scholarly journals Development of Active Numerating Side-scan for a High-Density Overwintering Location for Endemic Shortnose Sturgeon (Acipenser brevirostrum) in the Saint John River, New Brunswick

Diversity ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 23 ◽  
Author(s):  
Samuel N. Andrews ◽  
Antóin M. O’Sullivan ◽  
Jani Helminen ◽  
Daniel F. Arluison ◽  
Kurt M. Samways ◽  
...  
Keyword(s):  
New Brunswick ◽  
Rapid Assessment ◽  
Fork Length ◽  
Mapping Method ◽  
Population Estimate ◽  
Shortnose Sturgeon ◽  
River Population ◽  
Side Scan Sonar ◽  
Acipenser Brevirostrum ◽  
Saint John

In 1979, the Shortnose Sturgeon (Acipenser brevirostrum) population of the Saint John River, New Brunswick, was estimated at 18,000 ± 5400 individuals. More recently, an estimate of 4836 ± 69 individuals in 2005, and between 3852 and 5222 individuals in 2009 and 2011, was made based on a single Shortnose Sturgeon winter aggregation in the Kennebecasis Bay of the Saint John River, a location thought to contain a large proportion of the population. These data, in combination with the Saint John River serving as the sole spawning location for Shortnose Sturgeon in Canada prompted a species designation of “Special Concern” in 2015 under Canada’s Species at Risk Act (SARA). A three-decade span of scientific observations amplified by the traditional knowledge and concerns of local indigenous groups have pointed to a declining population. However, the endemic Shortnose Sturgeon population of the Saint John River has not been comprehensively assessed in recent years. To help update the population estimate, we tested a rapid, low-cost side-scan sonar mapping method coupled with supervised image classification to enumerate individual Sturgeon in a previously undescribed critical winter location in the Saint John River. We then conducted an underwater video camera survey of the area, in which we did not identify any fish species other than Shortnose Sturgeon. These data were then synchronized with four years of continuous acoustic tracking of 18 Shortnose Sturgeon to produce a population estimate in each of the five identified winter habitats and the Saint John River as a whole. Using a side-scan sonar, we identified > 12,000 Shortnose Sturgeon in a single key winter location and estimated the full river population as > 20,000 individuals > ~40 cm fork length. We conclude that the combined sonar/image processing method presented herein provides an effective and rapid assessment of large fish such as Sturgeon when occurring in winter aggregation. Our results also indicate that the Shortnose Sturgeon population of the Saint John River could be similar to the last survey estimate conducted in the late 1970s, but more comprehensive and regular surveys are needed to more accurately assess the state of the population.

Modeling the timing of spawning and hatching of shortnose sturgeon, Acipenser brevirostrum, in the Saint John River, New Brunswick, Canada

2012 ◽  
Vol 69 (8) ◽  
pp. 1316-1328 ◽  
Author(s):  
Sima Usvyatsov ◽  
Jeffrey Picka ◽  
Ryan Scott Hardy ◽  
Travis Dawson Shepherd ◽  
James Watmough ◽  
...  
Keyword(s):  
New Brunswick ◽  
Gompertz Model ◽  
Shortnose Sturgeon ◽  
Catch Per Unit Effort ◽  
Larval Size ◽  
Acipenser Brevirostrum ◽  
Inverse Prediction ◽  
Saint John ◽  
In The Wild ◽  
Timing Of Spawning

Timing of spawning and hatching of shortnose sturgeon, Acipenser brevirostrum , in the Saint John River, New Brunswick, Canada, was estimated using inverse prediction. We examined egg incubation periods at 5, 9, and 13 °C to back-calculate spawning dates. No larvae hatched at 5 °C. At 9 and 13 °C, hatching began after 18 and 8 days post fertilization, respectively. Lengths of yolk-sac larvae reared in the laboratory at 13–21 °C were used to develop a temperature-mediated Gompertz growth model. The inverted Gompertz model, predicting larval age from larval size and water temperature, was applied to 671, 164, and 746 larvae captured in the wild in 2008, 2009, and 2010, respectively. Estimated hatching distributions peaked in late May, and mean spawning events were predicted to occur in late April – early May (9 °C scenario) and middle to late May (13 °C scenario). Larval ages at the two sampling transects, 4.5 km apart, were similar, while catch per unit effort was lower downstream, indicating mortality during dispersal. Inverse prediction of larval ages provides fast and cost-effective estimates of the timing of spawning, hatching, and larval migration in the wild.

scholarly journals Understanding the basis of shortnose sturgeon (Acipenser brevirostrum) partial migration in the Gulf of Maine

