Components of the primary question
A PECO structure (population – exposure – comparator – outcomes) has been adopted to answer the research questions (the impacts of COVID-19 pandemic on the aquaculture industry) as follows:
Population: The population of interest is the aquaculture industry and its value chain network.
Exposure: Exposure refers to an introduction or change that a particular population must deal with. This study selected the COVID-19 pandemic as its exposure.
Comparator: No exposure or modification to the exposure.
Outcomes: The outcome of interest in this analysis are impact on (i) the production-related factors (land, labour, capital, entrepreneurs), (ii) animals (fish availability/fish welfare/fish feed/seed, (iii) logistics, (iv) demand and supply and (v) policy response.
Search strategy, terms, and language
This review is guided by the Reporting Standards for Systematic Evidence Syntheses (ROSES), which are designed specifically for systematic review and maps for the environmental management field (Haddaway et al. 2018). A structured and systematic electronic search strategy was conducted using ISI Web of Science core collection and Scopus bibliographic database.
The search was conducted in July 2021. As the search is done in July, it is an incomplete year because publications in bibliographic databases lag behind those in primary journals, and most journals were only halfway through their annual publishing cycle. English was the language used for the search string and the following search string was used:
Population terms: ((aquaculture) OR (mariculture) OR ("fish farm*") OR ("shellfish farm*") OR ("mussel farm*") OR ("oyster farm*") OR ("sea cage*") OR ("net pen*") OR ("fishpond*") OR ("seaweed farm*") OR ("macroalgal farm*") OR ("algal farm*"))
Exposure terms: (("COVID-19") OR (pandemic) OR (coronavirus) OR ("SARS-CoV 2"))
As the primary objective of the map is to focus on the impacts of COVID-19 on the global aquaculture industry, the studies will not be required to have a comparator and outcome. In addition, the outcome is sorted based on the retrieved articles.
Article screening and study eligibility criteria
Screening process
Article screening was conducted in two levels: (i) title and abstract level and (ii) full-text level. The study was assessed at each level using the eligibility criteria listed below. At the first level (title and abstract), articles were excluded based on those elements. Then, studies that met the inclusion criteria at the first level were reviewed at the second stage (full-text level). Articles that did not align with review criteria and relevancy were excluded, and the final articles were then synthesized for a final review. A record of inclusion/exclusion of articles was done for each stage. The two-stage screening was conducted by two reviewers (i.e., authors) (MI and MN). In the case of a retrieved publication authored or co-authored by one of the two reviewers, the publication was referred to another reviewer for assessment.
Eligibility Criteria
Articles included in the final synthesis were required to meet the following criteria:
Relevant populations
The relevant subjects in this review were related to aquaculture. Fisheries, recreational fishing, and other non-aquaculture types of agriculture were excluded as not meet the definition of aquaculture activities.
Relevant exposure
Relevant studies were those that discussed how the COVID-19 pandemic affected the population. Articles reviewing pandemic impact without explicit reference to COVID-19 were not included.
Relevant outcomes
The type of outcome review is the effect that exposure has on the aquaculture industry. Studies that measured the impact, which could be expressed by statistical data or studies reporting on the consequences, were included. Nonetheless, information on outcomes other than the COVID-19 pandemic reported by studies was not ignored when discussed in relation to the focus outcomes and was extracted as variables in the evidence synthesis.
Relevant timeframe
Only articles published between 2019 and 2021 were taken into account for this review. The year 2019 was chosen as it was the year the COVID-19 pandemic evolved.
Relevant type of study
Primary field studies (reviews and other secondary compilations were not included).
Language
Full text written in English.
Study validity assessment
Following the suggestion by (Mohamed Shaffril et al. 2021), articles that met the eligibility criteria were subject to critical appraisal. The article was categorized as having high, low, or unclear validity based on reviewers’ assessment of its clarity and susceptibility to bias. Only articles of high or moderate quality were included in the final review. Reviewers were guided by five standards:
- Were the articles' primary objectives related to review methodology?
