scholarly journals Different early post-settlement strategies between American lobsters Homarus americanus and rock crabs Cancer irroratus in the Gulf of Maine

1998 ◽  
Vol 162 ◽  
pp. 215-225 ◽  
Author(s):  
AT Palma ◽  
RA Wahle ◽  
RS Steneck
Keyword(s):  
Gulf Of Maine ◽  
Homarus Americanus ◽  
Cancer Irroratus ◽  
Settlement Strategies

Predicting bycatch hotspots based on suitable habitat derived from fishery-independent data

2020 ◽  
Vol 641 ◽  
pp. 159-175
Author(s):  
J Runnebaum ◽  
KR Tanaka ◽  
L Guan ◽  
J Cao ◽  
L O’Brien ◽  
...  
Keyword(s):  
Habitat Suitability ◽  
Mixed Model ◽  
Linear Mixed Model ◽  
Gulf Of Maine ◽  
Homarus Americanus ◽  
Management Tool ◽  
American Lobster ◽  
Suitable Habitat ◽  
Climate Conditions ◽  
Suitability Index

Bycatch remains a global problem in managing sustainable fisheries. A critical aspect of management is understanding the timing and spatial extent of bycatch. Fisheries management often relies on observed bycatch data, which are not always available due to a lack of reporting or observer coverage. Alternatively, analyzing the overlap in suitable habitat for the target and non-target species can provide a spatial management tool to understand where bycatch interactions are likely to occur. Potential bycatch hotspots based on suitable habitat were predicted for cusk Brosme brosme incidentally caught in the Gulf of Maine American lobster Homarus americanus fishery. Data from multiple fisheries-independent surveys were combined in a delta-generalized linear mixed model to generate spatially explicit density estimates for use in an independent habitat suitability index. The habitat suitability indices for American lobster and cusk were then compared to predict potential bycatch hotspot locations. Suitable habitat for American lobster has increased between 1980 and 2013 while suitable habitat for cusk decreased throughout most of the Gulf of Maine, except for Georges Basin and the Great South Channel. The proportion of overlap in suitable habitat varied interannually but decreased slightly in the spring and remained relatively stable in the fall over the time series. As Gulf of Maine temperatures continue to increase, the interactions between American lobster and cusk are predicted to decline as cusk habitat continues to constrict. This framework can contribute to fisheries managers’ understanding of changes in habitat overlap as climate conditions continue to change and alter where bycatch interactions could occur.

Larval lobster (Homarus americanus) distribution and drift in the vicinity of the Gulf of Maine offshore banks and their probable origins

2005 ◽  
Vol 14 (2) ◽  
pp. 112-137 ◽  
Author(s):  
G. C. HARDING ◽  
K. F. DRINKWATER ◽  
C. G. HANNAH ◽  
J. D. PRINGLE ◽  
J. PRENA ◽  
...  
Keyword(s):  
Gulf Of Maine ◽  
Homarus Americanus

Organic cation secretion by Cancer borealis urinary bladder

1987 ◽  
Vol 252 (1) ◽  
pp. R153-R159 ◽  
Author(s):  
D. S. Miller ◽  
C. W. Holliday
Keyword(s):  
Polyethylene Glycol ◽  
Urinary Bladder ◽  
Secretory Pathway ◽  
Organic Cation ◽  
Homarus Americanus ◽  
Cancer Borealis ◽  
Cancer Irroratus ◽  
Clearance Studies ◽  
Secretory Transport ◽  
Initial Clearance

In the crab, Cancer borealis, initial clearance studies showed a potent renal excretory system for the model organic cation, tetraethylammonium (TEA). TEA clearance averaged 145 +/- 32 ml/day, which was 18 times the paired polyethylene glycol clearance. TEA uptake by slices of urinary bladder was concentrative, saturable, inhibitable by N1-methylnicotinamide chloride, and dependent on glycolytic, but not oxidative, metabolism. When mounted in flux chambers, bladders exhibited a large net secretory flux. For 0.1 mM TEA, the ratio of secretory to reabsorptive fluxes was 65. Urinary bladders from another crab, Cancer irroratus, and a lobster, Homarus americanus, also exhibited net TEA secretion. In C. borealis bladder, secretory transport was concentrative, saturable, and nearly abolished by addition of 1 mM quinine to the serosal bath. Reabsorptive transport was not concentrative and was not reduced by luminal quinine. The data are consistent with a secretory pathway that is transcellular and mediated by carriers at both the serosal and luminal membranes.

