Red Drum, or Redfish
The red drum, Sciaenops ocellatus, is a marine species that spawns in near shore areas, spends several years in coastal habitats, and then schools in offshore waters, often living to 30 – 50 years of age. The species occurs naturally from Veracruz, Mexico to as far north as Massachusetts. In spite of this, the species is particularly vulnerable to sudden drops in temperature, and cold-related die-offs of juveniles in inshore habitats are common occurrences in wild populations. Similar cold-related losses are typical in outdoor culture ponds and tanks.
Consumer interest in the red drum increased greatly in the U.S. in the mid- 1980's, largely as a result of the temporary popularity of Cajun cuisine. As a result of overfishing, a subsequent moratorium on commercial harvests from the Gulf of Mexico led researchers and entrepreneurs to devote considerable resources in attempts to develop culture techniques for this species.
Apart from the prevailing supply and demand relationships at the time, a number of biological characteristics of red drum attracted the interest of researchers and culturists. Exceptionally good growth and survival were often exhibited under culture conditions and the species grew well over a broad range of salinities. Additionally, once the first captive breeding stocks were established in comfortable hatchery settings, production of fertile eggs was fairly straightforward.
In spite of these attributes, results of early red drum grow-out studies were highly variable. Parasitic infections and oxygen depletions often resulted in large losses, but on occasion yields were high (8,000 - 24,000 lb./acre), growth was acceptable (2.2 - 2.9 lb. average weight at harvest) and survival was high (88.7 - 94.9%). During the late 1980's and early 1990's, catastrophic winter losses attributable to sudden or severe freezing temperatures at several pioneering operations in the U.S. increased perceptions of technical and economic risk involved with red drum culture, and discouraged investment.
The relative intolerance of red drum to cold temperatures was never solved, and R&D efforts in the U.S. declined steadily through the 1990's as cold temperature intolerance, disease, cannibalism and cash flow risks were increasingly perceived to outweigh the potential for profits. Nevertheless, a small industry persisted in Texas.
While suitable farming sites can be found in coastal watersheds throughout the Gulf of Mexico and the southeastern Atlantic coast, factors limiting expansion of red drum culture in the U.S. include high capital costs, logistical problems with broodstock collection, complex hatchery production requirements, overwintering survival problems, regulatory constraints on site selection and marketing uncertainty. The severe freezing weather in Texas in February 2021 drove many producers in the Matagorda Bay region, the heart of the U.S. red drum industry, out of business due to severe or complete mortality of fish inventories in outdoor ponds.
In contrast, successful commercial production of red drum has been established in other parts of the world, with promising results to date. Some examples include the Bahamas, China, Ecuador, Israel, Martinique, Mexico, Singapore, Taiwan and the United Arab Emirates.
Regulatory constraints to the development and use of suitable sites have hindered and/or effectively prevented many attempts at red drum culture in the U.S. Additionally, permits and licenses to possess and culture red drum are often difficult or impossible to obtain, and requirements vary from state to state. A red drum facility requires access to both freshwater and saltwater, and this typically involves property in coastal zones. Acquiring permits to develop such property can be problematic in some areas, and the most suitable sites also tend to be highly vulnerable to damage from hurricanes and tropical storms.
Surface water and well water supplies have both been used successfully for red drum aquaculture, but surface water sources must be free from contaminants and disease organisms. To offset summertime evaporation in outdoor ponds, as much as 50 gpm of fresh water may be required per surface acre. Pond soils must have adequate clay content to prevent excessive water loss, and access to reliable electricity and suitable roadways is a necessity.
Limited commercial sources of fingerlings have motivated or compelled many grow-out farms to incorporate their own spawning and hatching operations to ensure uninterrupted production and sales. While capital intensive, this strategy is technically straightforward. Induced spawning of captive red drum has been practiced successfully for over 30 years based on manipulating temperature and photoperiod to mimic a natural annual cycle for fish maintained in tanks with either flow-through or recirculating water. Under these conditions, by bringing fish to maturation with an abbreviated (compressed) cycle and then slightly fluctuating temperatures, millions of eggs can be produced for each breeding female. Broodstock can then be subjected to a new maturation cycle, with lifespans in captivity easily reaching ten years or longer.
Within three days after hatching, red drum larvae require live feed. Although indoor feeding has been successful, beginning with rotifers and followed with brine shrimp nauplii, it is not economically practical for commercial production. The industry is dependent on pond-raised fingerlings, which are then stocked for further grow-out.
Larvae require at least 10 g/L salinity, but optimum survival and development occur with salinities between 25 and 35 g/L. Fingerling production ponds are generally less than 2 acres in size, to allow more control over fertilization and management of the zooplankton populations that serve as live food for the developing fry.
Timing of filling and fertilizing ponds must be based on 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.
After two to three weeks, producers begin to feed high protein powdered diets, gradually shifting to a crumbled diet by five weeks post-stocking. Fingerlings are harvested and graded by size, and then stocked out for the first growing season. Grow-out operations generally use a two-stage strategy to raise fingerlings to market size fish. Stockers are produced during the first growing season with the goal of getting the fish to 8 – 12 inches prior to the onset of winter.
Overwintering ponds are built with deeper areas (as deep as 8 feet) that serve as thermal refuges, and warm groundwater or deep surface water is pumped into these refuges when necessary to prevent water temperatures from falling below 40o F. If stockers survive their first winter, grow-out to a market size of 2 – 4 lb. is achieved in ponds during the second year, with harvests as high as 10,000 lb./acre occurring prior to the second winter season.
