Over May and June, Fish Welfare Initiative had the opportunity to visit the Portuguese Aquaculture Experimental Station (EPPO, Olhão) to assess the conditions in which fish are being reared. After background research on the different identified species’ biological and ecological welfare requirements, we focused on the recognized critical welfare-related infringements in aquaculture. We addressed the researchers/farmers' concerns, and outlined a few recommendations focusing on grow-out polyculture ponds.
This post outlines what we believe to be the main welfare improvements required in this farming system to enhance the safeguarding of fish welfare in their semi-intensive ponds. This work is intended to pilot what Fish Welfare Initiative sees for its possible future concerning aquaculture business consultation for better fish welfare. Though ambitious, we believe farm consultations hit close to the best possibility of a significant positive effect on fish welfare. This will not only help fish but also, to some extent, lower the environmental footprint of aquaculture and increase people's well-being in tandem.
“Small in size, but big in potential.”
People in Portugal repeat this phrase about their football players, referring to the high number of Portuguese born and raised athletes that rule the strongest teams across the globe. But this is only half-true concerning aquaculture, especially in any coastal country with a long fishing tradition, as is the case in Portugal. It is true that fisheries currently represents great economic importance to the country, while aquaculture remains only a secondary animal protein production activity. As such, fisheries’ environmental footprint is still a major obstacle to sustainability and the responsible use of natural resources.
As one of the leading fish consumers per capita, ranking 3rd in the world, it may be expected that Portugal would have already developed aquaculture practices that compete with larger aquaculture producers, match the market demand, and complement capture fisheries (Figure 1). However, despite aquaculture’s status in Portugal as “a player” still in its childhood, the industry's track record is already well-understood. Portugal, then, can make use of their own and others’ previous failures and lessons to aim for sustainable and responsible aquaculture, ultimately harming fewer fish.
Portugal's baby steps for Aquaculture
This industry has operated in transitional waters (estuaries and coastal lagoons), rich in nutrients, along with coastal areas. This means high availability of oxygen and natural feed, generating conditions that enable the farming of fish.
Aquaculture has experienced a slow development over the years, with semi-intensive and extensive systems becoming the most common systems used for fish production. Nevertheless, it is a sector that still rises in economic importance every year, and will continue to quickly expand in the following years -- with EPPO playing a key role in this development.
Portuguese Aquaculture Experimental Station (EPPO)
EPPO is a noteworthy producer in Portuguese aquaculture, having a unique intensive/semi-intensive infrastructure placed in an estuary in the south of the country. The station has sought out connections with the different actors involved in the development of aquaculture, namely, public entities and the productive sector (source: IPMA). It is designed to carry out research, development, and experimental demonstration at a pilot-scale (to eventually upscale to private companies). Their core goals are to:
Enhance aquaculture farming practices,
Develop new commercial species,
Promote the transfer of technology to the productive private sector and other actors, and
Be an essential pillar in scientific and technical training, both at the professional and university level.
They also provide farmers with seeds, knowledge, and technical assistance. As a public institute in Portugal, most of the fishes they raise are donated to non-profit institutions, and the remaining are given to other research institutions and private companies as potential broodstock.
EPPO’s potential welfare issues
Fishes’ development, and their consequent welfare, depends on the farming conditions to which the fish are subjected during their life cycle. Despite some room for improvement, the initial life stages were found to be close to optimal regarding the welfare that can be attained under culture conditions.
Fish Welfare Initiative decided to thus focus on the farmed species’ later stage of development. We chose this stage because semi-intensive production systems exercise reasonably poor control over environmental factors, namely, feed intake, water quality, predators, and biosecurity, and additionally, they require more difficult handling practices.
Estuaries are areas subjected to various human pressures, with high pollutant input from many different sources. Thus, these fishes’ long-term exposure may pose health risks and decrease growth performance. And when in polyculture, the population species’ composition may affect fish development and overall welfare. We found that a polyculture with meagre, seabream, seabass, grouper, and white seabream, species that have different trophic levels and welfare-related issues, is expected. Harvest practices (capture, handling, and slaughter) also often pose serious welfare issues.
“Blue card” for fair environmental play
EPPO is a clear example of good practices regarding infrastructures, technology, and routines. Just to mention a few:
Water entry is first subjected to sand filters, so biological/physical contamination is unlikely to occur. Water outflow passes through a reservoir tank, where potential chemicals and algae blooms are hindered. Overall, water quality was within the species’ optimal ranges.
Fish are inspected for diseases and growth performance with some frequency: at least once every three days in summer, or whenever the farmers suspect a health issue. Since 2014, fish diseases have decreased by 60%.
Feed is high quality. This is because of EPPO’s strong collaboration with feed companies that tailor feeds to their farmed species, life stages, and farming systems. Feed conversion ratios (FCRs) for almost all species in the pond were below 2.
