Investment Feasibility Analysis of Large Submersible Cage Culture in Taiwan: A Case Study of Snubnose Pompano (Trachinotus anak) and Cobia (Rachycentron canadum)

Abstract

Onshore farming for premium aquaculture is under scrutiny and criticism partially due to possible causes of adverse environmental impacts on other resource users and the surrounding environment. The best alternative to preventing or minimizing these impacts is to utilize open seawater by large submersible cage culture. The current operation in Taiwan has demonstrated that the culture operation is technically feasible but economically demanding because of high capital and operating costs. Therefore, this study conducted an economic analysis of the expansion of large submersible cage culture by selecting two premium species of snubnose pompano (Trachinotus anak) and cobia (Rachycentron canadum) and examined the profitability of large submersible cage culture investment. This study found that the current operation of four-unit cages highlighted a negative net present value and internal rate of return with a payback period of over ten and six years, respectively. Large submersible cage culture can be financially profitable when its operation unit expands from 8 to 24 units. Increasing unit cages to eight incurred a gross margin of 17.09%, BCR 1.21, with a payback period of 5.36 years. Expanding the operation to 24-unit cages was a potentially lucrative investment with a gross margin of 18.51%, BCR 1.23, PI 2.15, internal rate of return of 20.84%, and a payback period of 3.55 years. Sensitivity analyses revealed that market price and survival rate significantly impact the profitability of large submersible cage culture. Finally, it is suggested that producers could invest in 8-unit cages and maintaining the survival rate of snubnose pompano and cobia at 80% and 40%, respectively.

1. Introduction

Onshore farming for premium aquaculture is under scrutiny and criticism partially because they are believed to generate adverse environmental impacts on other resource users and the surrounding environment. Taiwan is located in the subtropical zone, surrounded by the sea on all sides, with a coastline of 1961 km. It has a high degree of marine biodiversity and a climate and environment suitable for the development of fisheries. Most of Taiwan’s aquaculture areas are in offshore and coastal areas, with aquaculture and fisheries covering an area of 44,000 hectares, and cage net aquaculture only accounting for about 30 hectares.

The major development of Taiwan’s cage culture occurred in 1988. Mostly in the littoral areas of Penghu and Pingtung, the peak yield was more than 5000 MT [1,2]. However, the culture facility and culture management techniques are immature. In recent years, the yield remains at about 2500 MT, accounting for about 1% of Taiwan’s culture fishery production [3]. There are merely 11 farmers at present. According to geographical location, two to three typhoons pass through Taiwan annually, and the China coastal current moves south in the winter. Therefore, the net cages are mostly concentrated in the Penghu basin or inshore waters of Pingtung to avoid the attack of typhoons and facilitate routine culture management operations [4,5,6,7]. However, the Penghu basin is not deep enough, and the water flows slowly. The culture waste cannot all be taken away by the ocean current or tides. Over the years, the sea areas became polluted gradually, inducing many fish diseases. Due to typhoons or heavy rainfall, the land-based pollution source is often brought into the Pingtung Sea area, thereby causing harm to net cages and the cultured organisms. Many environmental organizations worldwide criticize that the pollution source induced by inshore culture fishery is hazardous [5,8,9].

In recent years, cage culture has been progressively moved to wider waters in many countries. Open sea areas have deeper waters and stronger ocean currents, which could prevent environmental pollution and fish diseases. They are more friendly to the culture environment and favorable for sustainable operation [10,11,12,13]. Therefore, the government of Taiwan investigated the aquatic characteristics, tidal current, ocean waves, hydrology, water quality, coastal current of the sea areas around Taiwan, the constraints of the existing industrial equipment, the probability of addressing acquisition, and waterways in 2016. They selected a water depth of 40~70 m with an annual mean wave height under 0.1 m and an annual average flow velocity lower than 0.3 m/s to plan the possible areas for developing net cages in the open sea. This attempt aimed to assist the farmers in Pingtung area to build a demonstration field of large-sized net cages with a circumference of 100 m and a net depth of 15 m between 2017 and 2019 (Figure 1). The goal was to divert Taiwan’s cage culture industry to the large-scale and scale-up culture enterprise type.

