Joel P Heath

Arctic Eider Society

In subarctic marine environments, nutrient stocks are replenished through physical and biogeochemical processes in winter, largely setting an upper limit on new primary production for the next growing season. In spring, marine nutrient stocks are modified by freshwater-associated additions, especially in coastal areas. Hydroelectric development of...

Spatial patterns of bioaccumulated mercury were evaluated in coastal marine food webs of east Hudson Bay and east James Bay in the boreal subarctic of Canada. Two marine species, blue mussels (Mytilus edulis) and common eider ducks (Somateria mollissima) that consume mussels, were collected by a regional community-based monitoring network establish...

We investigated trophic transfer of cadmium (Cd) through an Arctic marine food web in Hudson Bay and compared it with mercury (Hg), a metal known to strongly biomagnify. We evaluated blue mussel, sea urchin, common eider, sculpin, Arctic cod, and ringed seal for the influence of dietary and biological variables on variation in Cd and Hg concentrati...

A large under‐ice plume forms because of the regulated winter discharge from the La Grande River hydroelectric complex (NE James Bay, Canada), which is among the largest winter discharges in the circumpolar north. In 2016–2017, field campaigns were completed to characterize the under‐ice plume's structure, extent, and short‐term dynamics related to...

The Hudson Bay system is undergoing climate-driven changes in sea ice and freshwater inflow and has seen an increase in winter river inflow since the 1960s due in part to flow regulation for hydropower production. Southeast Hudson Bay and adjacent James Bay are at the forefront of these changes, with more than 1-month shortening of the season of se...

Few ecotoxicological studies exist for rare earth elements (REEs), particularly field-based studies on their bioaccumulation and food web dynamics. REE mining has led to significant environmental impacts in several countries (China, Brazil, U.S.), yet little is known about the fate and transport of these contaminants of emerging concern. Northern e...

Few ecotoxicological studies exist for rare earth elements (REEs), particularly field-based studies on their bioaccumulation and food web dynamics. REE mining has led to significant environment impacts in several countries (China, Brazil, U.S.), yet little is known about the fate and transport of these contaminants of emerging concern. To understan...

Hudson Bay (HB) is a second largest saltwater bay in the world. It is relatively shallow with average depth of 100m and high tidal amplitudes (up to about 4m). Several major rivers are discharging into HB currently being regulated due to hydro dam development causing freshwater discharge to increase in winter months. All these factors make HB a uni...

Acknowledgements A special thanks goes to Dr. Joel Heath who urged researchers to take a closer look at the winter sea dynamics in southeast Hudson Bay and around the Belcher Islands. We have greatly appreciated the opportunity to work alongside members of the Arctic Eider Society and look forward to continue working with Lucassie Arragutainaq and...

Real quantities can undergo such a wide variety of dynamics that the mean is often a meaningless reference point for measuring variability. Despite their widespread application, techniques like the Coefficient of Variation are not truly proportional and exhibit pathological properties. The non-parametric measure Proportional Variability (PV) [1] re...

The degree of consistency with which groups of animals use the landscape is determined by a variety of ecological processes that influence their movements and patterns of habitat use. We developed a technique termed Distributional Consistency that uses survey data of unmarked individuals to quantify temporal consistency in their spatial distributio...

A Matlab.m file provided online allows calculating ‘Distributional Consistency’ from an input site (columns) by time interval (rows) matrix of survey data. (M)

The dynamics of resource patches and species that exploit such patches are of interest to ecologists, conservation biologists, modelers, and mathematicians. Here we consider how social interactions can create unique, evolving patterns in space and time. Whereas simple prey taxis (with consumable prey) promotes spatial uniform distributions, here we...

Foraging in association with other species can be an important strategy that facilitates locating or capturing prey. We studied the association of Marbled Murrelets with foraging Gray Whales along a 105 km transect on the west coast of Vancouver Island, British Columbia, in June 2005. Gray Whales forage on benthic invertebrates by scooping up botto...

To maximize fitness, animals must respond to a variety of processes that operate at different rates or timescales. Appropriate decisions could therefore involve complex interactions among these processes. For example, eiders wintering in the arctic sea ice must consider locomotion and physiology of diving for benthic invertebrates, digestive proces...

A variety of ecological, physiological and environmental factors influence the energy budgets of diving animals. For common eiders Somateria mollissima sedentaria wintering in sea ice habitats in the Canadian Arctic, time and energy costs of diving increase exponentially with tidal current speed. Here we use literature estimates of diving energetic...

Female Harlequin Ducks (Histrionicus histrionicus) incubate eggs and rear broods, while males normally depart the breeding grounds at the onset of incubation. On 27 July 2000, a male Harlequin Duck was observed in association with a female and brood of five ducklings on the Ikadlivik River in northern Labrador. The male maintained some distance (10...

Foraging behavior of Harlequin Ducks (Histrionicus histrionicus) and its response to changing environmental conditions during winter was investigated at Cape St. Mary's, Newfoundland. Behavioral synchrony among individuals permitted continuous observations of flocks to be conducted, sometimes over entire days. Overall foraging effort of Harlequin D...

Interactions between ecological processes operating at different scales are critical aspects of habitat suitability requiring careful consideration in conservation planning. Our previous research indicated that local abundance and demographics of subpopulations of Harlequin Ducks (Histrionicus histrionicus (L., 1758)), structured in 11 river canyon...

There has been wide empirical and theoretical interest in how diving animals allocate time between obtaining oxygen at the surface and foraging at depth. Assuming diminishing returns in oxygen gain at the surface, classic diving models predict that time on the surface should increase, while time spent foraging at depth should first increase and the...

Understanding variability of population abundances is of central concern to theoretical and applied evolutionary ecology, yet quantifying the conceptually simple idea has been substantially problematic. Standard statistical measures of variability are particularly biassed by rare events, zero counts and other ‘non-Gaussian’ behaviour, which are oft...

As raptor Populations recover following the banning of organochlorine pesticide use, there may be consequences for prey populations. While Bald Eagles (Haliaeetus leucocephalus) actively prey on Glaucous-winged Gulls and their offspring (Larus glaucescens), their presence at colonies and roost sites may also influence reproductive success of gulls...

Swim speed during diving has important energetic consequences. Not only do costs increase as drag rises non-linearly with increasing speed, but speed also affects travel time to foraging patches and therefore time and energy budgets over the entire dive cycle. However, diving behaviour has rarely been considered in relation to current velocity. Str...

Landscape features can have an important influence on the characteristics of populations, often resulting in heterogeneity in demographic processes. Therefore, local measurements of population parameters may not reflect regional characteristics. We studied populations of Harlequin Ducks (Histrionicus histrionicus L., 1758) breeding in 11 river cany...

Behavioural changes associated with reproduction were studied in captive Newfoundland martens (Martes americana atrata), an endangered species. Patterns of scent-marking and behavioural interactions were recorded before and after a male was introduced to two females. After introduction of the male, marking by the receptive female increased, whereas...

During an aerial survey on the Kingurutik River, northern Labrador, a Golden Eagle (Aquila chrysaetos) was observed attacking a female Harlequin Duck (Histrionicus histrionicus). Although the attack ended unsuccessfully, we believe this was only a result of disturbance by the presence of the helicopter. We overview previous reports of predation on...

Cover title. "December, 2001." Thesis (M. S.)--Memorial University of Newfoundland, 2001. Includes bibliographical references.

Thesis (M. Sc.)--Memorial University, 2002. Includes bibliographical references.