# Assessing the potential economic effects of mesopelagic fisheries as a novel source of fishmeal

Rohan Gowda Thanh Quang, Melina Kourantidou, Di Jin

► To cite this version:

Rohan Gowda Thanh Quang, Melina Kourantidou, Di Jin. Assessing the potential economic effects of mesopelagic fisheries as a novel source of fishmeal. Natural Resource Modeling, 2024, 37, pp.e12398. 10.1111/nrm.12398. hal-05244601

HAL Id: hal-05244601

https://hal.univ-brest.fr/hal-05244601v1

Submitted on 8 Sep 2025

HAL is a multi-disciplinary open access
archive for the deposit and dissemination of sci-
entific research documents, whether they are pub-
lished or not. The documents may come from
teaching and research institutions in France or
abroad, or from public or private research centers.

L'archive ouverte pluridisciplinaire HAL, est
destinée au dépôt et à la diffusion de documents
scientifiques de niveau recherche, publiés ou non,
émanant des établissements d'enseignement et de
recherche français ou étrangers, des laboratoires
publics ou privés.

<figure><img src="image_1.png" /></figure>

Distributed under a Creative Commons Attribution 4.0 International License
<figure><img src="image_2.png" /></figure>

# Assessing the potential economic effects of mesopelagic fisheries as a novel source of fishmeal

Rohan Gowda Thanh Quang<fnref n="1" /> | Melina Kourantidou<fnref n="2" />,<fnref n="3" />,<fnref n="4" /> ID |
Di Jin<fnref n="2" /> ID

<figure><img src="image_3.png" /></figure>

## Correspondence

Di Jin, Marine Policy Center, Woods Hole Oceanographic Institution, USA.
Email: djin@whoi.edu

## Funding information

WHOI's Ocean Twilight Zone program which is part of the Audacious Project, a collaborative endeavor, housed at TED; WHOI Summer Student Fellowship

## Abstract

The continuous growth of the aquaculture industry implies increased demand for efficient sources of aquafeed, such as fishmeal. Pelagic fish are a desirable source of fishmeal due to their high nutritional content. Nevertheless, several pelagic stocks that have been exploited extensively for fishmeal production face ecological limits due to commercial exploitation, and the aquaculture industry is now seeking novel, efficient, and sustainable sources of aquafeed. The mesopelagic zone, an ecosystem with many scientific uncertainties, is being considered as a potential source for fishmeal, largely owing to the abundance of mesopelagic fish and their robust nutritional profile. However, both the ecological and economic viability of commercial exploitation of mesopelagic fish are not yet well understood. To understand the conditions that would make such an endeavor economically viable in the context of global fishmeal production systems, we use a bioeconomic model that assesses the economic consequences of including mesopelagic fish as a fishmeal source. Through simulations, we assess the economic implications of this hypothetical mesopelagic

This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

© 2024 The Authors. *Natural Resource Modeling* published by Wiley Periodicals LLC.

<footnote n="1">¹Biology Department, Pomona College, Claremont, California, USA</footnote>

<footnote n="2">²Marine Policy Center, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, USA</footnote>

<footnote n="3">³Department of Sociology, Environmental and Business Economics, University of Southern Denmark, Esbjerg Ø, Denmark</footnote>

<footnote n="4">⁴Université de Bretagne Occidentale, AMURE, Plouzané, France</footnote>
<figure><img src="image_4.png" /></figure>

fishery on major pelagic fishmeal production systems. The mesopelagic fishery can be economically profitable for harvesters, and its addition to global fishmeal production reduces fishmeal market price, thus making it more accessible to aquaculture farmers and less profitable for pelagic fishers. While this may reduce fishing pressure on pelagic forage-fish stocks, the implications of commercial exploitation of mesopelagic on key ecosystem services remain a concern.

## KEYWORDS

aquaculture, fishmeal, forage fisheries, markets, mesopelagic, profitability

## Recommendations for Resource Managers

* The continuous growth of the aquaculture industry implies increased demand for efficient sources of aquafeed, such as fishmeal.

* Several pelagic stocks that have been exploited extensively for fishmeal production face ecological limits due to commercial exploitation, and the aquaculture industry is now seeking novel, efficient, and sustainable sources of aquafeed.

* The mesopelagic zone is being considered as a potential source for fishmeal. However, both the ecological and economic viability of commercial exploitation of mesopelagic fish are not yet well understood.

* We use a bioeconomic model to assess the economic consequences of including mesopelagic fish as a fishmeal source and the economic implications of this hypothetical fishery on major pelagic fishmeal production systems.

* The results show that mesopelagic fishery could be profitable for harvesters, and its addition to global fishmeal production would reduce fishmeal market price, thus making it more accessible to aquaculture farmers and less profitable for pelagic fishers.
<figure><img src="image_5.png" /></figure>

# 1 | INTRODUCTION

The aquaculture industry is the fastest-expanding food sector worldwide, driven by both income and population growth (Bouelet Ntsama et al., 2018; Naylor et al., 2021). Rising income levels have increased consumer food diversification, leading to higher spending on luxury items which include imported seafood. Further, recent decades have shown significant growth in aquatic food production and consumption, including in developing and least-developed countries, demonstrating clear associations with food and nutritional security (FAO, 2022; Garlock et al., 2022). Of the developmental conundrums within aquaculture, identifying aquafeed sources that are nutritious, economically and environmentally sustainable is of primary concern. Currently, aquaculture relies predominantly on forage fish from capture fisheries which are reduced to fishmeal/fish-oil (hereafter, we use “fishmeal” to reference both fishmeal and fish-oil) (Froehlich et al., 2018). However, as capture fisheries supply plateau due to ecological limits, aquaculture production systems are adopting novel feed sources and formulations to reduce their reliance on wild forage fish. Yet, these efforts have yielded mixed results as the feeds' nutritional content—omega-3 fatty acids, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA), specifically—needed for healthy fish growth is oftentimes compromised, unless some fishmeal is included in the aquafeed mixture (Geay et al., 2011; Liu et al., 2020, 2021).

