Developing a Resilient Fisheries Sector through Mariculture?

In the Bahamas, the significant impact of human activities and climate change on coastal ecosystems is only now becoming fully recognized. The removal of top predators and grazers has significantly altered the function and productivity of marine ecosystems. Subsequently, we have now reached the tipping point where we are now "Fishing Down the Food Chain," meaning that species not previously harvested, such as parrotfish, are now being encroached upon and sold commercially. For many years, locals have viewed the seas as inexhaustible, often saying, "there are many more fish in the sea." However, continuous encroachment on marine environments has led to the depletion of marine species populations. Given this depletion and the Anthropocene era we are entering, innovative solutions are required to address the challenges. One such solution is mariculture or locally known as fish farming, the farming and cultivation of marine organisms in brackish water. This article explores mariculture and its relationship to sustainability in the Bahamas.

The Bahamian Marine Environment

The Bahamas is an independent archipelago and a small island developing state surrounded by oligotrophic waters, roughly 760 nautical miles from southern Florida. Its unique marine environment has allowed us to attract tourists, which in turn brings substantial financial benefits; renowned for its crystal-clear waters, diverse marine life, and appealing cuisine. Sea farming has great potential of providing food and livelihoods that could help regulate fish populations. However, the overfishing epidemic poses a significant threat to our society if not addressed. Local divers states that poachers would continue to collect them indiscriminately.

The History and Potential of Mariculture in the Bahamas

Mariculture was introduced to the Bahamas in the late 1970s by various private companies. The first experiments were conducted at a dredged pond location in Rudder Cut, Exuma, but the project was abandoned after slow growth rates among oysters. The Wallace Groves Aquaculture Foundation of Freeport, Grand Bahama, also attempted a similar project on oysters, which also failed. In 1981, a project in the Berry Islands focused on the mass production of juvenile Queen Conch in hatcheries to replenish depleted populations of wild conch.

The first commercial aquaculture venture in the Bahamas was established in the early 1980s by Worldwide Protein Ltd., a subsidiary of the Maritek Corporation. The farm was set up on Long Island and successfully produced shrimp and redfish on a commercial scale. Other early operations included Aqualife Marine Research Corporation, which grew marine tropical fish for the aquarium trade, and Bahamas Marine Farms, which developed the first commercial tilapia farm in the Bahamas. Despite many failures due to a lack of knowledge and undercapitalization, these ventures demonstrated that aquaculture could be successful in the Bahamas.

The Vulnerability of the Nassau Grouper

The Nassau grouper has been heavily fished and is vulnerable to overfishing due to its biology and slow population replenishment rates. Spawning aggregations that appear at the same site each year are easy targets for fishers who can catch large numbers of fish very efficiently. During these spawning events, many reproductively mature fish are caught, leading to substantial declines in populations. In some countries, such as Cuba, a large proportion of the annual landings of the species is taken during these aggregations. As a result, many of these aggregations have declined substantially in numbers due to heavy fishing pressure, with few being adequately managed. Although this species experience great pressure the potential of mariculture can be utilized for lobster as seen with Tropical Seafood and conch as implemented in Turks and Caicos.

The Future of Mariculture and Climate Resilience

The evident decrease in fish stocks has led to an expansion of mariculture and aquaculture worldwide. By focusing on mariculture, Bahamians can generate healthy livelihoods without depleting marine resources. Banking and finance are the two major industries in the Bahamas, accounting for 15% of GDP. A growing number of Bahamian entrepreneurs are venturing into manufacturing, including pharmaceuticals, rum, salt, conch jewelry, and hair and skin products, which accounts for 8% of GDP.

The Bahamas is home to a vast quantity of spiny lobster species, but continual encroachment by both native and illegal foreign fishermen has severely depleted this resource. In 1999, commercial fishery landings for lobster tails totaled over 6 million pounds, valued at $62.6 million. To ensure sustainable lobster production, suitable sites for grow-out of wild-caught postlarvae or post-harvest impounding in ocean-based systems must be evaluated for water circulation, bottom type, protection from weather, access to shore facilities, and security.

Mariculture and Climate Resilience

Mariculture offers a promising solution to enhance climate resilience in the Bahamas. By reducing the pressure on wild fish stocks, mariculture can help maintain biodiversity and ecosystem health. Cultivating marine organisms can also provide a stable food source and support livelihoods, reducing the vulnerability of coastal communities to climate change impacts such as coral bleaching, sea-level rise, and more frequent and severe storms. Additionally, mariculture can contribute to carbon sequestration and improve water quality through the filtration capabilities of certain marine species.

