Fidelity of American Shad, Alosa sapidissima (Gupeidae), to its River of Previous Spawning

1986 ◽  
Vol 43 (3) ◽  
pp. 640-646 ◽  
Author(s):  
Gary D. Melvin ◽  
Michael J. Dadswell ◽  
James D. Martin
Keyword(s):  
Nova Scotia ◽  
Marine Environment ◽  
American Shad ◽  
Geographical Range ◽  
Bay Of Fundy ◽  
Alosa Sapidissima ◽  
St Lawrence River

Of 5074 adult American shad, Alosa spidissima, tagged in the Annapolis River, Nova Scotia, during the 1981 and 1982 spawning runs, 292 (5.8%) were recaptured, 180 in the river during the same year, 56 in the river in subsequent years, 53 at distant marine sites, and 1 in another Nova Scotia river. Recovery from 6124 adult shad tagged in a marine environment (Cumberland Basin, Bay of Fundy) was similar (395 recaptures, 6.5%) but distribution was markedly different. Thirty-five were taken in the Basin during the same year, but only 7 in subsequent years. Conversely, 139 were recaptured at distant marine sites, and 214 in rivers from the St. Lawrence River, Quebec, to the St. John's River, Florida. Assuming equal probabilities for recapture within this species' geographical range, Annapolis River freshwater recaptures were specific for the Annapolis River but Cumberland freshwater recaptures were nonspecific. Except for two returns, possible strays, fidelity to the Annapolis was 97%.

Effect of Turbidity on the Temporal and Spatial Utilization of the Inner Bay of Fundy by American Shad (Alosa sapidissima) (Pisces: Clupeidae) and its Relationship to Local Fisheries

1983 ◽  
Vol 40 (S1) ◽  
pp. s322-s330 ◽  
Author(s):  
M. J. Dadswell ◽  
G. D. Melvin ◽  
P. J. Williams
Keyword(s):  
Light Intensity ◽  
Atlantic Coast ◽  
American Shad ◽  
Bay Of Fundy ◽  
Eastern Canada ◽  
Alosa Sapidissima ◽  
Migration Timing ◽  
Swimming Depth ◽  
Preference Zone ◽  
High Turbidity

Since 1750, a unique, directed fishery for American shad (Alosa sapidissima) has existed in shallow, turbid, mega-tidal embayments of the inner Bay of Fundy during summer and fall. Tagging experiments indicated that migrating shad consisting of intermixed, river populations from the entire Atlantic coast of North America occur there between June and October. Shad migration was counterclockwise around the Bay following the residual current structure. Presence and duration of the shad run in Cumberland Basin was a result of interaction between migration timing, turbidity, and temperature. Mean daytime swimming depth was related to tidal phase and turbidity. High turbidity (Secchi [Formula: see text]) of the mega-tidal embayments apparently extends the preference zone for light intensity of ocean-feeding shad into surface waters (2–10 m), making them accessible to the local fishery.Key words: drift gillnets, shad migration, light intensity preference, swimming depth, mega-tidal, eastern Canada

Usefulness of Meristic and Morphometric Characters in Discriminating Populations of American Shad (Alosa sapidissima) (Ostreichthyes:Clupeidae) Inhabiting a Marine Environment

1992 ◽  
Vol 49 (2) ◽  
pp. 266-280 ◽  
Author(s):  
Gary D. Melvin ◽  
Michael J. Dadswell ◽  
Joseph A. McKenzie
Keyword(s):  
North Carolina ◽  
Atlantic Coast ◽  
American Shad ◽  
Cape Cod ◽  
Bay Of Fundy ◽  
Morphometric Characters ◽  
Alosa Sapidissima ◽  
Linear Discriminant ◽  
Percent Correct ◽  
Spawning Run

American shad (Alosa sapidissima) concentrate each summer in the basins of the inner Bay of Fundy during their coastal migration. Tag returns from 6124 marked shad indicated that these fish return to every important shad spawning stream on the Atlantic coast. Ten meristic and 16 morphometric characters of shad collected from 14 rivers (range: Florida to Quebec) were used to develop linear discriminant functions (LDF). Variables which differed significantly (p < 0.05) between the sexes, year of sampling, and the time of collection during the spawning run were removed prior to LDF classification. The highest mean percent correct classification was achieved by the allocation of fish into regional groups, after classification into individual rivers, using pooled meristic and morphometric variables: 87.2% for males and 82.4% for females. The functions were then used to assign shad from a mixed populations (Cumberland Basin) to individual rivers and regions. Of these, 10.9% were assigned to rivers south of Cape Lookout, North Carolina, 38.1% to rivers between Cape Lookout and Cape Cod, 32.5% into rivers of the Bay of Fundy, and 18.5% into rivers in the Gulf of St. Lawrence. In-river tag returns were compared with LDF classification and were found to be similar.

scholarly journals Length and restriction site heteroplasmy in the mitochondrial DNA of american shad (alosa sapidissima).

