Geographic and seasonal variation in biological characteristics of American eel elvers in the Bay of Fundy area and on the Atlantic coast of Nova Scotia

1998 ◽  
Vol 76 (12) ◽  
pp. 2172-2185 ◽  
Author(s):  
B M Jessop
Keyword(s):  
Nova Scotia ◽  
Atlantic Coast ◽  
Bay Of Fundy ◽  
Biological Traits ◽  
American Eel ◽  
East River ◽  
Commercially Important ◽  
The Mean ◽  
Seasonal Decline ◽  
Collection Date

Seasonal (April-July) patterns in the decline of length, mass, and condition and an increase in pigmentation stage of American eel (Anguilla rostrata) elvers collected during the estuarine commercial fishery and during entrance into fresh water varied among rivers in the Bay of Fundy and on the Atlantic coast of Nova Scotia. Elver mean length, adjusted to a mean collection date, varied among commercially fished rivers by up to 9%; mean mass varied by up to 27%. Within commercially fished rivers, mean length declined seasonally by 2-5%, mass by 0-60%, and condition by 0-44%. Elver condition declined 7-9% by the time 50% of the run (number of elvers) had entered the East River, Chester, and East River, Sheet Harbour, and by 21% at 95% of the run, while the mean pigmentation stage increased to 4.1-4.8 and 5.7-6.5, respectively, on a scale of 1-7. Such geographic variability in biological traits may result from the effect of varying annual and seasonal environmental conditions on the coastal distribution of elvers and on their run timing and physiological development in estuarine and stream habitats. The biological importance of the seasonal decline in elver length, mass, and condition is uncertain, but a seasonal decline in mass of 35% may be commercially important when elvers are sold by weight rather than count.

Biochemical Implications of Seasonal Trends in the Iodine Values and Free Fatty Acid Levels of Commercially Produced Atlantic Coast Herring Oils

1970 ◽  
Vol 27 (10) ◽  
pp. 1669-1683 ◽  
Author(s):  
R. G. Ackman ◽  
C. A. Eaton
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Nova Scotia ◽  
Atlantic Coast ◽  
Relative Proportion ◽  
Short Term ◽  
Iodine Values ◽  
Seasonal Decline ◽  
Fatty Acid Compositions

Annual surveys of commercial herring oils produced in summer and fall off southwestern Nova Scotia and in winter and spring off southwestern Newfoundland showed iodine values (IV) mostly within the range 135 to 105 in both locations for the years 1965–70. Two systematic trends in IV with season were detected. The first extended uniformly over the whole of each fishery season and was limited to no more than ± 5 IV units. It is believed to represent the influence of long-term average environmental conditions that may vary from year to year and that establish the basic fatty acid compositions of the fish entering the fishery. The second was observed as a seasonal decline, over 2–3 months, of 20 IV units in the Nova Scotia fishery, and of 10 IV units in the Newfoundland fishery. It is proposed that this short-term effect follows from an increase in the relative proportion of the low-density, long-chain, monoethylenic fatty acids characteristic of clupeid oils that could decrease residual fat density at a time of general fat depletion and corresponding density increase for the fish as a whole.Free fatty acids (FFA) in freshly produced oils were also examined. In both fisheries % FFA seldom exceeded 1 and under optimum conditions the % FFA were consistently about 0.2–0.3. Annual seasonal % FFA effects were apparently restricted to an increase in April in the Newfoundland fishery associated with high IV oils of a pink colour denoting heavy spring feeding.

scholarly journals Productivity of riverine habitats may be changing for American eel

2018 ◽  
Vol 75 (11) ◽  
pp. 1773-1777 ◽  
Author(s):  
Heather Dawn Bowlby
Keyword(s):  
Nova Scotia ◽  
Atlantic Coast ◽  
American Eel ◽  
Regional Productivity ◽  
Glass Eel ◽  
Watershed Characteristics ◽  
High Productivity ◽  
Enhanced Production ◽  
Juvenile Abundance ◽  
Riverine Habitats

The panmictic population of American eel (Anguilla rostrata) is at risk, making any region that supports enhanced production important from a recovery perspective. Strong glass eel runs to a small number of rivers along the Atlantic coast of Nova Scotia are thought to indicate high productivity, partially buffering declines occurring in other regions. However, contrary to glass eel indices of recruitment, an index representing older juveniles has strongly declined in riverine habitats throughout Nova Scotia from 1995 to 2005, with evidence of substantial differences in relative abundance among watersheds. This suggests that glass eel indices may not reflect trends of older juveniles and consequently that the contribution of Atlantic coast rivers to population persistence may be overstated. More recent monitoring from two rivers shows divergent trends in juvenile eel abundance, underscoring the importance of widespread surveys to assess changes in regional productivity. Further evaluation of the watershed characteristics associated with higher juvenile abundance would aid in understanding differences in productivity among watersheds and possibly in facilitating increased spawning escapement for American eel.