Marine living resources from the mesopelagic or “Ocean Twilight Zone,” defined as waters from approximately 200 to 1000 m in depth, are being considered for exploitation as a novel source of fishmeal for aquaculture (Alvheim et al., 2020; Grimaldo et al., 2020; Olsen et al., 2020). Their high nutritional content, particularly in terms of long-chain polyunsaturated fatty acids, makes them excellent candidates for fishmeal production (Grimaldo et al., 2020). Although mesopelagic fish biomass estimations vary widely, from 2.4 to over 15 billion metric tons, it is believed to be of scale incomparably larger than any existing commercial fish stock (Anderson et al., 2019; Irigoien et al., 2014). Experimental catch surveys in Norway found glacier lanternfish (Benthosema glaciale) and Mueller's pearlside (Maurolicus muelleri)—two abundant fish in the mesopelagic—to contain high EPA, DHA, and protein content, along with low levels of substances unsuitable for human consumption (Grimaldo et al., 2020). While the mesopelagic shows promise as a fishmeal source, commercial operations remain unviable due to technological limitations which impede catch and processing efficiency, which ultimately limits profitability (FAO, 1997; Roberts et al., 2020; Sigurdsson et al., 2015; Standal & Grimaldo, 2020; Valinassab et al., 2007). However, continued technological development and research, coupled with industry interest, and opportunities created by fisheries regulation of other species are expected to lift these economic barriers and allow the exploitation of mesopelagic resources to supply the fishmeal industry; such development is desirable in terms of global food and nutrition security (Gatto et al., 2023; Kourantidou & Jin, 2022; Paoletti et al., 2021; Prellezo, 2019).

Despite the abundance of mesopelagic resources, there are concerns that commercial exploitation may undermine important ecosystem services in multiple ways. These concerns pertain to the role of mesopelagic organisms as prey for higher trophic levels (Naito et al., 2013; Smith et al., 2011), and as a key component of the biological carbon pump and therefore carbon sequestration, through the diel vertical migration (Buesseler et al., 2022; Roberts et al., 2020; Saba et al., 2021). In practice, this means that the development of mesopelagic fisheries could possibly endanger conservation of ecologically and/or commercially important large marine mammals and fish (i.e., dolphins, sharks, whales, billfish, rays, and tunas) and disrupt carbon
<figure><img src="image_6.png" /></figure>

sequestration irreversibly, thus proving very costly to human wellbeing (Buesseler et al., 2022; Dowd et al., 2022; Hidaka et al., 2001; Johnson, 2012; Mariani et al., 2020; Martin et al., 2021; Roberts et al., 2020; Saba et al., 2021; Smith et al., 2011).

In this paper, we assess the implications of including mesopelagic fish as a new fishmeal source via economic linkages between fishmeal production systems. We run simulations using a bioeconomic model that allows us to understand how pelagic fishmeal production responds to the inclusion of hypothetical, economically viable mesopelagic fisheries. We discuss our results in the context of the global fishmeal sector and the needs of the aquaculture sector, along with the viability and expectations for an emerging mesopelagic fishery and relevant policy implications.

## 2 | METHODS

The model used in the study is an extension of the modeling framework of Merino et al. (2010) by adding a hypothetical mesopelagic fishery to three major forage-fish fisheries: Humboldt Current, Asia, and Europe. For the population dynamics of each of these fisheries, we use the standard logistic growth model and the Schaefer harvest function (see Appendix Figure A1 for the growth function of the four fisheries, including the mesopelagic):

$$X_{i}(t + 1) = X_{i}(t) + r_{i}X_{i}(t)\left(1 - \frac{X_{i}(t)}{K_{i}}\right) - Y_{i}(t), \quad (1)$$

where index i denotes the four production systems; $X_i(t)$ is the stock in fishery i and year t; r and K are the intrinsic growth rate and carrying capacity, respectively; and Y is the harvest:

$$Y_{i}(t) = \max[q_{i}E_{i}(t)X_{i}(t), Quota_{i}(t)], \quad (2)$$

which is given by the Schaefer (1954) harvest function $q_i E_i(t) X_i(t)$, with q as the catchability coefficient and E as the fishing effort, subject to a fishing quota constraint. The quota is set at maximum sustainable yield (MSY):

$$Quota_{i}(t) = Y_{MSY_{i}} = \frac{r_{i}K_{i}}{4}. \quad (3)$$

The global fishmeal market is modeled through a linear demand function as follows:

$$p(t) = \alpha - \beta Q(t), \quad (4)$$

where p is the fishmeal price, α is the choke price, β is the slope of the demand curve, and Q is the aggregate quantity of fishmeal supplied to the market, which is the sum of supplies from different fishmeal production systems:

$$Q(t) = \sum_{i=1}^{4} Q_{i} \quad (5)$$

with
<figure><img src="image_7.png" /></figure>

$$Q_i(t) = \lambda_i Y_i, \qquad (6)$$

where $\lambda$ is the yield-to-meal transformation ratio.

As fishmeal production systems all supply to a common global market, each system's production is linked to and determined by production from other systems, resulting in an economic equilibrium that determines the market price and quantity to be supplied (Mullon et al., 2009).

The net profit (R) for each fishmeal production system is calculated as

$$R_i(t) = \lambda_i p(t) Y_i(t) - f_i E_i(t) - m_i Y_i(t) - s_i d_i Q_i(t), \qquad (7)$$

where f is the unit cost of fishing effort, m is the cost of reducing fish into fishmeal, s is the cost of shipping fishmeal to international markets, and d is the distance to main consumers.

Each fishery adjusts their fishing effort based on expected future profits, which are determined by past economic performance (Merino et al., 2010; Mullon et al., 2009). Specifically, the fishing effort is updated as follows:

$$E_i(t + 1) = E_i(t) + j_i \left( \frac{R_i(t)}{v_i} \right), \qquad (8)$$

where v is the price of a new fishing unit, and j is a coefficient controlling investment in additional fishing effort.

