Marine Biology Research Group represented and awarded prize at Lipids in the Ocean Conference

Wednesday, November 28, 2018

PhD students Ivan Loaiza Alamo and Siel Wellens presented their research on the first Lipids in the Ocean Conference, held in Brest (France) from 20 to 22 November 2018 ( Ivan presented his topic on ‘Benefits and risks of seafood consumption in Peru: qualitative analysis of fatty acid and micro-contaminant intake’ and Siel presented her poster on ‘Temperature-induced changes in the fatty acid profile of the benthic copepod Platychelipus littoralis’. Siel was granted the ‘Lipids in the Ocean 2018 - Best Poster’ award.

‘Benefits and risks of seafood consumption in Peru: qualitative analysis of fatty acid and micro-contaminant intake’

Seafood consumption is associated with both beneficial and risks effects to human health. Omega-3 fatty acids (PUFAs) which improve mental development and cognition, and reduce the risk of cardiovascular disease, are found in high concentrations in marine organisms, but they also contain persistent contaminants that have accumulated. We therefore assessed concentrations of PUFAs (EPA + DHA) and metal contaminants (Mn, Fe, Cu, Ni, Zn, As, Cd, Pb) in 13 potentially edible species from Peru. Mantis shrimp (Squilla sp.) and octopus (Octopus mimus) were the species with the highest PUFA concentrations (182.8 and 158.2 mg/100g wwt respectively), which are comparable and in some cases higher than in commercial fish species (i.e. cod, hake, whiting). Nevertheless, Squilla sp. exhibited also the highest concentration of Cd which was 5.2 μg/g wwt. We simulated four exposure scenarios resulting from consumption of the above species, to assess the benefits of PUFA intake and the risks of metal exposure for seafood consumers. The first two exposure scenarios evaluate PUFA and metal intake when consuming species with low (a) and high (b) metal concentrations and a fixed ingestion rate. The latter two scenarios evaluate PUFA intake combined with low (c) and high (d) metal exposure, which is calculated based on the actual metal intake per species, i.e. by combining the metal content and estimated ingestion rate (FAO, 2018) per seafood species. Scenario (c) was found optimal for seafood consumption, providing nutritious PUFAs levels (~350 mg/day) and reduce the metal uptake to <0.61 and <0.31 ug/kg bw/day wwt. For inorganic As and Cd, respectively. In scenario (d) conversely, the PUFA’ intake was less than half and the uptake of metals about 6-fold much higher than in (c) (4.11 and 1.80 ug/kg bw/day wwt respectively for inorganic-As and Cd). Scenarios (a) and (b) led to low PUFA (< 140 mg/day) and high inorganic-As uptake (up to 4.74 ug/kg bw/day wwt) and where thus not suitable for human seafood consumption. Therefore, it is strategic to combine the most safe species (Argopecten purpuratus, O. mimus, Romaleon sestosum, Pagurus sp) at different ingestion rates to maximize the uptake of beneficial EPA and DHA. Nevertheless, the provisional tolerance daily intake (PTDI) and RfD must be considered for each metal intake, as well as other toxic persistent organic contaminants that accumulated in seafood. In conclusion, fatty acid profiling in combination with the analysis of micro-contaminants allowed to get insight in the quality of seafood.

‘Temperature-induced changes in the fatty acid profile of the benthic copepod Platychelipus littoralis

Current climate change predictions expect coastal ecosystems, such as estuaries, to be particularly vulnerable to rising temperatures. In these estuaries, benthic harpacticoid copepods (Crustacea, Copepoda) are the main consumers of primary producers (diatoms) and serve as an important food source for higher trophic levels (fish). Due to their high levels of energy-rich fatty acids taken up from their diatom diet, harpacticoids play an essential role in trophic energy transfer and in the maintenance of physiological functions in many organisms in estuarine food webs. In view of their trophic importance, stable fatty acid profiles in harpacticoid copepods are indicators for a healthy and stable ecosystem and any changes in these profiles are expected to cascade through the food web. This study examines the effects of temperature changes on the fatty acid profile of Platychelipus littoralis, one of the most abundant harpacticoid copepods in the Westerschelde estuary (The Netherlands).