Modeling shell disease in American lobster (Homarus americanus) as individual-based health trajectories

2014 ◽  
Vol 71 (6) ◽  
pp. 808-813 ◽  
Author(s):  
Michael F. Tlusty ◽  
Anita Kim ◽  
Kathleen M. Castro
Keyword(s):  
Conceptual Understanding ◽  
Gulf Of Maine ◽  
Homarus Americanus ◽  
Molt Cycle ◽  
Health Trajectories ◽  
Human Parasite ◽  
Before And After ◽  
Shell Disease ◽  
Lobster Fishery ◽  
Important Disease

The emergence of epizootic shell disease in American lobsters (Homarus americanus) has presented many new challenges to understanding the interface between disease and the management of the lobster fishery. While a variety of the potentially causative and correlative factors for shell disease have been explored, a clear etiological agent remains elusive. The recency of this disease and the lack of identifiable causal agents have hindered the development of conceptual models that can yield testable predictions. Here, a model originally developed for human–parasite interactions was applied to lobster shell disease as a means to unify the broad experimental and field observations. The model is a graphical means to understand the onset and severity of shell disease and is a function of the length of the molt cycle and the rate of the decrease of health both before and after lesion formation as a function of bacterial abundance and pathogenicity. The model also accounts for shell hardening and passive and active portals of entry for the bacteria. The timing for a conceptual understanding of the epidemiology of shell disease is critical because its prevalence is increasing in key fishing areas. Ideally, such a model will help researchers create hypothesis-driven predictive experiments from which we can further our understanding of an important disease to a critical member of the Gulf of Maine ecosystem.

scholarly journals Developing and evaluating harvest control rules with different biological reference points for the American lobster (Homarus americanus) fishery in the Gulf of Maine

2011 ◽  
Vol 68 (7) ◽  
pp. 1511-1524 ◽  
Author(s):  
Yuying Zhang ◽  
Yong Chen ◽  
Carl Wilson
Keyword(s):  
Gulf Of Maine ◽  
Homarus Americanus ◽  
The United States ◽  
Reference Points ◽  
Systematic Evaluation ◽  
American Lobster ◽  
Natural Mortality ◽  
Control Rules ◽  
The Status ◽  
Harvest Control Rules

Abstract Zhang, Y., Chen, Y., and Wilson, C. 2011. Developing and evaluating harvest control rules with different biological reference points for the American lobster (Homarus americanus) fishery in the Gulf of Maine. – ICES Journal of Marine Science, 68: 1511–1524. The American lobster (Homarus americanus) supports one of the most valuable commercial fisheries in the United States. Controversy exists, however, in terms of the biological reference point (BRP) used in assessing lobster stock status, and there is no fully established or evaluated harvest control rule (HCR). A sex-specific, size-dependent operating model is developed to evaluate the performance of two HCRs, discrete and continuous, which adjust annual fishing mortality discretely and linearly, respectively, based on the status of the fishery. For each HCR, different BRPs are considered along with management duration, recruitment dynamics, and natural mortality. HCRs with a suitable set of BRPs can drive the fishery from an undesirable status to an optimal status. The continuous HCR tends to perform better than the discrete one. The Ftarget of 0.31 year−1 showed the best performance in the long term by balancing the needs of the fishing industry and conservation bodies. However, this was not the case in the short term. An Ntarget of 49.6 million would allow the American lobster to be maintained at its current stock level, with high recruitment and stable natural mortality. The study provides a framework for a systematic evaluation of management regulations for the American lobster.

Cannibals by night? In situ video monitoring reveals diel shifts in inter- and intra-specific predation on the American lobster

2013 ◽  
Vol 70 (11) ◽  
pp. 1635-1640 ◽  
Author(s):  
Noah G. Oppenheim ◽  
Richard A. Wahle
Keyword(s):  
Video Surveillance ◽  
Population Regulation ◽  
Gulf Of Maine ◽  
Homarus Americanus ◽  
Quantitative Information ◽  
Video Monitoring ◽  
Predatory Fish ◽  
American Lobster ◽  
Population Densities

We conducted tethering experiments in the field to evaluate day–night differences in the identity and frequency of predators encountered by the American lobster (Homarus americanus) in coastal Maine, USA. Separate daytime and nighttime deployments were conducted using tethered lobsters under infrared-illuminated video surveillance. Supplemental tethering trials without video surveillance provided further quantitative information on diel and size-specific predation patterns. We found crabs to be the most common predators during the day, whereas lobsters prevailed at night. Contrary to expectations, we measured higher predation rates at night than during the day, suggesting that nocturnal interactions with conspecifics may play a more important role in lobster population regulation than previously thought when lobster population densities are high and large predatory fish are rare. As large predatory groundfish have been depleted in the Gulf of Maine, lobster populations have reached historic highs, making density-dependent feedbacks such as cannibalism more likely.

