SeaFish

Culinary Importance in Southeast Asia

Milkfish holds significant culinary importance in Southeast Asia and certain Pacific Islands. Despite its reputation for being bony, deboned milkfish, known as “boneless bangús” in the Philippines, has gained popularity in markets and stores. However, many Filipinos continue to enjoy milkfish in various preparations, including cooked dishes and even raw delicacies like kinilaw na bangus, where the fish is marinated in kalamansi juice or vinegar.

Indonesian Culinary Delights

In Indonesia, milkfish is showcased in various dishes, such as bandeng duri lunak from Central and East Java, where the fish is prepared with tender bones, or bandeng presto, where it is pressure-cooked until the bones become soft. Smoked milkfish, known as bandeng asap, is another popular option. Whether fresh or processed, milkfish remains a favored seafood product in Indonesian fishing towns like Juwana and Sidoarjo.

Historical Evolution of Milkfish Aquaculture

Milkfish aquaculture has a rich history, dating back around 800 years in the Philippines before spreading to Indonesia, Taiwan, and beyond into the Pacific. Traditional methods involved restocking ponds with wild fry, resulting in variability in quality and quantity across seasons and regions.

Advancements in Milkfish Aquaculture

In the late 1970s, a significant breakthrough occurred when farmers successfully spawned breeding fish. However, obtaining these breeding fish was challenging, and their egg viability was unreliable. It wasn’t until 1980 that spontaneous spawning was observed in sea cages. These eggs proved sufficient to establish a consistent supply for aquaculture farms, marking a pivotal moment in the development of milkfish aquaculture.

Feeding Habits and Behavior

Milkfish, like many other fish species, have a diverse diet consisting primarily of autotrophs, algae, and small invertebrates. Their preference for such food sources aligns with their habitat, often found schooling around coasts and islands adorned with vibrant coral reefs. These underwater ecosystems provide ample food and shelter, making them ideal feeding grounds for milkfish populations.

Life Cycle and Migration Patterns

The life cycle of the milkfish is a fascinating journey that takes them through various habitats as they grow and mature. After hatching, the young fry spend approximately two to three weeks at sea before embarking on a migration journey. During the juvenile stage, they navigate their way to mangrove swamps, estuaries, and sometimes even lakes, seeking refuge and nourishment in these diverse environments. Upon reaching sexual maturity, they return to the sea to spawn and continue the cycle of life.

Reproduction and Spawning

Female milkfish play a pivotal role in the continuation of their species by spawning millions of eggs into saline shallow waters. This spawning activity typically occurs during the evening hours, contributing to the replenishment of milkfish populations. The abundance of eggs ensures the survival of the species, especially in areas where environmental conditions are conducive to successful hatching and larval development.

Habitat and Distribution

Milkfish, scientifically known as Chanos chanos, is the sole species within the Family Chanidae. Its distribution is primarily confined to the low latitude tropics or the subtropical regions of the northern hemisphere. These fish thrive in waters where temperatures exceed 20°C, making their presence notable along continental shelves and around islands. From the Red Sea and South Africa to Hawaii and the Marquesas, and from Japan to Victoria, Australia, milkfish populations flourish in diverse marine environments. They are commonly observed in small to large schools near coasts or around islands, showcasing their well-developed, migratory nature.

Spawning Behavior and Environmental Influence

In their natural habitat, milkfish spawning events are closely tied to the warm months of the year, typically occurring near coral reefs. However, populations near the equator exhibit year-round spawning activity, highlighting the influence of environmental factors on reproductive behavior. These spawning events are crucial for maintaining robust milkfish populations and ensuring the ecological balance of their marine habitats.

Migration and Settlement of Older Larvae

As milkfish larvae mature, they embark on a remarkable migration journey, transitioning from offshore environments to coastal wetlands such as mangroves and estuaries. Some may even venture into freshwater lakes. During this juvenile stage, which is crucial for their development, they primarily feed on zooplankton and exhibit a remarkable tolerance for warm waters, thriving in temperatures as high as 32°C.

Harvesting and Utilization of Juvenile Milkfish

Once they migrate onshore, juvenile milkfish become vulnerable to harvesting, often caught using fine-mesh nets deployed along sandy beaches and mangrove areas. These young fish, known as ‘fry,’ typically measure between 10 to 17 millimeters in length and are frequently utilized as feedstock in grow-out ponds, pens, and cages for aquaculture purposes.

Habitat Preferences and Return to the Sea

In their natural habitat, juvenile milkfish are commonly found inhabiting mangrove areas, coastal lagoons, and occasionally even freshwater lakes. However, as they outgrow their nursery habitats or approach sexual maturity, they instinctively return to the sea. This cyclical movement ensures the sustainability of milkfish populations and allows for the continuation of their life cycle.

