Biology Faculty Research, Publications and Presentations: Recent submissions
Now showing items 41-60 of 185
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Estimating fertilization success in marine benthic invertebrates: A case study with the tropical sea star Oreaster reticulatus
Several factors can influence fertilization success, and for marine broadcast spawners, the main constraint is rapid dilution of gametes. Because the measurement of fertilization success in the field is logistically ... -
Detrital production in Nova Scotian kelp beds: patterns and processes
Connectivity via the transport of detrital material from areas of high to low productivity may be an important determinant of secondary productivity and biodiversity in receiving communities. On the Atlantic coast of ... -
Spatial and temporal variation in DMSP content in the invasive seaweed Codium fragile ssp fragile: effects of temperature, light and grazing
The methionine-derived secondary metabolite dimethylsulfoniopropionate (DMSP) is believed to function in cryoprotection, defense against herbivory, and reduction of oxidative stress in some seaweeds. The ability to produce ... -
Behaviour of sea urchin Strongylocentrotus droebachiensis grazing fronts: food-mediated aggregation and density-dependent facilitation
The occurrence of destructive grazing fronts is a common phenomenon in sea urchins, but mechanisms governing front formation and dynamics remain poorly understood. We experimentally examined the effect of kelp biomass ... -
Survival analysis of tethered juvenile sea scallops Placopecten magellanicus in field experiments: Effects of predators, scallop size and density, site and season
The impact of predation on survival of juvenile sea scallops Placopecten magellanicus has important implications for the population dynamics and aquaculture of this species. In field experiments using tethered juvenile ... -
Modelling phase shifts in a rocky subtidal ecosystem
The rocky subtidal ecosystem of the Atlantic coast of Nova Scotia is characterised by 2 community states, kelp beds and urchin barrens that alternate on a decadal time scale. While the shift from barrens to a kelp bed ... -
Spatial dynamics, ecological thresholds and phase shifts: modelling grazer aggregation and gap formation in kelp beds
On the Atlantic coast of Nova Scotia, transitions between alternative states of the subtidal ecosystem, kelp beds and sea urchin barrens, occur on a decadal scale. To explore the process of urchin aggregation within kelp ... -
Modelling phase shifts in a rocky subtidal ecosystem
The rocky subtidal ecosystem of the Atlantic coast of Nova Scotia is characterised by 2 community states, kelp beds and urchin barrens that alternate on a decadal time scale. While the shift from barrens to a kelp bed ... -
Fatty acids as dietary tracers in benthic food webs
Fatty acid (FA) analysis is a well-established tool for studying trophic interactions in marine habitats. However, its application to benthic food webs poses 2 particular challenges. First, unlike pelagic zooplankton, ... -
Fatty acid profiles in the gonads of the sea urchin Strongylocentrotus droebachiensis on natural algal diets
We examined fatty acid (FA) compositions of gonads of the green sea urchin Strongylocentrotus droebachiensis collected from a grazing aggregation (front) at the edge of a kelp bed and from barrens dominated by coralline ... -
Procedural effects of prey tethering experiments: Predation of juvenile scallops by crabs and sea stars
This study examines the effects of an experimental tethering procedure often used in field predation experiments. In laboratory experiments, juvenile sea scallops Placopecten magellanicus, either free or tethered, were ... -
Invasion-mediated shifts in the macrobenthic assemblage of a rocky subtidal ecosystem
We tracked changes in community composition that occurred with state shifts in the rocky subtidal ecosystem in Nova Scotia, Canada, from 1992 to 2008. At the beginning of our study, a dense aggregation of sea urchins was ... -
Spatial and temporal variability of patterns of colonization by mussels (Mytilus trossulus, M-edulis) on a wave-exposed rocky shore
Colonization rates of mussels (Mytilus trossulus and M. edulis) were measured on natural substrata in tidepools and on emergent rock in recently ice-scoured and non-scoured regions of a rocky shore near Halifax, Nova ... -
Non-Occurrence of Free-Living Paramoeba-Invadens in Water and Sediments of Halifax Harbour Nova Scotia Canada
Seawater and sediment samples from various sites in or near Halifax Harbour were cultured for Paramoeba as were tissues of the natural sea urchin host Stronglyocentrotus droebachiensis sampled from Halifax Harbour. An ... -
Fatty acids tracers for native and invasive macroalgae in an experimental food web
We assessed the potential of fatty acid (FA) markers for tracing primary production from an invasive green alga (Codium fragile ssp. fragile) and a native kelp (Saccharina longicruris) through 2 trophic levels in an ... -
Physical and biological factors influencing mussel (Mytilus trossulus, M. edulis) settlement on a wave-exposed rocky shore
Settlement rates of mussels Mytilus trossulus and M. edulis on artificial collectors (aquarium filter wool) and natural substrata were measured in tidepools and on emergent rock in recently ice-scoured and non-scoured ... -
Structure and dynamics of mussel patches in tidepools on a rocky shore in Nova Scotia, Canada
The distribution, size structure, and dynamics of mussel (Mytilus trossulus, M. edulis) patches in tidepools were studied on an exposed rocky shore near Halifax, Nova Scotia, Canada. The mussel patches were dynamic, ... -
Temporal and spatial variability in settlement and recruitment of echinoderms in kelp beds and barrens in Nova Scotia
Settlement and recruitment of echinoderms were measured in 2 adjacent habitats: a kelp bed (Laminaria longicruris) and an echinoid (Strongylocentrotus droebachiensis)-dominated barren ground at each of 2 sites in the ... -
Role of early post-settlement mortality in recruitment of benthic marine invertebrates
Newly settled invertebrates usually are subject to high rates of mortality (Type III survivorship). Therefore, knowledge of early post-settlement events is critical in determining if and when patterns of abundance and ...