Genetics ◽  
1988 ◽  
Vol 118 (3) ◽  
pp. 509-518
Author(s):  
P Bentzen ◽  
W C Leggett ◽  
G G Brown
Keyword(s):  
Mitochondrial Dna ◽  
South Carolina ◽  
Nova Scotia ◽  
Length Polymorphism ◽  
Restriction Site ◽  
Restriction Endonuclease Analysis ◽  
American Shad ◽  
Length Variation ◽  
Alosa Sapidissima ◽  
Size Classes

Abstract Restriction endonuclease analysis was used to assess mitochondrial DNA (mtDNA) variation in American shad (Alosa sapidissima) collected from 14 rivers ranging from Florida to Quebec. Two types of heteroplasmy were observed, one involving a major length polymorphism and the other a single restriction site. Shad mtDNA occurred in two principal size classes, 18.3 and 19.8 kb. Of 244 shad examined, 30 were heteroplasmic and carried both size classes of mtDNA in varying proportions; the remainder were homoplasmic for the smaller size class of mtDNA. The large mtDNA variant occurred most frequently at the southern end of the range, and except for two individuals from Nova Scotia, was not detected among shad from rivers north of the Delaware. In contrast, ten shad heteroplasmic for a SalI restriction site originated from rivers ranging from South Carolina to Nova Scotia. DNA mapping and hybridization experiments indicated that the length polymorphism is in the D-loop-containing region and consists of a tandemly repeated 1.5-kb DNA sequence occurring in two and three copies, respectively, in the two major size classes of shad mtDNA. Continuous length variation up to approximately 40 bp occurs among copies of the repeat both within and among individuals. Restriction site data support the conclusion that both forms of heteroplasmy in shad mtDNA have originated more than once.

Modeling migratory energetics of Connecticut River American shad (Alosa sapidissima): implications for the conservation of an iteroparous anadromous fish

2010 ◽  
Vol 67 (5) ◽  
pp. 806-830 ◽  
Author(s):  
Theodore Castro-Santos ◽  
Benjamin H. Letcher
Keyword(s):  
Reproductive Biology ◽  
Marine Environment ◽  
American Shad ◽  
Connecticut River ◽  
Alosa Sapidissima ◽  
Barrier Effects ◽  
Total Fecundity ◽  
Input Variables ◽  
And Behavior ◽  
Spawning Success

We present a simulation model in which individual adult migrant American shad ( Alosa sapidissima ) ascend the Connecticut River and spawn, and survivors return to the marine environment. Our approach synthesizes bioenergetics, reproductive biology, and behavior to estimate the effects of migratory distance and delays incurred at dams on spawning success and survival. We quantified both the magnitude of effects and the consequences of uncertainty in the estimates of input variables. Behavior, physiology, and energetics strongly affected both the distribution of spawning effort and survival to the marine environment. Delays to both upstream and downstream movements had dramatic effects on spawning success, determining total fecundity and spatial extent of spawning. Delays, combined with cues for migratory reversal, also determined the likelihood of survival. Spawning was concentrated in the immediate vicinity of dams and increased with greater migratory distance and delays to downstream migration. More research is needed on reproductive biology, behavior, energetics, and barrier effects to adequately understand the interplay of the various components of this model; it does provide a framework, however, that suggests that provision of upstream passage at dams in the absence of expeditious downstream passage may increase spawning success — but at the expense of reduced iteroparity.