- Were the articles providing all methodologies needed in developing the review?
- Were the articles clearly defined and in line with the authors needed review methodology?
- Was each of the guidance on review methodology in the articles properly justified?
- Were the articles providing any option or alternative to their suggested guidance on review methodology?
The reviewers had three possible responses for each of the criteria: yes, no, or cannot say. The reviewers decided that if the articles fulfilled four or five criteria, they were in a high-level of quality; if they fulfilled at least three criteria, they were of a moderate quality; and if they fulfilled just one or two criteria, they were of a low-level of quality. Thus, the reviewers of this study mutually agreed that 11 articles had met the minimum requirement (high or moderate).
Data Extraction Strategy
Data on COVID19 impact on aquaculture were collected in a data extraction matrix using an Excel spreadsheet. The data extraction and coding were handled by two members of the reviewing team. The following data were extracted:
Bibliographic information
- Study ID (unique numeric ID assigned to each article)
- Coder ID (unique ID assigned to each reviewer)
- Citation information
- Study design
- Study objective
- Study method
- Type of data
- Type of analysis
- Study Timeframe
- Study start and end.
- Study duration
- Population information
- Study location (country, state/province)
- Aquaculture species
- Demographic information
- Outcome components and subcomponents measured
- Policy response
- Impact on factors of production
- Impact on animals
- Impact on logistics
- Impact on demand and supply
- Impact on price
Data synthesis and presentation
A thematic analysis was applied to this review due to the extremely high heterogeneity across the selected studies (study approach, key concepts, study design, and study methods). High heterogeneity made it hard to do a standardized quality assessment tool across the studies. This thematic analysis adopted identifying prominent or recurrent themes from the collected data of selected previous studies and summarizing these data under thematic headings (Braun &Clarke 2006). (Flemming et al. 2019) concluded that thematic analysis is the most suitable in synthesizing mixed research design and researchers need to be cautious about the use of framework synthesis. This review hopes to improve the knowledge of the available evidence and current gaps for future research recommendations. Based on these results, recommendations are made on priorities for future research and mitigation of COVID-19 impact. The complete database containing the data extracted from each study will be made available for download.
Review findings
The searches in the Web of Science and Scopus databases yielded 173 articles in total. After removing duplicates, the record included 112 articles. The title and abstract screening of the articles left 12 articles that were considered potentially relevant to the review. Full-text screening of the 12 articles led to the exclusion of one article (Waiho et al. 2020), which was based on its study design that focused on the forecast of impact without using any concrete data. All 11 pertinent articles had passed the studies' critical evaluation. Inter-rater reliability agreement of title and abstract screening was moderate (Cohen's Kappa value of 0.69). For illustrating the study selection, PRISMA guidelines were used as shown in figure 1.
Description of studies
The structural details of the review articles with frequencies of the objective of the article, year of publication, data collected, focus countries, data timeline, and aquaculture animals (i.e., animals) focus were shown in table 1. All the included articles were descriptive studies. All articles used primary data except for two articles that used secondary data. Three studies were specifically conducted in Bangladesh, two studies in India, and one study on a global scale. Four out of eleven articles started their data collection in the year 2020. However, three articles did not report on their data collection date. Salmons and freshwater shrimps/prawns are animals with the highest focus (two articles each).
COVID-19 impact on aquaculture
Many aspects of COVID-19 impact on aquaculture are being covered in this review and is designated into six thematic categories: (i) policy response, (ii) impact on factors of production, (iii) impact on animals, (iv) impact on logistics, (v) impact on demand and supply, and (vi) impact on price.