The tested annual output of offshore large net cage cultured snubnose pompano is 200 tons/cage year. The cage culture is a high-risk and high-profit capital concentrated industry. For farmers to be offshore, upsizing and scaling-up will certainly increase capital expenditure and operating costs. The culture management model and challenges are also different from traditional inshore culture. Therefore, comprehensive evaluation and planning are required before investment [1,14,15,16].

The technical, economic, and legal feasibility should be considered in the investment in culture fishery [17]. Taiwan is actively involved in research, development, and discussions at the technical and legal levels. From the economic perspective, this study adopted the cost-effective method and sensitivity analyses to analyze the economic feasibility and investment potential of developing offshore cage culture in Taiwan. It also evaluated the appropriate production scale of initial investment to provide integrated information on industrial transformation and trade investment in cage culture in Taiwan.

2. Materials and Methods

2.1. Study

All data in this study were collected from the research site based on the sea area of the Haikou Offshore Demonstration Field in Checheng Township, Pingtung County, Taiwan (Figure 1). This study selected two species, snubnose pompano (Trachinotus anak) and cobia (Rachycentron canadum). The analytic data were divided into preliminary data and secondary data. The questionnaire for the preliminary data was designed according to the variables influencing the production benefit of cage culture, including economic, biological, and technical variables. Farmers, scholars, and experts of cage culture were interviewed on-site in May 2020 to find out about the farmers’ business processes, considerations in production, and risk management in the cage culture industry. The secondary data were derived from the market statistics on the global information network of fishery products of the Fisheries Agency from 2015 to 2019. Quote the exchange rate published by the Bank of Taiwan on 15 July 2022. This study evaluated the selling price range and occurrence probability according to the market prices of snubnose pompano and cobia for the past five years.

2.2. Offshore Cage Aquaculture Facility

A basic schematic of the offshore cage aquaculture facility is summarized in Figure 2, and

Table 1. Submerged circular cage net system specifications and construction costs.

Variable	Specification
Circular diameter of inner pipe	31.5 m
Net depth	15 m
Circular perimeter of inner pipe	102 m
1 cage volume	12,058 m3
4 cages volume	48,230 m3
Deformation rate	20%
Actual volume (4 cages)	38,584 m3
Cage system	Cost (thousand NTD)
Anchor	6000
Cage frame	3500
Cage netting	7000
Net cover	1500
Total	18,000

Note: One US dollar is equal to 30 NTD (15 July 2022).

summarizes its general specifications.

2.3. Cost–Benefit Analysis

The cost–benefit analysis adopted in this study was based on previous studies [17,18]. The experiment selected five economic indicators: benefit–cost ratio (BCR), profitability, net present value (NPV), internal rate of return (IRR), and cost recovered years. It set a 10-year term of investment for simulated evaluation of investing in different target species in cage culture. The BCR was used for evaluating culture productivity in culture economics [2,19,20,21,22,23]. The cost was divided into operating expense (OPEX) and depreciation cost (DC) in the cost–benefit analysis operation. The OPEX referred to the expenses required in the cage culture process, such as the costs of fries, water and electricity, personnel, and feed. It excluded the initial investment in construction. The DC referred to the acquisition cost of hardware facilities, such as net cage systems and automated equipment. The depreciation period of each equipment is not consistent, and the depreciation amount amortized each year has little impact on the overall calculation. This study excludes the depreciation expense and does not recognize it. The cost–benefit ratio and profitability were calculated based on net revenue. The NPV, IRR, and cost recovered years were calculated using cash flow (CF) [24]. The discount rate is calculated by using the Weighted Average Cost of Capital (WACC) as the determined discount rate, for which the loan interest rate of 6% is the summary of the interest rates reported by the Credit Department of the 283 Agricultural Associations in Taiwan in August 2020. The average basic lending rate in the table and the expected return on investment of shareholders are 10%. Based on this, the discount rate of this study is calculated to be 10%.