scholarly journals LARGE EPIBENTHIC INVERTEBRATES IN THE BRAS D’OR LAKES

2002 ◽  
Vol 42 (1) ◽  
Author(s):  
M. John Tremblay
Keyword(s):  
Egg Production ◽  
Carcinus Maenas ◽  
Homarus Americanus ◽  
Strongylocentrotus Droebachiensis ◽  
Green Crab ◽  
American Lobster ◽  
Placopecten Magellanicus ◽  
Cancer Irroratus ◽  
Trawl Surveys ◽  
Epibenthic Invertebrates

The distribution of large epibenthic invertebrates (lobster and crabs, bivalve molluscs and echinoderms) in the Bras d’Or Lakes is reviewed, and possible limiting factors are identified. The review is based on published and unpublished studies, including recent trawl surveys directed at fish, and trapping studies directed at American lobster Homarus americanus and green crab Carcinus maenas. The reduced salinities within the Lakes probably limit the distribution of several species (rock crab Cancer irroratus, sea scallop Placopecten magellanicus and possibly American lobster), particularly during the more sensitive larval period. Lobsters and eastern oysters Crassostrea virginica serve to illustrate the multiple factors limiting epibenthic invertebrate distribution within the Bras d’Or Lakes. Lobsters are less abundant within the Bras d’Or Lakes than on the outer coast of Cape Breton Island. Possible reasons are the reduced salinity and limited cobble bottom substrate in the Bras d’Or Lakes, coupled with low food availability and low egg production. Low egg production may be the result of overfishing of lobsters in the past. The life history and physiology of the eastern oyster appears to be well suited to the areas of the Lakes with warm summer temperatures. The oyster populations in the Bras d’Or Lakes are limited by natural predators (e.g. starfish and green crab), competitors (e.g. blue mussel Mytilus edulis and M. trossulus), and overfishing. The green crab, a new arrival to the Bras d’Or Lakes, will likely have negative effects on bivalves such as oysters, but the overall effect of green crab on the Bras d’Or Lakes food web is difficult to predict. Recent trawl surveys indicate both sea urchins Strongylocentrotus droebachiensis and starfish are present in considerable abundance, but little is known about their ecological roles in the Bras d’Or Lakes.La distribution des grands invertébrés épibenthique (les homards et les crabes, les mollusques bivalves et les échinodermes) dans les lacs du Bras d’Or est examinée et les coefficients possiblement limitatifs sont identifies. La revue est basée sur des études publiées et non-publiées englobant les plus récentesétudes sur la pêche au chalut dirigées vers les poissons et les études sur la pêche aux casiers dirigées vers les homards américains Homarus americanus et les crabes verts Carcinus maenas. Salinités réduites dans les lacs du Bras d’Or limitent probablement la distribution de quelques espèces crabes roches Cancer irroratus, pétoncle géant Placopecten magellanicus et possiblement le homard américain, en particulier, pendent l’époque sensible du larvaire. Les homards et les huîtres de l’Est Crossostrea virginica montrent plusieurs facteurs coefficients limitatifs de la distribution des invertébrés épibenthique dan les lacs du Bras d’Or. Les homards sont moins abondants ici que sur la côte extérieure de L’Ille du Cap Breton. Des explications possibles sont la réduction de l’eau saline du pavé rond limite dans le substratum de lacs, ainsi que la pauvre disponibilité de mangé et la production basse des oeufs. Cette dernière est peut-être le résultat d’un trop grand prise de homards au passè. L’histoire et la physiologie des huîtres semblent être bien adaptés aux lieux des lacs de Bras d’Or, qui ont des temperatures chaudes dan l’été. La population des huîtres dans les lacs est limitée par des proies natures ( ie étoiles de mer et les crabes verts) compétiteurs ( ie. Moules bleus Mytilus edulis et M. trossulus) et une trop grande prise de poissons. Le crabe vert, une arrivée nouvelle dans les lacs du Bras d’Or va sans doute avoir des impacts négatifs sur les bivalues comme les huîtres, mais leurs impacts en general sur la chaîne nutritive est difficile à prédire. Les études les plus recents sur la pêche au chalut montrent qu’il y a ungrand nombre d’oursins de mer Strongylocentrotus droebachiensis et des étoiles de mer, mais on ne connait pas quel est leur rôle écologique dans les lacs du Bras d’Or.

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