Maurice River Research Articles

Discovery and Genomic Characterization of a Novel Hepadnavirus from Asymptomatic Anadromous Alewife (Alosa pseudoharengus).

The alewife (Alosa pseudoharengus) is an anadromous herring that inhabits waters of northeastern North America. This prey species is a critical forage for piscivorous birds, mammals, and fishes in estuarine and oceanic ecosystems. During a discovery project tailored to identify potentially emerging pathogens of this species, we obtained the full genome of a novel hepadnavirus (ApHBV) from clinically normal alewives collected from the Maurice River, Great Egg Harbor River, and Delaware River in New Jersey, USA during 2015-2018. This previously undescribed hepadnavirus contained a circular DNA genome of 3146 nucleotides. Phylogenetic analysis of the polymerase protein placed this virus in the clade of metahepadnaviruses (family: Hepadnaviridae; genus: Metahepadnavirus). There was no evidence of pathology in the internal organs of infected fish and virions were not observed in liver tissues by electron microscopy. We developed a Taqman-based quantitative (qPCR) assay and screened 182 individuals collected between 2015 and 2018 and detected additional qPCR positives (n = 6). An additional complete genome was obtained in 2018 and it has 99.4% genome nucleotide identity to the first virus. Single-nucleotide polymorphisms were observed between the two genomes, including 7/9 and 12/8 synonymous vs nonsynonymous mutations across the polymerase and surface proteins, respectively. While there was no evidence that this virus was associated with disease in this species, alewives are migratory interjurisdictional fishes of management concern. Identification of microbial agents using de novo sequencing and other advanced technologies is a critical aspect of understanding disease ecology for informed population management.

Methylmercury in northern pike (Esox lucius) liver and hepatic mitochondria is linked to lipid peroxidation

Methylmercury (MeHg) readily bioaccumulates and biomagnifies in aquatic food webs leading to elevated concentrations in fish and may thus induce toxicity. Oxidative stress is a suggested effect of MeHg bioaccumulation in fish. However, studies on how MeHg triggers oxidative stress in wild fish are scarce. The purpose of this study was to link the subcellular distribution of MeHg in the liver of northern pike from the St. Maurice River (Québec, Canada), affected by two run-of-river (RoR) dams, artificial wetlands, forest fires, and logging activity, to lipid peroxidation as an indicator of oxidative stress. We also evaluated the protective effects of the glutathione (GSH) system and selenium (Se), as they are known to alleviate MeHg toxicity. A customized subcellular partitioning protocol was used to separate the liver into metal-sensitive (mitochondria, microsome/lysosome and HDP – heat-denatured proteins) and metal-detoxified fractions (metal-rich granules and HSP – heat-stable proteins). We examined the relation among THg, MeHg, and Se concentration in livers and subcellular fractions, and the hepatic ratio of total GSH (GSHt) to oxidized glutathione (GSSG) on lipid peroxidation levels, using the concentrations of malondialdehyde (MDA), a product of lipid peroxidation. Results showed that hepatic MDA concentration was positively correlated with the combined MeHg and Se concentrations in northern pike liver (r2 = 0.88, p < 0.001) and that MDA concentrations were best predicted by MeHg associated with the mitochondria (r2 = 0.71, p < 0.001). This highlights the need for additional research on the MeHg influence on fish health and the interactions between Hg and Se in northern pike.

Enhanced Bioaccumulation and Transfer of Monomethylmercury through Periphytic Biofilms in Benthic Food Webs of a River Affected by Run-of-River Dams.

Run-of-river (ROR) power plants impound limited terrestrial areas compared to traditional hydropower plants with large reservoirs and are assumed to have reduced impacts on mercury cycling. We conducted a study on periphyton and benthic communities from different habitats of the St. Maurice River (Québec, Canada) affected by two ROR power plants and their effect on the bioaccumulation and biomagnification of monomethylmercury (MMHg). Proportion of total mercury as MMHg reached maximum values about 2.9 times higher in flooded sites compared to unflooded sites. Impoundment by ROR would therefore provide favorable environments for the growth of periphyton, which can produce and accumulate MMHg. Periphyton MMHg concentrations significantly explained concentrations in some benthic macroinvertebrates, reflecting a local transfer. Through the analysis of δ13C and δ15N signatures, we found that flooding, creating scattered lenthic habitats, led to modifications in trophic structures by the introduction of new organic matter sources. The computed trophic magnification slopes did not show significant differences in the transfer efficiency of MMHg between sectors, while intercepts of flooded sectors were higher. Increases in MMHg concentrations in flooded areas are likely due to the impoundment, combined with watershed disturbances, and the creation of small habitats favorable to periphyton should be included in future predictive models.