As with all economic analyses, assumptions need to be made to simplify the study and maintain the focus of the analysis on the appropriate areas. With four cages as a unit, the assumptions used in this study were developed using the actual data from cages. Different constructs, i.e., 4, 8, 16, 20, 24 cages, are included in our assumptions. Taking a group of four-unit cages as an example, the construction cost of matching aquaculture production equipment is 15.96 million NTD (

Table 2. Cost–benefit analysis of 4 cages during ten-year production.

Production Cost (Thousand NTD)	Snubnose Pompano (Trachinotus anak)	%	Cobia (Rachycentron canadum)	%
Depreciation
Cage system equipment	7200		7200
Automation equipment	3555		3555
Workshop and boat	5200		5200
Fry	38,584	26.7	19,292	15.0
Feed	95,496	66.1	99,316	77.0
Labor	3120	2.2	3120	2.4
Power	600	0.4	600	0.5
Fuel	3600	2.5	3600	2.8
Other	3000	2.1	3000	2.3
Total	149,600		134,128
Profit
Gross Revenue	169,771		162,825
Net Revenue	20,171		33,897
Profitability Measure
Gross margin (%)	14.94		20.82
Benefit–cost ratio	1.18		1.26
Profitability index	0.98		1.31
Net present value	−56,696		−22,126
IRR (%)	−0.49		6.11
Payback period (year)	10.04		6.69

Note: thousand NTD; One US dollar equals 30 NTD.

). All income, operating costs, and biological data were based on data obtained during the ten years of operation of the offshore cage aquaculture. The cost of equipment attaching to different cage constructs is assumed to be the same in our experiments. When the number of cages reaches sixteen units, to improve operation efficiency and ship transportation capacity, an additional CT-5 fishing boat is required (20 million NTD), and the rest of the equipment configuration is unchanged.

2.4. Operational Scale of Cage Culture

Economic models were developed in this study to assess and compare the effects of the operational scale of cage culture on profitability for hypothetical 8, 16, 20, and 24 cages aquaculture. The economic analysis techniques used were based on 4 cages aquaculture. The data obtained from 4 cages were sound, and assumptions were developed for these larger-scale facilities. Based on the market price analysis results for the 4 cages aquaculture, income data were applied to these models to determine the long-term income projections for 8, 16, 20, and 24 cages. Most operating costs for 8, 16, 20, and 24 cages were developed based on costs incurred for 4 cages, with additional expert opinion provided by breeding experts who actually operate the cage culture as to how these costs may change at different scales.

2.5. Analysis of Key Variables Affecting Offshore Cage Aquaculture Profitability

A sensitivity analysis was conducted to highlight areas where improvement of the offshore cage aquaculture may have the greatest performance and economic impact. The survival rate and farm price were addressed by comparing the financial performance in a variable range. The farm price used for sensitivity analysis was derived from the highest occurrence over a period of five years (Figure 3).

3. Result

Table 1, Table 2 and

Table 3. Initial investment for cage aquaculture.

Item	Quantity	Price (Thousand NTD)	Remark
Cages	4	72,000	4 cages + mooring system
Bait boat	1	20,000	with crane
Automatic washing machine	1	7500
Automatic fish suction machine	1	4350	Fish-containing water separation and counting system
Instant fixed underwater lens	1	930
Instant mobile underwater camera (ROV)	1	970
Real-time underwater sonar detection system	1	300
Real-time water quality environmental monitoring module	1	800
Power Communication System	1	700
CT-3Work boat	2	24,000	including crane and live fish cabin
Large rubber raft work boat	1	10,000
Unpowered offshore platform	1	1500
Repair base	1	10,000
Primary processing refrigeration equipment	1	1500
Transportation and heavy machinery equipment	1	5000
Total		159,550

One US dollar is equal to 30 NTD.

show the cage aquaculture specifications and its construction costs. The total investment for 4 cages is NTD 159.550 million. The cages are a significant proportion of the investment (NTD 72 million), and the workboat is the second largest investment.

Table 4. Basic production parameter of cage aquaculture (4 cages).