Theme 1: Policy response
Six studies describe the policy response by policymakers as the most significant challenge faced during the beginning of the COVID-19 pandemic (Azra et al. 2021, Belton et al. 2021, Hasan et al. 2021, Islam et al. 2021, Kumaran et al. 2021, Manlosa et al. 2021). Most countries implemented a complete lockdown policy that included a total economic shutdown with restriction of movement for the citizens to mitigate the novel coronavirus outbreak. The complete lockdown policy severely disrupted business as it created a logistical bottleneck that was considered the most crucial challenge in the pandemic situation. Aquaculture industries have been exempted from this restriction as it was deemed an essential industry. However, the movement restriction policy was deemed fragmented due to the lack of coordination and failure to include the whole aquaculture supply chain as an essential industry.
For example, during the total lockdown in Malaysia, the fish mill manufacturing factories were not allowed to operate (Azra et al. 2021). In India, where aquaculture is classified as essential; although access to machinery and parts required for farm operation is not part of the essential services (Belton et al. 2021, Kumaran et al. 2021). In the United States of America, the total lockdown policy disrupted aquaculture farmers due to unavailability of veterinary services, repair, maintenance, and construction (van Senten et al. 2021). Moreover, during the total lockdown, the fish markets opening hours were also shortened in multiple countries. The market economic transactions were negatively impacted by this limited time and physical distancing requirements (Hasan et al. 2021, Islam et al. 2021, Manlosa et al. 2021).
This pandemic situation is often mitigated by the introduction of social support initiatives for aquaculture farmers. Government was the primary initiator, with trade associations and non-governmental organizations also playing significant roles. Based on research findings, the types of initiatives deemed the most effective by aquaculture farmers are food aid, financial assistance, and institutional livelihood support (Azra et al. 2021, Belton et al. 2021, Manlosa et al. 2021). In India, the government launched a "Blue Revolution'' program with the hope to strength the value chain, double farmers' income, increase employment, and increase farmers' resilience (Kumaran et al. 2021). The Myanmar government implemented a cash transfer scheme, while Bangladesh government initiated a bank loan with a 4% interest rate for business providers. Many farmers claimed that they received a flawed support system following the lockdown, which impacted their income and socio-economic status, particularly psychosocial well-being (Belton et al. 2021, Hasan et al. 2021).
Aquaculture stakeholders perceive financial aid as not focusing on support for business sustainability but more on social protection transfers for households or individuals. Aquaculture stakeholders in Bangladesh, Egypt, and Nigeria also perceived the aid as too slow and difficult to obtain for informal businesses without bank accounts (Belton et al. 2021). There is also a perceived inequality in the kind of value chain stakeholder or community receives the aid. Some of the aid is unheard of for the farmers who live in rural areas, as most of them have no awareness of the initiative. The majority of aquaculture farmers perceived that aid such as bank loans is impossible to obtain as most of the farmers and intermediaries are in marginalized group communities, and no bank will approve their loan due to their low financial security (Belton et al. 2021, Hasan et al. 2021, Islam et al. 2021, Kumaran et al. 2021).
The aid aquaculture farmers deemed as effective and helped in sustaining their livelihood is the institutional livelihood support. Such aid facilitates securing passes for mobility and connecting farmers with new markets. Farmers involved in registered organizations in the Philippines have received documentation such as vendor passes that made it easier for them to transport their products during the lockdown. Additionally, the Philippines government set up a mobile market for aquaculture farmers to sell their products. The local government initiative in the Philippines also included opening a city market for the aquaculture farmers during lockdown (Belton et al. 2021, Hasan et al. 2021, Islam et al. 2021, Kumaran et al. 2021).
Theme 2: Factors of production
The COVID-19 outbreak has been harmed most of the aquaculture sector, as evidenced from the review articles, bringing a negative impact on the communities regardless of their income level. Eight articles pointed out the negative impact of the COVID-19 pandemic on the aquaculture industry in production terms such as farm operation, storage, and labour (Azra et al. 2021, Belton et al. 2021, Hasan et al. 2021, Islam et al. 2021, Kumaran et al. 2021, Manlosa et al. 2021, Soto et al. 2021, van Senten et al. 2021). Even though the fixed costs associated with aquaculture remained unchanged during the pandemic, the operational costs have risen more than they did before the pandemic.
