The importance of fisheries and aquaculture production for nutrition and food security.

Aquatic food has a significant role to play in global nutrition and food security but is often ignored in that debate. Understanding its potential role is made difficult by the fact that aquatic food covers a large number of species which come from both capture fisheries and aquaculture and the marine and freshwater environments, including finfish, crustacea, molluscs, echinoderms, aquatic plants and other aquatic animals. Further complications arise from the fact that both supply and consumption vary significantly between countries. There are several criteria which need to be considered when discussing nutrition and food security. These include: how much food is produced, whether that production is sustainable, whether the production supports livelihoods, what the nutritional content of the food is and whether that food is safe. The authors conclude that there are many benefits to aquatic food under each of these criteria but there are also some hurdles which need to be overcome. Increased production to feed a growing global population relies on the growth of aquaculture. Challenges to such growth include the supply of raw ingredients for aquafeeds, losses due to disease outbreaks, being able to ensure high standards of food safety and overcoming environmental limitations to expansion. There are also problems with welfare conditions for people working in the supply chain which need to be addressed. Given the challenges to nutrition and food security which the world is currently facing, it is essential that aquatic food is brought into the debate and the significant benefits that aquatic foods provide are acknowledged and exploited.


Introduction 26
In order to achieve nutrition and food security, all people need to have access at all times to the 27 adequate utilization and absorption of nutrients in food, in order to be able to live a healthy and 28 active life (1). Access implies that there needs to be enough food available, that is safe to eat and 29 that people can afford to buy it. Therefore five key elements to consider when looking at the role of 30 5 of the dietary ingredients within the farmed aquatic animal (20). Research within this field is gaining 128 momentum but must be integrated within a holistic approach that ensures the health of the farmed 129 stocks. Addressing shortages in aquafeed production and changes in dietary components alone, will 130 not resolve the sustainability issues in aquaculture. Development and intensification of the 131 aquaculture sector will only be achieved in we deliver high quality feed alternatives/management 132 practises in combination with improved animal health and welfare. Infectious disease outbreaks 133 continue to threaten the development of this rapidly expanding food sector (21). The lack of 134 efficacious vaccines against infectious agents resulting in large scale disease outbreaks is 135 contributing towards the continued reliance on antibiotics in aquaculture. This has significant 136 repercussions for food security as well as public health. Further research is required to provide 137 suitable alternatives to antimicrobials, particularly in low and middle income countries (LMIC) where 138 intensification of terrestrial and aquatic food is predicted to expand (22). Ensuring that all food is 139 safe to eat, is one of the core pillars in global food security (23) and must be applied to aquatic food 140 irrespective of supplier. 141

2) Livelihoods: 142
Aquatic food production supports a range of livelihoods along the supply chain, from primary 143 producer/fisher to retail sector. In the 2016 FAO report (2), nearly 60 million people globally were 144 engaged in the primary production of edible seafood products which included both farmed and 145 capture fisheries. Small scale operations (both in fisheries and aquaculture) play a critical role in 146 supporting livelihoods, particularly in rural areas by supporting food security and reducing poverty 147 (2). In 2014, 84% of the global population engaged in the aquatic food production sector were in 148 Asia, and 94% of jobs in aquaculture are also in Asia. Gender studies have highlighted that 19% of 149 those engaged in fisheries and aquaculture sectors are women, and in the secondary sector 150 engagement (e.g. processing) 50% of the workforce is women (24). The role of women in seafood 151 supply chain varies tremendously not only between countries but also between providers of the 152 seafood. In Nigeria, 73% of the fisheries workforce is women, involved in both harvest and post-153 harvest roles whereas in EU only 21% are women (24). Women are more traditionally involved in the 154 rural, small scale aquaculture operations, as these can be better integrated into their other 155 livelihood activities, but a higher number of women are employed in processing of farmed aquatic 156 food, often in low paid, unreliable employment with no welfare considerations (25). Encouraging 157 women's participation in aquaculture can be beneficial to their own status in the family and 158 community, as well as providing production benefits -in a Bangladesh-based study, fish production 159 increased 10-20% when women were engaged in small-scale aquaculture (24). Such increases in 160 6 women's participation can lead to improved production, income levels, and nutrition security for the 161 whole family, as women in aquaculture have been found to prioritise family consumption of their 162 home-grown fish more highly than men (26,27,28 approaches which reduce vulnerability to multiple stressors, as well as recognition of the 170 opportunities that climate change could bring and of the potential contribution of fisheries to 171 mitigation efforts either through emission reductions or carbon sequestration (29). It is likely that 172 climate change will also impact on the species which can be produced through aquaculture and the 173 diseases which might infect farms; fish farmers will have to be able to adapt to these changes (30). 174

