Reconsidering residency: characterization and conservation implications of complex migratory patterns of shortnose sturgeon (Acispenser brevirostrum)

2013 ◽  
Vol 70 (1) ◽  
pp. 119-127 ◽  
Author(s):  
Phillip E. Dionne ◽  
Gayle B. Zydlewski ◽  
Michael T. Kinnison ◽  
Joseph Zydlewski ◽  
Gail S. Wippelhauser

Efforts to conserve endangered species usually involve attempts to define and manage threats at the appropriate scale of population processes. In some species that scale is localized; in others, dispersal and migration link demic units within larger metapopulations. Current conservation strategies for endangered shortnose sturgeon (Acipenser brevirostrum) assume the species is river resident, with little to no movement between rivers. However we have found that shortnose sturgeon travel more than 130 km through coastal waters between the largest rivers in Maine. Indeed, acoustic telemetry shows that shortnose sturgeon enter six out of the seven acoustically monitored rivers we have monitored, with over 70% of tagged individuals undertaking coastal migrations between river systems. Four migration patterns were identified for shortnose sturgeon inhabiting the Penobscot River, Maine: river resident (28%), spring coastal emigrant (24%), fall coastal emigrant (33%), and summer coastal emigrant (15%). No shortnose sturgeon classified as maturing female exhibited a resident pattern, indicating differential migration. Traditional river-specific assessment and management of shortnose sturgeon could be better characterized using a broader metapopulation scale, at least in the Gulf of Maine, that accounts for diverse migratory strategies and the importance of migratory corridors as critical habitat.

2018 ◽  
Vol 75 (3) ◽  
pp. 464-473 ◽  
Author(s):  
Matthew E. Altenritter ◽  
Gayle Barbin Zydlewski ◽  
Michael T. Kinnison ◽  
Joseph D. Zydlewski ◽  
Gail S. Wippelhauser

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.


1973 ◽  
Vol 30 (4) ◽  
pp. 563-564 ◽  
Author(s):  
Stephen M. Fried ◽  
James D. McCleave

Thirty-one shortnose sturgeon (Acipenser brevirostrum) were caught in gillnets in Montsweag Bay in the Sheepscot River system during June and July of 1971 and 1972. Of nine fish preserved for study, six were longer than any previously documented and four exceeded the maximum total length previously postulated. These specimens represent the second population of this endangered species found in the Gulf of Maine.


2002 ◽  
Vol 18 (4-6) ◽  
pp. 491-494 ◽  
Author(s):  
M. R. Collins ◽  
D. W. Cooke ◽  
T. I. J. Smith ◽  
W. C. Post ◽  
D. C. Russ ◽  
...  

1970 ◽  
Vol 36 (2) ◽  
pp. 139-144 ◽  
Author(s):  
Fergan Karaer ◽  
Ferhat Celep

Scorzonera amasiana Hausskn. and Bornm. was described from type specimens collected by J.F.N. Bornmueller in 1889 but it was not collected again until 1993, when it was found near Amasya, Turkey. Populations of S. amasiana were quite small at that limited locations and were vulnerable to human impacts. Therefore, suitable conservation strategies should be developed immediately in order to protect the species from probable extinction. Here, an additional three small populations are reported. Brief history, morphology, habitat and ecology of this endemic species have been discussed. Its current conservation status was reevaluated with respect to the latest IUCN criteria. A key to distinguish it from the other closely related Turkish species is also provided and its distribution map is appended.   Key words: Endangered, Rediscovery, Scorzonera, Turkey DOI = 10.3329/bjb.v36i2.1502 Bangladesh J. Bot. 36(2): 139-144, 2007 (December)


2007 ◽  
Vol 64 (9) ◽  
pp. 1248-1257 ◽  
Author(s):  
Xinhai Li ◽  
Matthew K Litvak ◽  
John E. Hughes Clarke

The overwintering habitat use of shortnose sturgeon (Acipenser brevirostrum) was investigated from January to March 2005 in the upper Kennebecasis River, New Brunswick, Canada, using a novel underwater video camera system and modeling approach. Following a random sampling procedure, 187 holes were drilled into the ice, and 234 sturgeon were counted and video-recorded. We found that sturgeon concentrated in a 2 ha area at the confluence of the Kennebecasis and Hammond rivers on a flat sandy substrate at a depth of 3.1–6.9 m. Generalized linear models were developed to describe the relationship of shortnose sturgeon density and habitat variables. The model indicated that the shortnose sturgeon had significant preference to deeper areas within this region. The total abundance of shortnose sturgeon in the area was estimated to be 4836 ± 69 (mean ± standard error) using the ordinary kriging method to interpolate sturgeon density at unsampled sites. This overwintering habitat of shortnose sturgeon can be defined as critical habitat following the identification policies of the Canadian Species at Risk Act (SARA).