Crop production and water quality under 1.5 °C and 2 °C warming: Plant responses and management options in the mid-Atlantic region

The 2015 “Paris Agreement” aims to limit the global average temperature rise to significantly less than 2 °C, preferably within 1.5 °C above pre-industrial levels. A multitude of studies have focused on evaluating how different sectors respond to such levels of warming. Nonetheless, most of these studies fail to provide a clear roadmap to mitigate these impacts. A case in point is the anticipated decline in corn and soybean yields and increased phosphorus (P) and nitrogen (N) discharge into water bodies, a trend linked to past agricultural practices and climate change. In this research, we employ a novel assessment of how existing management practices under 1.5 °C and 2 °C global warming (GW) scenarios can affect nutrient availability in time and space as well as crop yield in a typical agricultural watershed in the Mid-Atlantic Region, specifically the Upper Maurice River Watershed (UMRW) in New Jersey.Using the Soil and Water Assessment Tool (SWAT) with multiple Global Climate Model (GCM) projections, we found that compared to 1.5 °C, a 2 °C GW scenario would exacerbate runoff, leading to amplified nutrient leaching. These losses decrease nutrient availability during the crop growing season. Moreover, a mismatch between the timing of fertilizer application and crop nutrient absorption caused nutrient-related stress. This nutrient and anticipated temperature stress resulted in a more significant decrease in crop yields under the 2 °C GW scenario than the 1.5 °C scenario. We have designed a management scenario to reduce future nutrient losses while increasing crop yields. The strategy involves altering the timing of planting/harvesting and the fertilizer application rate in response to a warming climate. This approach is projected to increase corn and soybean yields by +39 % (+21 %) and +2 % (+17 %), respectively, under the 1.5 °C (2.0 °C) GW scenario for the RCP-4.5 pathway. Simultaneously, it is expected to decrease the N and P loads at 1.5 °C (2.0 °C) GW. Comparable projections are also observed under the RCP-8.5 pathway.

Myxozoan parasites vary in river herring according to life history stage and habitat.

Anadromous river herring have declined in many parts of their range, leading to fisheries management efforts to help repopulate this species by improving connectivity of rivers and restoring populations by fish transfers. With data lacking on parasites in these species, this study sought to better understand myxozoans across various life stages and habitats in river herring populations in New Jersey, USA. We compared fish from riverine habitats during early-life growth and adults returning to spawn, marine-phase fish, and landlocked Alewife populations. Three myxozoan species were identified in young-of-the-year (YOY) anadromous river herring, including Kudoa clupeidae in the skeletal musculature, Myxobolus mauriensis in the rib cartilage, and an uncharacterized coelozoic myxozoan within the lumen of mesonephric tubules. In YOY river herring, Blueback Herring were 2 times more likely to be infected by K. clupeidae than Alewife (p = 0.019) and in the Maurice River, fish were 4 times more likely to be infected with M. mauriensis than fish from Great Egg Harbor River (p = 0.000) and 11 times more likely than the Delaware River (p = 0.001). Spawning adult river herring were infected with a previously undescribed myxozoan parasite infecting the kidney. Sequencing the 18S rDNA indicated this species is closely related to Ortholinea species. Myxobolus mauriensis and the Ortholinea-like species were absent from marine-phase river herring indicating that infections were linked to river environments occurring during early-life growth and spawning, respectively. No myxozoans were present in landlocked Alewife, showing that similar infections occurring in rivers were absent in lake environments in the region.