Variable	Snubnose Pompano (Trachinotus anak)	Cobia (Rachycentron canadum)
Stocking density (fish/m3)	50	10
Total stocking	1,929,216	385,843
Fry size (gram/fish)	30	200
Fry Price (NTD/fish)	20	50
Harvest size (kg/fish)	0.6	5
FCR	2.0	2.6
Survival rate (%)	80	30
Grow out (kg/m3)	21	15
Farming cycle	12	12
Production (kg)	810,270.7	578,765
Feed price (kg)	55	55

shows the summary production variables of snubnose pompano (Trachinotus anak) and cobia (Rachycentron canadum) in 4 cages. Table 2 shows the expenditure and financial performance of both species. Feed is the main expense of production, and fry is the second largest expense. The net revenue of snubnose pompano was NTD 20.1 million and cobia was NTD 28.6 million. The gross margin of snubnose pompano and cobia was 14.94% and 20.82%, respectively. The cost–benefit ratios of both species were 1.18 and 1.26, but snubnose pompano incurred a profit index of 0.98. This indicates that the project is not feasible for investment. In addition, both species incurred a negative NPV, showing the producers to have suffered a loss in both species. Snubnose pompano’s producers also incurred a negative IRR, and the payback period was 10.04 years.

Table 5. Investment, production cost, and revenue of snubnose pompano and cobia production in different number of cages.

	Variable	8 Cages	%	12 Cages	%	16 Cages	%	20 Cages	%	24 Cages	%
Snubnose pompano	Initial investment	231,550		303,550		395,550		467,550		539,550
	Production cost
	Fry	77,168	27.4	115,752	27.6	154,337	27.8	192,921	27.8	231,505	27.9
	Feed	190,992	67.8	286,488	68.4	381,984	68.7	477,480	68.9	572,977	69.0
	Labor	4160	1.5	5200	1.2	6240	1.1	7280	1.1	8320	1.0
	Power	630	0.2	660	0.2	690	0.1	720	0.1	750	0.1
	Fuel	4680	1.7	5760	1.4	6840	1.2	7920	1.1	9000	1.1
	Other	3900	1.4	4800	1.1	5700	1.0	6600	1.0	7500	0.9
	Gross revenue	339,542		509,313		679,084		848,855		1,018,626
Cobia	Initial investment	231,550		303,550		395,550		467,550		539,550
	Production cost
	Fry	38,584	15.4	57,876	15.5	77,168	15.6	96,460	15.7	115,752	15.7
	Feed	198,632	79.3	297,948	80.0	397,264	80.4	496,580	80.7	595,896	80.8
	Labor	4160	1.7	5200	1.4	6240	1.3	7280	1.2	8320	1.1
	Power	630	0.3	660	0.2	690	0.1	720	0.1	750	0.1
	Fuel	4680	1.9	5760	1.5	6840	1.4	7920	1.3	9000	1.2
	Other	3900	1.6	4800	1.3	5700	1.2	6600	1.1	7500	1.0
	Gross revenue	325,651		488,477		493,902		615,560		976,954

Note: Thousand NTD; One US dollar equals 30 NTD.

shows the scenario of increasing the cages’ units for raising both species. Capital expenditure for 8 units is NTD 231.5 million. This cost increased with increasing cages’ units. Total expense for 24 units was NTD 539.5 million, which was 3.3 times higher compared to 4 units. There was an additional CT-3 and CT-5 workboat from 16- to 24-unit cages’ operation. Increasing the cages’ units also affected production costs. The operation cost of subnose pompano doubled from 8 to 24 units, increasing significantly. The feed cost remained the main expense. In cobia farming, feed is also the main expense, and fry is the second-largest expense covering 95% of the production cost.

The profitability measure highlighted that the gross margin increased from 8 units, but gross margin and BCR almost remained similar from 16 to 24 units (

Table 6. Summary of financial indicators of snubnose pompano and cobia production in different number of cages.