2014 ◽  
Vol 71 (5) ◽  
pp. 763-774 ◽  
Author(s):  
Denis Roy ◽  
David C. Hardie ◽  
Margaret A. Treble ◽  
James D. Reist ◽  
Daniel E. Ruzzante

Assessment of population structure is critical to the design and implementation of sound management and conservation strategies. However, population structure must be assessed using markers attuned to population genetic processes such as genetic drift and gene flow, which reflect actual levels of reproductive isolation among putative genetic clusters. This is critical for highly exploited, commercial species that form the backbone of regional and local economies. Here, we show extremely low levels of population genetic differentiation among Greenland halibut (Reinhardtius hippoglossoides) collected from throughout the Northwest Atlantic, which cannot be statistically differentiated from panmixia using 12 species-specific polymorphic microsatellite markers. In contrast, some previous studies have demonstrated significant differences among individuals collected from various parts of the species’ range using a variety of both genetic and nongenetic techniques. In accordance with other reports and consistent with the species’ life history, we demonstrate that the most parsimonious explanation reconciling observed patterns is a repeated high degree of local differentiation of new recruits and colonizers originating from a common gene pool. Such a scenario has important conservation implications in terms of devising more appropriate strategies balancing species persistence and replenishment with sustainable resource use.


<em>Abstract.</em>—The shortnose sturgeon, <em>Acipenser brevirostrum</em>, is a long-lived species that grows slowly, matures at an advanced age, and spawns only intermittently. In the Connecticut River, there are two distinct subpopulations of shortnose sturgeon, which have been separated by the Holyoke Dam for 157 years. My research addressed the viability and persistence for these two separate populations and the effects of dispersal, variation in survival and reproduction, and catastrophes. My risk-based approach used a stage-based metapopulation model that I constructed in RAMAS<sup>®</sup> GIS incorporating the available data. Based on the existing data, this population model for the shortnose sturgeon metapopulation in the Connecticut River made several predictions. The observed stability of the two subpopulations was possible either: with reproduction in both upper and lower subpopulations and small to moderate rates of dispersal between them; or with no reproduction in the lower subpopulation, very high reproduction in the upper subpopulation and high rate of net downstream dispersal. My results provided estimates of extinction risk for the shortnose sturgeon metapopulation under various management options and highlighted three key areas for future research, demonstrating the value of a risk-based approach. This approach is particularly useful for management of long-lived aquatic species.


<em>Abstract</em>.—Traditional approaches to fish conservation have focused on the protection of small habitat patches or on individual species at risk of extinction. These strategies have been important yet largely have been too little and too late for widespread protection of aquatic faunas. Such small-scale and reactive approaches also are costly in terms of recovery programs and aggressive in terms of regulatory controls. Further, the linear nature of streams and the networked configuration of drainage systems suggest that a fundamentally different approach to reserve design and protected areas is necessary for effective conservation of freshwater communities when compared to terrestrial systems. Larger-scale, multispecies approaches to native fish conservation offer a more efficient and effective conservation strategy because entire fish communities and the ecological processes that support maintenance of habitat diversity can be sustained before the status of individual species deteriorates to critical levels. Protecting entire communities and watersheds also offers some resistance to climate change impacts, which rapidly are altering flow regimes and disturbance dynamics in aquatic systems. Identification and protection of high-value aquatic communities will provide an important supplement to current conservation strategies during times of increasing threats and future uncertainty.


2019 ◽  
Vol 374 (1781) ◽  
pp. 20190012 ◽  
Author(s):  
Joseph A. Tobias ◽  
Alex L. Pigot

Insights into animal behaviour play an increasingly central role in species-focused conservation practice. However, progress towards incorporating behaviour into regional or global conservation strategies has been more limited, not least because standardized datasets of behavioural traits are generally lacking at wider taxonomic or spatial scales. Here we make use of the recent expansion of global datasets for birds to assess the prospects for including behavioural traits in systematic conservation priority-setting and monitoring programmes. Using International Union for Conservation of Nature Red List classifications for more than 9500 bird species, we show that the incidence of threat can vary substantially across different behavioural categories, and that some types of behaviour—including particular foraging, mating and migration strategies—are significantly more threatened than others. The link between behavioural traits and extinction risk is partly driven by correlations with well-established geographical and ecological factors (e.g. range size, body mass, human population pressure), but our models also reveal that behaviour modifies the effect of these factors, helping to explain broad-scale patterns of extinction risk. Overall, these results suggest that a multi-species approach at the scale of communities, continents and ecosystems can be used to identify and monitor threatened behaviours, and to flag up cases of latent extinction risk, where threatened status may currently be underestimated. Our findings also highlight the importance of comprehensive standardized descriptive data for ecological and behavioural traits, and point the way towards deeper integration of behaviour into quantitative conservation assessments. This article is part of the theme issue ‘Linking behaviour to dynamics of populations and communities: application of novel approaches in behavioural ecology to conservation’.


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