2018 ◽  
Vol 75 (3) ◽  
pp. 464-473 ◽  
Author(s):  
Matthew E. Altenritter ◽  
Gayle Barbin Zydlewski ◽  
Michael T. Kinnison ◽  
Joseph D. Zydlewski ◽  
Gail S. Wippelhauser
Keyword(s):  
Gulf Of Maine ◽  
Fork Length ◽  
Resource Limitation ◽  
Individual Characteristics ◽  
Shortnose Sturgeon ◽  
River Population ◽  
Acipenser Brevirostrum ◽  
Penobscot River ◽  
Major River ◽  
Kennebec River

Movement of shortnose sturgeon (Acipenser brevirostrum) among major river systems in the Gulf of Maine is common and has implications for the management of this endangered species. Directed movements of 61 telemetered individuals monitored between 2010 and 2013 were associated with the river of tagging and individual characteristics. While a small proportion of fish tagged in the Kennebec River moved to the Penobscot River (5%), a much higher proportion of fish tagged in the Penobscot River moved to the Kennebec River (66%), during probable spawning windows. This suggests that Penobscot River fish derive from a migratory contingent within a larger Kennebec River population. Despite this connectivity, fish captured in the Penobscot River were larger (∼100 mm fork length) and had higher condition factors (median Fulton’s K: 0.76) than those captured in the Kennebec River (median Fulton’s K: 0.61). Increased abundance and resource limitation in the Kennebec River may be constraining growth and promoting migration to the Penobscot River by individuals with sufficient initial size and condition. Migrants could experience an adaptive reproductive advantage relative to nonmigratory individuals.

Timing and Extent of Drift of Shortnose Sturgeon Larvae in the Saint John River, New Brunswick, Canada

2013 ◽  
Vol 142 (3) ◽  
pp. 717-730 ◽  
Author(s):  
Sima Usvyatsov ◽  
Jeffrey Picka ◽  
Andrew Taylor ◽  
James Watmough ◽  
Matthew Kenneth Litvak
Keyword(s):  
New Brunswick ◽  
Shortnose Sturgeon ◽  
Saint John

scholarly journals FIRST VERIFIED RECORD FOR SHORTNOSE STURGEON, Acipenser brevirostrum LeSueur, 1818, IN MINAS BASIN, BAY OF FUNDY, NOVA SCOTIA, CANADA

2013 ◽  
Vol 47 (2) ◽  
Author(s):  
Michael J. Dadswell ◽  
George Nau ◽  
Michael J.W. Stokesbury
Keyword(s):  
Nova Scotia ◽  
New Record ◽  
Fork Length ◽  
Fish Fauna ◽  
Bay Of Fundy ◽  
Shortnose Sturgeon ◽  
Acipenser Brevirostrum ◽  
The Past ◽  
Photographic Evidence ◽  
Fish Weir

A shortnose sturgeon was caught in fisherman Wayne Linkletter’s intertidal fish weir in Minas Basin near Economy, Nova Scotia, on June 29, 2013. It was an adult, 73.7 cm fork length and weighed ~4.5 kg. Fishers in Minas Basin relate that they have captured shortnose sturgeons in their weirs in the past decade (1 or 2 fish/y) but this is the first sighting verified by photographic evidence. In Canada shortnose sturgeons were previously known only from the Saint John River and Harbour. The new record extends the coastal range of the species by approximately 165 km and is a new addition to the fish fauna of Nova Scotia.

Description of some larval shortnose sturgeon (Acipenser brevirostrum) from the Holyoke Pool, Connecticut River, Massachusetts, U.S.A., and the Saint John River, New Brunswick, Canada

1980 ◽  
Vol 58 (6) ◽  
pp. 1125-1128 ◽  
Author(s):  
Bruce D. Taubert ◽  
Michael J. Dadswell
Keyword(s):  
New Brunswick ◽  
Head Width ◽  
Entire Body ◽  
Shortnose Sturgeon ◽  
Connecticut River ◽  
Acipenser Brevirostrum ◽  
Pectoral Fins ◽  
Dorsal Fin ◽  
Mouth Width ◽  
Preanal Length

Shortnose sturgeon (Acipenser brevirostrum) protolarvae, ranging from 8.0 to 12.5 mm TL, had 20–23 postanal and 33–36 preanal myomeres and the preanal length was 66–70% of TL. The yolk sac was large, the pectoral fin buds were barely visible, and the entire body was covered with expanded melanophores. Mesolarvae of 13.0–14.7 mm TL had 22 postanal and 34 preanal myomeres, and preanal length was 61% of TL. The yoke sac was nearly gone, barbels, mouth, and pectoral fins were well developed and the anlage of the dorsal fin was visible. Mouth width of the 14.7 mm TL mesolarva was 71% of the head width and teeth were present.