Atikamekw and Euro-Canadian Territorialities around the Saint-Maurice River (1850–1930)

This essay focuses on the processes of territorialization, deterritorialization and reterritorialization through which Euro-Canadian society extended its control along the valley of the St. Maurice River between 1850 and 1930. That territory had been settled by the Atikamekw people where they had established their hunting and fishing grounds for centuries. However, the Atikamekw people were confronted by environmental and technological transformations around the St. Maurice River with the implementation of sociotechnical systems during that time period, as two successive phases of industrialization based on specific water use brought along a proliferation of urban centers and the arrival of the large-scale industry. This was particularly the case when the proliferation of hydroelectric dams along the St. Maurice River and its tributaries followed the construction of fluvial infrastructure to facilitate the floating of wood pulp harvested in the upper basin of the river. Not only did the technical activities surrounding the construction of hydroelectric facilities materially transform the St. Maurice River watershed, they also allowed a symbolic appropriation of the land by the production of maps and surveys that ‘erased’ the presence of the Atikamekw. Physical and symbolic boundaries resulting from these new forms of organization and configuration of the territory restricted the spatial practices and representations of the Atikamekw. Logging confined these people within isolated enclaves (the so-called “Indian reserves”), while dams bypassed their networks of exchange and communication. The aim of this essay is to understand the conflicts between the territorialities of the Atikamekw and that of the Euro-Canadians by focusing on the place of water uses within the geographical imaginations and the land use patterns of these populations.

Role of organic matter and microbial communities in mercury retention and methylation in sediments near run-of-river hydroelectric dams

Run-of-river power plants (RoRs) are expected to triple in number over the next decades in Canada. These structures are not anticipated to considerably promote the mobilization and transport of mercury (Hg) and its subsequent microbial transformation to methylmercury (MeHg), a neurotoxin able to biomagnify in food webs up to humans. To test whether construction of RoRs had an effect on Hg transport and transformation, we studied Hg and MeHg concentrations, organic matter contents and methylating microbial community abundance and composition in the sediments of a section of the St. Maurice River (Quebec, Canada). This river section has been affected by the construction of two RoR dams and its watershed has been disturbed by a forest fire, logging, and the construction of wetlands. Higher total Hg (THg) and MeHg concentrations were observed in the surface sediments of the flooded sites upstream of the RoRs. These peaks in THg and MeHg were correlated with organic matter proportions in the sediments (r2 = 0.87 and 0.82, respectively). In contrast, the proportion of MeHg, a proxy for methylation potential, was best explained by the carbon to nitrogen ratio suggesting the importance of terrigenous organic matter as labile substrate for Hg methylation in this system. Metagenomic analysis of Hg-methylating communities based on the hgcA functional gene marker indicated an abundance of methanogens, sulfate reducers and fermenters, suggesting that these metabolic guilds may be primary Hg methylators in these surface sediments. We propose that RoR pondages act as traps for sediments, organic matter and Hg, and that this retention can be amplified by other disturbances of the watershed such as forest fire and logging. RoR flooded sites can be conducive to Hg methylation in sediments and may act as gateways for bioaccumulation and biomagnification of MeHg along food webs, particularly in disturbed watersheds.

Myxobolus mauriensis n. sp. Infecting Rib Cartilage of Young-of-the-Year River Herring in New Jersey: Notes on Pathology, Prevalence, and Genetics.

: River herring populations, including Alosa pseudoharengus and Alosa aestivalis , have significantly declined as a result of anthropogenic factors throughout their range in eastern North America. To better understand the health of the species, parasite surveys were conducted in several New Jersey rivers. A novel myxozoan parasite, Myxobolus mauriensis n. sp., is described infecting the cartilage of pleural ribs in young-of-the-year fish. The parasite forms large polysporic plasmodia forming pseudocysts within the ribs, which extend into the musculature. Pathology associated with infection includes costochondritis, breaks in the rib bones, and deformed bone growth. Rupture of large pseudocysts and release of mature spores are associated with myositis, dermatitis, and peritonitis. Phylogenetic analysis reveals that M. mauriensis n. sp. occurs in a long-branching clade basal to other myxobolids, grouping with several Myxobolus species from marine fish (Myxobolus groenlandicus, Myxobolus aeglefini, and Myxobolus albi). The closest identity is to M. groenlandicus, with 83% identity based on a 1,762-bp sequence of the SSU 18S rDNA. Similarly, spore morphology, tropism for cartilage, and association with marine/brackish environments are shared in these 4 species. Mature spores of M. mauriensis n. sp. are similar to other reported myxobolids, though spores are slightly wider (12.1 ± 0.44 μm) than long (11.4 ± 0.44 μm), with a length:width relationship of 0.94 (±0.04), a feature not commonly described for other species of Myxobolus. Prevalence was studied by histology and fresh observation. In both Blueback Herring and Alewife, the highest infection prevalence occurred in the Maurice River at around 20%, and lower prevalence was found in the Great Egg Harbor River at around 5%. In the Delaware River, prevalence was about 2% in Blueback Herring, while the parasite was not detected in Alewife samples.

