Copper contamination and cadmium, silver, and zinc concentrations in the digestive glands of American lobster (Homarus americanus) from the inner Bay of Fundy, Atlantic Canada

2000 ◽  
Vol 65 (4) ◽  
pp. 470-477 ◽  
Author(s):  
C. L. Chou ◽  
L. A. Paon ◽  
J. D. Moffatt ◽  
B. Zwicker
Keyword(s):  
Homarus Americanus ◽  
Bay Of Fundy ◽  
American Lobster ◽  
Atlantic Canada ◽  
Copper Contamination ◽  
Zinc Concentrations ◽  
Digestive Glands

scholarly journals Newly Hatched Stage I American Lobster (Homarus americanus) Survival Following Exposure to Physically and Chemically Dispersed Crude Oil

2021 ◽  
Author(s):  
Benjamin de Jourdan ◽  
Tahereh Boloori ◽  
Les Burridge
Keyword(s):  
Environmental Protection Agency ◽  
Native Species ◽  
Toxicity Testing ◽  
Homarus Americanus ◽  
Larval Survival ◽  
Stage I ◽  
Toxicity Tests ◽  
American Lobster ◽  
Atlantic Canada ◽  
Test Species

Abstract Standard model species are commonly used in toxicity tests due to their biological and technical advantages but studying native species increases the specificity and relevance of results generated for the potential risk assessment to an ecosystem. Accounting for intraspecies variability and other factors, such as chemical and physical characterization of test medium, is necessary to develop a reproducible bioassay for toxicity testing with native species. In this study, larval stage I American lobster (Homarus americanus) was selected as the test species, which is native to Atlantic Canada. Toxicity tests were first conducted exposing lobster larvae to a reference toxicant of copper sulfate (CuSO4) and then to physically and chemically dispersed oil. The effect on larval survival was estimated by calculating the median effect concentration (EC50) as 2.54-9.73 mg TPH/L when all trials are considered together. The HC5 or PNEC value was 2.52 mg TPH/L and therefore a narrow difference from the EC50 value. The inter-trial variability (coefficient of variability = 17%) was lower than the US Environmental Protection Agency standard test species of mysid shrimp (Americamysis bahia) and inland silversides (Menidia bervillina). Our results indicate that the described larval lobster bioassay is reliable to produce repeatable results for this commercially important and native species of Atlantic Canada.

Morphology and Systematics of the Nemertean Pseudocarcinonemertes homari (Hoplonemertea:Mortostilifera) from the American Lobster, Homarus americanus

1985 ◽  
Vol 42 (2) ◽  
pp. 342-350 ◽  
Author(s):  
L. S. Uhazy ◽  
D. E. Aiken ◽  
A. Campbell
Keyword(s):  
Developmental Stages ◽  
Morphological Characteristics ◽  
Original Description ◽  
Homarus Americanus ◽  
Bay Of Fundy ◽  
American Lobster ◽  
Free Living ◽  
The Family ◽  
Passamaquoddy Bay ◽  
Stylet Length

Our study of the morphology and systematics of the nemertean Pseudocarcinonemertes homari Fleming and Gibson, 1981 is based on specimens removed from the damaged egg masses of American lobsters, Homarus americanus, caught in the type locality at Grand Manan, N.B., in the Bay of Fundy and nearby Passamaquoddy Bay. Morphological characteristics and measurements of males, females, and developmental stages, obtained through examination of live and preserved nemerteans plus stained histological sections, revealed differences and provided additional indications of variability in measurements of taxonomic characters when compared with the original description. Specifically, female nemerteans are longer and slightly wider than males; the rhynchodael opening is subterminal; sensory bristles occur lateral to the rhynchodael and anal openings; cephalic furrows are observable on living specimens; the combined stylet–basis length is longer than reported and stylet length appears a stable character; the bulbous or sacculate foregut joins to a distinct pyloric tube; ova are large, 260 × 251 μm in length and width; and larvae retained in the membranous brood sac lack anterior and posterior cirri or tufts. Comparison of characters that define Pseudocarcinonemertes and differentiate it from Carcinonemertes with those defining free-living hoplonemerteans strongly supports its removal from the family Carcinonemertidae to the family Tetrastemmatidae.

Geographic Distribution and Seasonal Occurrence of the Nemertean Pseudocarcinonemertes homari on the American Lobster, Homarus americanus

1985 ◽  
Vol 42 (2) ◽  
pp. 360-367 ◽  
Author(s):  
J. Brattey ◽  
A. Campbell ◽  
A. E. Bagnall ◽  
L. S. Uhazy
Keyword(s):  
Homarus Americanus ◽  
Bay Of Fundy ◽  
American Lobster ◽  
Wild Populations ◽  
Intensity Of Infection ◽  
Egg Masses ◽  
Mean Intensity ◽  
Life History Stages ◽  
Egg Incubation ◽  
The Impact

