A combination of DGPS/GIS mapping, invertebrate surveys and environmental monitoring over one year (July 2004--July 2005) were used to examine the recovery of permanent tidal pools on a salt marsh in the lower Bay of Fundy which underwent an unmanaged restoration after breach of the dyke over 50 years ago. The results are compared to those of a nearby relatively undisturbed reference marsh. / Pools were found to represent a substantial portion of the marsh habitat, comprising 13% of the total marsh area in the recovering marsh and 4.8% in the natural marsh. Observations indicate ice may be an important mechanism of pool formation and growth in these marshes. Water temperature in the pools ranged from freezing (-2°C) to a maximum of 36°C with ice covering pools for up to one month in the winter. Salinity of the pools ranged from near freshwater (4) to hypersaline (41). Environmental variability was mainly driven by climatic conditions with increased tidal flooding of pools at low elevations tending to make the conditions more stable. / A total of 42 macroinvertebrate taxa were identified in pools of the two marshes, with species richness (S) of individual pools ranging from 13 to 23. An estimated 50 years since dyke failure, the invertebrate fauna of pools in the recovering marsh is indistinguishable from that of the reference marsh. No significant differences in macroinvertebrate communities were detected between sampling dates, pool size or pool depth. Non metric multidimentional scaling and hierarchical cluster analysis supported separating the pool invertebrate communities of this study into those occurring in regularly flooded pools, and those occurring in irregularly flooded pools. Average production of pool macroinvertebrates ranged from 1.79 to 4.03 g dry wt m-2, depending on the amount of vegetative cover in the pools. The pools are characterized by low equitability in species abundance and biomass. The numerically dominant organisms of the pools were mites (Acarina), the gastropod Hydrobia tottentei, Tubificidae oligochaetes, and Chironomus sp. larvae as well as copepods and ostracods.

No description available.

No description available.

No description available.

In 1996, four cores (∼30 cm depth) were extracted from the high marsh zone of Dipper Harbour salt marsh in the Bay of Fundy. Soil bulk densities are shown to be controlled by mineral density and are higher than those reported for salt marshes in the northeastern United States. Examination of variations in mineral content suggests that regular tidal action and ice rafting deposits the majority of the mineral sediment to the high marsh zone. Dating techniques (based upon pollen, 137Cs, 210Pb and total Pb) were applied to selected cores, suggesting accretion rates from 0.25 to 0.31 cm yr-1 which are higher than the rates of local relative sea level rise. Correlation of trace metal densities (Cu, Fe, Pb and Zn) to Al densities were used to justify Al normalization. After consideration of natural sources and adsorption factors, the normalized Pb profiles are shown to reflect historical pollution levels of leaded gasoline consumption. Carbon storage values in the upper 25 cm of sediment range from 7.3--10.5 kg C m-2 and carbon accumulation rates vary from 95 to 124 g C m-2 yr-1, representing 15--29% of the salt marsh macrophyte productivity.

No description available.

Saltwater marshes in the Bay of Fundy act as greenhouse gases sinks and reservoirs by fixing atmospheric carbon dioxide and storing it in carbon rich deposits. There are approximately 3,131.5 hectares of saltwater marsh in the Bay of Fundy, of which 958 ha are currently owned by the government or conservation organizations and 2,173.5 ha are owned by private landowners. A multiple bounded discrete choice contingent valuation survey was conducted to estimate landowners' willingness to accept compensation for selling their saltwater marshes to a conservation program. A multiple bounded model developed by Gregory Poe and Michael Welsh (1995) was used to analyze the responses. Mean willingness to accept compensation for one hectare of saltwater marsh was estimated to be $1,004.22, and aggregate willingness to accept compensation for the total of 2,173.5 ha of saltwater marsh owned by private landowners was approximately $2,180,000. Using these estimates and the rate of carbon dioxide-equivalent absorption of saltwater marshes, the opportunity cost of one tonne of carbon dioxide-equivalent sequestered by saltwater marshes in the Bay of Fundy was calculated to range between $16.70 and $19.95. Decision-makers can use this result for policy purposes concerning the achievement by Canada of its greenhouse gases emission reduction commitment under the Kyoto Protocol (1997).

The threat of environmental mercury (Hg), particularly methylmercury (MeHg), exposure to the health of humans has been well documented. Thus, it is important to monitor exposure and body burden for public health protection. The first objective of this thesis was to characterize the risk of Hg exposure in two Canadian coastal communities: Grand Marian (n = 91) and St. Andrews/St. Stephen (n = 52), New Brunswick, Canada, using dietary questionnaires and hair analysis. Average Hg intakes and body burden were below the most conservative guidelines. We attributed these results to the low Hg concentrations found in the species commonly consumed: haddock, canned tuna, lobster and pollock (all below 0.2 mg/kg). The analytical method employed to determine Hg in hair, cold vapor atomic absorption (CV-AAS), required a bundle of 100-150 hair strands and involved lengthy chemical digestion procedures which reduce throughput. Direct solid introduction techniques minimize these weaknesses. Our second and third objectives were to evaluate two such methods: (1) combustion, gold amalgamation, atomic absorption spectrometry (C-GA-AAS) and (2) laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) for measuring total Hg in single hair strands. Hair samples with a wide range of Hg exposure were obtained from communities. A 1:1 relationship was observed between C-GA-AAS and the established CV-AAS for analysis of 1-cm hair segments. Additionally, the average relative standard deviation (RSD) of Hg between hair strands within an individual was 6.5 +/- 2.8%, thus justifying the use of a single hair strand for biomonitoring. With a limit of quantification of 0.10 ng of total Hg, a single hair strand with average weight of 0.5 mg and Hg concentrations of 0.2 mg/kg can be measured routinely. Using LA-ICP-MS, we showed that a single laser shot can sample hair material within 50 mum along a single hair strand which is equivalent to less than one day of

No description available.

No description available.