Based on the articles reviewed, the operational costs that highly impacted the industry are pond preparation, labor, and storage (Islam et al. 2021, Langford et al. 2021, Manlosa et al. 2021, Murray et al. 2021, van Senten et al. 2021). Due to the lockdown policy, aquaculture farmers kept their fish in the ponds longer than usual, which increased the amount of electricity used due to the extended operation of pumping facilities (Hasan et al. 2021, Islam et al. 2021). Pond maintenance costs increased as most of the items were harder to procure due to lockdown situations. For example, (Hasan et al. 2021) showed a farmer unable to replace a damaged watergate; without a watergate to control water inflow and outflow, the farmer was unable to restock the pond.
Aquaculture farmers also faced difficulty in fish storage. Aquaculture products had to be sold live; the live fish did not leave the farms until purchased by buyers. When the live fish are not sold as anticipated, they remain in the same units as before and grows bigger, making it harder for farmers to start a new cycle. As the pandemic-affected fish production cycle getting more prolonged with bigger-sized fish than expected, the usual processing standards of practice cannot be easily reset to accommodate larger fish without additional costs (Azra et al. 2021, Belton et al. 2021, Manlosa et al. 2021, Soto et al. 2021).
COVID-19 pandemic also resulted in challenges with the aquaculture industry labour market such as temporary loss of employees due to lockdown orders, illness, and furloughs, as well as permanent loss of employees due to forced terminations by the lack of revenue resulting from marketing channel disruptions (Hasan et al. 2021, Islam et al. 2021, Kumaran et al. 2021). Reductions in farming also reduced the labour demand for harvesting, transportation, and other services, with significant adverse outcomes for many workers who depend on these activities. (Manlosa et al. 2021) have shown that some farmers had to lay off their permanent and non-technical staff and replace them with seasonal workers or engage their family members to reduce farm production costs. The loss of workers has impacted the time of active fish surveillance. On average, the aquaculture workers have decreased from 51% in February to 34% in April.
Theme 3: Aquaculture animal welfare
The pandemic has harmed aquaculture animals health and welfare by affecting the fish feed cost, medicine cost, and fish farming season (Belton et al. 2021, Hasan et al. 2021, Islam et al. 2021, Kumaran et al. 2021, Langford et al. 2021, Manlosa et al. 2021, Murray et al. 2021, van Senten et al. 2021). As the fish are kept longer than usual during a pandemic situation, farmers need to buy more fish feed than anticipated. The eight articles in this theme stated an increase in feed costs due to COVID-19 (Belton et al. 2021, Hasan et al. 2021, Islam et al. 2021, Kumaran et al. 2021, Langford et al. 2021, Manlosa et al. 2021, Murray et al. 2021, van Senten et al. 2021). In India, the sales of non-pelleted feeds such as rice bran and oilcake had increased from April to May; indicating that farmers used them as an alternative to more expensive pellet feeds (Belton et al. 2021, Kumaran et al. 2021). Some findings also showed that the farmers having difficulty in procuring fish feed due to the lockdown policy. Malaysia, Bangladesh, and India have recorded a shortage of ready feed and feed ingredients in the market (Azra et al. 2021, Belton et al. 2021, Kumaran et al. 2021). The increased cost and shortage of fish feed have led to farmers getting lower quality feed which creates long-term issues for fish welfare and sustainability as it leads to poor stock growth, extended production cycle, and degrading fish quality.
The aquaculture farmer is also experiencing an increased production costs for pharmaceutical products during the pandemic situation. These potential impacts are identified as occurring through two pathways: (i) harvesting and stocking, which has an impact on disease management and population densities, which are significant factors for the spread of diseases and parasites; and (ii) surveillance and veterinary interventions for the control of diseases and parasites (Murray et al. 2021, van Senten et al. 2021). Regulations on the COVID-19 pandemic for biomass limitation and sea lice infestation, leading to additional negative environmental impacts. The delayed fish harvesting could also reduce resources and increase the fish biomass in farms, increasing the risk of mortality (Azra et al. 2021, Hasan et al. 2021, Kumaran et al. 2021, Murray et al. 2021, van Senten et al. 2021).