Species	Profitability Measure	4 Cages	8 Cages	12 Cages	16 Cages	20 Cages	24 Cages
Snubnose Pompano	Gross margin (%)	14.94	17.09	17.8	18.16	18.37	18.51
	Benefit–cost ratio	1.18	1.21	1.22	1.22	1.23	1.23
	Profitability index	0.98	1.54	1.83	1.92	2.05	2.15
	Net present value *	−56,696	3631	63,958	104,285	164,612	224,940
	IRR (%)	−0.49	10.43	15.6	16.97	19.21	20.84
	Payback period (year)	10.04	5.36	4.29	4.06	3.75	3.55
Cobia	Gross margin (%)	20.82	23.05	23.79	24.17	24.39	24.54
	Benefit–cost ratio	1.26	1.3	1.31	1.32	1.32	1.33
	Profitability index	1.31	1.99	2.35	2.45	2.61	2.73
	Net present value *	−22,126	72,770	167,667	242,563	337,460	432,357
	IRR (%)	6.11	18.26	24.18	25.66	28.29	30.19
	Payback period (year)	6.69	3.88	3.18	3.04	2.82	2.69

* Note: Thousand NTD (One US dollar equals 30 NTD).

). NPV increased significantly with increasing cages’ units, and the IRR also followed a similar trend. Additionally, increasing the cages’ units decreased the payback period. The 24 units showed a payback period of 3.55 years. The gross margin of cobia farming in 24 units was 24.54%, and the benefit–cost ratio was 1.33. NPV also increased as the cages’ units increased. The 24 units gained the highest IRR (30.19%) and the lowest payback period (2.69 years).

Table 6 shows that when the scale of the cages’ units was increased every four units, the fish fry and feed expenditure of the snubnose pompano and cobia increased with an increase in the number of fish. Other expenses decreased with the increase in the number of cage units. The unit production cost of snubnose pompano fell from 155 NTD/kg (4 units) to 149 NTD/kg (24 units). Additionally, the unit production cost of cobia dropped from 167 NTD/kg (4 units) to 159 NTD/kg (24 units).

This study analyzed the sensitivity based on the survival rate and the market price. The simulation comprised of three survival rate scenarios and four market price ranges (

Table 7. Sensitivity analysis of snubnose pompano and cobia at different farm prices and survival rates.

		16 Cages						24 Cages
Species	Price NTD	Survival Rate						Survival Rate
		70%		80%		90%		70%		80%		90%
Snubnose Pompano	181	1.26 a	7.03 b	1.78	4.44	2.27	2.24	1.38	6.08	1.96	3.94	2.49	3.04
		−67,060,529 c	5% d	69,967,352	15%	195,732,120	23%	−46,814,900	7.59%	158,726,028	17.75%	347,373,181	26.41%
	191	1.77	4.47	2.36	3.18	2.94	2.47	1.95	3.97	2.59	2.83	3.23	2.22
		67,369,289	15%	219,413,262	24%	371,457,236	33%	154,828,933	17.56%	382,894,894	27.99	610,960,854	37.99%
	201	2.28	3.31	2.93	2.48	3.59	1.97	2.50	2.95	3.22	2.33	3.94	1.79
		198,765,315	23%	369,580,150	33%	540,394,985	43%	351,922,973	26.61%	608,145,225	37.87%	864,367,477	48.84%
	211	2.78	2.63	3.51	2.02	4.23	1.66	3.06	2.63	3.86	1.81	4.66	1.50
		330,161,342	31%	519,747,038	42%	709,332,734	53%	549,017,013	35.30%	833,395,557	47.52%	1,117,774,101	59.54%
		16 Cages						24 Cages
Species	Price NTD	Survival Rate						Survival Rate
		30%		40%		50%		30%		40%		50%
Cobia	201	1.27	6.94	1.97	3.94	2.66	2.76	1.40	6.08	2.16	3.52	2.93	2.49
		−64,026,738	5.44%	117,424,918	17.81%	298,876,574	29.10%	−42,265,150	7.83%	229,912,310	21.07%	502,089,771	33.25%
	211	1.63	4.97	2.45	3.04	3.26	2.20	1.79	4.42	2.69	2.7	3.59	1.97
		29,827,567	12.04%	242,563,991	25.66%	455,300,415	38.42%	98,516,295	14.87%	417,620,904	29.54%	736,725,513	43.40%
	221	1.99	3.88	2.92	2.49	3.86	1.83	2.19	3.47	3.22	2.23	4.24	1.65
		123,681,872	18.22%	367,703,064	33.23%	611,724,257	47.56%	239,297,740	21.50%	605,329,497	37.75%	971,361,254	53.37%
	231	2.35	3.19	3.40	2.09	4.46	1.57	2.58	2.84	3.74	1.87	4.9	1.42
		217,536,176	24.12%	492,842,137	40.63%	768,148,098	56.59%	380,079,185	27.87%	793,038,091	45.80%	1,205,996,996	63.25%