When all fisheries are managed to maintain their MSYs, the long-term steady-state fishmeal supply quantity and price at the global market are given by the following system of equations:

$$Q_{MSY} = \sum_{i=1}^{4} \lambda_i Y_{MSYi}, \qquad (9)$$

$$p_{MSY} = \alpha - \beta Q_{MSY}. \qquad (10)$$

We characterize the pelagic fish production systems in three regions: the Humboldt Current (Peru and Chile, harvesting Peruvian anchoveta), Asia (Vietnam, China, and Thailand, harvesting Japanese anchovy), and Europe (Norway and EU, harvesting North Sea sandeel). Together, they comprise close to 70% of global fishmeal production and consumption (IndexMundi, 2023; Merino et al., 2010). Monthly fishmeal prices 2014–2023 can be found in Figure A2 in the appendix. Initial fishmeal production was updated using data from IndexMundi (Table 1), and cost data were adjusted to 2023 dollars using price index (US GDP deflator). Data for the mesopelagic fishery was from Kourantidou and Jin (2022). Bioeconomic parameters for the mesopelagic are largely uncertain, but they are generally known to be less favorable than those for the existing production systems. For the simulation, the mesopelagic fishery has lower catchability as well as higher fishing cost (EUMOFA, 2018; Kourantidou & Jin, 2022; Underwood et al., 2021). In addition, we include the cost of adding new vessels. Table 2 presents the parameters used for model simulations.

Our model treats the whole ocean mesopelagic zone as a single fishery (harvesting Mueller's pearlside or Glacier lanternfish that are the most commonly targeted species and part of sampled families; Fjeld et al., 2023), ecologically and technically separate from the regional pelagic production systems; only an economic linkage is considered. Realistically, fishing in the
<figure><img src="image_8.png" /></figure>

<table><caption>TABLE 1 Fishmeal production (10³ t/year).</caption><thead><tr><th rowspan="2">Year</th><th colspan="2">Humboldt</th><th colspan="3">Asia</th><th colspan="2">Europe</th></tr><tr><th>Peru</th><th>Chile</th><th>Vietnam</th><th>China</th><th>Thailand</th><th>Norway</th><th>EU</th></tr></thead><tbody><tr><td>2014</td><td>754</td><td>450</td><td>423</td><td>450</td><td>450</td><td>200</td><td>455</td></tr><tr><td>2015</td><td>660</td><td>450</td><td>450</td><td>400</td><td>480</td><td>204</td><td>480</td></tr><tr><td>2016</td><td>972</td><td>435</td><td>435</td><td>436</td><td>350</td><td>210</td><td>466</td></tr><tr><td>2017</td><td>1000</td><td>368</td><td>450</td><td>400</td><td>335</td><td>230</td><td>420</td></tr><tr><td>2018</td><td>1068</td><td>345</td><td>470</td><td>364</td><td>340</td><td>220</td><td>435</td></tr><tr><td>2019</td><td>910</td><td>410</td><td>460</td><td>350</td><td>335</td><td>230</td><td>405</td></tr><tr><td>2020</td><td>1169</td><td>370</td><td>450</td><td>350</td><td>340</td><td>230</td><td>400</td></tr><tr><td>2021</td><td>1150</td><td>369</td><td>530</td><td>365</td><td>350</td><td>220</td><td>400</td></tr><tr><td>2022</td><td>1100</td><td>369</td><td>440</td><td>400</td><td>340</td><td>230</td><td>400</td></tr><tr><td>2023</td><td>1100</td><td>375</td><td>500</td><td>430</td><td>370</td><td>230</td><td>400</td></tr><tr><td>Country mean</td><td>988.3</td><td>394.1</td><td>460.8</td><td>394.5</td><td>359</td><td>220.4</td><td>426.1</td></tr><tr><td>Regional mean</td><td>1382.4</td><td></td><td>1214.3</td><td></td><td></td><td>646.5</td><td></td></tr></tbody></table>

Source: IndexMundi compilation of US Department of Agriculture data. https://www.indexmundi.com/Agriculture/?commodity=fish-meal&graph=production.

mesopelagic may exert technical (e.g., vessels crowding out ground space from other pelagic fleets) and ecological (e.g., predator-prey and competition relationships) impacts on pelagic production systems in the same region (Ulrich et al., 2002). Further, fisheries operating in the same region are unlikely to target pelagic or mesopelagic fish exclusively; rather, fisheries would exploit both resources, either incorporating seasonal operations or expanding current pelagic fleets to house the increased catch from the mesopelagic (Standal & Grimaldo, 2020). However, these points are beyond the scope of this study.

## 3 | RESULTS AND DISCUSSION

As discussed in Kourantidou and Jin (2022), a large-scale mesopelagic fishery is potentially viable in terms of economic profitability in the near future under certain price and fishing cost conditions. Figure 1 depicts the mesopelagic fishery in its first 10 years. Increasing fishing effort and harvest will drive down the stock as well as the global fishmeal price. As a result, the initial profit level will not be maintained. In the model, all four fisheries will be under quota management with MSY as constraints (Equations 2 and 3), so that the mesopelagic stock will not collapse in the long run (see Figure A3 in the appendix).

We use “Scenario 1” to denote simulation results without incorporating the mesopelagic fishery, while “Scenario 2” denotes results incorporating the mesopelagic. In both scenarios, changes in total fishmeal production and fishmeal price follow similar trajectories, differing mainly due to the additional quantity of fishmeal provided by the mesopelagic (Figure 2). We emphasize that fishmeal production is a supply function that is conditioned on the linear demand function specified for the baseline simulation
<figure><img src="image_9.png" /><figcaption>TABLE 2 Baseline parameters for the simulation.</figcaption></figure>