By harnessing mariculture call allow for the protection of marine resources, support of the economy, and preservation of sustainible livelihoods, thus making it more resilient in the face of climate change. Mariculture offers a sustainable and innovative approach to conserving the fisheries industry and ensuring a resilient future for the Bahamas.

Negative Effects of Mariculture

a. Growth and Maturity

Female grouper often struggle to reach maturity in captivity, necessitating the use of hormones to induce maturity.

b. Waste Management

Reducing feeding wastes can be achieved by using floating pellets and environmentally friendly formulated diets. Optimizing feeding based on behavior and ontogenetic changes in feeding practices also helps.

c. Nutrient Flow

Closed systems can contain domesticated species, preventing them from mixing with wild populations and reducing nutrient flow. Rotating cages through the farm site allows fallow time for the mineralization of accumulated nutrient wastes.

d. Use of Antibiotics

Modern aquaculture employs a wide variety of chemicals. Antibiotics and biocides treat illness or prevent the establishment of harmful organisms. Hormones induce maturation, spawning, and sex-reversal for culturing monosex crops. Anaesthetics narcotize organisms before handling, harvesting, or transport. Vitamins, minerals, and chemical pigments ensure adequate nutrition or impart desirable color to the flesh of cultured organisms. There are concerns about how these potential chemical pollutants may affect surrounding natural systems and the effects of chemical residues in the flesh of cultured animals on human consumers.

Advantages of Mariculture

a. Decreased Pressure on Wild Fisheries

Bahamian waters face significant pressure from both native and foreign fishermen. With the growing human population, most marine biologists agree that wild-captured fish will not meet seafood demands. Aquaculture, defined by the U.S. National Oceanic and Atmospheric Administration (NOAA) as "the propagation and rearing of aquatic organisms in controlled or selected environments," is seen as the best way to fill the gap.

b. Less Harmful Fishing Techniques

Whether aquaculture depletes or enhances net fish supplies depends largely on resource market management. The lack of regulations or price disincentives on coastal pollution by fish farms limits mollusk farming and slows the adoption of non-polluting technologies by other marine aquaculture systems. Government subsidies to the ocean fisheries sector often prevent farmed fish from undercutting the market for wild-caught fish until ocean fisheries are fully depleted. The economics and policies of fisheries in various nations significantly influence whether farmed fish can replace or provide market alternatives for ocean catches.

High fixed costs of fishing fleets, labor considerations, and continued subsidies to the ocean fisheries sector—subsidies that currently approach 20 to 25 percent of gross fisheries revenue globally—may prevent increased aquaculture production from lowering catches of wild fish in the short term. For instance, despite increased farm production, salmon catches worldwide rose by 27 percent between 1988 and 1997. Similarly, despite rapid growth in farmed fish like tilapia, wild capture of hake and haddock has remained relatively stable over the past decade.

Sustainable Fish Production

Mariculture, the farming of marine organisms, enables the controlled production of species like grouper and tilapia, which hold significant economic and ecological value. By cultivating these species in controlled environments, we can meet the growing demand for seafood without exerting undue pressure on wild populations. This practice helps maintain the balance of our marine food webs by allowing key species to recover from overfishing and continue fulfilling their ecological roles. Additionally, mariculture can be tailored to optimize the health and growth rates of farmed species, ensuring a consistent and high-quality supply of seafood.

Economic Diversification

Investing in mariculture opens up new avenues for economic development, particularly in coastal communities that have traditionally relied on fishing. The establishment of mariculture farms can create a wide range of job opportunities, from hatchery technicians and farm managers to processing and distribution workers. This diversification not only reduces the economic vulnerability of these communities but also fosters the development of ancillary industries, such as feed production, equipment manufacturing, and research and development. Furthermore, mariculture can attract investment and stimulate local economies by creating a reliable source of income and promoting the sustainable use of marine resources.

Environmental Protection

One of the most significant advantages of mariculture is its potential to reduce the environmental impact of fish production compared to traditional fishing methods. By farming fish in controlled settings, we can minimize the disruption to natural ecosystems and prevent the overexploitation of wild populations. Mariculture practices can be designed to optimize resource use and minimize waste, such as using floating pellets and environmentally friendly diets to reduce feeding waste. Additionally, rotating cages and allowing fallow periods can help manage nutrient flow and prevent the accumulation of waste. By implementing strict biosecurity measures, mariculture can also prevent the spread of diseases and invasive species, further protecting marine biodiversity.