Seasonal occurrence of waterbirds in Minas Passage, Bay of Fundy, Nova Scotia, Canada, 2010 to 2012

2021 ◽  
Vol 135 (2) ◽  
pp. 124-141
Author(s):  
Patrick L. Stewart ◽  
Fulton L. Lavender ◽  
Heather A. Levy
Keyword(s):  
Nova Scotia ◽  
Atlantic Coast ◽  
Early Summer ◽  
Seasonal Abundance ◽  
Bay Of Fundy ◽  
Somateria Mollissima ◽  
Migration Pathway ◽  
Cepphus Grylle ◽  
Surf Scoter ◽  
Abundance And Diversity

We determined patterns of seasonal abundance and diversity of seabirds and coastal waterfowl in Minas Passage, Bay of Fundy, Nova Scotia, Canada using quantitative, shore-based point surveys from mid-March to late August and mid-October to December 2010 to 2012. This area experiences the world’s highest tides and greatest tidal currents. We showed that species and seasonal cycles of waterbirds in Minas Passage reflect patterns typical of the inner Bay of Fundy and the northeast Atlantic coast of North America. The study highlights the importance of Minas Passage as an important local migration pathway for waterbirds including Black Scoter (Melanitta americana) and Red-throated Loon (Gavia stellata) passing through the Bay of Fundy. Large numbers of sea ducks (Black Scoter, Surf Scoter [Melanitta perspicillata], White-winged Scoter (Melanitta fusca), and Long-tailed Duck [Clangula hyemalis]), and Red-throated Loon were observed at the site in spring and fall, corresponding to known peak movements elsewhere in the Bay of Fundy. Fewest species and smallest abundances of waterbirds overall occurred in summer and early winter, while most species and largest abundances occurred in April-May and early November. Of the 46 species observed, resident breeders such as Herring Gull (Larus argentatus), Great Black-backed Gull (Larus marinus), Common Eider (Somateria mollissima), Black Guillemot (Cepphus grylle), and Double-crested Cormorant (Phalacrocorax auritus), were most abundant in spring to early summer during breeding and migrants including Red-throated Loon, Black Scoter, Ring-billed Gull (Larus delawarensis), Surf Scoter, and Northern Gannet (Morus bassanus) occurred in moderate numbers during migration periods.

Herring Migrations in the Passamaquoddy Region

1958 ◽  
Vol 15 (6) ◽  
pp. 1329-1343 ◽  
Author(s):  
R. A. McKenzie ◽  
B. E. Skud
Keyword(s):  
Nova Scotia ◽  
Gulf Of Maine ◽  
Far East ◽  
Bay Of Fundy ◽  
Total Length ◽  
Straight Line ◽  
Passamaquoddy Bay ◽  
Straight Line Distance ◽  
The Mean ◽  
Mean Time

From June 20 to November 21, 1957, 37,495 herring were tagged in the southern part of the Bay of Fundy and Gulf of Maine. These fish were immature and ranged in total length from 14.2 to 18.7 cm. and in age from 1 to 3 years. Recovery of 792 (2.1%) tagged individuals indicated that the herring moved in and out of Passamaquoddy Bay throughout the summer and early autumn. No interchange of herring took place between Passamaquoddy Bay and the coast of Maine or Nova Scotia. Herring moved into Passamaquoddy from as far south as Grand Manan Island and as far east as Point Lepreau. The greatest straight-line distance moved was 55 miles, the mean time before recapture was 12 days, and the longest time 82 days.

scholarly journals A review of the fishes and fisheries of Minas Basin and Minas Passage, Nova Scotia, and their potential risk from tidal power development