<table><thead><tr><th>Variable</th><th>Description</th><th>Unit</th><th>Humboldt (i = 1)</th><th>Asia (i = 2)</th><th>Europe (i = 3)</th><th>Mesopelagic (i = 4)</th></tr></thead><tbody><tr><td>Q<sub>i</sub>(0)</td><td>Initial fishmeal production</td><td>Mt year<sup>-1</sup></td><td>1.38</td><td>1.21</td><td>0.65</td><td>0.004</td></tr><tr><td>Y<sub>i</sub>(0)</td><td>Initial fish production</td><td>Mt year<sup>-1</sup></td><td>6.00</td><td>2.68</td><td>2.41</td><td>0.02</td></tr><tr><td>K<sub>i</sub></td><td>Carrying capacity</td><td>Mt</td><td>49.99</td><td>18.95</td><td>6.4</td><td>100</td></tr><tr><td>X<sub>i</sub>(0)</td><td>Initial fish stock</td><td>Mt</td><td>18.5</td><td>9.47</td><td>3.2</td><td>100</td></tr><tr><td>r<sub>i</sub></td><td>Intrinsic growth rate</td><td>year<sup>-1</sup></td><td>1</td><td>0.5</td><td>0.991</td><td>0.478</td></tr><tr><td>q<sub>i</sub></td><td>Catchability coefficient</td><td>10<sup>-6</sup> fishing unit<sup>-1</sup></td><td>1.5</td><td>1.42</td><td>1.93</td><td>1</td></tr><tr><td>E<sub>i</sub>(0)</td><td>Initial fishing effort</td><td>Total fishing unit (m<sup>3</sup>)</td><td>63,206</td><td>58,052</td><td>42,500</td><td>65,000</td></tr><tr><td>E<sub>max</sub><sub>i</sub></td><td>Maximum fishing effort</td><td>Total fishing unit (m<sup>3</sup>)</td><td>200,000</td><td>55,000</td><td>50,000</td><td>200,000</td></tr><tr><td>f<sub>i</sub></td><td>Fishing costs</td><td>$ fishing unit<sup>-1</sup></td><td>65</td><td>65</td><td>103.48</td><td>105</td></tr><tr><td>ν<sub>i</sub></td><td>Price of increasing fishing capacity</td><td>$ m<sup>-3</sup></td><td>2600</td><td>2860</td><td>5850</td><td>6500</td></tr><tr><td>m<sub>i</sub></td><td>Fishmeal transformation costs</td><td>$ t<sup>-1</sup></td><td>130</td><td>260</td><td>294.71</td><td>260</td></tr><tr><td>s<sub>i</sub></td><td>Shipping costs</td><td>$ t<sup>-1</sup> km<sup>-1</sup></td><td>0.026</td><td>0.026</td><td>0.026</td><td>0.026</td></tr><tr><td>d<sub>i</sub></td><td>Distance to main consumer</td><td>km</td><td>13,000</td><td>500</td><td>500</td><td>600</td></tr><tr><td>j<sub>i</sub></td><td>Fleet investment coefficient</td><td>Dimensionless</td><td>0.2</td><td>0.2</td><td>0.2</td><td>0.2</td></tr><tr><td>α</td><td>Choke fishmeal price</td><td>$ t<sup>-1</sup></td><td>1700</td><td></td><td></td><td></td></tr><tr><td>β</td><td>Slope of demand curve</td><td>$ t<sup>-2</sup></td><td>60</td><td></td><td></td><td></td></tr></tbody><tfoot><tr><td colspan="7">Abbreviations: Mt, 10<sup>6</sup> metric tons; t, metric ton.</td></tr></tfoot></table>
<figure><img src="image_10.png" /></figure>

Mesopelagic

<figure><img src="image_11.png" /><figcaption>FIGURE 1 Simulation results for the mesopelagic fishery.</figcaption></figure>

<figure><img src="image_12.png" /><figcaption>FIGURE 2 Simulation results for the global fishmeal market. (Left) Fishmeal traded in the global market (million metric tons). (Right) Fishmeal market price. The blue line denotes trajectory without the mesopelagic fishery (Scenario 1). The red line denotes trajectory incorporating a mesopelagic fishery (Scenario 2).</figcaption></figure>

(Table 2); as long as fish stocks are above the levels corresponding to MSYs, total production output is able to increase. By Year 10, Scenario 2 yields 5.74 Mt of fishmeal produced, suggesting that global fishmeal supply could meet its projected production of 5.6 Mt by 2031 (OECD & FAO, 2022). Larger fishmeal production drives price down for Scenario 2, making it more accessible for aquaculture farmers to source as aquafeed, facilitating the continued growth of the industry.
<figure><img src="image_13.png" /></figure>

Humboldt

<figure><img src="image_14.png" /><figcaption>FIGURE 3 Simulation results for the Humboldt Current. The blue line denotes trajectory without the mesopelagic fishery (Scenario 1). The red line denotes trajectory incorporating a mesopelagic fishery (Scenario 2).</figcaption></figure>

Asia

<figure><img src="image_15.png" /><figcaption>FIGURE 4 Simulation results for Asia. The blue line denotes trajectory without the mesopelagic fishery (Scenario 1). The red line denotes trajectory incorporating a mesopelagic fishery (Scenario 2).</figcaption></figure>

Simulated global fishmeal production in Scenario 2 increases until Year 4, after that annual increase rate becomes lower (Figure 2). The rapid increase in production between Years 1 and 4 is a result of increased fish harvests in all four production systems under quota management (Figures 1 and 3–5). This is most evident when looking at the three existing production systems in Humboldt Current, Asia, and Europe, where harvest and fish stock levels both increase until Year 4, after which
<figure><img src="image_16.png" /></figure>

<figure><img src="image_17.png" /><figcaption>FIGURE 5 Simulation results for Europe. The blue line denotes trajectory without the mesopelagic fishery (Scenario 1). The red line denotes trajectory incorporating a mesopelagic fishery (Scenario 2).</figcaption></figure>

an equilibrium is reached such that harvest level roughly equals stock replenishment, with fishing quota set at MSY (Figures 3 and 5). For Asia, the simulated effort control leads to stock growth and increased harvest (Figure 4). Introducing a mesopelagic fishery has considerable impacts on their net profits (Figures 3–5). This is due to the lowered price for fishmeal, making each of the existing systems less profitable. In contrast, the mesopelagic fishery has a small negative or negligible impact on stock, harvest, and fishing effort for the three pelagic production systems. This is because in the model, different fisheries are linked only through the fishmeal market, and the three exiting forage-fish production systems are affected only by the change in fishmeal price. Fishing efforts and harvests will be mostly the same when positive profits are maintained (Equation 7). Minor variations are due to adjustment in fishing effort with respect to profit (Equation 8). Because of overcapacity, the effort reduction and the associated stock and harvest in Asia follow the same trajectory with or without the mesopelagic fishery.

Overall, the model simulation results suggest that sourcing fishmeal from the global mesopelagic stock may be economically profitable for mesopelagic harvesters. The reduction in fishmeal price also makes it a more economically viable feed source for aquaculture farming. On the other hand, a lower price leads to profit reductions for existing forage-fish production systems. Incorporating the mesopelagic fishery as an additional source of fishmeal presents a significant economic opportunity, but ecological and environmental impacts need to be carefully considered to prevent potential overfishing, local extinction, and subsequent resource depletion.

