Seasonal changes in particulate size spectra, biochemical con~position, fatty acid and sterol content were followed from winter to fall in a small north Atlantic coastal basin. Strong seasonality, related to both spnng-bloom and summer biological production, was recorded for most chemical and biochemical descriptors. Size spectra were generally characterized by donunance of small particles in the size range 6.35-25.4 pm equivalent diameter, except in early summer when an additional component in the 32.0-64.0 pm size range became important. Changes in either C:N ratio or carbohydrate:protein ratio indicated physiological changes which could be related to nutrient limitation or senescence The fatty a c~d and sterol composition of the lipid fraction displayed major seasonal changes which reflected: (1) the seasonal heterogeneity of the taxonomic composition of the particles; (2) the physiological changes w t h i n each group of organism; and (3) the various penods of low production or bloom decay. Spring bloom production of small to medium size particles (12.7-50.8 pm) was associated with C16 polyunsaturated acid, 20:5w3, 24 methylene-cholesterol and desmosterol. Summer production of small particles (2.0-6.4 pm) was associated w t h C18 polyunsaturated acids, 2 2 : 6~3 , nor-24-cholesterol and isofucosterol, while the late winter-early spring period displayed close relationships between some saturates as well as monoenes (18.0, 18-lw9, 20:lw9, 2 2 . 1~9 ) and cholesterol Post-bloom decay associated another group of saturates and monoenes (14.0, 20:0, 22:0, 16 lw9, 16:ltA3) and p-sitosterol. Overall particulate biochemical dynamics is discussed in terms of both phytoplankton metabolism and trophic influence for the zooplankton consumers.

Lipid classes and fatty acid details of sea urchins Strongylocentrotus droebachiensis harvested in subtidal water near Halifax, and in deep water in St. Margaret's Bay, were compared. All samples contained an eicosenoic acid with 5,6-ethylenic unsaturation and two non-methylene-interrupted eicosadienoic acids (NMID) with the one 5,6 bond and a second in either the 11,12 or 13,14 positions. Structures were identified by combinations of ozonolysis, partial hydrazine reduction and argentation-TLC and by mass spectra of pyrrolidine derivatives. No 3,11-eicosadienoic acid was observed and elongation of C20 materials with few ethylenic bonds to C22 homologues was confined to 11–20:1 and to the minor 5,13–20:2 NMID and did not include either the relatively important 5–20:1. monoene or the 5,11–20:2 NMID. Individual animals showed considerable variation in total lipid and lipid classes, but the consistent distribution of the fatty acids with 5,6 unsaturation, irrespective of the nutritional status of the animal, suggests a basic role in membrane function.Key words: Strongylocentrotus droebachiensis, sea urchin lipids, sea urchin fatty acids, non-methylene-interrupted fatty acids, eicosadienoic fatty acids

A gas–liquid chromatographic examination of the component fatty acids of the milk of the grey (Atlantic) seal confirms previous findings that in general composition the milk fats of marine mammals resemble the depot fat. An empirical correction system is suggested for argon ionization detectors.

Ozonolysis of oleic acid in methanol, a reacting solvent, with s~i b s e q~~e n t decomposition of the ozonide products by hydrogen peroxide in formic acid, gives yields of principal dicarboxylic acid fission products exceeding 95y0 with a mini111~1m of secondary acidic products.The method is highly reproducible and offers unique advantages in the total recovery of the dicarboxylic acids and the eliininatioil of peroxidic materials. The principal non-acidic byp r o d~~c t s were tentatively identilied as the CS alcohols and their for111yl esters.

Blubber fats from six fin whales, four sei whales, and one humpbacked whale taken in Nova Scotian waters have been studied. Dorsal, lateral, and ventral samples were compared for thickness, fat contents of inner and outer layers, and the iodine values of the recovered fats. The concept that in "fat" mysticeti whales the iodine value is higher in the inner blubber than in the outer blubber was supported by the results. It is concluded that iodine value fluctuations in one animal in a fattening stage represent surplus polyunsaturated acids deposited first in the inner layer and first in the ventral area. Correspondingly, the outer dorsal blubber is the most stable. Species differences correspond to those for Antarctic animals.