Seasonal studies of seston lipids in relation to microplankton species composition and scallop growth in South Broad Cove, Newfoundland

Abstract

ABSTRACT. The concentration and nutritional awlity of suspended particulate matter at an experimental scallop aquaculture site on the east -1 of Newfoundland, Canada, was determined at 3 depths over an 8 mo sampling period. Lip~d r-lassaand fatty acids were measured chromatographically and the seston components were identified and quantified by microscopy. These measurements were correlated and then related to the growth of j u l -d e scallops Placopecten magellanicus introduced to the site. The low seston concentrations obsewad throughout the year were punctuated by 4 large inputs: the spring diatom bloom, a resuspension ment. a summer microzooplankton and nanoflagellate bloom, and a fall increase in zooplankton faecal :pellet and heterotrophic dinoflagellate concentrations. The largest inputs of lipids were associated w~t h the: resuspension event and the summer bloom. The resuspended particles included the benthic permate diatom Cyrosigrna spp. which contained large lipid globules. High concentrations of polvunwrmated triacylglycerols occurred at this time; more saturated triacylglycerols were prominent ~n the sunmer The acyl lipids contained unusually high proportions of the long-chain polyunsaturated fatty acid 20:406 which was correlated (p < 0.05) with the proportion of mlcrozooplankton in the seston. n.e C,, fatty acid ratio 16:1~7/16:0, used previously as a diatom biomarker, was strongly correlated (p c O.01) with the proportion of centric diatoms. Scallop growth appeared to be related less to the major-ts of total lipids to the water column and more to the proportion of the essential fatty acid 2 2 : 6 d m the acyl lipids. This fatty acid was associated principally with cryptophytes (p < 0.02).KEY WORDS: Lipid classes . Fatty acids -M i c r d g a e . Microzooplankton . Blooms . Resuspension

Biosynthesis of macromolecular and lipid classes by phytoplankton in the Northeast Water Polynya

“…Laws 1991, Parrish et al 1995. Actively growing phytoplankton with an abundant supply of inorganic nutrients generally synthesize mainly protein and lesser amounts of storage compounds such as neutral lipids, carbohydrates and low molecular weight metabolites (Morris 1981, Laws 1991.…”

“…Of the various macromolecular classes, lipids are of special interest for their nutritional importance to consumers and potential for contaminant transfer (Kattner et al 1989, Wainmann & Lean 1992, Parrish et al 1995. Nutrients and taxonomic affiliation both influence the proportion of fixed carbon that phytoplankton direct to lipids (Shifrin & Chisholm 1981, Madariaga 1992, Fernandez et al 1994a) and there has been some success in predicting lipid biosynthesis from environmental factors in freshwater phytoplankton communltles (Wainmann & Lean 1992).…”

Fatty acid biomarkers in coldwater eelgrass meadows: elevated terrestrial input to the food web of age-0 Atlantic cod Gadus morhua

“…Therefore, net tow data presented here, from late summer and fall, are probably not representative of plankton at other times of the year. The typical seasonal pattern of phytoplankton abundance in cold North Atlantic nearshore waters shows diatom lipid markers dominating in spring, followed by terrestrial plant material, small flagellates, zooplankton, and bacterial sources becoming more important in late summer and fall (Mayzaud et al 1989, Parrish et al 1995. Seasonal changes in lipid composition of particulate matter can be caused by changes in taxonomic source or physiological changes within a taxonomic group (Mayzaud et al 1989).…”

“…Rather, smaller flagellates, bacteria, and terrestrial material likely accounted for most of the seston. Parrish et al (1995) looked at seasonal seston microplankton species composition in South Broad Cove, Newman Sound. They also noted high levels of microzooplankton in the water column during summer, particularly after a storm mixing event.…”

Role of environmental factors for the vertical distribution (0–1000 m) of marine bacterial communities in the NW Mediterranean Sea

“…Since lipid classes are useful markers to determine sources and fate of organic matter in marine systems (Parrish, 1988) they have widely been used as biological tracers (Parrish et al, 1995;Derieux et al, 1998;Goutx et al, 2000), but only once in conjunction with bacterial community structure changes (Ghiglione et al, 2007). In the present study CCA analysis showed that dissolved lipids from chloroplast origin (LC), which indicate phytoplankton source of DOM (Goutx et al, 1990), were the main biotracer associated with bacterial community structure, due surely to their high concentration at particular samples of 5-20 m depths (Fig.…”