Examination of 1041 trap-caught lobsters from the Bay of Fundy, Grand Manan, Browns and German Banks, south and east Nova Scotia, and Northumberland Strait indicated that Pseudocarcinonemertes homari occurs on American lobsters, Homarus americanus, throughout Canadian Maritime waters. Male lobsters were rarely infected and ovigerous females generally had a higher prevalence (percentage infected) and mean intensity of infection (number of nemerteans per infected lobster) than nonovigerous females. Sexually immature nemerteans were found on male and nonovigerous female lobsters, but all P. homari life history stages including brood sacs occurred on ovigerous lobsters. No seasonal trends were evident on ovigerous lobsters caught near Grand Manan; prevalence was consistently high (60–93%) and mean intensity ± SE was variable (15 ± 4.0 to 86 ± 63.1). The nemertean developed to maturity on ovigerous lobsters, reproduced on the host egg masses throughout the year, and appeared to produce three generations during a lobster egg incubation period. When lobsters completed egg incubation, nemertean reproduction ceased and some nemerteans either died, left the lobster, or perhaps were shed at molting. Prevalence and mean intensity increased with the size of ovigerous lobsters, and the distribution of nemerteans among ovigerous lobsters was highly aggregated. Ovigerous lobsters infected with >200 nemerteans had extensively damaged egg masses, but were rarely encountered (5 of 291). The impact of P. homari on the egg mortality of wild populations of H. americanus is unknown.

Pathology of two forms of shell disease of the American lobster Homarus americanus Milne Edwards in Atlantic Canada

2013 ◽  
Vol 37 (6) ◽  
pp. 577-581 ◽  
Author(s):  
R Smolowitz ◽  
R A Quinn ◽  
R J Cawthorn ◽  
R L Summerfield ◽  
A Y Chistoserdov
Keyword(s):  
Homarus Americanus ◽  
American Lobster ◽  
Atlantic Canada ◽  
Shell Disease

Declining fecundity and factors affecting embryo quality in the American lobster (Homarus americanus) from the Bay of Fundy

2015 ◽  
Vol 72 (3) ◽  
pp. 352-363 ◽  
Author(s):  
Heather N. Koopman ◽  
Andrew J. Westgate ◽  
Zachary A. Siders
Keyword(s):  
Embryo Quality ◽  
Gulf Of Maine ◽  
Energy Content ◽  
Homarus Americanus ◽  
Striking Difference ◽  
Bay Of Fundy ◽  
American Lobster ◽  
Female Size ◽  
Factors Affecting ◽  
Old Females

Recent perturbations in ecosystem and environmental dynamics in the habitat of the American lobster have led to increases in abundance, with unprecedented high landings in some regions. Despite the commercial value of this species, surprisingly little is known about maternal and environmental influences on its reproductive output. We measured fecundity and embryo quality in 1370 ovigerous lobsters from the Bay of Fundy, Canada, during 2008–2013. Female size was generally positively correlated with fecundity (P < 0.001), although some of the very large (and presumably old) females brooded significantly fewer eggs than expected. Egg energy content and lipid content and composition exhibited significant annual differences, indicating environmentally based variation. The most striking difference was a 31% decline in fecundity from 2008 to 2013 (8%–10% per year). We hypothesize that recent warming trends could be responsible for reduced fecundity. Decreased fecundity may be a cause for concern for future recruitment in this population, which has been shown to be an important source of larvae for the Gulf of Maine metapopulation.

Evidence that mud seafloor serves as recruitment habitat for settling and early benthic phase of the American lobster Homarus americanus H. Milne Edwards, 1837 (Decapoda: Astacidea: Nephropidae)

2019 ◽  
Vol 39 (5) ◽  
pp. 594-601
Author(s):  
Kristin M Dinning ◽  
Rémy Rochette
Keyword(s):  
Body Condition ◽  
Relative Abundance ◽  
Size Range ◽  
Homarus Americanus ◽  
Bay Of Fundy ◽  
American Lobster ◽  
Differential Growth ◽  
The Past ◽  
Current Potential ◽  
Important Habitat

Abstract Structurally complex cobble seafloor protects against predators, and is generally assumed to be the only meaningful habitat for settlement and benthic recruitment of American lobsters (Homarus americanus H. Milne Edwards, 1837). Accordingly, historical surveys on featureless substrates such as mud have found few and only older juveniles. Mud, however, is far more common than cobble across the lobster’s range, and may be of increasing importance in regions where the lobster population has been growing over the past few decades. As a first step to determining whether mud seafloor serves as meaningful recruitment habitat for juvenile lobsters, we deployed artificial habitats (bio-collectors) at five locations varying from 100% mud to mostly cobble, in Maces Bay, Bay of Fundy, NB, Canada, to capture young lobsters. A broad size range of lobsters, from new settlers up to adolescents, colonized bio-collectors in all locations, suggesting that lobsters settle and spend at least some of their juvenile life on mud. Differences in body condition (length-standardized mass) of lobsters sampled from the different locations suggest that some individuals must reside on mud for at least months to years, long enough to show differential growth between habitats. The greater relative abundance of adolescents in bio-collectors on mud also suggests their net movement from densely populated cobble beds into mud habitat. We propose that mud seafloor may be a more important habitat for settlement and early survival of American lobsters than is currently appreciated, especially given the current potential saturation of scarce cobble nursery habitat by growing lobster populations and, in some regions, reduced predation on mud seafloor due to overfishing of groundfish.

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