Variability of North Atlantic Diadromous Fish Populations:
Establishing Reference Points for Restoration Assessment
26 - 27 May 2011
University of Maine, Orono, Maine
The goal of this workshop was to bring together fisheries, habitat, and climate specialists to investigate variability in diadromous fish populations over time and among watersheds spanning species’ ranges. Participants were asked to share data with other workshop participants and/or collaborate on analyses and manuscripts identified as products of this workshop.
The decline of diadromous species is widespread. Unlike classic approaches to species assessment which focus on population numbers, this workshop will focus on variability (e.g. relative standard error, CV, quintiles of variability, variograms, and/or other measures of variance) of population characteristics (e.g., number, size, run timing, age structure, survival) over time and space. We will use variability measures as response variables for blocks of data (e.g., group of years, group of rivers within a year). To make this effort manageable, we will focus on one or two Northeast diadromous species for which the most data are available.
Questions addressed in this workshop included:
- Are there patterns in the variability of adult run timing in Eastern North American coastal rivers that can be related to geographic (lat long, watershed characteristics), hydrologic, and oceanic variables?
- Are there patterns in the variability of juvenile emigration timing in Eastern North American coastal rivers that can be related to geographic (lat long, watershed characteristics) and hydrologic variables?
- Are there patterns in the variability of population growth in rivers under restoration that can be related to management (stocking and barrier removal or passage) practices and geographic (lat long, watershed characteristics) and hydrologic variables?
- Are there freshwater habitat characteristics that have been associated with successful restorations?
- Can we assess natural variability (apart from other variability) in populations?
What data are needed for variability assessment of other diadromous species in the Northeast?
- Analyze variability in population, climate, and habitat parameters for river herring, a species with the longest temporal data record in the northeast,
- Use comparative approaches to determine if variability in population characteristics is related to climate or habitat, and
- Identify reference points for restoration.
Potential Workshop Products
- An assessment of the variability of population characteristics over time and space for one or two diadromous species
- Reference points by which restoration goals, efforts and success can be assessed
- Tools for assessing variability in diadromous species populations
Our ultimate goal is to provide information necessary to prioritize and assess restoration efforts, topics that will be covered in a 2012 management workshop as well as report back to the greater restoration science community at the final DSRRN conference in 2013.
Barbara S. Arter
Science Information Coordinator
Diadromous Species Restoration Research Network
Workshop Participants Enter Here