The pandemic has also impacted the farmers during the most crucial farming season. The mid-March to early April is usually the end season cycle for fish farming for farmers in tropical areas like Bangladesh, India, Myanmar, and Malaysia (Azra et al. 2021, Belton et al. 2021, Hasan et al. 2021, Islam et al. 2021, Kumaran et al. 2021, Murray et al. 2021, van Senten et al. 2021). The pandemic has caused a more significant impact on farmer losses and activities, primarily based on the harvest and stocking season. This period is linked to seasonal variations in rainfall and temperatures. Bangladesh and India both reported having low activities compared to the year before the pandemic; this situation caused some hatcheries to destroy large quantities of seed. For many sectors in the United States, the pandemic lockdown policy in spring is the peak marketing period for producers of aquaculture products like mollusks, trout, sportfish, and baitfish (van Senten et al. 2021).
Findings from (van Senten et al. 2021) also revealed that the lockdown coincided with the driest months of the year, which corresponds to low metabolism for fish. This season has shown a low feed procurement in Egypt, India, and Bangladesh (Belton et al. 2021). The season also usually has high fish deaths statistics. The pandemic exacerbated this existing stressor by triggering a cascade of impacts that collectively made it hard for fish farmers to cope. However, not all fish farmers are impacted negatively by the changing season; salmon farming in Chile shown significant resilience during the lockdown period, as studies showed it might be more sensitive to lockdown in the autumn than in the spring (Soto et al. 2021).
Theme 4: Logistics
Nine studies have reported that logistics in the aquaculture industry value chain are affected by the pandemic in terms of higher transportation costs, restricted mobility, and increasing border restrictions (Azra et al. 2021, Belton et al. 2021, Hasan et al. 2021, Islam et al. 2021, Kumaran et al. 2021, Manlosa et al. 2021, Sarà et al. 2022, Soto et al. 2021, van Senten et al. 2021). Like every other economic sector, transportation costs in the aquaculture industry (raw material and finished products) has increased due to the general lockdown policy. Access to buyers was severely impacted and has not yet fully recovered even when the lockdown restrictions were gradually withdrawn. The transportation costs increase resulted in considerable impacts on the farmers. Many farmers feared their business might shut down even after the lockdown (Azra et al. 2021, Belton et al. 2021, Hasan et al. 2021, Islam et al. 2021, Kumaran et al. 2021, Manlosa et al. 2021, Sarà et al. 2022, Soto et al. 2021, van Senten et al. 2021).
Two studies included in this review described the impact of restricted mobility on their aquaculture business. (Belton et al. 2021) found that the limitation of individual mobility, business hours, and restaurant closing had disrupted the supply chain, leaving 50% of restaurants to stop or reduce buying even after the lockdown period as they worried about a recurrence of the situation. Many of the producers were also afraid to start a new farm cycle because of uncertainties in their understanding of the export and local market activities (Azra et al. 2021, Belton et al. 2021, Hasan et al. 2021, Islam et al. 2021, Kumaran et al. 2021, Manlosa et al. 2021, Sarà et al. 2022, Soto et al. 2021, van Senten et al. 2021).
One study investigated the effect of urban and rural areas on market availability (Belton et al. 2021). The study found that food logistics in rural areas than in urban area were impacted more during the lockdown8. Mobility is better manageable in urban areas due to more markets and shorter transportation ranges. Therefore, the market remains stronger in urban areas with better transportation availability than in rural areas with little connectivity.
