scholarly journals The unique giant Irish moss (Chondrus crispus) from Basin Head: health assessment in relation to reference sites on Prince Edward Island

Botany ◽  
2018 ◽  
Vol 96 (11) ◽  
pp. 805-811 ◽  
Author(s):  
Paula Tummon Flynn ◽  
David Garbary ◽  
Irene Novaczek ◽  
Anthony Miller ◽  
Pedro A. Quijón
Keyword(s):  
Prince Edward Island ◽  
Health Assessment ◽  
Pulse Amplitude ◽  
Chondrus Crispus ◽  
Single Location ◽  
Irish Moss ◽  
Yield Values ◽  
The Common ◽  
Unique Strain ◽  
Resorcinol Method

Irish moss (Chondrus crispus Stackhouse) is a red alga that is common in Atlantic Canada. A unique strain of this species, the giant Irish moss, grows in a single location and is under strict protection. Unlike the common coastal form, the giant Irish moss reproduces solely by fragmentation and is found in gametophyte form. A 99.9% decline in giant Irish moss abundance (1999–2012) prompted this study to address two questions: whether the giant Irish moss remains 100% vegetative and gametophytic, and whether such decline is related to factors leading to a reduction in photosynthetic health. Six populations of the common Irish moss strain were compared with two populations of giant Irish moss, and their life history phases determined using a resorcinol method. The common Irish moss populations exhibited a 65%–86% ratio of gametophytic:tetrasporophytic fronds, while both giant strain populations were 100% gametophytic. Photosynthetic efficiency was measured with Pulse-Amplitude-Modulation (PAM) fluorometry and neither giant moss population had significantly different quantum yield values from the littoral populations. Hence, these analyses provided no evidence of giant Irish moss being exposed to particular sources of stress linked to water or habitat quality and alternative factors explaining the decline of this unique strain are proposed.

The role of the non-indigenous green crab (Carcinus maenas) in the decline of a unique strain of Irish moss (Chondrus crispus): direct and indirect effects

2019 ◽  
Vol 76 (7) ◽  
pp. 2338-2348 ◽  
Author(s):  
Paula Tummon Flynn ◽  
Kassandra Devon Lynn ◽  
David K Cairns ◽  
Pedro A Quijón
Keyword(s):  
Carcinus Maenas ◽  
Red Alga ◽  
Green Crab ◽  
Chondrus Crispus ◽  
Direct And Indirect Effects ◽  
Blue Mussels ◽  
Irish Moss ◽  
Plausible Mechanism ◽  
Unique Strain

Abstract A unique strain of the red alga Irish moss (Chondrus crispus) is found solely amongst clumps of blue mussels (Mytilus edulis) in a coastal lagoon in Atlantic Canada. Since about 2000, its bed area has shrunk by >99.9%, coinciding with the arrival of the non-indigenous green crab (Carcinus maenas). This study tested two mechanisms by which green crabs may harm the Irish moss. The hypothesis that green crabs directly consume the alga was tested by exposing fronds and clumps to crabs. Crab interaction with the clumps caused limited fragmentation, consumption was very small, and the condition (visible grazing damage) of fronds did not change significantly. A second hypothesis, that during predation and handling of mussels green crabs indirectly displace the seaweed and remove its attachment substrate, was addressed by placing crabs with Irish moss-mussel clumps containing either large or small mussels. Green crabs removed and ate up to 100% of the small mussels but did not consume or displace large mussels. This study concludes that direct consumption is not a plausible mechanism for green crabs to harm this strain. Instead, green crabs harm could be mediated by mussels, whose removal deprives the giant Irish moss of positional stability.

scholarly journals Theoretical Models for Interpreting the Dielectric Behaviour of HF-doped Ice

1978 ◽  
Vol 21 (85) ◽  
pp. 123-141 ◽  
Author(s):  
G. C. Camplin ◽  
J. W. Glen ◽  
J. G. Paren
Keyword(s):  
Single Crystals ◽  
Electrical Conduction ◽  
Fluoride Concentration ◽  
Theoretical Models ◽  
Data Set ◽  
Wide Range ◽  
Yield Values ◽  
Full Knowledge ◽  
The Common ◽  
Ice Lattice

