Understanding marine food web dynamics using fatty acid signatures and stable isotope ratios: Improving contaminant impacts assessments across trophic levels

Abstract

Understanding marine food web dynamics using fatty acid signatures and stable isotope ratios: Improving contaminant impacts assessments across trophic levels. Estuarine, Coastal and Shelf Science, [106327].

Diet and feeding strategy of Northeast Atlantic mackerel (Scombrus scomber) in Icelandic waters

“…Consequently, a more comprehensive and alternative analysis of a fish´s diet can be informative and relevant, not only in strengthening and widening the results, but also to discover if there are prey species that were not detectable by visual analysis alone. These methods could be in the form of stable isotope analysis of different fish tissues [76,77], fatty acid profiling [78,79] or genetic analysis of stomach content [80]. In this study, conventional methods were used to evaluate the feeding strategy of the Northeast Atlantic mackerel from stomach content analyses, which showed that mackerel is a specialised feeder upon copepods while in Icelandic waters.…”

The concentration and biomagnification of trace metals and metalloids across four trophic levels in a marine food web

“…Sample collection and preparation is discussed in detail in Madgett et al, 2019. In summary, 211 samples, including seven fish species (haddock, whiting, hake, plaice, dab, herring and sprat), one shark species (small-spotted catshark) and thirteen invertebrate species (horse mussel, brittle star, hermit crab, edible crab, common starfish, swimming crab, shore crab, European lobster, Nephrops, whelk, sea mouse, squat lobster and veined squid) were collected from nine locations around Scotland between 2015 and 2017 during December and February (Fig.…”

“…Due to factors such as species, location and sample yield, pools were composed of three to six individuals for fish, catshark, common starfish and squid. The remaining invertebrates ranged from twenty to one hundred individuals per pool (Madgett et al, 2019). The length was recorded for all fish and catshark and whole animal weight was recorded for individuals except squat lobsters, swimming crabs, hermit crabs, shore crabs, Nephrops and brittle star where the overall pool was weighed (due to the small size and large quantity of individuals).…”

“…The current TMF approach assumes that diet is the major route of contaminant exposure and trophic level is the main driver of their accumulation in the food web. It was concluded in Madgett et al (2019) that to conduct effective environmental assessments using TMFs, influencing factors need to be considered (besides appropriate trophic level data) to fully understand the complexity of marine systems and contaminant trophic transfer, instead of using nominal TMFs or trophic level values from databases (e.g. Fishbase, 2019) or other studies which introduce errors in the trophic level adjustment (Won et al, 2018).…”

“…Samples were divided into sixteen sample categories (refer to Madgett et al, 2019 for the categorisation of twenty-three species using fatty acid and stable isotope ratio analysis). The samples were from different marine locations around Scotland.…”