It is important to note that the potential economic effects of mesopelagic fisheries as a source of fishmeal are sensitive to future demand conditions. Assuming that, in the long-run steady state, all four fisheries are well managed with harvests at their MSY levels. The total fishmeal supply quantity will be 4.37 million metric tons under Scenario 1 and 6.98 million metric tons under Scenario 2. However, the corresponding fishmeal price and, in turn, fisheries' profitability, will be different depending on the demand parameters (Equations 9 and 10). As shown in Table 3, under the baseline parameters ($α$ = 1700 and $β$ = 60), the fishmeal price is $1438/t$ (Scenario 1) and $1281/t$ (Scenario 2),
<figure><img src="image_18.png" /><figcaption>TABLE 3 Global fishmeal price at steady state under different demand parameters.</figcaption></figure>

<table><thead><tr><th rowspan="2">Scenario</th><th rowspan="2">α</th><th colspan="3">β</th></tr><tr><th>60</th><th>120</th><th>180</th></tr></thead><tbody><tr><td>1</td><td>1700</td><td>1438</td><td>1175</td><td>913</td></tr><tr><td>2</td><td></td><td>1281</td><td>862</td><td>443</td></tr><tr><td>Change (%)</td><td></td><td>10.90</td><td>26.70</td><td>51.50</td></tr><tr><td>1</td><td>2100</td><td>1838</td><td>1575</td><td>1313</td></tr><tr><td>2</td><td></td><td>1681</td><td>1262</td><td>843</td></tr><tr><td>Change (%)</td><td></td><td>8.50</td><td>19.90</td><td>35.80</td></tr><tr><td>1</td><td>2500</td><td>2238</td><td>1975</td><td>1713</td></tr><tr><td>2</td><td></td><td>2081</td><td>1662</td><td>1243</td></tr><tr><td>Change (%)</td><td></td><td>7.00</td><td>15.90</td><td>27.40</td></tr></tbody></table>

Mesopelagic

<figure><img src="image_19.png" /><figcaption>FIGURE 6 Simulation results for the Mesopelagic fishery at three fishmeal transformation costs: $260/t (cost in Asia, red), $294.71/t (cost in Europe, blue), and $303.55/t (3% higher cost than that in Europe, black).</figcaption></figure>

respectively. With growing demand, the fishmeal price will be higher ($2081/t when α = 2500), and all fisheries more profitable. Changes in the demand slope (β) will make the effects of adding the mesopelagic fishery more significant (greater difference between prices under Scenarios 1 and 2).

4 | SENSITIVITY ANALYSIS

We conduct a sensitivity analysis with respect to the most influential parameters which control the economic viability of fishmeal from the mesopelagic fishery and the fishmeal demand function. Figure 6 summarizes the results of model runs at three different fishmeal
<figure><img src="image_20.png" /></figure>

<figure><img src="image_21.png" /><figcaption>FIGURE 7 Sensitivity analysis: global fishmeal market under a steeper sloped demand curve (compared with the baseline). The blue line denotes trajectory without the mesopelagic fishery (Scenario 1). The red line denotes trajectory incorporating a mesopelagic fishery (Scenario 2).</figcaption></figure>

transformation costs ($260, $294.71, and $303.55/t). The simulation results suggest that if the fishmeal transformation cost for mesopelagic is more than 3% of that for the European production system ($303.55/t), the mesopelagic fishmeal production would not be profitable.

Another concern is that a sharp increase in fishmeal supply could lead to a large reduction in price, affecting fishery profitability. This effect can be simulated by increasing the slope of the demand function (Equation 4). Using the data on fishmeal production quantity and price (in Table 1 and Figure A2), we estimated the demand parameters as $\alpha = 3,445$ and $\beta = 512$, which are similar to the parameter values in Mullon et al. (2009). This slope is significantly steeper than that of our baseline demand function ($\alpha = 1,700$ and $\beta = 60$), so that the price drop is more profound in response to a surge in fishmeal supply from the mesopelagic. Selected results of simulations using the steeper demand curve are depicted in Figures 7–9. The introduction of a large-scale mesopelagic fishery will drive the fishmeal price below $1000/t$ (Figure 7), leading to negative profits in the mesopelagic fishery (Figure 8). Furthermore, the price drop will make the high-cost production system (Europe) lose profitability (Figure 9). An important point is that a sharp increase in fishmeal supply triggered by the mesopelagic may cause market disturbance and significant negative impacts on existing fisheries. Thus, to meet future growth in fishmeal demand and avoid large/abrupt market disruptions, a slow buildup of the mesopelagic fleet will be less impactful.

5 | CONCLUSIONS AND FUTURE OUTLOOK

The existing bioeconomic studies on future fishmeal supply have focused on the current production systems (Merino et al., 2010; Mullon et al., 2009), our study extends this literature by providing insights into the ways the systems may be impacted by the introduction of a new
<figure><img src="image_22.png" /></figure>

Mesopelagic

<figure><img src="image_23.png" /></figure>

**FIGURE 8** Sensitivity analysis: the mesopelagic fishery under a steeper sloped demand curve (compared with the baseline).

Europe

<figure><img src="image_24.png" /></figure>

**FIGURE 9** Sensitivity analysis: European forage fishery under a steeper sloped demand curve (compared with the baseline). The blue line denotes trajectory without the mesopelagic fishery (Scenario 1). The red line denotes trajectory incorporating a mesopelagic fishery (Scenario 2).

source for fishmeal from a mesopelagic fishery. This responds to the growing interest in the commercial exploitation of mesopelagic fish for supplying the aquaculture industry and the need to understand the trade-offs present alongside potential shifts in global market dynamics. Understanding these shifts, trade-offs and possibilities is instrumental to determining the key components that feed into decision making and policy design for managing these fisheries into
<figure><img src="image_25.png" /></figure>

the future. Although technological, economic, and knowledge constraints have thus far largely
limited the success of attempts to harvest mesopelagic fish at a commercial scale, the pressure
to expand aquaculture production for meeting the world's nutritional needs (FAO, 2022;
HLPE, 2014; Merino et al., 2012) and the subsequent pressure for novel and more efficient
sources of aquafeeds is opening the way to overcome these constraints. This work therefore
contributes to a growing body of literature that assesses the economic viability of the potential
development of a commercial-scale mesopelagic fishery (Kourantidou & Jin, 2022; Paoletti
et al., 2021; Prellezo, 2019). Prior research has predominantly concentrated on assessing
economic viability at regional levels, examining various scenarios, trade-offs, and associated
opportunity costs using technical, financial, and market analyses, alongside simulations of
current fisheries and their dynamics (Paoletti et al., 2021; Prellezo, 2019; Vastenhoud
et al., 2023), as well as ecological-economic interactions with epipelagic fisheries (Kourantidou
& Jin, 2022). Our work here introduces the fishmeal market dimension that drives incentives
for the commercial exploitation of mesopelagic fish and explores economic viability
implications through this lens, including implications to global fishmeal production systems.
This is particularly timely as technological barriers recede and conservation policies are
considered to ensure that key ecosystems services provided by mesopelagic ecosystems, will not
degrade as a result of commercial exploitation (St. John et al., 2016). While the science
community is still working on understanding fundamental processes in the Ocean Twilight
Zone such as the biological carbon pump, or food web dynamics, among others, policy makers
need to be prepared to manage any emerging commercial activities and understand the human
and economic drivers of such activities.

