scholarly journals Role of grazing by sea urchins Strongylocentrotus droebachiensis in regulating the invasive alga Codium fragile ssp. tomentosoides in Nova Scotia

2005 ◽  
Vol 292 ◽  
pp. 203-212 ◽  
Author(s):  
CBT Sumi ◽  
RE Scheibling
Keyword(s):  
Nova Scotia ◽  
Sea Urchins ◽  
Strongylocentrotus Droebachiensis ◽  
Codium Fragile ◽  
Invasive Alga

Relationship Between Destructive Grazing by the Sea Urchin, Strongylocentrotus droebachiensis, and the Abundance of American Lobster, Homarus americanus, on the Atlantic Coast of Nova Scotia

1981 ◽  
Vol 38 (11) ◽  
pp. 1339-1349 ◽  
Author(s):  
W. G. Wharton ◽  
K. H. Mann
Keyword(s):  
Population Structure ◽  
Nova Scotia ◽  
Sea Urchins ◽  
Atlantic Coast ◽  
Homarus Americanus ◽  
Strongylocentrotus Droebachiensis ◽  
American Lobster ◽  
History Of ◽  
Kelp Bed ◽  
The Relationship

Relationships between percentage cover of macroalgae, population structure of sea urchins (Strongylocentrotus droebachiensis), and the history of the lobster fishery were examined at nine sites distributed along the Atlantic coast of Nova Scotia from Guysborough County in the northeast to Pubnico in the southwest. At Pubnico there was dense algal cover and a small number of urchins living in crevices, and at Cape Sable there was an area of transition, but at all other sites there were urchin-dominated barren grounds. When the population structure of the urchins was compared with that previously observed in St. Margaret's Bay before, during, and after destruction of beds of kelp (Laminaria spp. and Agarum) by overgrazing, it was concluded that kelp bed destruction occurred on the coast north of Halifax prior to 1970, and on the coast south of Halifax after 1970. From the records of American lobster (Homarus americanus) catches it was concluded that a critical decline in catches at each site occurred a few years after kelp bed destruction. Information from various sources is synthesized into a coherent theory of the relationship between lobsters, other predators, sea urchins, and kelp.Key words: lobsters, Homarus americanus; sea urchins, Strongylocentrotus droebachiensis; destructive grazing, kelp, Laminaria, Agarum

Predation by Rock Crabs (Cancer irroratus) on Diseased Sea Urchins (Strongylocentrotus droebachiensis) in Nova Scotia

1984 ◽  
Vol 41 (12) ◽  
pp. 1847-1851 ◽  
Author(s):  
Robert E. Scheibling
Keyword(s):  
Nova Scotia ◽  
Sea Urchins ◽  
Mass Mortality ◽  
Strongylocentrotus Droebachiensis ◽  
Significant Preference ◽  
Laboratory Findings ◽  
Cancer Irroratus ◽  
Feeding Experiments ◽  
Defensive Behaviors ◽  
Strong Attachment

Predation of morbid sea urchins (Strongylocentrotus droebachiensis) by rock crabs (Cancer irroratus) and other predators was observed using SCUBA during an outbreak of disease in southwestern Nova Scotia in August 1983. Disease increases susceptibility of sea urchins to predation by precluding natural defensive behaviors including spine projection, strong attachment to the substratum, and aggregation. In laboratory feeding experiments, rock crabs preferred diseased or narcotized sea urchins over healthy ones and fed upon them at a much higher rate than crabs given only healthy sea urchins as prey. Rock crabs showed no significant preference between diseased and narcotized sea urchins. Rock crabs clearly preferred mussels over healthy or diseased sea urchins. Although rock crabs do not appear to be important predators of healthy sea urchins, from field and laboratory findings I conclude that they contribute to mass mortality of sea urchins by preying upon morbid individuals during outbreaks of disease.

The role of proteoglycan in the development of sea urchins

1979 ◽  
Vol 123 (2) ◽  
pp. 229-236 ◽  
Author(s):  
S. Kinoshita ◽  
H. Saiga
Keyword(s):  
Sea Urchins

Studies on the flowering biology of red sorrel (Rumex acetosella) ramets from lowbush blueberry (Vaccinium angustifolium) fields in Nova Scotia, Canada

Botany ◽  
2015 ◽  
Vol 93 (1) ◽  
pp. 41-46 ◽  
Author(s):  
Scott N. White ◽  
Nathan S. Boyd ◽  
Rene C. Van Acker ◽  
Clarence J. Swanton
Keyword(s):  
Nova Scotia ◽  
Combined Effects ◽  
Perennial Species ◽  
Weed Species ◽  
Vaccinium Angustifolium ◽  
Perennial Weed ◽  
Flowering Response ◽  
Lowbush Blueberry ◽  
Rumex Acetosella

Red sorrel (Rumex acetosella L.) is a ramet-producing herbaceous creeping perennial species commonly found as a weed in commercially managed lowbush blueberry (Vaccinium angustifolium Aiton) fields in Nova Scotia, Canada. Flowering and seed production occur primarily in overwintering ramets of this species, indicating a potential vernalization requirement for flowering. This study was therefore initiated to examine the role of vernalization, photoperiod, and pre-vernalization stimulus on ramet flowering. Red sorrel ramets propagated from creeping roots and seeds collected from established red sorrel populations in lowbush blueberry had an obligate requirement for vernalization to flower. Ramet populations maintained under pre- and post-vernalization photoperiods of 16 h flowered following 12 weeks of vernalization at 4 ± 0.1 °C, whereas those maintained under constant 16, 14, or 8 h photoperiods without vernalization did not flower. Vernalization for 10 weeks maximized, but did not saturate, the flowering response. Pre-vernalization photoperiod affected flowering response, with increased flowering frequency observed in ramet populations exposed to decreasing, rather than constant, photoperiod prior to vernalization. This study represents the first attempt to determine the combined effects of vernalization and photoperiod on red sorrel flowering, and the results provide a benchmark for the future study of flowering and sexual reproduction in this economically important perennial weed species.

Truth and Privilege

2021 ◽  
Author(s):  
Lyndsay Campbell
Keyword(s):  
Nova Scotia ◽  
Social History ◽  
American Revolution ◽  
Institutional Design ◽  
Freedom Of Expression ◽  
Over Expression ◽  
Essential Question ◽  
The Press ◽  
The Common

Truth and Privilege is a comparative study that brings together legal, constitutional and social history to explore the common law's diverging paths in two kindred places committed to freedom of expression but separated by the American Revolution. Comparing Nova Scotia and Massachusetts, Lyndsay Campbell examines the development of libel law, the defences of truth and privilege, and the place of courts as fora for disputes. She contrasts courts' centrality in struggles over expression and the interpretation of individual rights in Massachusetts with concerns about defining protective boundaries for the press and individuals through institutional design in Nova Scotia. Campbell's rich analysis acts as a lens through which to understand the role of law in shaping societal change in the nineteenth century, shedding light on the essential question we still grapple with today: what should law's role be in regulating expression we perceive as harmful?

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