Spawning dynamics of American shad (Alosa sapidissima) in the St. Lawrence River, Canada-USA

2010 ◽  
Vol 19 (4) ◽  
pp. 586-594 ◽  
Author(s):  
E. Maltais ◽  
G. Daigle ◽  
G. Colbeck ◽  
J. J. Dodson
Keyword(s):  
American Shad ◽  
Alosa Sapidissima ◽  
St Lawrence River

Parasites of American shad, Alosa sapidissima (Osteichthyes: Clupeidae), from rivers of the North American Atlantic coast and the Bay of Fundy, Canada

1993 ◽  
Vol 71 (5) ◽  
pp. 941-946 ◽  
Author(s):  
W. E. Hogans ◽  
Michael J. Dadswell ◽  
Leslie S. Uhazy ◽  
Ralph G. Appy
Keyword(s):  
Atlantic Coast ◽  
Geographic Location ◽  
Diversity Indices ◽  
American Shad ◽  
Bay Of Fundy ◽  
Alosa Sapidissima ◽  
The North ◽  
Abundance And Diversity ◽  
First Time ◽  
Hysterothylacium Aduncum

Parasites belonging to a total of 26 taxa were recovered from 695 American shad (Alosa sapidissima) sampled from six rivers and one marine location (Cumberland Basin, Bay of Fundy) on the east coast of North America. Of these, 23 taxa are reported from American shad for the first time. Species identified were predominantly boreal marine forms that have low host specificities and widespread distributions. Two species, Hysterothylacium aduncum and Scolex pleuronectis, were found in American shad from all localities (> 60% prevalence). Relative abundance and diversity indices of the parasite assemblages varied in relation to geographic location and temporally in Cumberland Basin. These data suggest that there is different timing of arrival and departure of shad from individual river populations in Cumberland Basin. High levels of prevalence and incidence of exotic, southern parasite species, such as Genitocotyle atlantica, in shad from Cumberland Basin and most or all river populations indicate that all individual shad spend some portion of their life at or near the southern extent of their reported range.

Autumn Stranding of a Northern Bottlenose Whale (Hyperoodon ampullatus) in the Bay of Fundy, Nova Scotia

1975 ◽  
Vol 32 (7) ◽  
pp. 1019-1040 ◽  
Author(s):  
Edward Mitchell ◽  
V. Michael Kozicki
Keyword(s):  
Nova Scotia ◽  
Rhode Island ◽  
Growth Curve ◽  
North American ◽  
Labrador Sea ◽  
Bay Of Fundy ◽  
Winter Migration ◽  
Hyperoodon Ampullatus

A 615-cm male northern bottlenose whale (Hyperoodon ampullatus) stranded in Cobequid Bay, Bay of Fundy, in early October 1969. The skull, mandible, tympano-periotics, and teeth are described and illustrated. Five growth layers in the lower teeth place the animal below a growth curve based on samples from the Labrador Sea taken in May and June. A summary of nine other North American occurrences of 12 individuals, mainly south of Sable Island, indicates a winter migration to waters offshore of Massachusetts and Rhode Island.

Limnetic Zooplankton Assemblages in Atlantic Canada with Special Reference to Acidification

1986 ◽  
Vol 43 (2) ◽  
pp. 444-456 ◽  
Author(s):  
J. C. H. Carter ◽  
W. D. Taylor ◽  
R. Chengalath ◽  
D. A. Scruton
Keyword(s):  
Nova Scotia ◽  
New Brunswick ◽  
Fish Predation ◽  
Low Ph ◽  
Buffering Capacity ◽  
The Other ◽  
Bay Of Fundy ◽  
Factor Scores ◽  
Multiple Discriminant Analysis ◽  
Biological Factors

Crustacean and rotifer plankton assemblages of 93 lakes in Labrador, 107 in Newfoundland, and 142 in New Brunswick – Nova Scotia were investigated for evidence of correlations with lake morphometric, chemical, or biological factors. Labrador assemblages were almost completely lacking in identifiable structure. Newfoundland species clustered into two groups of different body size, suggesting the influence of fish predation. Only one species in Labrador and Newfoundland was significantly correlated with a derived factor related to lake water buffering capacity. New Brunswick – Nova Scotia species clustered into two groups, one featuring significant positive and the other significant negative correlations with the buffering factor. From this we conclude that acidification is having an impact on the limnetic zooplankton of these two provinces. Multiple discriminant analysis was used to demonstrate that New Brunswick – Nova Scotia lakes differing in their buffering capacity were also distinct in zooplankton composition. Lakes with low factor scores (low pH, alkalinity, and calcium) were mainly located in the Bay of Fundy region; this area has above average fog and precipitation, and lies within the summer air flow carrying pollutants from the south.

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