Note: ^a Profitability index, ^b payback period, ^c NPV, ^d IRR.

). When the price of snubnose pompano remained unchanged at 181 NTD/kg and the survival rate was 70%, producers incurred a gross profit margin of 13.81%, BCR of 1.16, profitability index of 1.26, negative NPV (−67,061), IRR of 5.21%, and a payback period of 7.03 years. Increasing the survival rate to 90%, producers incurred NPV NTD of 195.7 million and a payback period of 2.24 years. The financial and economic indicators showed that increasing survival rates led to an economically feasible investment. A similar trend was also revealed in cobia farming, whereby increasing the survival rate to 50% led to an economically feasible investment.

4. Discussion

The analysis of 4 cages on snubnose pompano and cobia found that the investment forecast was not economically viable. After the 10-year projection, the investment incurred a negative NPV of –NTD 56,696 and –NTD 22,126, respectively (Table 6). The current investment highlights that such losses are difficult to accept the investment in 4 cages.

According to profit indicators, snubnose cobias and pompanos are unprofitable. All indicators were negative, with an investment payback period for snubnose pompano over ten years and cobia over six years. These results are contrary to an economic analysis of cobia on a large production scale in Brazil [25]. Cobia farming in Brazil by an installation of twenty-four 1607 m³ cages, a total volume of 38,568 m³ unit cages, stocking density of 3 fish/m³, yield of 316,358 kg/year, and selling price of 8.62 USD/kg, incurred a positive NPV of USD 297,615 and a payback period of 3.88 years. The feed cost is the main expense (64.43%) and is more sensitive to FCR, selling price, and productivity fluctuation. The operation expense in Brazil and Taiwan is almost similar. The main reason for the high discrepancy in profitability is due to the high initial investment in Taiwan. Producers in Taiwan have invested in several supporting infrastructures, such as workboats, repair bases, primary processing refrigeration equipment, and heavy machinery equipment. Moreover, the different market prices also reveal the gap in profit incurred. The selling price in Brazil is 8.62 USD/kg and in Taiwan is 7.3 USD/kg. The high selling price in Brazil means producers incur a better profit performance.

The operational scale of cage culture can be discussed due to the development of economic models for hypothetical 8 to 24 cage investment. In contrast to the non-viability of 4 cage investment, the hypothetical 8 cages for snubnose pompano farming appeared marginally viable, with a positive NPV of NTD 3.631 million. The hypothetical 16 cages incurred a gross margin of 18.16%, BCR of 1.22, and a payback period of 4.06 years. Further increasing the unit cages to 20 units gained a gross margin of 18.37%, NPV of NTD 164.612 million, IRR of 19.21%, and payback period of 3.75 years. The data highlight the importance of the potential for economic viability at higher output levels. The hypothetical 20-unit cage investment demonstrates the importance of the operational scale of cage culture for economic viability (Table 6). The results also indicate that the 24 cage was economically viable with a gross margin of 18.51%, BCR of 1.23, PI of 2.15, IRR of 20.84%, and a payback period of 3.55 years. Investment in 8 or more units not only showed better financial performance than the 4 cages, but also appeared to be a potentially lucrative investment opportunity (Figure 4). The financial indicator in cobia farming suggests a similar trend: increasing cages’ units increases the profit gained by producers. The economic analysis of large cage culture in [17] demonstrated that the profit indicators of more than 8 cages are positive. The profitability is gradually improved with the increased number, and 16-unit cages are recommended due to their reasonable investment and easiness to manage. For 16 cages, cobia’s total annual breeding cost is NTD 493.903 million, with a BCR of 1.32, an NPV of NTD 242.563 million, and an IRR of 25.66%. The breeding cost of snubnose pompano is NTD 555.792 million, with a BCR of 1.22, an NPV of NTD 104.285 million, and an IRR of 16.97%. The payback periods of the two species are less than four years and have sufficient profits. According to the recent management experience in cage aquaculture in Taiwan, 16-unit cages can be managed with the presented hypothetical manpower, operating vessels, and automated equipment. Moreover, risk management and environmental carrying capacity must be considered to facilitate environmentally sustainable operation. The previous study reported that cobia has the greatest potential among all candidate species for offshore cage culture in Taiwan [1]. Increasing the system size in cobia production would be more profitable. Cobia farming is highly profitable compared to other aquaculture species [26].