2021 ◽  
Vol 51 (1) ◽  
pp. 39
Author(s):  
Michael J. Dadswell ◽  
Roger A. Rulifson
Keyword(s):  
Nova Scotia ◽  
Cold Water ◽  
Atlantic Coast ◽  
Taxonomic Diversity ◽  
Seasonal Occurrence ◽  
Bay Of Fundy ◽  
Species Status ◽  
Power Development ◽  
Tidal Power ◽  
Potential Impact

A total of 85 species of fish are known or suspected from Minas Basin and Minas Passage, Nova Scotia, Canada. This systematic review details their seasonal occurrence, habitat, abundance, migratory behavior, fisheries and potential impact from tidal power development. The fish assemblage is a mixture of species common to the Bay of Fundy and the Atlantic coast of Nova Scotia as well as numerous warm- and cold-water visitors seldom found elsewhere in Canada. Minas Basin fisheries exploit some species especially those that migrate through the Basin during summer. Fishes were captured or observed using angling, seines, benthic long lines, drift and fixed gill nets, intertidal fish weirs, bottom trawls and sightings while on vessels. Fishes are categorized with respect to their taxonomic diversity, seasonal occurrence, status, fisheries and the potential impact from tidal lagoons and propeller turbines resulting from development of tidal power in Minas Basin and Minas Passage. Keywords: Bay of Fundy, habitat, species status, propeller turbines, taxonomic relationship, tidal lagoons.

scholarly journals First visual record of rare purple-colored dogwhelks (Nucella lapillus) on the Atlantic coast of Nova Scotia, Canada

F1000Research ◽  
2017 ◽  
Vol 5 ◽  
pp. 2435
Author(s):  
Sonja M. Ehlers ◽  
Julius A. Ellrich
Keyword(s):  
Nova Scotia ◽  
Field Experiments ◽  
Atlantic Coast ◽  
Rocky Intertidal ◽  
Bay Of Fundy ◽  
Nucella Lapillus ◽  
Shell Color ◽  
The North ◽  
Intertidal Gastropod ◽  
Visual Record

The dogwhelk Nucella lapillus is a rocky intertidal gastropod of the North Atlantic coast. Individual shell color varies. Common colors range between white and brown, with darker dogwhelks being more affected by heat stress than lighter-colored conspecifics. Other reported shell colors are purple, black, mauve, pink, yellow, and orange from UK coasts, red and gray from the Bay of Fundy coast of New Brunswick and Nova Scotia (Canada), and purple, black, gray, yellow, and orange from the coasts of Maine and Massachusetts (USA), with purple being considered as a rare color. On the Atlantic coast of Nova Scotia, dogwhelks are active from April until November, but information on dogwhelk shell color is missing for this coast. On 16 June 2016, we found two purple-colored dogwhelks in the mid-to-high intertidal zone of a moderately wave-exposed rocky shore near Duncans Cove, on the Atlantic coast of Nova Scotia while collecting dogwhelks (n= 1000) during low tide for manipulative field experiments. All other dogwhelks collected on that day were of common white and brown colors. During earlier dogwhelk collections in Atlantic Nova Scotia (between 2011-2013) and field surveys in Duncans Cove (between 2014-2016), we did not find any purple-colored dogwhelks, indicating the rareness of this color in that region. Apparently, our observations provide the first visual record of rare purple-colored dogwhelks on the Atlantic coast of Nova Scotia, Canada.

Total Mercury and Methylmercury Content of the American Eel (Anguilla rostrata)

1973 ◽  
Vol 30 (3) ◽  
pp. 454-456 ◽  
Author(s):  
H. C. Freeman ◽  
D. A. Horne
Keyword(s):  
Nova Scotia ◽  
Total Mercury ◽  
Mercury Content ◽  
Human Consumption ◽  
Anguilla Rostrata ◽  
American Eel ◽  
The Mean ◽  
American Eels

In American eels (Anguilla rostrata) caught in Nova Scotia, the total mercury content was found to be 0.72 ± 0.05 ppm and the methylmercury content was 0.40 ± 0.06 ppm (mean ± SE for 23 fish). Since the mean total mercury content was less than 1 ppm and the toxic methylmercury content was 50% of this, or less than the 0.5 ppm guideline, such eels may be acceptable for human consumption.

scholarly journals First visual record of rare purple dogwhelks (Nucella lapillus) on the Atlantic coast of Nova Scotia, Canada