3) Environmental impacts 175
There are several possible measures of sustainability (4, 31, 32) but on most of those aquatic foods 176 perform well, particularly in comparison to red meats. For example, in animal husbandry practise 177 feed conversion ratio (FCR) is used as a measure of the efficiency with which animal feed is 178 converted into the food output. If we consider feed conversion efficiency in terms of units of output 179 per units of feed input in production units then the least efficient dietary protein source is beef (e.g. 180 31, 32, 33). Farmed fish are one of the most efficient forms of meat production, with an FCR 181 efficiency that is similar to poultry (31, 32). In their recent paper, Fry et al (33) suggested that FCR, 182 which is the commonly used measure, does not account for differences in feed content, feeding 183 rates during production, edible portion of an animal, or nutritional quality of the final product. There 184 are also other factors to consider including the production length which is much shorter for farmed 185 fish compared with cattle. Fry et al. (33) considered both protein and calorie retention for a range of 186 different aquatic and terrestrial species, their results showed that calorie and protein retention rates 187 were similar for aquaculture and terrestrial animals but that chicken and Atlantic salmon performed 188 best for these two measures (32). 189 In terms of carbon equivalent footprint, beef and sheep have the highest emissions regardless of 190 whether they are intensively or extensively farmed with means ranging from ~25 (beef intensive) to 191 ~58 (beef extensive) kg CO2 per kg product (Figure 2. in ref 4). Seafood supplied from fisheries 7 produce ~12 kg CO2 per kg product, while pork has very similar emissions to seafood from 193 aquaculture, at approx. 6 kg CO2 per kg product, meaning on emissions they are both slightly worse 194 than poultry (4). There is increasing pressure for land and water resources meaning that expansion 195 of both terrestrial animal and aquaculture farming is limited under the current farming practices. To 196 address food insecurity technical, environmental and cost-effective solutions must be implemented 197 that support sustainable intensification of all food production. Scope for expansion in aquatic food 198 production may, therefore, lie more in the marine environment than the inland aquaculture sector 199 which remains a user of land and water resources, particularly freshwater (34). If aquatic food is to 200 play a more significant role in addressing food insecurity then we must consider the diversity in 201 production systems, species and food products supplied as strengths but only if production can be 202 achieved through sustainable resource use, and without negative impacts on ecosystem services and 203 biodiversity. It is important to bear in mind these ecosystem services in the management of sustainable fisheries, 213 to ensure management practices do not interfere with key thresholds and ecological cycles. 214 Ecosystem service trade-offs should also be considered, as, for example, enhancement stocking may 215 provide beneficial regulating services, as well as increasing the number of fish available for harvest, 216 but also decrease native biodiversity (39); determining which is the priority for a given location 217 requires site-specific consideration. 218 Where waste is appropriately handled, and ecosystem trade-offs carefully considered, fish farming 219 has the potential to provide food with relatively few negative environmental impacts while also 220 providing important aquatic ecosystem services. 221 Negative environmental consequences of fish farming through the release of organic wastes which 222 detrimentally affect ecosystem community structure and biodiversity (40,41) must also be taken into 223 account when considering the net impact of fish production. This organic waste, however, while 224 8 potentially dangerous when left as untreated and unprocessed effluent, can also potentially provide 225 nutrients needed for other forms of food production. In integrated systems which have been in use 226 in China for more than 1200 years, carp are co-produced in rice paddies, where they not only reduce 227 the need for fertilizer (by 24% as compared with monocultures) through production of organic waste 228 products, but also reduce pesticide inputs (by 68%) largely by disturbance of rice plants and causing 229 insect pests to fall into the water below, where they are consumed (42). While such integrated 230 production cannot, alone, solve the issues surrounding fish waste products at current levels of fish 231 demand, multi-trophic aquaculture raises the possibility of co-producing aquatic organisms from 232 different trophic levels in the same system, potentially reducing environmental impact without 233 negatively impacting production (43, 44). A number of multi-trophic systems have been proposed 234 including the use of bivalves around fish cages to recycle effluent (45); the use of plants as filtration 235 agents (46); and those which combine both plant and bivalve filtration in multi-layered systems (47, 236 48) -in each case, such systems provide additional food products as well as environmental benefits. 237 Fish effluents can also provide a nutrient rich fertilizer, which has been trialled and found to be a 238 suitable replacement for inorganic nitrogen across a range of crops, including guineagrass (49) monocytogenes contamination in seafood products, particularly given the increased demand for 324 11 lightly preserved e.g. smoked and ready-to-eat products. This raises the need for complete 325 compliance on hygiene and sanitation practises within food processing sector and a greater 326 emphasis on disinfection in the production line. 327

