Seasonal Distribution and Movements of Atlantic and Shortnose Sturgeon in the Penobscot River Estuary, Maine

Joseph D. Zydlewski; Stephen J. Fernandes; Gayle B. Zydlewski; Gail S. Wippelhauser; Michael T. Kinnison

doi:10.1577/t09-122.1

Home/Archive/USGS

USGS · 70171366

Seasonal Distribution and Movements of Atlantic and Shortnose Sturgeon in the Penobscot River Estuary, Maine

Joseph D. Zydlewski·Stephen J. Fernandes·Gayle B. Zydlewski·Gail S. Wippelhauser·Michael T. Kinnison

View original source ↗Export metadata ↓

Abstract

Relatively little is known about the distribution and seasonal movement patterns of shortnose sturgeon Acipenser brevirostrum and Atlantic sturgeon Acipenser oxyrinchus oxyrinchus occupying rivers in the northern part of their range. During 2006 and 2007, 40 shortnose sturgeon (66–113.4 cm fork length [FL]) and 8 Atlantic sturgeon (76.2–166.2 cm FL) were captured in the Penobscot River, Maine, implanted with acoustic transmitters, and monitored using an array of acoustic receivers in the Penobscot River estuary and Penobscot Bay. Shortnose sturgeon were present year round in the estuary and overwintered from fall (mid-October) to spring (mid-April) in the upper estuary. In early spring, all individuals moved downstream to the middle estuary. Over the course of the summer, many individuals moved upstream to approximately 2 km of the downstream-most dam (46 river kilometers [rkm] from the Penobscot River mouth [rkm 0]) by August. Most aggregated into an overwintering site (rkm 36.5) in mid- to late fall. As many as 50% of the tagged shortnose sturgeon moved into and out of the Penobscot River system during 2007, and 83% were subsequently detected by an acoustic array in the Kennebec River, located 150 km from the Penobscot River estuary. Atlantic sturgeon moved into the estuary from the ocean in the summer and concentrated into a 1.5-km reach. All Atlantic sturgeon moved to the ocean by fall, and two of these were detected in the Kennebec River. Although these behaviors are common for Atlantic sturgeon, regular coastal migrations of shortnose sturgeon have not been documented previously in this region. These results have important implications for future dam removals as well as for rangewide and river-specific shortnose sturgeon management.

Explore related subjects

Transactions of the American Fisheries Society Article

Source-reported bounding extent: 43.866218006556394° to 45.213003555993964° latitude; -69.521484375° to -68.15917968749999° longitude. This indicates report coverage, not an exact sampling location. View area on OpenStreetMap.

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

Joseph D. Zydlewski, Stephen J. Fernandes, Gayle B. Zydlewski, Gail S. Wippelhauser, Michael T. Kinnison. 2011-01-09. Seasonal Distribution and Movements of Atlantic and Shortnose Sturgeon in the Penobscot River Estuary, Maine. https://doi.org/10.1577/t09-122.1

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related USGS reports

USGS2026

Effects of temperature on standard metabolic rate, hypoxia tolerance, and critical thermal maxima in invasive cichlids

Objective Jaguar Guapote Parachromis managuensis and Red Devil/Midas cichlids Amphilophus spp. are highly invasive species in the family Cichlidae native to Central America. These cichlids are popular within the aquarium trade, leading to their broad introduction outside of their native range. Information about potential environmental plasticity of a species can improve predictions of invasion potential. In this respect, measures of environmental influences on metabolic rate and hypoxia tolerance are important for understanding limitations in adaptability and subsequently guiding the management of invasive species. Methods Standard metabolic rate (SMR), hypoxia tolerance, and critical thermal maxima (CT max ) were compared between Jaguar Guapote and Amphilophus spp. For SMR and hypoxia tolerance, a range of temperatures spanning subtropical to tropical environments (i.e., 22, 28, and 34°C) was used, followed by stepwise decreases in oxygen saturation until loss of equilibrium. Results Jaguar Guapote and Amphilophus spp. both had lower SMR at 28°C than at 34°C, SMR at 22°C was not different from either temperature. Both Jaguar Guapote and Amphilophus spp. were the most sensitive to hypoxia at the coolest temperature (22°C) relative to warmer temperatures (28°C and 34°C). Upper thermal tolerance (CT max ) was similar between species (∼42°C), although Jaguar Guapote were more resilient based on a higher agitation temperature and recovery following high temperature exposure. Conclusions These results indicate temperatures that are representative of their natural distribution (i.e., near 28°C) offer energetic savings for Jaguar Guapote and Amphilophus spp. relative to warmer temperatures (34°C), with cooler temperatures (22°C) having higher metabolic costs than expected. Both Jaguar Guapote and Amphilophus spp. are sensitive to hypoxia at cooler temperatures (22°C). Therefore, these species are relatively resilient to high temperatures, but low temperatures may restrict their invasiveness.