F1000Research ◽  
2016 ◽  
Vol 5 ◽  
pp. 2435
Author(s):  
Sonja M. Ehlers ◽  
Julius A. Ellrich
Keyword(s):  
Nova Scotia ◽  
Field Experiments ◽  
Atlantic Coast ◽  
Rocky Intertidal ◽  
Bay Of Fundy ◽  
Nucella Lapillus ◽  
Shell Color ◽  
The North ◽  
Intertidal Gastropod ◽  
Visual Record

The dogwhelk Nucella lapillus is a rocky intertidal gastropod of the North Atlantic coast. Individual shell color varies. Common colors range between white and brown, with darker dogwhelks being more affected by heat stress than lighter-colored conspecifics. Other reported shell colors are black, mauve, pink, yellow, and orange from European coasts, red and grey from the Bay of Fundy coast of New Brunswick and Nova Scotia (Canada), and purple, black, gray, yellow, and orange from the coasts of Maine and Massachusetts (USA), with purple being considered as a rare color. On the Atlantic coast of Nova Scotia, dogwhelks are active from April until November, but information on dogwhelk shell color is missing for this coast. On 16 June 2016, we found two purple dogwhelks in the mid-to-high intertidal zone of a moderately wave-exposed rocky shore near Duncans Cove, on the Atlantic coast of Nova Scotia while collecting dogwhelks (n= 1000) for manipulative field experiments. All other dogwhelks collected on that day were of common white and brown colors. During earlier dogwhelk collections in Atlantic Nova Scotia (between 2011-2013) and field surveys in Duncans Cove (between 2014-2016), we did not find any purple dogwhelks, indicating the rareness of this color in that region. Interestingly, the purple dogwhelks were detected on a relatively cool day (12.3 ± 0.4 °C, mean ± se, n= 96 temperature measurements) compared to the intertidal temperatures of all other survey days (≥ 18.2 ± 0.5 °C), suggesting that purple dogwhelks may find it less thermally stressful to venture out of crevices and macroalgal cover under relatively cool temperatures. Our observations provide the first visual record of rare purple dogwhelks on the Atlantic coast of Nova Scotia, Canada.

scholarly journals First visual record of rare purple dogwhelks (Nucella lapillus) on the Atlantic coast of Nova Scotia, Canada

2016 ◽  
Author(s):  
Sonja M. Ehlers ◽  
Julius A. Ellrich
Keyword(s):  
Nova Scotia ◽  
Field Experiments ◽  
Atlantic Coast ◽  
Rocky Intertidal ◽  
Bay Of Fundy ◽  
Nucella Lapillus ◽  
Shell Color ◽  
The North ◽  
Intertidal Gastropod ◽  
Visual Record

The dogwhelk Nucella lapillus is a rocky intertidal gastropod of the North Atlantic coast. Individual shell color varies. Common colors range between white and brown, with darker dogwhelks being more affected by heat stress than lighter-colored conspecifics. Other reported shell colors are black, mauve, pink, yellow, and orange from European coasts, red and grey from the Bay of Fundy coast of New Brunswick and Nova Scotia (Canada), and purple, black, gray, yellow, and orange from the coasts of Maine and Massachusetts (USA), with purple being considered as a rare color. On the Atlantic coast of Nova Scotia, dogwhelks are active from April until November, but information on dogwhelk shell color is missing for this coast. On 16 June 2016, we found two purple dogwhelks in the mid-to-high intertidal zone of a moderately wave-exposed rocky shore near Duncans Cove, on the Atlantic coast of Nova Scotia while collecting dogwhelks (n= 1000) for manipulative field experiments. All other dogwhelks collected on that day were of common white and brown colors. During earlier dogwhelk collections in Atlantic Nova Scotia (between 2011-2013) and field surveys in Duncans Cove (between 2014-2016), we did not find any purple dogwhelks, indicating the rareness of this color in that region. Interestingly, the purple dogwhelks were detected on a relatively cool day (12.3 ± 0.4 °C, mean ± se, n= 96 temperature measurements) compared to the intertidal temperatures of all other survey days (≥ 18.2 ± 0.5 °C), suggesting that purple dogwhelks may find it less thermally stressful to venture out of crevices and macroalgal cover under relatively cool temperatures. Our observations provide the first visual record of rare purple dogwhelks on the Atlantic coast of Nova Scotia, Canada.

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