This type of analysis has space for improvement to inform with more accuracy the patterns
expected for mesopelagic commercial exploitation based on market dynamics, needs for
fishmeal production and trends in existing productions systems. For example, going beyond the
regions assessed and encompassing the global fishmeal production (beyond the ~70% captured
here) could help provide more granular detail to the price and production dynamics alongside
their trajectories following the introduction of a mesopelagic fishery. Incorporating additional
cost components related to fleet or fishing operational details could also lead to different fishing
efforts and net profits. Biological and ecosystem interactions may also affect outcomes and
should be incorporated in future exercises of this type, through for example assessing how the
introduction of a new mesopelagic fishery may affect the pelagic production system (i.e.,
considering any prey-predatory relationship and other food web interactions). While here we
model them as separate ecological and technical units, in practice spatial use conflict may be
present between pelagic and mesopelagic fleets or also synergies so that the same fleet harvests
both pelagic and mesopelagic fish, that is, during different seasons and/or different
technological/gear equipment for harvest and storage. Depending on the time horizons
assessed, climate variations and their effects on stock level may also need to be incorporated for
a more accurate picture of the trends expected.

The simple framework provided here to build a basic understanding of trade-offs and
market dynamics of fishmeal production can be advanced by capturing more complexity of the
fishery systems and incorporating some of the aforementioned details into the model.
Nevertheless, these fundamental insights into how stocks, harvests, fishing effort and net
profits shift with the addition of mesopelagic fish as a source of fishmeal, are necessary for
understanding what to expect from fisheries and aquaculture stakeholders in the future and for
informing policy accordingly. The (large) size of the mesopelagic fish biomass alone and the
desire to utilize this untapped resource to cover the aquaculture industry's needs are not
<figure><img src="image_26.png" /></figure>

enough to inform whether and how this can become a reality considering the current fishmeal market conditions. Indeed, more carefully designed scientific evaluations of social economic and ecological effects associated with resource exploitation in the mesopelagic zone are much needed for the development of an effective governance framework for this important marine ecosystem (Schadeberg et al., 2023).

## AUTHOR CONTRIBUTIONS

**Rohan Gowda Thanh Quang:** Conceptualization; writing—original draft; software; writing—review and editing; formal analysis. **Melina Kourantidou:** Conceptualization; writing—review and editing; validation; formal analysis. **Di Jin:** Conceptualization; funding acquisition; writing—review and editing; software; formal analysis; project administration; data curation; supervision; methodology; investigation; validation.

## ACKNOWLEDGMENTS

This study is supported by WHOI's Ocean Twilight Zone program which is part of the Audacious Project, a collaborative endeavor, housed at TED. Rohan Gowda Thanh Quang would like to thank the WHOI Summer Student Fellowship program for support. We also wish to thank the two anonymous reviewers for their constructive comments.

## DATA AVAILABILITY STATEMENT

The data that support the findings of this study are available from the corresponding author upon reasonable request.

## ORCID

Melina Kourantidou http://orcid.org/0000-0001-9595-3354

Di Jin http://orcid.org/0000-0002-6403-7983

## REFERENCES

Alvheim, A. R., Kjellevold, M., Strand, E., Sanden, M., & Wiech, M. (2020). Mesopelagic species and their potential contribution to food and feed Security—A case study from Norway. *Foods*, *9*(3), 344. https://doi.org/10.3390/foods9030344

Anderson, T. R., Martin, A. P., Lampitt, R. S., Trueman, C. N., Henson, S. A., & Mayor, D. J. (2019). Quantifying carbon fluxes from primary production to mesopelagic fish using a simple food web model. *ICES Journal of Marine Science*, *76*(3), 690–701. https://doi.org/10.1093/icesjms/fsx234

Bouelet Ntsama, I. S., Tambe, B. A., Tsafack Takadong, J. J., Medoua Nama, G., & Kansci, G. (2018). Characteristics of fish farming practices and agrochemicals usage therein in four regions of Cameroon. *Egyptian Journal of Aquatic Research*, *44*(2), 145–153. https://doi.org/10.1016/j.ejar.2018.06.006

Buesseler, K., Jin, D., Kourantidou, M., Levin, D., Ramakrishna, K., & Renaud, P. (2022). *The ocean twilight zone's role in climate change*. Woods Hole Oceanographic Institution.

Dowd, S., Chapman, M., Koehn, L. E., & Hoagland, P. (2022). The economic tradeoffs and ecological impacts associated with a potential mesopelagic fishery in the California Current. *Ecological Applications*, *32*(4), e2578. https://doi.org/10.1002/eap.2578

EUMOFA. (2018). *Blue bioeconomy. Situation, report and perspectives*. European Commission. https://www.eumofa.eu/documents/20178/84590/Blue+bioeconomy_Final.pdf

FAO. (1997). Lanternfishers: A potential fishery in the Northern Arabian Sea? In *Review of the State of World Fishery Resources: Marine Fisheries*. FAO Fisheries Circular 920 FIRM/C920. https://www.fao.org/3/w4248e/w4248e34.htm.

