Undesirables in Mesopelagic Species and Implications for Food and Feed Safety—Insights from Norwegian Fjords

Abstract

The increase in the global population demands more biomass from the ocean as future food and feed, and the mesopelagic species might contribute significantly. In the present study, we evaluated the food and feed safety of six of the most abundant mesopelagic species in Norwegian fjords. Trace elements (i.e., arsenic, cadmium, mercury, and lead), organic pollutants (i.e., dioxins, furans, dioxin-like polychlorinated biphenyls, and polybrominated flame-retardants), and potentially problematic lipid compounds (i.e., wax esters and erucic acid) were analyzed and compared to existing food and feed maximum levels and intake recommendations. Furthermore, contaminant loads in processed mesopelagic biomass (protein, oil, and fish meal) was estimated using worst-case scenarios to identify possible food and feed safety issues. While most undesirables were low considering European food legislation, we identified a few potential food safety issues regarding high levels of fluoride in Northern krill, wax esters in glacier lanternfish, and long-chain monounsaturated fatty acids in silvery lightfish. Our estimates in processed biomass indicated high levels of undesirable trace elements in the protein fraction, frequently exceeding the maximum levels for feed ingredients. However, in fish meal, almost no exceedances were seen. In the oil fraction, dioxins and furans were above the maximum levels, given for food and feed ingredients. The present study is crucial to enable an evaluation of the value of these species; however, more data is needed before proceeding with large-scale harvesting of mesopelagic biomass.

Processing Mixed Mesopelagic Biomass from the North-East Atlantic into Aquafeed Resources; Implication for Food Safety

“…On the other hand, the use of plant products has also reduced the level of potential harmful environmental contaminants that follow marine aquafeed ingredients such as persistent organic pollutants (POPs) including dioxins (PCDDs), furans (PCDFs), dioxin-like polychlorinated biphenyls (DL-PCBs), organochlorine pesticides (OCPs) and polybrominated diphenyl ethers (PBDE), as well as and metals and metalloids such as arsenic (As), cadmium (Cd), mercury (Hg), and lead (Pb) [2,19,20]. The suggested use of mesopelagic marine resources in the now dominantly plant-based aquafeeds can reintroduce marine nutrients to farmed seafood [21,22], but would also likely reintroduce marine environmental contaminants [21]. Lipid and protein fractions (i.e., oil and meal), processed from mixed mesopelagic biomasses, are the most likely nutrient resources for formulated aquafeeds.…”

“…Lipid and protein fractions (i.e., oil and meal), processed from mixed mesopelagic biomasses, are the most likely nutrient resources for formulated aquafeeds. Processing of mesopelagic catches into oil and meal alters the level of the different chemical compound groups of undesirables [21,23]. Fat soluble organic pollutants (i.e., PCDD/Fs, PCBs, PBDE) are likely to be up-concentrated in the oil fraction while the metals and metalloids (i.e., As, Cd, Hg, Cd) would increase in the meal fraction [21,23].…”

“…Processing of mesopelagic catches into oil and meal alters the level of the different chemical compound groups of undesirables [21,23]. Fat soluble organic pollutants (i.e., PCDD/Fs, PCBs, PBDE) are likely to be up-concentrated in the oil fraction while the metals and metalloids (i.e., As, Cd, Hg, Cd) would increase in the meal fraction [21,23]. The fat-soluble POPs are known to readily biomagnify in an aquatic food web resulting in higher levels in organisms at a higher trophic level [24].…”

“…The EU feed legislation aims to control the level of contaminants at the start of a food production chain, thus protecting consumer safety at an early stage. As novel mesopelagic feed ingredients are being investigated for possible implementation in seafood production [9,21], compliance with EU feed and food safety risk assessment is important. In studies on mixed mesopelagic biomass, catches containing mixtures of amphiphods had levels of cadmium above that allowed for feedstuffs.…”

“…[9]. Other studies on individual mesopelagic species have provided theoretical calculations of the expected levels of contaminants in processed oil and meal fractions [21]. These estimates indicate high levels of undesirable trace elements such as and F in the protein fraction, frequently exceeding the MLs for feed ingredients.…”