Moreover, mariculture operations can be integrated with other sustainable practices, such as polyculture systems that combine different species to mimic natural ecosystems and enhance productivity. These practices contribute to a more holistic approach to marine resource management, ensuring that the environmental footprint of fish farming is minimized.

In summary, mariculture presents a compelling solution for achieving sustainable fish production, economic diversification, and environmental protection. By embracing this innovative approach, we can create a resilient fisheries sector that supports both human and ecological well-being.

Technical Evaluation of Mariculture in the Bahamas

Requirements for Introducing New Species

1. Compelling Need: There must be a strong justification for growing the proposed non-native species that cannot be met through cultivating native species and strains.
2. Risk of Escapes: Evidence must indicate that accidental escapes to the natural environment will not establish reproductive populations or hybridize with indigenous species. Facilities should be designed to minimize the likelihood of escapement.
3. Pest and Disease Control: The introduced species should not carry pests, parasites, or diseases that could affect native species or strains.

Steps to Reduce Biological Impacts

1. First Generation Progeny: Introductions should come from first-generation progeny derived from quarantined broodstock rather than direct transplantation from donor populations.
2. Monosex or Sterile Organisms: Grow monosex or reproductive sterile organisms (e.g., hybrids, triploids, sex-reversal) when available.
3. Veterinary Inspections: Conduct inspections by qualified veterinarians for each consignment prior to or following arrival, with quarantine or disinfection as appropriate.
4. Pathogen-Free Broodstock: Establish and maintain certified specific pathogen-free (SPF) broodstock. Periodically inspect imported material to confirm freedom from disease and introducible pests.
5. Effluent Sterilization: Sterilize effluents from quarantine facilities before release to ensure all living organisms contained are killed.
6. Ongoing Monitoring: Conduct ongoing studies and monitoring of the introduced species in its new environment, with regular progress reports submitted to the government.

Ensuring Sustainable Mariculture Practices

Long-term growth of the mariculture industry in the Bahamas relies on ecologically sound practices and sustainable resource management. Governments can promote these practices by:

• Regulating the creation of new farming facilities in mangroves and other coastal wetlands.
• Establishing fines to minimize fish escapes from aquaculture pens.
• Enforcing strict disease control measures for stock movement.
• Mandating effluent treatment and in-pond recirculation of wastewater.

Many aquaculture operations have adopted such practices due to increasing environmental concerns. However, in some countries, these policies may not be politically enforceable or economically and socially feasible.

Role of Government and Private Sector

Governments can support sustainable mariculture by:

• Investing in research and development for environmentally friendly aquaculture systems.
• Eliminating subsidies for ecologically harmful practices.
• Establishing and enforcing regulations to protect coastal ecosystems.

The private sector must also recognize that practices leading to further pressure on ocean fish stocks, destruction of coastal habitats, water pollution, and introduction of pathogens and non-native fish are counterproductive to the industry's long-term health. If public and private interests work together to reduce the environmental costs of fish farming, the current unsustainable trends can be reversed, allowing aquaculture to contribute positively to global fish supplies.

Conclusion

As world fish production from capture fisheries has leveled off since the 1990s, the demand for seafood continues to rise due to population growth and the perception of seafood as a healthy food choice. Scientists believe natural ocean production will not increase. Therefore, to meet future seafood demand, mariculture and freshwater aquaculture production must increase significantly.

Mariculture, the cultivation and farming of fish, is not new to the Bahamas. Previous efforts with tilapia have shown promise, and now focusing on snapper and grouper farming could help maintain a balanced ocean ecosystem. Marine aquaculture production should involve critical evaluations based on biological, marketing, and financial criteria. As Goodwin suggested, when demand exceeds supply, achieving equilibrium is crucial, and mariculture provides a viable solution. Using harvesting strategies such as mariculture and scaling up this method can be a resilient solution to the decrease the pressure on fisheries and enhance resilience in country.

For further information, especially on conch fisheries in the Bahamas, read "The Fall of Conch Fisheries."

References

• Department of Marine Resources, The Bahamas
• The Bahamas National Trust
• Eleuthera Island School
• Scientific Journal Articles
• Battershill, C.N., & Duckworth, A.R. (1999). Sponge aquaculture for drug production. World Aquaculture ’99.
• Croft, R.A. (1999). The birth of a new aquaculture industry in Micronesia – culturing commercial sponges. World Aquaculture ’99.
• University of Hawaii Sea Grant College Program. (1996). Starting a successful commercial sponge aquaculture farm. Center for Tropical and Subtropical Aquaculture Publication No. 120.