Informing conservation strategies for the endangered Atlantic sturgeon using acoustic telemetry and multi-state mark-recapture models

Abundance estimates are essential for fisheries management, but estimating the abundance of open populations with low recapture rates has historically been unreliable. However, by using mark-recapture data modulated with survivability parameters obtained from analysis of acoustic telemetry data, more accurate abundance estimates can be made for species that exhibit these characteristics. One such species is the Atlantic sturgeon, for which abundance estimates were designated a research priority following precipitous population declines throughout the 20th century. We addressed this research need in the Saco River Estuary (SRE), a system where the Atlantic sturgeon has been extensively studied using mark-recapture and acoustic telemetry methods since 2009. These data were analyzed using Bayesian analysis of a Lincoln-Peterson estimator, constrained with parameters from a Cormack-Jolly-Seber model, to provide an initial abundance estimate for the system. The resulting estimate indicated that approximately 3 299 (95% Credible Interval: 1 462–6 828) Atlantic sturgeon utilize the SRE yearly, suggesting that the SRE provides critical foraging habitat to a large contingent of the species within the Gulf of Maine. The present study demonstrated the method utilized herein was effective in generating a reasonable estimate of abundance in an open system where recapture events are rare, and therefore may provide a valuable technique for supplying initial estimates of fish abundance in additional systems that display similar characteristics.

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Net-avoidance behaviour in platypuses

Australian Mammalogy ◽

10.1071/am12051 ◽

2013 ◽

Vol 35 (2) ◽

pp. 245 ◽

Cited By ~ 7

Author(s):

Josh Griffiths ◽

Tom Kelly ◽

Andrew Weeks

Keyword(s):

Acoustic Telemetry ◽

Direct Evidence ◽

Avoidance Behaviour ◽

Mark Recapture ◽

Abundance Estimates ◽

Ornithorhynchus Anatinus

It has been suggested that platypuses (Ornithorhynchus anatinus) may avoid nets following capture, compromising abundance estimates using mark–recapture models. Here, we present the first direct evidence of net avoidance behaviour by the platypus. Using acoustic telemetry, we record a platypus bypassing several nets following capture. Understanding variation in capture probabilities will lead to better estimation of platypus abundance, which is currently lacking.

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Mobility, habitat selection and population connectivity of the butterfly Lycaena helle in central Sweden

Journal of Insect Conservation ◽

10.1007/s10841-020-00254-y ◽

2020 ◽

Vol 24 (5) ◽

pp. 821-831 ◽

Cited By ~ 1

Author(s):

Hanna Modin ◽

Erik Öckinger

Keyword(s):

Habitat Quality ◽

Threatened Species ◽

Laser Scanning ◽

Predictive Power ◽

Population Connectivity ◽

Solar Irradiation ◽

Conservation Strategies ◽

Selection Function ◽

Large Network ◽

Mark Recapture

Abstract To be able to predict habitat quality and potential distribution of threatened species is key to developing successful conservation strategies for threatened species with fragmented distributions. The aim of this study was to assess factors that limit the local distribution and density of Lycaena helle, an endangered butterfly, in central Sweden, and to estimate its mobility in order to classify local populations according to their importance for the connectivity on a regional level. An additional aim was to test if L. helle habitat quality could be assessed using remotely-sensed data such as laser scanning (LiDAR). We derived potential predictors of L. helle occurrence from laser scanning data and used a resource selection function to assess their predictive power. We used a mark-recapture approach to study L. helle movement and estimate dispersal distances. The probability of occurrence of L. helle increased with higher solar irradiation and was negatively affected by sloping terrain, but the LiDAR data generally had low predictive power. Population density increased with host plant density, but this effect was weak. The mark-recapture study confirmed that L. helle is very sedentary, with a mean movement distance of only 114 m and a maximum of 600 m. The studied population extends over a large network of interconnected linear habitats, which probably facilitates dispersal and thereby population persistence. Our study highlight the importance of a warm micro-climate and of man-made habitats like road verges and power-line corridors for the conservation of L. helle.

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Integrating side-scan sonar and acoustic telemetry to estimate the annual spawning run size of Atlantic sturgeon in the Hudson River

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/cjfas-2019-0398 ◽

2020 ◽

Vol 77 (6) ◽

pp. 1038-1048 ◽

Cited By ~ 1

Author(s):

David C. Kazyak ◽

Amy M. Flowers ◽

Nathan J. Hostetter ◽

John A. Madsen ◽

Matthew Breece ◽

...

Keyword(s):

Acoustic Telemetry ◽

Hudson River ◽

Large River ◽

Atlantic Sturgeon ◽

Side Scan Sonar ◽

Novel Approach ◽

The Status ◽

Acoustic Tags ◽

Spawning Run ◽

Traditional Approaches

There is considerable interest in evaluating the status and trends of sturgeon populations, yet many traditional approaches to estimating the abundance of fishes are intractable due to their biology and rarity. Side-scan sonar has recently emerged as an effective tool for censusing sturgeon in rivers, yet challenges remain for censusing open populations that may visit specific habitats over periods of time (e.g., spawning runs). We use a hierarchical model to integrate side-scan sonar with acoustic telemetry, to estimate the proportion of a spawning run fitted with acoustic tags (12%; 95% CrI = 8%–16%) and extrapolate to the total run size in 2014. Our investigation represents a novel approach to generating run size estimates in a large river and provides the first estimate of Atlantic sturgeon (Acipenser oxyrinchus oxyrinchus) spawning run size for the Hudson River ([Formula: see text] = 466; 95% CrI = 310–745) since the fishery moratorium in the 1990s. Our estimate suggests that the Hudson River holds one of the largest contemporary populations of Atlantic sturgeon, but also indicates that it remains sharply depleted relative to virgin conditions.

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