Biology and population characteristics of the shortnose sturgeon, Acipenser brevirostrum LeSueur 1818 (Osteichthyes:Acipenseridae), in the Saint John River Estuary, New Brunswick, Canada

1979 ◽  
Vol 57 (11) ◽  
pp. 2186-2210 ◽  
Author(s):  
M. J. Dadswell
Keyword(s):  
Fresh Water ◽  
Growth Parameters ◽  
Saline Water ◽  
River Estuary ◽  
Fork Length ◽  
Population Characteristics ◽  
Shortnose Sturgeon ◽  
Acipenser Brevirostrum ◽  
Length Relationship ◽  
Population Weight

During a 4-year study, 4178 shortnose sturgeon were captured and 2453 marked with numbered tags and released. For adults, Z was estimated as 0.12–0.15 and F was estimated as 0.01. The population weight–length relationship was log W = 3.21 (log FL) − 5.45, where W = weight in kilograms and FL = fork length in cm. The oldest female was 67 years; the oldest male was 32 years. Von Bertalanffy growth parameters L∞, W∞, and K were 127.0 cm, 24.8 kg, and 0.047 for females, and 108.7 cm, 13.9 kg, and 0.063 for males. Sex ratio of adults was 2:1 for females. Males spawned first about age 12 and probably at 2-year intervals thereafter; females spawned at 18 years and 3- to 5-year intervals thereafter. Fecundity was 27 000 – 208 000 eggs per female. Spawning occurs in freshwater, riverine sections of the upper estuary during May–June at 10–15 °C. Feeding occurred only during May to October in fresh water but continued all year in saline water. Juveniles ate mainly insects and crustaceans; adults ate small molluscs. Juveniles remained in fresh water until they attained 45 cm, then joined the regular annual migration of adults, which moved upstream in spring–summer and seaward in fall. Many ripening females migrated upstream in fall and overwintered in deep, freshwater sites adjacent to spawning grounds. The Seber-Jolly estimate of the adult (> 50 cm) population was 18 000 ± 30%.

Transmission and development of Capillospirura pseudoargumentosa (Appy and Dadswell, 1978) (Nematoda: Cystidicolidae)

1983 ◽  
Vol 61 (4) ◽  
pp. 848-859 ◽  
Author(s):  
R. G. Appy ◽  
M. J. Dadswell
Keyword(s):  
New Brunswick ◽  
River Estuary ◽  
Shortnose Sturgeon ◽  
Fourth Stage ◽  
Developmental Morphology ◽  
Gammarus Tigrinus ◽  
Acipenser Brevirostrum ◽  
Infective Larvae ◽  
The Third ◽  
Third Stage

The cystidicolid nematode, Capillospirura pseudoargumentosa (Appy and Dadswell, 1978) (Habronematoidea) moulted twice and developed to the infective third stage in Gammarus tigrinus and G. fasciatus (Amphipoda) but not in isopods, decapods, mysids or other amphipods. At 10–14 °C development to the third stage in G. tigrinus took between 28 and 40 days and at 21–25 °C, it took between 10 and 15 days. Infective larvae fed to shortnose sturgeon, Acipenser brevirostrum, moulted from the third to the fourth stage within 15 days. Moulting third- and fourth-stage larvae were found in naturally infected sturgeon collected in the Saint John River estuary, New Brunswick. The developmental morphology of C. pseudoargumentosa is compared with that of other cystidicolid nematodes.

Anadromous Sturgeons: Habitats, Threats, and Management

2007 ◽  
Keyword(s):  
Atlantic Coast ◽  
Fork Length ◽  
Physical Habitat ◽  
Shortnose Sturgeon ◽  
Atlantic Sturgeon ◽  
Acipenser Brevirostrum ◽  
Neuse River ◽  
Logistic Regression Models ◽  
Gill Net ◽  
Ultrasonic Transmitter

Abstract. – Shortnose sturgeon <em>Acipenser brevirostrum</em> historically occurred in most major Atlantic Coast rivers from Saint Johns River, New Brunswick, Canada to St. John’s River, Florida. However, there are few records of shortnose sturgeon occurrences within North Carolina and none from the Neuse River. We conducted a 2-year intensive gill-net survey, following the National Marine Fisheries Service sampling protocol, and a reward program in order to determine their population status within the Neuse River. No shortnose sturgeon were observed, although 10 juvenile Atlantic sturgeon (506–992 mm fork length) were encountered. Habitat surveys of the lower Neuse River, where shortnose sturgeon would be expected to occur during summer, showed that bottom waters were severely hypoxic during June–September of 2001–2002. A juvenile Atlantic sturgeon tagged with an ultrasonic transmitter moved upstream of the unsuitable summer habitat and remained in a restricted area until late fall, when water quality improved due to increased flows and lower temperatures. We developed logistic regression models of watershed and river characteristics based on 36 Atlantic Coast rivers with a known presence or absence of shortnose sturgeon. Model predictions suggest that the Neuse River should contain a population of shortnose sturgeon based on the amount of physical habitat. We hypothesize that shortnose sturgeon have been extirpated from the Neuse River due to a lack of suitable summer habitat. Population recovery may be impossible until habitat quality can be improved.

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