FAO. (2022). *The state of world fisheries and aquaculture 2022. Towards blue transformation*. https://doi.org/10.4060/cc0461en
<figure><img src="image_27.png" /></figure>

Fjeld, K., Tiller, R., Grimaldo, E., Grimsmo, L., & Standal, I.-B. (2023). Mesopelagics—New gold rush or castle in the sky? *Marine Policy, 147*, 105359. https://doi.org/10.1016/j.marpol.2022.105359

Froehlich, H. E., Jacobsen, N. S., Essington, T. E., Clavelle, T., & Halpern, B. S. (2018). Avoiding the ecological limits of forage fish for fed aquaculture. *Nature Sustainability, 1*, 298–303. https://doi.org/10.1038/s41893-018-0077-1

Garlock, T., Asche, F., Anderson, J., Ceballos-Concha, A., Love, D. C., Osmundsen, T. C., & Pincinato, R. B. M. (2022). Aquaculture: The missing contributor in the food security agenda. *Global Food Security, 32*, 100620. https://doi.org/10.1016/j.gfs.2022.100620

Gatto, A., Sadik-Zada, E. R., Özbek, S., Kieu, H., & Nguyen Huynh, N. T. (2023). Deep-sea fisheries as resilient bioeconomic systems for food and nutrition security and sustainable development. *Resources, Conservation and Recycling, 197*, 106907. https://doi.org/10.1016/j.resconrec.2023.106907

Geay, F., Ferraresso, S., Zambonino-Infante, J. L., Bargelloni, L., Quentel, C., Vandeputte, M., Kaushik, S., Cahu, C. L., & Mazurais, D. (2011). Effects of the total replacement of fish-based diet with plant-based diet on the hepatic transcriptome of two European sea bass (*Dicentrarchus labrax*) half-sibfamilies showing different growth rates with the plant-based diet. *BMC Genomics, 12*, 522. https://doi.org/10.1186/1471-2164-12-522

Grimaldo, E., Grimsmo, L., Alvarez, P., Herrmann, B., Møen Tveit, G., Tiller, R., Slizyte, R., Aldanondo, N., Guldberg, T., Toldnes, B., Carvajal, A., Schei, M., & Selnes, M. (2020). Investigating the potential for a commercial fishery in the Northeast Atlantic utilizing mesopelagic species. *ICES Journal of Marine Science*, 77(7-8), 2541–2556. https://doi.org/10.1093/icesjms/fsaa114

Hidaka, K., Kawaguchi, K., Murakami, M., & Takahashi, M. (2001). Downward transport of organic carbon by diel migratory micronekton in the western equatorial Pacific: Its quantitative and qualitative importance. *Deep Sea Research Part I: Oceanographic Research Papers*, 48(8), 1923–1939. https://doi.org/10.1016/S0967-0637(01)00003-6

HLPE. (2014). *Sustainable fisheries and aquaculture for food security and nutrition. A report by the high level panel of experts on food security and nutrition* (HLPE Report). FAO. http://www.fao.org/3/a-i3844e.pdf
IndexMundi. (2023). *Fish meal production by country in 1000 MT*.

Irigoien, X., Klevjer, T. A., Røstad, A., Martinez, U., Boyra, G., Acuña, J. L., Bode, A., Echevarria, F., Gonzalez-Gordillo, J. I., Hernandez-Leon, S., Agusti, S., Aksnes, D. L., Duarte, C. M., & Kaartvedt, S. (2014). Large mesopelagic fishes biomass and trophic efficiency in the open ocean. *Nature Communications*, 5(1), 3271. https://doi.org/10.1038/ncomms4271

Johnson, P. M. (2012). *Trade-offs between biodiversity conservation and maintaining fisheries yield from Australian marine environments: Approaches using the Atlantis ecosystem modelling framework*. University of Tasmania.

Kourantidou, M., & Jin, D. (2022). Mesopelagic–epipelagic fish nexus in viability and feasibility of commercial-scale mesopelagic fisheries. *Natural Resource Modeling*, 35, e12350. https://doi.org/10.1111/nrm.12350

Liu, T., Han, T., Wang, J., Liu, T., Bian, P., Wang, Y., & Cai, X. (2021). Effects of replacing fish meal with soybean meal on growth performance, feed utilization and physiological status of juvenile redlip mullet *Liza haematocheila*. *Aquaculture Reports*, 20, 100756. https://doi.org/10.1016/j.aqrep.2021.100756

Liu, X., Han, B., Xu, J., Zhu, J., Hu, J., Wan, W., & Miao, S. (2020). Replacement of fishmeal with soybean meal affects the growth performance, digestive enzymes, intestinal microbiota and immunity of *Carassius auratus* gibelio♀ × *Cyprinus carpio* ♂. *Aquaculture Reports*, 18, 100472. https://doi.org/10.1016/j.aqrep.2020.100472

Mariani, G., Cheung, W. W. L., Lyet, A., Sala, E., Mayorga, J., Velez, L., Gaines, S. D., Dejean, T., Troussellier, M., & Mouillot, D. (2020). Let more big fish sink: Fisheries prevent blue carbon sequestration—half in unprofitable areas. *Science Advances*, 6(44), eabb4848. https://doi.org/10.1126/sciadv.abb4848

Martin, A. H., Pearson, H. C., Saba, G. K., & Olsen, E. M. (2021). Integral functions of marine vertebrates in the ocean carbon cycle and climate change mitigation. *One Earth*, 4(5), 680–693. https://doi.org/10.1016/j.oneear.2021.04.019

Merino, G., Barange, M., Blanchard, J. L., Harle, J., Holmes, R., Allen, I., Allison, E. H., Badjeck, M. C., Dulvy, N. K., Holt, J., Jennings, S., Mullon, C., & Rodwell, L. D. (2012). Can marine fisheries and aquaculture meet fish demand from a growing human population in a changing climate. *Global Environmental Change*, 22(4), 795–806. https://doi.org/10.1016/j.gloenvcha.2012.03.003
<figure><img src="image_28.png" /></figure>

Merino, G., Barange, M., & Mullon, C. (2010). Climate variability and change scenarios for a marine commodity: Modelling small pelagic fish, fisheries and fishmeal in a globalized market. *Journal of Marine Systems, 81*, 196-205.