Intestinal coccidiosis of anadromous and landlocked alewives, Alosa pseudoharengus, caused by Goussia ameliae n. sp. and G. alosii n. sp. (Apicomplexa: Eimeriidae).

Anadromous alewives, Alosa pseudoharengus, have experienced significant population level declines caused by factors including habitat destruction. Alewives occur in two different life histories, anadromous and landlocked forms. The landlocked alewife evolved from ancestral anadromous populations, resulting in an exclusively freshwater and phenotypically unique form. The occurrence of parasites in a host is linked to the environment, making alewives an ideal model to compare parasitology within a single species with contrasting life histories. Currently, little information exists on the presence and impacts of parasites in these fish populations; the present study sets out to better understand coccidiosis in the threatened anadromous populations and to understand how coccidian parasites compare in both life history forms. The intestinal coccidian, Goussia ameliae n. sp., was described infecting the pyloric cecum of 76% and 86% of young-of-the-year and adult anadromous alewives, respectively, from the Maurice River, New Jersey, USA. The coccidian was found in landlocked alewife populations with a prevalence of 92% and 34% in YOY and adult fish, respectively. An analysis of the small subunit 18S ribosomal RNA gene of G. ameliae from both life history forms demonstrated that the coccidian had 100% sequence identity, confirming the same parasite species in both forms. Though genetic analysis demonstrated G. ameliae to be identical, some differences were observed in sporulation and morphology of the parasite within the two populations. The sporocysts in anadromous populations were shorter and wider, and sporulation timing differed from that of landlocked fish. These differences may either be attributed to differences in the host type or to the sporulation environment. Lastly, alewives from landlocked populations were frequently co-infected with a second coccidian species in the posterior intestine, which occurred at a lower prevalence. This species, G. alosii n. sp., was described based on morphological characters of the sporulated oocysts in fresh parasitological preparations.

Integrated damage management reduces grazing of wild rice by resident Canada geese in New Jersey

ABSTRACTTidal freshwater marshes of the Maurice River, New Jersey, USA, have been long renowned for robust stands of wild rice (Zizania aquatica). During the 1990s, these marshes experienced an apparent decline in wild rice. During 2000–2002, I used paired fenced exclosures and open control plots to measure herbivory by the Atlantic Flyway Resident Population of Canada geese (Branta canadensis) on wild rice and response of rice to an integrated damage management program (IDMP). The IDMP consisted of rendering goose nests unhatchable, shooting, and culling molting geese. The IDMP reduced the number of goslings by 60% during the first year and essentially eliminated recruitment during the second year. Prior to the IDMP, grazing by geese reduced the density of rice by 78% and the height of plants surviving grazing by 17%. With implementation of an IDMP, rice density between exclosures and control plots did not differ. Wetland managers should consider the grazing impacts that resident population Canada geese can incur on native plant communities and develop a plan for mitigating that damage. © 2014 The Wildlife Society.