Social licence 328
Public and media perception is another issue which can cause problems for the aquaculture industry. 329 In a recent paper Froehlich (67) analysed approx. 1500 newspaper headlines from 1984-2015 from 330 both developed and developing countries and found an increasing positive trend in aquaculture 331 coverage generally, but with developing countries producing proportionally more positive headlines 332 than developed ones. An FAO report in 2015 (68) found that the rapid growth of aquaculture had 333 caused concern about environmental impact, human health, including food safety, and social issues. 334 However, it was also found that whilst most of the production is in Asia, the opposition to increased 335 aquaculture development largely comes from the western world. The report from Bacher (68) found 336 that the most significant consumer concern was the health and safety aspects of farmed fish. 337 People's perceptions of environmental impact and animal welfare concerns varied geographically. 338 However, most people were unaware whether the fish they bought was wild or farmed in origin. 339 Overall the report concluded that the public perceptions of aquaculture focussed on risks and did 340 not weigh up the costs and benefits. They went on to recommend ways of addressing these public 341 concerns. One key conclusion was that it is important to put aquaculture in a wider perspective by 342 comparing its costs and benefits with other animal production systems (69). 343

Consumer preferences 344
Despite the nutritional benefits, and the lower environmental impact of fish in comparison with 345 other animal products, a number of socio-cultural barriers to fish consumption exist in western 346 populations. Even within the EU fish consumption varies both within and between countries. The role of aquatic food in nutrition and food security is further complicated by the wide range of 374 different species that come from two very different production systems. Capture fisheries are very 375 different to most of other sources of food, there are very few food sources in which wild food is 376 caught and none which exist at the scale and volume of capture fisheries. In this case the ways in 377 which we can influence the amount of food that we can catch are either through protecting fisheries 378 resources by more sustainable fisheries management, which may include limiting fishing, or through 379 creating marine protected areas. Aquaculture on the other hand shares many common features with 380 other food production systems (both livestock and crops) including the need for sustainable feeds, 381 the risks that come with disease outbreaks and issues around food safety. Aquaculture also uses 382 similar technologies to other food production systems in order to improve production. Including 383 genetic selection for disease resistance, genetic modification for improved growth and functional 384 feeds. However, aquaculture has some unique benefits and challenges. Benefits include the fact that 385 it is a relatively young production system and there is potential to increase yield in the same way 386 that terrestrial systems have in the past. There are also more species which are farmed than for 387 13 terrestrial animals. This can be both positive, because of the potential for diversification of species 388 and to expand production by exploiting new species, and negative because each new species needs 389 new research into efficient production, closure of the production cycle etc.. Challenges include the 390 difficulties in observing and handling animals which live in water and the proximity to and 391 interaction, including pathogen exchange, with wild fish which is closer than in many terrestrial 392 animal systems. 393 When we consider the role of aquatic food in food security beyond production we have seen that 394 there are currently significant contributions to livelihoods, particularly in rural areas and in LMICs. In 395 addition, aquatic food can provide both protein and essential micronutrients and thus can 396 contribute to a diverse and healthy diet, helping to tackle lifestyle diseases. 397 We know that the world is facing a number of challenges when it comes to feeding the population, 398 these include population growth, increasing demands for animal protein and climate change all of 399 which mean that our food supply will become more precarious. This is a complex problem which 400 needs to be tackled from a number of different angles. The sustainable nutrition approach requires 401 us to reduce our demands by wasting less and eating more sustainably. This means eating less red 402 meat (particularly in developed, Western country's diets) and more fruit and vegetables, but can 403 also mean eating more fish instead of meat which brings both environmental and health benefits. 404 The sustainable intensification approach advocates producing more whilst protecting biodiversity 405 and ecosystem services, this approach cannot be applied to fisheries, but there is certainly potential 406 to grow aquaculture and to increase yield using many of the same techniques, such as genetic 407 improvement and precision agriculture, which are used in terrestrial systems. It is essential then that 408 aquatic foods take their place at the table when it comes to discussing nutrition and food security. 409 We must recognise the significant benefits that aquatic food can bring, acknowledge and deal with 410 the limitations across the supply chain and expend more effort exploiting the gains that could be 411 made by considering aquatic foods alongside terrestrial systems. 412