Mullon, C., Mittaine, J.-F., THÉBAUD, O., PÉRON, G., Merino, G., & Barange, M. (2009). Modeling the global fishmeal and fish oil markets. *Natural Resource Modeling, 22*(4), 564–609. https://doi.org/10.1111/j.1939-7445.2009.00053.x

Naito, Y., Costa, D. P., Adachi, T., Robinson, P. W., Fowler, M., & Takahashi, A. (2013). Unravelling the mysteries of a mesopelagic diet: A large apex predator specializes on small prey. *Functional Ecology, 27*(3), 710–717. https://doi.org/10.1111/1365-2435.12083

Naylor, R. L., Kishore, A., Rashid Sumaila, U., Issifu, I., Hunter, B. P., Belton, B., Bush, S. R., Cao, L., Gelcich, S., Gephart, J. A., Golden, C. D., Jonell, M., Zachary Koehn, J., Little, D. C., Thilsted, S. H., Tigchelaar, M., & Crona, B. (2021). Blue food demand across geographic and temporal scales. *Nature Communications, 12*(1), 5413. https://doi.org/10.1038/s41467-021-25516-4

OECD & FAO. (2022). OECD-FAO agricultural outlook 2022–2031. https://doi.org/10.1787/f1b0b29c-en

Olsen, R. E., Strand, E., Melle, W., Nørstebø, J. T., Lall, S. P., Ringø, E., Tocher, D. R., & Sprague, M. (2020). Can mesopelagic mixed layers be used as feed sources for salmon aquaculture? *Structure and Functioning of the Norwegian, Iceland, Irminger and Labrador Seas Ecosystems: A Comparative Study, 180*, 104722. https://doi.org/10.1016/j.dsr2.2019.104722

Paoletti, S., Nielsen, J. R., Sparrevohn, C. R., Bastardie, F., & Vastenhoud, B. M. J. (2021). Potential for mesopelagic fishery compared to economy and fisheries dynamics in current large scale danish pelagic fishery. *Frontiers in Marine Science, 8*, 720897. https://www.frontiersin.org/articles/10.3389/fmars.2021.720897

Prellezo, R. (2019). Exploring the economic viability of a mesopelagic fishery in the Bay of Biscay. *ICES Journal of Marine Science, 76*(3), 771–779. https://doi.org/10.1093/icesjms/fsy001

Roberts, C. M., Hawkins, J. P., Hindle, K., Wilson, R. W., & O'Leary, B. C. (2020). *Entering the twilight zone: The ecological role and importance of mesopelagic fishes*. Blue Marine Foundation.

Saba, G. K., Burd, A. B., Dunne, J. P., Hernández-León, S., Martin, A. H., Rose, K. A., Salisbury, J., Steinberg, D. K., Trueman, C. N., Wilson, R. W., & Wilson, S. E. (2021). Toward a better understanding of fish-based contribution to ocean carbon flux. *Limnology and Oceanography, 66*(5), 1639–1664. https://doi.org/10.1002/lno.11709

Schadeberg, A., Kraan, M., Groeneveld, R., Trilling, D., & Bush, S. (2023). Science governs the future of the mesopelagic zone. *Npj Ocean Sustainability, 2*(1), 2. https://doi.org/10.1038/s44183-023-00008-8

Schaefer, M. B. (1954). Some aspects of the dynamics of populations important to the management of the commercial marine fisheries. *Inter-American Tropical Tuna Commission Bulletin, 1*(2), 23–56.

Sigurdsson, T., Magnusson, A., Bardarson, B., Sólmundsson, J., & Jónsson, S. (2015). *State of marine stocks in Icelandic waters 2014/2015 and prospects for the quota year 2015/2016* (182; Marine Research in Iceland). Marine Research Institute.

Smith, A. D. M., Brown, C. J., Bulman, C. M., Fulton, E. A., Johnson, P., Kaplan, I. C., Lozano-Montes, H., Mackinson, S., Marzloff, M., Shannon, L. J., Shin, Y.-J., & Tam, J. (2011). Impacts of fishing low-trophic level species on marine ecosystems. *Science, 333*(6046), 1147–1150. https://doi.org/10.1126/science.1209395

Standal, D., & Grimaldo, E. (2020). Institutional nuts and bolts for a mesopelagic fishery in Norway. *Marine Policy, 119*, 104043. https://doi.org/10.1016/j.marpol.2020.104043

St. John, M. A., Borja, A., Chust, G., Heath, M., Grigorov, I., Mariani, P., Martin, A. P., & Santos, R. S. (2016). A dark hole in our understanding of marine ecosystems and their services: Perspectives from the mesopelagic community. *Frontiers in Marine Science, 3*, 31. https://www.frontiersin.org/articles/10.3389/fmars.2016.00031

Ulrich, C., Le Gallic, B., Dunn, M. R., & Gascuel, D. (2002). A multi-species multi-fleet bioeconomic simulation model for the English Channel artisanal fisheries. *Fisheries Research, 58*(3), 379–401. https://doi.org/10.1016/S0165-7836(01)00393-9

Underwood, M. J., Utne Palm, A. C., Øvredal, J. T., & Bjordal, Å. (2021). The response of mesopelagic organisms to artificial lights. *Aquaculture and Fisheries, 6*(5), 519–529. https://doi.org/10.1016/j.aaf.2020.05.002

Valinassab, T., Pierce, G. J., & Johannesson, K. (2007). Lantern fish (*Benthosema pterotum*) resources as a target for commercial exploitation in the Oman Sea. *Journal of Applied Ichthyology, 23*(5), 573–577. https://doi.org/10.1111/j.1439-0426.2007.01034.x
<figure><img src="image_29.png" /></figure>

Vastenhoud, B. M. J., Bastardie, F., Andersen, K. H., Speirs, D. C., & Nielsen, J. R. (2023). Economic viability of a large vessel mesopelagic fishery under ecological uncertainty. *Frontiers in Marine Science, 10*, 1285793.
https://doi.org/10.3389/fmars.2023.1285793

**How to cite this article:** Gowda Thanh Quang, R., Kourantidou, M., & Jin, D. (2024). Assessing the potential economic effects of mesopelagic fisheries as a novel source of fishmeal. *Natural Resource Modeling*, 37, e12398. https://doi.org/10.1111/nrm.12398

APPENDIX

<figure><img src="image_30.png" /><figcaption>FIGURE A1 Logistic growth functions for the four forage-fish production systems.</figcaption></figure>
<figure><img src="image_31.png" /></figure>

<figure><img src="image_32.png" /><figcaption>FIGURE A2 Monthly fishmeal price (2014–2023). Source: IndexMundi compilation of World Bank data. https://www.indexmundi.com/commodities/?commodity=fish-meal&months=240.</figcaption></figure>

<figure><img src="image_33.png" /><figcaption>FIGURE A3 Simulation results for the mesopelagic fishery: 30-year horizon.</figcaption></figure>