Ten years of resident Canada goose damage management in a New Jersey tidal freshwater wetland

ABSTRACTIntensive grazing by Atlantic Flyway Resident Population Canada geese (Branta canadensis) has been shown to dramatically reduce wild rice (Zizania aquatica) abundance in tidal freshwater marshes in the Mid‐Atlantic Region of the United States. From 2001 to 2010, I implemented an integrated damage management program (IDMP) during spring to abate Canada goose herbivory to wild rice in tidal freshwater marshes of the Maurice River, New Jersey, USA. The IDMP consisted of shooting, rendering goose nests unhatchable, and euthanizing molting geese. With implementation of an IDMP, the number of nests on the study area declined 70% over 10 years and the number of geese declined over time. Consequently, the amount of IDMP effort needed to sustain rice was reduced. Because the study area was a key nesting site for ospreys (Pandion haliaetus), which are state‐threatened species, there was concern that disturbance from IDMP activities could have a negative impact on osprey nesting or recruitment. The mean annual number of nesting ospreys doubled and the mean number of young fledged/nest was similar between years prior to and during implementation of the IDMP, suggesting that the IDMP did not have a negative impact on ospreys. Wetland managers should consider damage from excessive herbivory caused by non‐native, breeding waterfowl, such as resident Canada geese or mute swans (Cygnus olor), in their suite of wetland mitigation strategies. © 2013 The Wildlife Society.

Long-term response of fishes and other fauna to restoration of former salt hay farms: multiple measures of restoration success

This synthesis brings together published and unpublished data in an evaluation of restoration of former salt hay farms to functioning salt marshes. We compared nine years of field measurements between three restored marshes (Dennis, Commercial, and Maurice River Townships) and a reference marsh (Moores Beach) in the mesohaline portion of Delaware Bay. In the process, we compared channel morphology, geomorphology, vegetation, sediment organic matter, fish assemblages, blue crabs, horseshoe crabs, benthic infauna, and diamondback terrapins. For fishes we compared structural (distribution, abundance) and functional (feeding, growth, survival, reproduction, production) aspects to evaluate the restored marshes in an Essential Fish Habitat context. Marsh vegetation and drainage density responded gradually and positively with restored marshes approximating the state of the reference marsh within the nine-year study period. The fauna responded more quickly and dramatically with most measures equal or greater in the restored marshes within the first one or two years after restoration. Differences in response time between the vegetation and the fauna imply that the faunal response was more dependent on access to the shallow intertidal marsh surface and intertidal and subtidal creeks than on characteristics of the vegetated marsh. The fishes in created subtidal creeks in restored marshes responded immediately and maintained fish assemblages similar to the reference marsh over the study period. The intertidal creek fish assemblages tended to become more like the reference marsh in the last years of the comparison. Overall, these results document the success of the restoration and how marshes function for both resident and transient fauna, especially fishes.

Modeling the Hydrology and water quality using BASINS/HSPF for the upper Maurice River watershed, New Jersey

Results of developing a watershed model for the Upper Maurice River watershed are presented. The model was calibrated against observed stream-flow using local coastal plain meteorology as input, for the ultimate purpose of estimating future development impacts on local hydrology, stream-flow and water quality. Due to insufficient data, the model has not been validated yet. Typically, development impacts expected to include are more frequent peak flows, flooding, increased channel-bed erosion, loss of wetlands, loss of forested land and more surface runoff, while water quality impacts expected to occur are an increase in nuisance vegetation in lakes and streams, and stream/lake-water quality degradation due to increased loads of pollutants. This paper reveals that a significant decrease in recharge of the Kirkwood-Cohansey unconfined aquifer system, lying below the watershed, will occur with further development, because development will alter the land-use toward more urbanization resulting in less water infiltration, hence less recharge of the aquifers below. Hydrologic Simulation Program, Fortran (HSPF), within the USEPA's BASINS-3 software system, was the modeling program used.

Seasonal Abundance and Occurrence of the Asian Isopod Synidotea laevidorsalis in Delaware Bay, USA

In 1999 the marine isopod Synidotea laevidorsalis (Miers 1881), indigenous to the northwest Pacific, was first documented in Delaware Bay, USA. We monitored weekly recruitment of this isopod and several other motile species in the Maurice River, a tributary of Delaware Bay. A spatial survey was also conducted. Abundance of S. laevidorsalis varied seasonally but overwhelmingly dominated other co-occurring species by an order of magnitude or more throughout most of the year. Isopod abundance increased through the summer of 2004 and peaked in September, coincident with the passing of Hurricane Ivan. Field observations documented large populations, frequently associated with pilings and buoy lines, throughout Delaware Bay in salinities of 4 through 22 ppt. The dramatic abundance of this isopod indicates that there is considerable potential for altering community structure. This isopod has yet to be observed along the Atlantic Coast of New Jersey or in Chesapeake Bay, but it has been reported near Charleston, SC.