The sensitivity analyses on investing in different units of cages found that increasing the sale price and survival rate are the two key variables that have the most significant effect on the profitability of large-scale submersible cage culture. The analyses also showed that the survival rate of 70% of snubnose pompano was profitable at a price of 191 to 211 NTD/kg. Moreover, the survival rate of 30% in cobia farming was profitable at a price of 211 to 231 NTD/kg. The analysis revealed that an increase in the survival rate to 80% of snubnose pompano contributed to better economic performance in 16 to 24 cages. Additionally, increasing the survival rate to 40% of cobia resulted in better financial indicators (Table 7). Another study found that a 16-unit cage was the optimal production scale based on cost–benefit analysis using PR, NPV, IRR, and payback period. As shown in Figure 4, the optimum production scale conditions were satisfied with the economic benefits of investment when 16-unit cages were constructed. The breakeven point for cobia was achieved at a survival rate of 50% and a purchasing price of 235 NTD/kg. In other words, at an average survival rate of 50%, dealers can still make profits if the purchasing price of cobias drops to 201 NTD/kg. At a purchasing price of 231 NTD/kg, it only takes a survival rate of 30% to make profits. Regarding investments in snubnose pompano, profits can still be made at an average survival rate of 90% if the price drops to 181 NTD/kg. At a purchasing price of 191 NTD/kg, it only takes a survival rate of 70% to break even.

The development of large cage culture also has a negative impact that is not well-regulated. The rapid development of offshore mariculture also brings environmental challenges and requests for carrying capacity management [27,28]. The environmental restrictions of sea cage culture prevent the accumulation of particulate pollutants at the sediment level through migration and transportation [29,30,31]. The accumulation of particulate matter is a cumulative process, and most of the particles are deposited around the fish farms. The results of [31] indicated that sea cage culture has a limited influence on seawater environmental quality, whereas higher pollution levels were predicted for the sediment. A high stocking density and excessively using commercial feed had a negative impact on the environment. In the form of uneaten feeding pellets and fish-released feces, particulate waste is considered the primary source of ecological impact on the benthic community [32,33]. The feed composition directly determines the number of pollutants generated by the cage, especially in the release of nitrogen and phosphorus [34,35,36,37]. Therefore, exploring the sea area by determining the carrying capacity is useful for sustainable environmental management of large submersible cage culture.

In recent years, the government of Taiwan has advocated developing agriculture as a business operation and encouraged agriculture and fishery to transform smallholder economy into the business management model and use strategic and technical operations for initial public offerings. The government also assists companies to enter the extensive capital market to effectively raise funds for their future development, debt refunding, and operating costs. The enterprises interested in such direction can establish internal audit, internal control, and sound auditing systems to manage the operational risks, identify corporate competitiveness, adjust the operating guidelines, and improve the financial structure. However, there are serious challenges to asset risk control and produce yield improvement in the evolutionary process of culture fishery. The industry’s biological assets and non-biological assets (net cage facilities) are on the sea, making it undesirable as compared to the onshore culture. The asset risk control is difficult, and the asset insurance (cultured species or facilities) is unavailable. The financial institutions are hesitant to approve the loan. To collect funds from the public, the pre-operation is complicated, the working liabilities are increased, and the required cost is high. It is very difficult for the enterprises without the scale of operation, sound financial statement, or stable profit.