Size, Weight, and Fisheries Importance

Milkfish are known to grow to impressive sizes, with males or unsexed individuals reaching a maximum length of 180 centimeters (SL), while females typically attain lengths of up to 124 centimeters (SL). The largest recorded specimen weighed 14.0 kilograms and lived for 15 years. Despite their potential for substantial growth, milkfish exhibit low resilience, with population doubling times ranging from 4.5 to 14 years.

Commercial and Cultural Significance

The fisheries significance of milkfish is substantial, particularly in the realm of aquaculture, where they are cultivated for commercial purposes. Additionally, milkfish hold cultural significance in Southeast Asia, where they are highly valued as a meal fish and are often incorporated into traditional cuisines. Their versatility as both a food source and bait for sport fishing further underscores their importance in coastal communities and beyond.

Farming Strategies for Milkfish

Fry Rearing: Milkfish fry is reared in various environments, including sea cages, large saline ponds (e.g., Philippines), or concrete tanks (e.g., Indonesia, Taiwan). The fry grows to sexual maturity at different rates depending on the rearing method.

Breeding Cycle and Spawning Induction: Once milkfish reach sexual maturity (around 1.5 kg or 3.3 lb), breeding cycles occur, with millions of eggs produced per cycle. Natural environmental cues primarily induce spawning, although attempts have been made to induce spawning using gonadotropin-releasing hormone analog (GnRH-A).

Hatcheries: Milkfish hatcheries contain a variety of cultures, including rotifers, green algae, and brine shrimp, alongside the target species. Hatchery methods can be intensive or semi-intensive, with semi-intensive methods proving more profitable but requiring higher labor expertise.

Nursery Techniques: Milkfish nurseries vary in density and commercialization across regions like Taiwan, Indonesia, and the Philippines. Commercial nurseries often have high densities, with methods including pond culture, pen culture, and cage culture.

Culture Methods: Culture methods include shallow and deep pond culture, with shallow ponds prevalent in Indonesia and the Philippines, while deep ponds offer more stable environments and are less susceptible to disease outbreaks. Cage culture occurs in coastal bays, relying on natural food sources or commercially produced feeds.

Harvesting Practices: Harvesting occurs when milkfish reach a certain size and weight, typically between 20–40 cm long or 250–500 g in weight. Partial harvests remove uniformly sized individuals, while total harvests result in a variety of sizes. Forced harvests may occur in response to environmental issues like depleted oxygen levels due to algal blooms.

Health Management: Milkfish farming faces potential challenges from parasites like nematodes, copepods, protozoa, and helminths, which are treatable with chemicals and antibiotics. Proper health management practices are essential to ensure the sustainability and productivity of milkfish farming operations.

Challenges and Opportunities in Milkfish Farming

Milkfish farming faces both challenges and opportunities as producers and consumers benefit from new technologies. While advancements have improved productivity, issues persist with unreliable broodstock technology and the inconsistent supply of fry.

Cultural Significance and Changing Consumption Patterns

Despite its traditional status as a staple food in the Philippines, Indonesia, and Taiwan Province of China, milkfish consumption faces hurdles, particularly among the younger generation who tend to avoid its bony flesh. This presents a challenge in creating new markets for milkfish products.

Economic Factors Driving Innovation

The combination of high land values and relatively low milkfish prices necessitates the introduction of new technologies to increase productivity per unit of land. As a result, milkfish aquaculture is transitioning towards reliance on formulated feed rather than solely on natural productivity.

Expansion of Hatchery Operations

The growth of hatchery operations, particularly in Indonesia and the Taiwan Province of China, is anticipated to reduce fry costs through increased availability and improved spawning technology. This expansion will contribute to the sustainability and scalability of milkfish aquaculture.

Diversification and Market Development

To capitalize on emerging opportunities, the development, marketing, and promotion of new product types are essential. This includes exploring innovative ways to process and market milkfish to appeal to diverse consumer preferences.

Integration with the Baitfish Industry

The mass production of milkfish fry in hatcheries opens up opportunities for the baitfish industry, as surplus fingerlings become available for this sector. This integration highlights the interconnectedness and potential synergies within the aquaculture industry. Motivation – Mind – Success – Thinking – Productivity – Happiness

Continued Research and Development

Further research and development efforts are necessary to address ongoing challenges and unlock new opportunities in milkfish farming. This includes exploring advancements in marketing strategies, processing techniques, and product innovation to meet the evolving needs of producers and consumers alike.