Fish population trends and life history theory: evidence for changing flows in the Potomac River

• Details: I report results from a recent study investigating fish population trends in the Potomac River (Chesapeake Bay watershed). We evaluated temporal trends in abundance from data collected by Maryland Department of Natural Resources at 10 locations over 43 years (1975-2017). Increasing species were characterized by opportunistic life history strategies (i.e., small-bodied species with rapid maturity; e.g., banded killifish [Fundulus diaphanus]), whereas decreasing species were characterized by periodic or equilibrium strategies (i.e., large-bodied species that delay reproduction to invest in growth or parental care; e.g., smallmouth bass [Micropterus dolomieu]). Most increasing species are native to the study area and therefore probably do not indicate recent introductions. Results indicated that river flows during spawning have become less stable and less predictable over time, consistent with observed increases in spring peak-flows as well as predictions from land-use and climate change research.

• Presenters: Dr. Nathaniel Hitt (USGS)

• Recorded: June 11, 2020

• Duration: 46 minutes

• Resources: Journal Article

Forecasting Spring Chinook Salmon Adult Returns Within a Management Decision Context

• Details: Fishery managers are often faced with making decisions under uncertainty. Pre-season adult return forecasts are used by managers to set harvest levels and hatchery broodstock collection plans, however forecast models often have wide prediction intervals around the forecast, indicating a high level of uncertainty. We used a retrospective analysis approach to assess different forecast models for hatchery and wild Spring Chinook Salmon (Oncorhynchus tshawytscha) returns to the Deschutes River, OR. Within the Deschutes River basin, Warm Springs National Fish Hatchery produces Spring Chinook Salmon for Tribal harvest and distribution to tribal members of the Confederated Tribes of the Warm Springs Reservation of Oregon, as well as contribution to sport harvest opportunities. Based on our retrospective analysis, the four “best” performing models for hatchery and wild returns are used to produce annual pre-season forecasts. Using these forecasts, managers then set harvest levels and broodstock collection plans that they feel will best meet their multiple objectives. Given the low predictive performance that even the best performing forecast models exhibit, we are starting to develop additional tools to assist managers in their decision-making.

Presenters: David Hand (USFWS)

• Recorded: November 5, 2020

• Duration: 65 minutes

Standardized Fishing with Electrical Fields

• Details: The modern idea of standardized electrofishing began with Larry Kolz’ concept of maximum power transfer from water to fish. It is based on water conductivity effects on this power transfer. It is not intuitive for fisheries biologists, and several biologists do not use the Power Transfer Theory or Model because they aren’t familiar with the concept or because they lack the electrical metering required. The purpose of this presentation is to demystify standardized electrofishing by explaining electrical fields. The field size is what is being standardized across water conductivity.

• Presenters: Dr. Jan Dean (Dean Electrofishing)

• Recorded: July 28, 2020

• Duration: 63 Minutes

Structured Decision Making for Habitat Restoration - Assessing Landscape Needs and Implementation to Achieve Population Success

• Details: The geographic area of responsibility for the Green Bay FWCO Habitat Program encompasses the entire Lake Michigan basin. The aim of our program is to restore quality aquatic habitat, protect aquatic species, mitigate non-climate stressors exacerbated by climate change, and manage ecosystems by pro-actively considering climate change impacts across the basin. When faced with problem of how to balance largescale landscape needs with local population goals and implement on the ground projects to achieve both, we used structured decision making to help us identify where and how to direct our work to have the greatest impact. Through this process, we devised a strategic habitat plan to prioritize our work and incorporate multiple competing priorities including species and population needs, partner and stakeholder interests, and climate impacts. In this presentation, we provide a brief overview of our strategic habitat plan development and examples of how we are implementing our restoration program at the landscape (Lake Michigan Basin), watershed (HUC 8) and local (project) levels to help us achieve resiliency and population success.

• Presenters: Dr. Jessica Collier (USFWS)

• Recorded: August 27, 2020

• Duration: 61 Minutes

Use of age structured models to diagnose overfishing and identify fish management options

• Details: Dr. Mike Allen presents some results and examples of use of population modeling for diagnosing overfishing, and for potential to overfish invasive species (lionfish, carp, etc.). Basics of modeling will be presented with spreadsheet examples that can be shared after the seminar to diagnose recruitment and growth overfishing.

• Presenters: Dr. Mike Allen (University of Florida)

• Recorded: June 25, 2020

• Duration: 60 Minutes

Using Technology to Improve Habitat Mapping and Suitability Modeling In Small Rivers and Streams

• Details: Fundamental to effective fisheries management is understanding the distribution and quality of habitat available to your target species. Unfortunately, collecting high-quality habitat data is expensive, time-consuming, and rarely gathered at a scale appropriate to address the life history events of most fish and aquatic species. Additionally, many aquatic species have unique habitat characteristics that may be poorly captured in general survey protocols necessitating additional habitat surveys as management needs change. The High Definition Stream Survey (HDSS) system was designed to rapidly collect a broad suite of georeferenced instream and stream corridor data over miles of rivers or streams in single day. The field data is classified using a flexible, user-driven method that allows the field data to be appropriately applied to different species or management goals. The classified data then flows easily into powerful suitability models that support informative maps, graphics, and statistics. The results are suitable to be used in decision support tools or for strategic planning. Additionally, archived field data is easily reanalyzed to support other stream related activities such as permitting, compliance, watershed planning, impact assessments, and predictive modeling giving you an excellent way to increase collaborations, decrease costs, and improve conservation outcomes.

• Presenters: James Parham and Dane Shuman (Trutta Environmental Solutions)

• Recorded: July 9, 2020

• Duration: 61 Minutes

Yukon River Subsistence Salm Fisheries Management, Assessment and Collaboration

• Details: Look into the management of the Yukon River fisheries with a reflection on the historical and cultural influences. The Fairbanks FWCO staff cooperate with state tribal and local partners to balance the management of Yukon River salmon in relation to the US-Canada Treaty objectives. The Yukon River management process has broad applicability to other FWCOs in working with Native American organizations and state agencies on fishery management.

• Presenters: Gerald Maschmann, Jan Conitz and Matt Keyse (USFWS)

• Recorded: September 24, 2020

• Duration: 52 Minutes