Although red drum have few disease problems compared to many other cultured fishes, during the fingerling and stocker phases of production bird predation is a significant concern for most growers. Measures must be taken to constantly exclude and discourage predators. Acceptable dissolved oxygen levels are maintained through the use of aerators.
The USDA’s 2018 Census of Aquaculture reported a total of 12 red drum farms in the U.S. Texas led the nation with 8 red drum farms, followed by Delaware and South Carolina, each with two operations. Of these, only one reported selling fingerlings or fry in addition to food size fish. Total sales reported were $19,448,000 as compared to a value of $10,161,000 in the 2013 Census. Harvests of food size fish in 2018 totaled 7,153,000 lb.
Red drum that had been shipped as fry from Texas in 1991 were spawned successfully in Taiwan in the 1990’s. Technical information on red drum culture was soon available locally and in mainland China for those interested in producing this fish. By the late 1990’s, a representative of the Taiwan Fisheries Consultants group described the local red drum market in Taiwan as “flooded,” with local hatcheries shipping “millions of fry and fingerlings” to mainland China and other regional countries.
Today, China produces more than 20 times as much red drum as the U.S. and container-loads of frozen red drum can be imported from several Asian countries. Substantial volumes of red drum products, specifically IQF filets, have been imported into the U.S. over the years to take advantage of market demand in the Gulf coast and Atlantic states. This competition from imports requires U.S. red drum producers to market their fish as a premium product, emphasizing attributes such as superior food safety, locally grown benefits and fresh-not-frozen.
Few areas of current research stand out as potential avenues to improve profitability and reduce risk in commercial production of red drum in the U.S. One approach that may hold some promise is recirculating aquaculture system (RAS) production. Red drum have been shown to adapt fairly well to tank culture, as evidenced by successes at various research facilities, and RAS technology is continually advancing. While market conditions could not justify the costs associated with RAS production prior to the pandemic and the Texas freeze of 2021, RAS cost and revenue projections may deserve a new analysis. At constant optimum temperatures, an RAS facility should produce 2.2 lb. fish in 11 months.
High levels of mortality among fingerlings and smaller food-size fish are associated with cannibalism and aggressive behavior, requiring grading at every phase of production prior to final grow-out. Although red drum can reach marketable sizes of 2 to 2.5 lb. in less than two growing seasons, in all but the most southerly regions of the U.S. pond production requires growers to overwinter their fish at least once, amounting to unavoidable high levels of risk. Although climate change trends may be increasing the average temperatures for pond production in the southern U.S., they may also be increasing the frequency and severity of extreme cold events which are lethal to red drum.
Fingerling availability continues to be a problem for potential growers. And while disease losses are minimal in red drum, mortality related to handling and transport stress are major problems at all life stages. Many compounds which could reduce losses cannot yet be applied to red drum because of a lack of appropriate label registrations. All of these factors complicate production scheduling and sales forecasts, with the potential to create major marketing disruptions.
When planning a red drum farming facility, or purchasing one that has gone out of business, it will be necessary to calculate the carrying capacity of the system in order to estimate capital costs, operating costs, projected production, revenues and input requirements. 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. These projections will also help determine if settling ponds, constructed wetlands or other measures will be required to reduce downstream environmental impacts from the farm discharge.
Accurate and detailed cost projections are essential when establishing any fish farming business. Projected costs (variable, fixed, marketing and opportunity costs) must be compared to prevailing market prices for the sizes and quality of the fish to be produced. Keep in mind economies of scale – a smaller independent operation will have higher per-fish costs and may require a number of small-volume, local markets such as restaurants and seafood dealers that are willing and able to pay higher prices.
When a small aquaculture operation loses a customer, alternatives may be limited or nonexistent. Input suppliers (feed, fingerlings and equipment) must be reliable and trustworthy, even when their larger customers are competitors. Feed requirements must be considered – who will supply it, at what cost, and in what quantities will it be delivered? Red drum require high-protein diets, and if buying in bags instead of bulk deliveries, the cost of production will automatically go up.
Markets must be available to accommodate production when it is ready for harvest because maintaining red drum beyond a harvestable size requires excessive feed, labor and energy costs as well as unproductive use of facilities and capital. If harvestable fish are subjected to a second overwintering phase, the risk of losses increases significantly. Prior to the 2021 freeze, one producer controlled more than half of the market, and several other operations marketed their harvests through that business. If farming redfish on a large scale and selling to a broker, keep in mind that developing and maintaining committed relationships with both suppliers and buyers will be crucial.
No matter what a red drum operation’s scale of production will be, quality control, harvest scheduling and customer service will be crucial for success. In turn, buyers must also be willing to provide reliable outlets for fish. Selling to a competitor may complicate or disrupt the arrangements associated with this basic requirement.
Small scale red drum production may not be profitable without a competitive edge in local markets gained through accessibility, customer service and logistics. Fee fishing or on-site processing and sales may improve revenues, but these approaches usually involve excessive focus on permits, licenses and liability insurance. In fact, smaller red drum grow-out operations may not make economic sense unless more reliable supplies of fingerlings become available, because a small-volume farm will probably not be able to absorb the costs of integrated spawning facilities. Conversely, while the potential for industry expansion prior to the 2021 freeze suggested opportunities for independent fingerling producers, the question of when or if the food fish production sector can rebound will determine the economic feasibility of entering the fingerling production market.
Prior to the Pandemic and the freeze impacts in 2021, red drum producers in Texas were receiving roughly $3.50 per lb. of live weight fish. Shifts in both supply and demand make it difficult to predict market trends for the immediate future.
Prepared by C. Greg Lutz, Louisiana State University Agricultural Center