This article provides a review of the routine methods currently utilized for total naphthenic acid analyses. There is a growing need to develop chemical methods that can selectively distinguish compounds found within industrially derived oil sands process affected waters (OSPW) from those derived from the natural weathering of oil sands deposits. Attention is thus given to the characterization of other OSPW components such as oil sands polar organic compounds, PAHs, and heavy metals along with characterization of chemical additives such as polyacrylamide polymers and trace levels of boron species. Environmental samples discussed cover the following matrices: OSPW containments, on-lease interceptor well systems, on- and off-lease groundwater, and river and lake surface waters. There are diverse ranges of methods available for analyses of total naphthenic acids. However, there is a need for inter-laboratory studies to compare their accuracy and precision for routine analyses. Recent advances in high- and medium-resolution mass spectrometry, concomitant with comprehensive mass spectrometry techniques following multi-dimensional chromatography or ion-mobility separations, have allowed for the speciation of monocarboxylic naphthenic acids along with a wide range of other species including humics. The distributions of oil sands polar organic compounds, particularly the sulphur containing species (i.e., OxS and OxS2) may allow for distinguishing sources of OSPW. The ratios of oxygen- (i.e., Ox) and nitrogen-containing species (i.e., NOx, and N2Ox) are useful for differentiating organic components derived from OSPW from natural components found within receiving waters. Synchronous fluorescence spectroscopy also provides a powerful screening technique capable of quickly detecting the presence of aromatic organic acids contained within oil sands naphthenic acid mixtures. Synchronous fluorescence spectroscopy provides diagnostic profiles for OSPW and potentially impacted groundwater that can be compared against reference groundwater and surface water samples. Novel applications of X-ray absorption near edge spectroscopy (XANES) are emerging for speciation of sulphur-containing species (both organic and inorganic components) as well as industrially derived boron-containing species. There is strong potential for an environmental forensics application of XANES for chemical fingerprinting of weathered sulphur-containing species and industrial additives in OSPW.

The abundance and distribution of lesser scaup (Aythya affinis) may bc influenced by the availability of amphipod crustaceans, since these invertebrates represent an important food source, particularly for immature birds. Another important factor may be degradation of habitat, since scaup nest in wetland margins and adjacent upland habitats. The objective of this study was to evaluate the relative importance of amphipods, wetland features such as area and water depth, and indices of margin/upland habitat, on the distribution and abundance of scaup. A subsample of 108 oligosaline wetlands was chosen on twelve sites located in three eco-regions of southern Saskatchewan, Canada. Data were gathered during 1995 on relative amphipod abundance, wetland area, fall water depth, upland nesting habitat type, wetland margin impacts, and spring numbers of lesser scaup. Scaup use of wetlands was significantly affected by the availability of amphipods, wetland margin impacts, and wetland area. Controlling tbr the effect of area showed that scaup were most common on ponds with abundant amphipods and minimal margin impacts. In the southernmost mixed grassland eco-region, scaup were affected by amphipod availability only, whereas in the moist mixed grassland and parkland eco regions, results indicated that both margin impact and amphipod availability were significant factors. Results are consistent with hypotheses that decreases in scaup numbers since the mid1980s may be due to (1) loss, resulting from both human and climatic factors, of natural wetlands capable of supporting rich amphipod populations and (2) continuing agricultural encroachment on remaining wet lands.

Annual production of the amphipod, Hyalella azteca, was estimated in three habitats of the upper littoral zone of Dock Lake, Ontario, over a 2-year period (1980–1981). Cohort production (P) by the size frequency method was 1.39 g/m2 (dry weight), mean annual biomass (B) was 0.36 g/m2, and the P/B ratio was 3.9 for the 1980 year class. Five other methods for estimating production were applied to this cohort, providing comparable estimates ranging from 1.21 (instantaneous growth) to 1.65 (cohort G) g/m2. Size frequency estimates of annual production for 1980 and 1981 were 1.24 and 1.40 g/m2, respectively. The annual P/[Formula: see text] ratios of 3.9 and 4.0 for these 2 years agree with the cohort value. A comparison of production estimates for Hyalella azteca in the literature shows a gradient of production which correlates with the habitat temperature regime.

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The field biology of the Costa Rican landhopper (Crustacea: Amphipoda: Talitridae) Cerrorchestia hyloraina Lindeman was investigated in the Monteverde Cloud Forest Reserve, Costa Rica. On the Pacific (leeward) side of the continental divide, local distribution follows a gradient of moisture, from densities of over 200 m-2 in the elfin forest at 1600 m, to extremely low densities in drier forest types. Below 1400m, the leaf litter is apparently too dry to support landhopper populations. On the Caribbean (windward) side of the continental divide, landhoppers occur well below 1400m. A discussion of geographic distribution is included. Landhoppers prefer aged (microfaunally pre-processed) leaves as food, and move about only at night or in the mornings of heavily overcast days. Average female fecundity is seven eggs, with progressive loss of marsupium contents over time. The sex ratio is biased towards females. In cloud forest, breeding apparently is continuous throughout the year, with some increase after the beginning of the rainy season. There are 9-10 juvenile instars and 5-6 adult instars. The relationship of antennal segment number to total body length is linear.