Summary Statement: Our goal in partnership between UMass/USGS and SRBTC is to conduct research that will support the goals of the Sea Run Brook Trout Coalition to stop the loss of remaining sea-run brook trout populations as well as restore populations in southeast New England and Long Island, NY.

The overall research question is whether a ‘fish is a fish’ or whether certain individual brook trout inhabiting coastal streams are predisposed (genetically) to anadromy. Understanding what controls anadromy in coastal brook trout populations will allow us to determine the role natural and anthropogenic disturbances play in maintaining and restoring sea-run brook trout stocks. Our research will be divided into three critical research questions:

Patterns of anadromy: To what extent does use of saltwater vary among populations? Can this be related to variation in functional genes among populations? What is the spatial ecology of sea-run brook trout populations, especially in coastal waters?

Genetic vs. environmental control of anadromy: How does individual growth history influence anadromy? Does extent of anadromy vary among populations with different historical opportunities for anadromy and for individuals with different functional genes? Mechanisms of anadromy: What controls anadromy and what are the consequences of anadromy for population persistence?

Question 1: Patterns of anadromy

Systematic survey of historical brook trout streams to document the presence/absence of anadromous and resident brook trout.

For a selected set of streams that contain a) anadromous fish and b) resident fish that have been isolated for varying amounts of time, we will examine:

• Length distribution of fish within populations

• Patterns of saltwater use by fish (isotopes and acoustic tagging)

• Genetic analysis with Single Nucleotide Polymorphism (SNP) markers in functional genes to identify:

• Historical population relationships

• Genes associated with migratory tendency

Question 2: Genetic vs. environmental control

Tendency to migrate to the ocean may be influenced by the environment, but the way populations respond to environmental cues could be controlled by genetic factors. This is of interest because the tendency to migrate may be lost due to selection against migration following extended isolation of formerly anadromous populations. As such, we will conduct an experimental test to determine the environmental sensitivity of migratory tendency within and among coastal brook trout populations.

• Three coastal stream types: (1) anadromous, (2) resident above anthropogenic shorter-term barrier, (3) long-isolated resident above natural barrier

• Juveniles will be captured from the three stream types and exposed to three diet treatments (low, medium, high) in the laboratory for one month to induce variation in growth rate

• Reciprocal transplantation of PIT tagged fish back to streams from which parents were taken

• PIT tag antennas at stream mouths will identify migrants and migratory tendency will be related to stream type and diet treatment

• Individual SNP genotypic variation will be related to migratory tendency

• Future years could involve experimental crosses within and among stream types to determine the genetic basis of anadromy.

Question 3: Mechanisms of anadromy

A comprehensive long-term analysis of three anadromous streams is necessary to understand how individual variation in fitness contributes to overall population dynamics and long-term persistence of populations.

• Demographic analysis (PIT tags, acoustic telemetry, physiological indicators of stress, detection systems, modeling)

• Genetic analysis (SNP markers, sibship and multi-generation pedigree reconstruction)

• Quantitative genetic estimates of genetic basis of migratory tendency, growth rate, and body size estimates of the effects of size selective harvest, fragmentation, climate change

Scientific Advisory Board

Andy J. Danylchuk PhD
Assistant Professor
of Fish Conservation
DNRC
U Mass Amherst
Amherst, MA 01003

Andrew Whiteley PhD
Assistant Professor
of Fish Conservation
DNRC
U Mass Amherst
Amherst, MA 01003

Ben Letcher PhD
Fish Population Ecologist
Conte Anadromous
Fish Research Center,
USGS/BRD
Turners Falls, MA 01376

Brendan Annett MS
VP, Coalition for
Buzzards Bay
620 Belleville Ave
New Bedford, MA 02745

Steve Hurley MS
Southeast District
Fisheries Manager
Massachusetts DFG
195 Bournedale Road
Buzzards Bay, MA 02532

Tim Purinton MS
Acting Director
Division of Ecological
Restoration
Massachusetts DFG
251 Causeway St.
Boston, MA 02114