Referring to the developed countries of cage culture, the automatic and intelligent big data system is an essential tool for mariculture industry upgrade. Developing the scale efficiency is necessary to implement the profit of mariculture. The scale efficiency decision-making aims at the optimum economic benefit, which should be presented by appropriate asset allocation or reasonable production conditions. Having a good culture sea area environment, appropriate culture sea area, and adequate working capital is the foremost step in the scale-up development of the cage culture industry. When the culture sea area is diverted to the unshaded deep-sea area far from the coast, the culture environment is closer to nature and a better culture management technique is required. Therefore, the countries where the marine cage culture develops rapidly are oriented to scale-up, automation, and big data intelligence, aiming to resist the worst sea conditions, high yield, and intelligent accurate management.

The findings of this study show that only the scale operation of cage culture has good economic feasibility, but the demand for funds is high. A stable and adequate flow of funds is an important factor in enterprise operation. The techniques of operations cannot be enhanced without funds. Furthermore, the biological culture management improvement or importing the automated and advanced equipment, professional teams, talent cultivation, brand operation, and marketing channels are closely related to enterprises’ activable and available funds. The FAO [38] presented opinions on the development of marine cage culture in Asia in a global outline and regional comments on cage culture. The cage culture industry in Asia has a promising future. The cobia is very promising to be a global product. Under the cultural influence, Asia cannot expand development by vertical integration as Norway or Chile do, but the enterprises can develop in a cooperative manner to exert effective industrial power. For developing large-scale disaster-resistant submersible cages with a circumference over 100 m and 3 km away from the coast in Taiwan, time- and labor-saving, safe, intelligent, and automated equipment should be used. These systems could be automatic sensing systems for hydrology and images, automatic bait-casting systems, automatic net-washing machines, automatic fish pumps, and automatic dead fish clearing. Only the large data-based AI decision-making system can increase the culture efficiency, reduce the culture cost, and effectively protect biological and nonbiological assets on the sea.

5. Conclusions

Taiwan’s onshore culture area is about 40,000 ha. The culture production is about 300,000 MT. In recent years, the Taiwan government has been dedicated to green energy. The green energy is estimated to be 25% of the total electricity generation of Taiwan in 2025. A part of land-based fishponds will evolve into fishery-electricity symbiosis, and 3000 ha of land for fishponds has been planned for developing solar energy. The culture fishery production will be influenced in the future. Taiwan’s culture fishery is mostly petty-farmer management, and the industry lacks international competitiveness. The net cages in the open sea are of capital-intensive industry, and the labor-intensive culture management should be changed into a technology-intensive management style. The application of various automated equipment contributes to the transformation of the traditional culture fishery of Taiwan. Taiwan is surrounded by seas, but the cage culture yield only accounts for 1%. This refers to the underutilization of sea resources. As the onshore culture area gradually decreases and the offshore area is polluted, Taiwan’s cage culture will certainly develop towards far and deep-sea areas. In 2016, the FAO conducted a survey on the coastal countries suitable for the development of cage net aquaculture in the world, and evaluated the conditions such as water depth, flow rate, and cost-effective sea area. In the countries suitable for the development of offshore cage net conditions, Taiwan ranked third, and the production base of offshore cage net aquaculture was quite similar, excellent and regarded as having great potential for development. Taiwan is surrounded by seas with a high degree of marine biodiversity, and the climate and environment are suitable for the development of fisheries. Taking advantage of the sea area to expand the area of marine cage net aquaculture can not only increase the share of marine aquaculture, but also reduce freshwater consumption and carbon emissions. The inevitable development trend of Taiwan’s aquaculture industry is to overcome the risks brought by strong winds, waves, and flow speed in the open sea through aquaculture-related equipment automation and intelligent technology, ocean energy power generation equipment, genetic breeding, feed processing, vaccine production, aquatic product processing, cold chain logistics, Internet of Things, and other industrial chains, in order to create rural economic development and increase employment. The findings of this paper have economic feasibility. Future investors need to carefully evaluate the levels of culture technique and operating management.