless, additional markets exist on the west coast and in Asian and Hispanic communities throughout the country. Consumers in some of these communities will pay a premium for live fish. Hybrid striped bass can also be competitive with other finfish species in many markets, but a lack of consumer awareness often requires significant effort to educate buyers as to the qualities of the fish. Some producers sell advanced fingerlings to stock for recreational fisheries, and this market imposes fewer requirements in terms of constant supply.

Hybrid striped bass producers have utilized a number of marketing channels, including seafood brokers, seafood retailers and wholesalers, live haulers, supermarkets and grocery wholesalers, restaurants, and food service distributors. Brokers and distributors usually buy whole hybrid striped bass, partially process them, and then sell to restaurants and high-end retailers. Retailers are focused on fresh, skin-off fillets while wholesalers tend to deal in whole gutted fish, and fillets to a lesser extent.

Live haulers are particularly effective in identifying and supplying live fish to ethnic markets, especially Asian American consumers, but locating live haulers can be difficult in some parts of the country. Whole fish brokers and distributors regularly move hybrid striped bass to Hispanic markets around the country and to more traditional consumers along the Atlantic seaboard. All of these potential buyers require regular, year-round supplies.

When planning a hybrid striped bass farming facility it will be necessary to calculate the carrying capacity of the system in order to estimate capital costs, projected production, revenues and input requirements (especially fry/fingerlings and feed). At this point, an evaluation can begin in order to determine if the operation will be large enough to generate profits and if so, a market analysis can be undertaken. Markets must be available to accommodate production when it is ready for harvest because maintaining fish beyond a harvestable size requires excessive feed, labor and energy costs as well as unproductive use of facilities and capital.

Developing and maintaining committed relationships with both suppliers and buyers will be crucial, especially for large operations. No matter what the scale of production will be, hybrid striped bass producers must provide value through quality control, harvest scheduling and customer service. In turn, customers must also be willing to provide reliable outlets for marketable fish when the producer needs to move them.

Projected costs (variable, fixed, marketing and opportunity costs) must be compared to prevailing market prices for the sizes and quality of the fish that will be produced. Keep in mind economies of scale – a smaller operation will have higher per-fish costs and will require a number of small-volume, local markets that are willing and able to pay higher prices for food size fish. When a small operation loses a customer, alternatives may be limited or nonexistent. Input suppliers (feed, fry/fingerlings and equipment) must be reliable and trustworthy, even when larger customers are potentially competing for those same inputs. Considerable attention must be paid to projected feed requirements – who will supply it, at what cost, and in what quantities will it be delivered?  Bulk delivery only makes sense if the entire quantity will be used before its quality begins to deteriorate. However, if buying feed in bags instead of bulk deliveries, costs of production will automatically go up.

Seasonality of fingerling production and availability also impacts production schedules in hybrid striped bass farming, and marketing activities must be adapted to this constraint. Multiple ponds will allow varying stocking rates to make harvestable fish available year-round, or at least over a more extended period. This, in turn, will influence the minimum size and scale of the operation in order for it to be competitive and profitable.

Farm raised hybrid striped bass have commanded $3.85 to $4.30 per lb. in the past several years. Over the same period, wild-caught striped bass have sold for $2.95 to $4.60 per lb. depending on the season and the size of the fish. Pandemic impacts on hybrid striped bass consumption and pricing are not yet clear, but it seems that demand will recover and continue growing. Hybrid striped bass are considered superior quality fish when properly raised, harvested and handled. They exhibit firm, lean flaky meat, with a mild flavor, and can compete favorably with a number of other species when proper promotional and educational campaigns are utilized.          

To date, hybrid striped bass producers in the U.S. have not faced significant competition from imported products. Nonetheless, hybrid striped bass are produced in Germany, Israel and Italy, and the parental species and their hybrids have been introduced in a number of countries including China, France, Mexico, Portugal, Russia and Taiwan.

Resources

Prepared by C. Greg Lutz, Louisiana State University Agricultural Center