Transactions of the American Fisheries Society↗

USGS2026

The value of electronic tagging and tracking studies for understanding fish–hypoxia interactions

Objective Hypoxia (i.e., low dissolved oxygen availability) is a natural phenomenon but can also be induced by human activities (e.g., nutrient enrichment from runoff). Given that dissolved oxygen is essential for aquatic life, periods of hypoxia tend to have negative consequences (e.g., sublethal disturbances, mortality) for most fishes. Extensive laboratory research has documented hypoxia thresholds and physiological and behavioral outcomes for a variety of freshwater and marine fishes and there is also an extensive body of fieldwork assessing population-level responses (e.g., survival, distribution). Yet, studying how individual fish respond to hypoxia in the wild has proved challenging; electronic tagging and tracking tools (e.g., biotelemetry, biologging) have made it easier to study individual responses to hypoxia and complement other tools like hydroacoustics that tend to focus on population-level responses. Methods We review what has been learned from contemporary studies that employ electronic tagging and tracking tools to understand how fish respond to hypoxia in the wild. Topics explored include identifying and validating hypoxia thresholds, habitat compression, connectivity, mortality, physiological and bioenergetic consequences, and extreme weather conditions. We also consider what we have learned about evaluating various management plans for hypoxia and reflect on how electronic tags have also been used in aquaculture systems and in hybrid studies that combine laboratory and field research. We highlight fishes in Lake Erie as a research narrative to demonstrate how electronic tagging and tracking have markedly improved our understanding of a longstanding hypoxia issue. Results Our synthesis revealed that electronic tagging and tracking have provided critical information on how fish respond to hypoxia in the field, revealing complex trade-offs and compensatory mechanisms as well as cryptic hypoxia-induced mortality. Beyond just illuminating space use and mortality, tags equipped with various sensors are revealing how fish deal with hypoxia in real time in terms of physiology, bioenergetics, and behavior. Conclusions As electronic tagging and tracking methods experience further innovation and are increasingly applied to understand the effects of hypoxia on fish, we expect more unanticipated findings about the effects of hypoxia on fish in all aquatic ecosystems, which will strengthen our ability to manage and mitigate hypoxia. Combining tools and approaches (e.g., lab and field) is perhaps the best way to generate comprehensive understanding.

Transactions of the American Fisheries Society↗

USGS2026

Life history traits and population dynamics of Freshwater Drum across large river gradients

Objective Monitoring and assessment of nongame native fishes is limited, but conservation interest in these species is growing. Freshwater Drum Aplodinotus grunniens are a wide-ranging species that serve important functional roles and could serve as an indicator for similar but less common species. Our overall objectives were to quantify and compare population dynamic rates and life history of Freshwater Drum among study reaches in the upper Mississippi and Illinois rivers and relate these metrics to hypothesized environmental and anthropogenic factors. Methods We integrated recently collected age data with monitoring data to estimate age and size distributions, growth curves, maturation schedules, mortality rates, and young-to-adult ratios of Freshwater Drum in six study reaches spanning 1,500 km of river. Principal component analyses and linear regression were used to relate environmental and anthropogenic gradients (latitude, commercial harvest, hydrologic dynamics, primary productivity) to life history traits and population dynamic rates. Results We found latitudinal gradients in life history traits and population dynamic rates whereby Freshwater Drum in upstream, higher-latitude study reaches generally exhibited later maturity, slower growth, smaller maximum size, and lower mortality rates compared with those in lower-latitude study reaches. Further, young-to-adult ratios positively corresponded with chlorophyll- a concentration. No clear relationships were apparent between population dynamic rates and hydrologic variation or commercial harvest. Conclusions Latitude is an important structuring component of life history traits and population dynamics of Freshwater Drum in the upper Mississippi and Illinois rivers likely due to both temperature seasonality and disturbance regimes. The presence of demographic structure in a widespread, common species such as Freshwater Drum suggests similar patterns likely exist in other long-lived native fishes.

Illinois, Iowa, Minnesota, Missouri, Wisconsin↗