Elucidating Causes ofDiporeiaDecline in the Great Lakes via Metabolomics: Physiological Responses after Exposure to Different Stressors

Abstract

The benthic macroinvertebrate Diporeia spp. have been extirpated from many areas of the Laurentian Great Lakes, but the mechanisms underlying such declines are not fully understood. Diporeia declines coinciding with the invasion of exotic dreissenid mussels (zebra and quagga) have led to the hypothesis that Diporeia declines are a result of decreased food availability from increasing competition with dreissenids for diatoms. There is additional evidence that Diporeia are negatively affected when in close proximity to dreissenids, probably because of exposure to toxins present in the mussels' pseudofeces. Diporeia are also known to be sensitive to anthropogenic contaminants (such as polychlorinated biphenyls [PCBs]) present in Great Lakes sediments. To better understand the physiological responses of Diporeia to diverse stressors, we conducted three 28-d experiments evaluating changes in the metabolomes of Diporeia (1) fed diatoms (Cyclotella meneghiniana) versus starved, (2) exposed (from Lake Michigan and Cayuga Lake) to quagga mussels (Dreissena bugensis), and (3) exposed to sediments contaminated with PCBs. The metabolomes of samples were examined using both two-dimensional gas and liquid chromatography coupled with mass spectrometry. Each stressor elicited a unique metabolome response characterized by enhanced citric acid cycle, fatty acid biosynthesis, and protein metabolism in diatom-fed Diporeia; impaired glycolysis, protein catabolism, and folate metabolism in Diporeia from Lake Michigan irrespective of quagga mussel exposure, suggesting lake-specific adaptation mechanisms; and altered cysteine and phospholipid metabolism during PCB exposure. Subsequent comparisons of these stressor-specific metabolic responses with metabolomes of a feral Diporeia population would help identify stressors affecting Diporeia populations throughout the Great Lakes.

Long-term trends in Lake Ontario's benthic macroinvertebrate community from 1994–2008

“…Barbiero et al (2011) reported declining numbers of Diporeia in Lake Huron despite much lower abundances of Mussels there, and Mussels coexist with Diporeia in several smaller lakes (Dermott et al, 2005b;Watkins et al, 2012), suggesting that Dreissenids may not be directly implicated in the Diporeia decline. Interestingly, Diporeia from declining populations do not show decreased condition (Nalepa et al, 2009a), and stressors applied to the animals give the same metabolic response regardless of the presence of Quagga Mussels (Maity et al 2013). Furthermore, the decline in the spring bloom observed in Lake Michigan (Mida et al, 2010;Vanderploeg et al, 2010;Kerfoot et al, 2010) did not occur in Lake Ontario, even though Diporeia declined in both lakes .…”

A Crab Is Not a Fish: Unique Aspects of the Crustacean Endocrine System and Considerations for Endocrine Toxicology

“…(C) Moult stages and main modifications of exoskeleton and growth (non-proportional presentation with respect to duration of each period). Abbreviations: CCAP, crustacean cardioactive peptide; CHH, crustacean hyperglycemic hormone; EcR, ecdysteroid receptor; MF, methyl farnesoate; MIH, moult-inhibiting hormone; MOIH, mandibular organ-inhibiting hormone; 20E, 20-hydroxyecdysone; PoA, ponasterone (A) 1 (70); 2 (71); 3 (72); 4 (73); 5 (74); 6 (75); 7 (76); 8 (77); 9 (78); 10 (79).…”

“…This ecological and economical wealth is, however, endangered by habitat loss, climate change, pollution, overexploitation, invasive species and other anthropogenic stressors ( 8 ). In the early nineties, drastic declines of amphipods were reported in some of the Great Lakes ( 9 , 10 ). Similarly, populations of the amphipod Gammarus lacustris significantly declined in the Selenga River delta, the main tributary to Lake Baikal ( 11 ).…”

Population dynamics of the glacial relict amphipods in a subarctic lake: role of density‐dependent and density‐independent factors

“…Amphipoda is a well-established and long-recognized indicator of good ecosystem health for assessing the ecological status of aquatic environments (Dauvin, 2018). In particular, pontoporeiid species are known to be highly sensitive to climate warming and different local environmental disturbances like eutrophication, pollution, acidification (Demandt et al, 2012;Goedkoop, 2006;Maity et al, 2013). In the Baltic Sea, M. affinis is used as a bioindicator to monitor benthic community ecology and biological effects of contaminants (Löf et al, 2016;Sundelin & Eriksson Wiklund, 1998).…”