AbstractTo understand the recent dielectric measurements made on HF-doped ice single crystals requires a full knowledge of the concentration of electrical defects present in ice and their subsequent interactions. Previous interpretations of the behaviour of HF-doped ice have concentrated upon specific features in isolation, whereas this paper presents analyses of a data set of 139 temperature and impurity combinations from 17 HF-doped ice single crystals. The interpretation of the behaviour of these crystals is in terms of several possible theoretical models. All models are based upon the common assumptions that HF molecules enter the ice lattice substitutionally and that excess Bjerrum and ionic defects can be formed at the HF sites. They also use the theory of electrical conduction in ice by Jaccard (1959) and the defect equilibria analysis in ice by Kroger (1974).All models yield values for the concentration, mobility, energy of formation and charges for the different types of electrical defect considered to be generated.From the model which assumes that only three fluorine centres exist, the approximate derived values of the mobility and charge for the L-defect and positive ionic defect are as follows: μL = 5 × 10-8 m2 V-1 s-1 at 273 K, eDL = 0.44e; μ+ = 2.7 × 10-8 m2 V-1 s-1 at 273 K, e± 0.73e.Finally, using the derived defect conductivities and the Jaccard theory of electrical conduction, the relaxation tune of HF-doped ice has been successfully predicted over a wide range of temperature and fluoride concentration.

Theory and Application of Pulse Amplitude Modulated Chlorophyll Fluorometry in Coral Health Assessment

2015 ◽  
pp. 506-523 ◽  
Author(s):  
Peter J. Ralph ◽  
Ross Hill ◽  
Martina A. Doblin ◽  
Simon K. Davy
Keyword(s):  
Health Assessment ◽  
Pulse Amplitude ◽  
Coral Health

Potential utilization of a lambda carrageenan polysaccharide, derived from a cultivated, clonal strain of the red seaweed Chondrus crispus (Irish moss) against toxic actions of venom of Bothrops jararaca and B. jararacussu snakes

2020 ◽  
Vol 32 (6) ◽  
pp. 4309-4320
Author(s):  
Ana Cláudia Rodrigues da Silva ◽  
Kelly Ketely Granja Pereira ◽  
Alan Trevor Critchley ◽  
Eladio Flores Sanchez ◽  
André Lopes Fuly
Keyword(s):  
Red Seaweed ◽  
Chondrus Crispus ◽  
Clonal Strain ◽  
Bothrops Jararaca ◽  
Irish Moss

EFFECT OF PROCESSING AND STORAGE ON THE QUALITY OF GELOSE FROM IRISH MOSS (CHONDRUS CRISPUS)

1948 ◽  
Vol 26f (3) ◽  
pp. 160-167
Author(s):  
D. MacDougall
Keyword(s):  
Relative Humidity ◽  
Moisture Content ◽  
East Coast ◽  
Storage Temperature ◽  
Chondrus Crispus ◽  
Irish Moss ◽  
Optimum Ph ◽  
Processing And Storage ◽  
And Storage

Irish moss (Chondrus crispus) from Canada's east coast was used to study possible improvements in the production and storage of gelose. The optimum pH for the extraction of gelose from Irish moss was between 6 and 7. Fine leaf particles, which prevent rapid filtration, were readily removed by supercentrifuging. Comparison of drum drying and drying from the frozen state showed that the former caused a marked lowering of viscosity but had little effect on suspending power or jelly strength. The logarithm of the viscosity determined by means of a MacMichael viscosimeter was related directly to the concentration; therefore, viscosity measurements can be corrected for the moisture content of the samples. The effect of storage temperature on deterioration was greater than the effect of relative humidity. Samples stored at 0° and 40° F. for 12 weeks showed no significant changes in viscosity or suspending power, whereas those stored at 80° and 120° F. deteriorated very rapidly. Material was vacuum ice-dried to 2% moisture without damage but the quality decreased when the extracts were stored at high temperatures.

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