The farming ponds are covered with a simple, but well thought out, net cover, mitigating welfare concerns for the fish and for predators.
EPPO rotates pond use, allowing for best practice pond preparation and a lower negative impact on fish welfare. Pond sediments are always dried after each production cycle, and when necessary, lime is applied to increase pH and reduce anoxic areas.
No red cards, but still a few yellow cards for fish welfare
The main issues identified by FWI were debated with the farmers to better understand a practical route for improvement. FWI researchers started by providing training in Aquaculture Best Practices and the main welfare-related issues affecting their farming system. Overall, feedback was positive, and despite many things being “old news” to EPPO, some minor aspects were not entirely clear to them.
One good example was the different trophic levels of the polycultured species, and how much they may impact the animals' welfare, or to what extent they could be used to prevent welfare issues.
Additionally, they were not aware of the best slaughter practices for their species. The apparent mistake made was using an electrical stunner without any previous research and knowledge, and expecting to kill fish with the electrical shocks rather than stunning them and then killing them by bleeding or ice.
Overall, the broad categories of welfare improvements that FWI helped implement were:
1. Healthy stocking densities in polyculture
a. Ensure healthy stocking densities: stocking densities were misfitted for the farming system’s overall conditions and carrying capacity. Departing from 4kgs per cubic meter (varying weight and size, depending on the species), the researchers/farmers committed to not exceed 2.5kg/m3, with the typical final density at 1.5kg/m3. Species composition was debated, and the species involved in the polyculture will be better selected according to their trophic level and behavior, e.g., seabream and seabass; or meagre, white seabream, and grouper. If meagre is polycultured with seabream, for example, the respective proportion should be at least 7:1, and the meagre should be settled in the pond first. Additionally, partial harvest will be performed each time one species becomes too dominant (if they are already commercial size) and begins affecting the others’ foraging behavior.
2. Best harvest practices (handling, capture, and slaughtering)
a. The farmers practice partial harvesting. Since clients very often prefer just one or two species, handling days affect all the fish while removing just a few. After observing the fishes’ behavior on a prior harvest day, the farmers were advised to focus on different points of the harvest net according to the target species’ typical escape behavior. For example, seabream swim more on the bottom alongside white seabream on the lateral side of the net seine, while seabass and meagre are found closer to the surface of the net funnel. Grouper spreads across the entire water surface. When the species were specifically targeted like this, handling and overcrowding time was reduced, and fish suffered fewer injuries. They were also, most likely, less prone to diseases given the lower stress levels. No mortality was found in the next few days, as opposed to what usually occurs.
b. Harvest procedures were preceded by a 48h starvation period, rather than their common practice of 24h, given that the fish were being harvested for killing and not for sampling. Due to this longer duration, stress levels from the slaughter method were reduced, and the fish became stunned faster.
c. Harvest procedures started in the early hours of the morning, so that they occurred close to or within the optimal temperature range of the species.
d. During handling, minimize density as much as possible by involving fewer fishes in the procedure, avoiding seine net overload, and crowding the fish in steps instead of all at once. When done correctly, the fishes’ maximal stress responses are avoided. "Drying up” time should also be made as short as possible, reducing exhaustion, asphyxiation, injuries, and deaths. The rule of thumb when taking fish from the harvest net to the slaughter container is “minimize the time fish are outside water.”
e. In the absence of better conditions, ⅓ of ice slurry to ⅔ of water was recommended to stun/kill fish faster. Electrical stunning was not adapted for the different species, and their stunning parameters were not known, so using it may have caused more harm than good.
Implications for our work
Many of these improvements are relatively easy for producers to apply, and may constitute a major boost to fish welfare. The recommended welfare improvements helped around 4,500 individuals just in one pond. Considering that EPPO has 10 ponds of the same size, usually with the same stocking densities, transferring these practices to future harvests across all the different ponds will impact ~45,000 fish per farming cycle. Like with aquaculture in Portugal, even baby steps towards better fish lives are headed in the right direction to spare millions of fish from suffering.
The future increasingly looks to finding solutions adapted to the environment, animals, and the demand and needs of the market: transversal sustainability. Offshore farming in Portugal is in development, and for the present, there are nearly 100 cages in use -- but this number is trending upwards. To feed this growth, hatcheries will need to provide juvenile fish. Given EPPO’s standout role in the national aquaculture licencing and knowledge transfer, Fish Welfare Initiative couldn’t have imagined a better opportunity to start working with a farm in Portugal and increase awareness for a critical factor for these new businesses: the fishes’ welfare. Impacting and improving welfare standards in their facilities may well be the best approach to increasing welfare improvements’ cost-effectiveness, and more quickly impact the way their partners, private farmers, will farm their fish in the future. Linking with Governmental Institutes like EPPO, or FPOs with recognized roles in the country's industry, seems to be an effective way forward to improve the lives of fish.