Theme 5: Demand and Supply
Nine studies reported that aquaculture industries were significantly impacted by their value chain demand and supply (Azra et al. 2021, Belton et al. 2021, Hasan et al. 2021, Islam et al. 2021, Kumaran et al. 2021, Manlosa et al. 2021, Sarà et al. 2022, Soto et al. 2021, van Senten et al. 2021). The loss of demand as a percent of total annual sales due to pandemic incidence was estimated to be 38% for tilapia, 29% for crustaceans, 24% for ornamentals, and 21% for finfish (Azra et al. 2021, Belton et al. 2021, Hasan et al. 2021). Overall, the purchase of aquaculture inputs fell around 35% to 65% points, compared to February 2019 sales. The cost and nutritional qualities encourage consumers to switch to aquaculture products (Belton et al. 2021, Hasan et al. 2021). However, most fish consumption was reduced with consumers switching to eggs for their prime protein source. Based on the previous studies, the lower price of other food products and their preparation, as well as the people's perception of a better immune system, is the other reason for the change in aquaculture product's demand (Sarà et al. 2022, Soto et al. 2021, van Senten et al. 2021).
The closure of supermarkets and restaurants depressed the market demand and therefore impacted the value chain price on the upward chain due to supply larger than demand (Sarà et al. 2022, Soto et al. 2021, van Senten et al. 2021). In India, the demand for food has reduced by nearly 50% from March to May 2020. However, not all countries were facing the same problem of demand in each aquaculture value chain segment. The pandemic has also seen an increase in aquaculture demand due to the opening of a new market segment. In the Philippines, the market remained strong due to online purchase and delivery systems in the urban areas (Manlosa et al. 2021). Consumers may have preferred to buy in the virtual market due to easy processing and the fact that it requires less social interaction, thereby boosting their health security.
Interestingly, some findings showed that market channels also determine price change. Those who sold to distributors and restaurants reported a decrease in demand. Additionally, this type of market channel is also reported to have a greater loss in domestic sales and more canceled contracts. Players who sell from farm to processing plant and then sell to distributors or food service companies experience a little decrease in aquaculture product demand (Hasan et al. 2021, Manlosa et al. 2021, van Senten et al. 2021).
Theme 6: Price
Other than demand and supply issues, prices of aquaculture animals and related products are also impacted during the pandemic (Azra et al. 2021, Belton et al. 2021, Hasan et al. 2021, Islam et al. 2021, Kumaran et al. 2021, Manlosa et al. 2021, Sarà et al. 2022, Soto et al. 2021, van Senten et al. 2021). From the review, price changes occurred all along the value chain, impacting upstream (farmers) to downstream (consumers). Many farmers reported that prices had decreased due to low demand in the markets. Prices received by farmers were lower, with approximately 5% to 35% less than before the lockdown policy in India and Myanmar. In Bangladesh, farmer sales prices had reportedly fallen on average by 15% (Belton et al. 2021, Hasan et al. 2021, Islam et al. 2021).
Mediators and retailers were also affected severely during the pandemic, especially during the lockdown period. In India, the traders' sales dropped on average 15% during the lockdown period. Certain types of fish such as tilapia and catfish prices have dropped, and the price for pangasius and other catfish dropped more than 13%. This pattern is likely an effect of slow demand from downstream transmitted to upstream and targeting the intermediaries such as traders (Azra et al. 2021, Belton et al. 2021, Hasan et al. 2021, Islam et al. 2021, Kumaran et al. 2021, Manlosa et al. 2021, Sarà et al. 2022, Soto et al. 2021, van Senten et al. 2021). The changes in the product's price by the intermediaries and retailers have shown that consumers pay higher prices for pangasius and carp but less for tilapia and other catfish. As tilapia and catfish are cheaper aquaculture species than pangasius and carp (depending on species and countries), consumer demand for them has risen, leading to a higher price for the competitive product (Azra et al. 2021, Belton et al. 2021, Hasan et al. 2021, Islam et al. 2021, Kumaran et al. 2021, Manlosa et al. 2021, Sarà et al. 2022, Soto et al. 2021, van Senten et al. 2021).