Arsenic Redistribution between Sediments and Water near a Highly Contaminated Source

Mechanisms controlling arsenic partitioning between sediment, groundwater, porewaters, and surface waters were investigated at the Vineland Chemical Company Superfund site in southern New Jersey. Extensive inorganic and organic arsenic contamination at this site (historical total arsenic > 10 000 microg L(-1) or > 130 microM in groundwater) has spread downstream to the Blackwater Branch, Maurice River, and Union Lake. Stream discharge was measured in the Blackwater Branch, and water samples and sediment cores were obtained from both the stream and the lake. Porewaters and sediments were analyzed for arsenic speciation as well as total arsenic, iron, manganese, and sulfur, and they indicate that geochemical processes controlling mobility of arsenic were different in these two locations. Arsenic partitioning in the Blackwater Branch was consistent with arsenic primarily being controlled by sulfur, whereas in Union Lake, the data were consistent with arsenic being controlled largely by iron. Stream discharge and arsenic concentrations indicate that despite large-scale groundwater extraction and treatment, > 99% of arsenic transport away from the site results from continued discharge of high arsenic groundwater to the stream, rather than remobilization of arsenic in stream sediments. Changing redox conditions would be expected to change arsenic retention on sediments. In sulfur-controlled stream sediments, more oxic conditions could oxidize arsenic-bearing sulfide minerals, thereby releasing arsenic to porewaters and streamwaters; in iron-controlled lake sediments, more reducing conditions could release arsenic from sediments via reductive dissolution of arsenic-bearing iron oxides.

Gate Failure, Numerical And Physical ModellingAt Gouin Dam

Gouin dam is the main structure on the Saint Maurice river. A gate failure in 2002 prompted this study. Over the years, many modifications and attempts to correct the problems and obtain smooth operation of the bottom outlets were carried out, but with limited success. The numerical results gave a good representation of the flow conditions in the zone of pressure flow before the separation and free surface flow zone but in this latter regime the results were less satisfactory. As a result, a new physical hydraulic model was requested and built. The solution retained has significant advantages when compared to the previous one. In summary, the numerical simulation, due to the power of a strong graphics display, allowed a good preliminary evaluation of the problems. However, a physical model was an essential tool in studying aspects such as airwater mixture and the free surface instability as well as giving information on the vibration and cavitation problems associated with the interaction of high velocity flow and the gate structure. A final solution was found.

Contribution aux recherches sociales du Québec par une étude des variations régionales du nombre des vocations sacerdotales

This study, one of the first ever published in that field of research, is devoted to the geography of sacerdotal vocations and is divided in two parts. The first part deals with the differential rates of sacerdotal vocations which characterize some regions of the Province of Québec. The author bas calculated « index numbers of sacerdotal fecundity », and he studies the variability of these indexes within the limits of the diocese of Trois-Rivières. The data show that, before 1950, the St. Lawrence Lowlands region bas given a greater number of priests than the Valley of the St. Maurice River and a much greater number than the Laurentian Uplands. The second part of the article is more elaborated and treats of some « exterior » conditions which usually explain the number of vocations and justify the different contributions of various parts of the diocese. The various factors examined are demographic, familial, religious, economic, social, academic and historical. On this basis, the author formulates a series of observations which, taking into account the limited value of conclusions reached in social research, seem valuable for the understanding of the specific subject of this paper but also of many other problems concerning the social geography of the Province of Québec.

Changes in contaminant levels in New Jersey osprey eggs and prey, 1989 to 1998.

Ospreys are good indicators of the health of estuarine areas because they feed almost exclusively on fish with the balance on other aquatic biota. Through the 1980s, ospreys nesting on Delaware Bay in New Jersey had reduced reproductive success relative to those nesting on the Atlantic coast and the Maurice River, a tributary of Delaware Bay. Earlier research suggested that elevated levels of DDT and polychlorinated biphenyl (PCB) contaminants identified in addled osprey eggs contributed to this reduced productivity. We repeated egg and prey sampling initially conducted in 1989 to evaluate the trends of contaminants in the last decade. Most organochlorine contaminants declined in osprey eggs in 1998 relative to 1989. Across three study areas, PCBs decreased from 4.1-7.7 ppm in 1989 to 1.8-3.2 ppm in 1998; DDE decreased from 1.2-3.2 ppm in 1989 to 0.7-1.2 ppm in 1998. Lead in eggs increased from an average of 0.01 to 0.30 ppm wet weight, and mercury averaged 0.12 ppm and increased only in Atlantic coast eggs. Most of these contaminant changes were also found in typical prey fish: PCBs decreased from 0.18-1.2 ppm in 1989 to 0.06-0.43 ppm in 1998; DDE decreased from 0.05-0.69 ppm in 1989 to 0.03-0.13 ppm in 1998. Lead and mercury increased in most fish samples. The improvement in most organochlorine contaminants in osprey eggs and prey reflected improved nest success in the Delaware Bay study area, and the nesting populations in the Atlantic and Maurice River study areas increased approximately 200% since 1989. PCBs and DDE in osprey eggs were below levels considered to be toxic to egg development. This study documents significant improvements in organochlorine contaminants in southern New Jersey ospreys, but justifies continued monitoring of heavy metals, such as lead and mercury, in aquatic ecosystems.

Regional Flood Peak and Volume Estimation in Northern Canadian Basin

It is often necessary to estimate extreme events at sites where little or no hydrometric data are available. In such cases, one may use a regional estimation procedure, utilizing data available from other stations in the same hydrologic region. In general, a regional flood frequency procedure consists of two steps, delineation of hydrologically homogeneous regions and regional estimation. This paper focuses on the development of a regional flood frequency procedure based on canonical correlation analysis (CCA) and its application to data from a northern Canadian basin in which floods are dominated by spring snowmelt. This CCA-based procedure allows the joint regional estimation of spring flood peaks and volumes. The CCA method allows the determination of pairs of canonical variables such that the correlation between the canonical variables of one pair is maximized and between the variables of different pairs is equal to zero. Therefore, it is possible to infer hydrological canonical variables, knowing the physiographical-meteorological canonical variables. The methodology developed was applied to the St. Maurice River basin system, which is operated by Hydro-Quebec and characterized by the relatively low precision of flow data available. Results show that the proposed method allows for a significant reduction in the 100-year spring flood and volume quantile estimation bias and mean square error. The study also shows that, in 60% of cases, the method that was previously used overestimates quantile values, which leads to an overdesign of retention structures.

Determining the effect of negative allometry (length/height relationship) on variation in otolith shape in lake trout (Salvelinus namaycush), using Fourier-series analysis

Geometric mean regression analysis between log(length) and log(height) of otoliths from lake trout (Salvelinus namaycush) from six lakes revealed that the growth of this structure was negatively allometric, indicating that otolith shape varies throughout the life of the fish. Otolith shape was quantified using harmonic amplitudes 2-10 (A2-A10) extracted from Fourier-series analyses. We found harmonic amplitudes 2 (A2) and 5 (A5) to be associated with the length/height relationship. Some recent studies have suggested that growth of fish otoliths affects their shape. Our results indicate that part of this otolith-growth effect could be due to an intrinsic change in shape associated with allometric nature of the length/height relationship. There were no differences in otolith shape between males and females. Otolith shape was also compared among the six populations. Major differences were observed between Lake Normand (Saint Maurice River watershed) and the five lakes in the Ottawa River watershed, suggesting that genotype could be an important factor affecting otolith shape. The percentage of reclassification using a discriminant function analysis was high (86%) for the Lake Normand population. Among populations from the Ottawa River watershed, differences in otolith shape were more subtle, with reclassification percentages ranging from 50 to 75%. However, one population in the Ottawa River watershed (Lake Duval), which was introduced as hatchery-raised individuals, differed slightly from the other populations from the same watershed, including Lake Trente et un Milles, from which it originated.