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Rough notes from the DSRRN 2013 Science Meeting
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1-baseline.markdown

Setting the baseline: the historial decline of diadromous fish and ecological connections lost.

Productive capactity

  • Exosystems have heterogenity in energy production.
  • Area around the Bay of Fundi is particularly productive.

Migrations

  • ATS, River herring, American eel, Sturgeon.
  • Getting a better understanding of fish movement and migration patterns.

The Industrial Revolution

  • Habitat loss declines starts in the 1700.
  • Fisheries begin to lose contribution from larger watersheds.
  • Distributions shift to small coastal ponds as the primary source of production.
  • In addition to habitat loss, we start overharvesting, crushing the population.

Population declines limits resilience.

Challenges

  • Different population drivers for each River
  • Dams, flow characteristics and fish passage
  • Fishways aren't being fully utilized? Can't assume they are a solution. Strong impact on flow dynamics. Boon to predators?
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2-evolution.markdown

Human induced evolution and the restoration of diadromous fishes.

The Puzzle Analogy

  • Think about components, the species withing an ecosystem, interact with one another.
  • Understand the species, and the interactions, and you can understand how the Ecosystem works?
  • The 'shapes' of each puzzle piece may differ from part to part.

Traits of species are actually quite malleable on a contemporary timescales.

Two main pathways

  1. Modification of Gene Flow
  2. Modifying the selection process. Favoring traits that wouldn't naturally be favored.

Means of change

  1. Stocking
  • Increased gene flow. Aritificially moving genes around the landscape. Stocked runs are more homogenous.
  • Hatchery selection can favor traits that are detrimental to fitness in the wild
  1. Dam construction, decreased gene flow, freshwater residency selection
  • Zooplankton dynamics very different between landlocked and anadromous populations.
  1. Harvest, selection on age and size at maturation
  2. Aquaculture, gene flow between wild and domestic fish
  3. Hydrology,
  4. Climate change

Conclusions

  1. Human induced evolution is occuring in diad.
  2. Potential to impact eco processes such as spec. interactions
  3. Eco consquences may impact rest efforts.
  4. Reocvet requires restoration of evolutionary as well as ecological processes.
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3-lifehistory.markdown

Diversity in life histories and genetic structures in a large population complex of wild Atlantic salmon in the River Teno, Northeastern Europe.

Salmon populations are diverse. So are the methods of fishing.

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4-coevolved.markdown

Interactions among coevolved diadromous species and their implications for Atlanic salmon recovery

A New Era of Management

Diversity amongst East Coast species: Atlantic salmon, Sea Lamprey, & River herring.

Trends

Decreasing elements: Shad, Sturgeon, River Herring. Increasing elements: Stripers

Different story for different fish.

4 ways that ATS interact with other diadromous fishes:

  1. Food source
  2. Predation buffering
  3. Marine derived nutriets
  4. Habitat conditioning

Buffer Concept

  • Similar size to smolts
  • Spatial/temporal overlap
  • Abundance

Alewife and Smolt windows timing overlaps variably between Rivers.

We can expect a 10x increase in Smolts in the Penobscot, because of recent restoration efforts.

Marine-derived Nutrients (M Guyette)

Sea lamprey event is important to successfuly Juvenile ATS growth in the summer.

MDN => Dissolved Nutrients => Periphyton => Macroinverts => ATS

MDN addition has a clear impact on YOY ATS size

Barrier Removal (S Coghlan)

Sea Lamprey the East Coast analogue to Pacific salmon habitat engineering?

Sedgeunedunk

  • Meadow dam removed
  • Mill dam removed

Lots of new habitat access as a result. Habitat variables were measured for change. In summary: increased habitat complexity, and substrate coarsening.

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5-variability.md

Natural variability in historical...

Context is essential. What does the historical data tell us?

  • Are patterns apparent in variability?
  • Are patterns related to drivers?
  • Is variability a useful response variable?

Visualizing variability patterns.

  • Points estimates. Not always useful.
  • Variability of points estimates over periods. More useful. IE, mean catch per day/week/month

Variability may show triggers for or indicators of change.

Historical Records

  • Do we have enough data?
  • Are these data actually historical, representative of pristine habitat?
  • Shifting events are a concern
  • As are rare events.

IE, is a particular 'high point' a rare event, and thus a poor reference?

Resilience and Regime Shifts

  • Alternating stable states
  • Monotonic change

Initial stable state -> Change -> Resistance -> Critical Threshold reached -> 'new' Stable state

  • Inability to respond to additional stressors

Triggers and Tipping points

.... and wow that got technical fast!

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6-habitat.md

Habitat requirements of diadromous fishes...

Defining 'habitat' is not simple.

Includes physical characteristics of a plce

  • Flow
  • Substrate
  • Water quality
  • Cover/shelter

Includes biological characteristics

  • Food
  • Predators

Habitat associations assumed to indicated 'preference'

However, fish selections under certain conditions in a stream can vary from year to year and place to place. IE, low or high numbers of fish. Associations with conspecifics (grouping). Territoriality.

Habitat could include areas not directly used by fishes!

IE, upstream food sources, nearby urbanization, etc.

Diadromous species have a particularly dynamic concept of habitat

Connectivity and heterogeneity particular important to these species.

Conenctivity

  • Dams, culverts, falls
  • Low oxygen, temp extremees, pollution plumes, confusing currents, predator aggregations.
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7-hydrogeo.md

What do fish care about hydrogeomorphology?

Dynamic Rivers = Healthy Ecosystems

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gistfile1.txt
Process based restoration and implications for habitat conservation.
===
Re-establish processes that sustrain river and fllodplain ecosystems.a
Features
- Dynamic
- Self-sustaining, low maintenance
- Allows natural biodiversity to emerge.
Principles
- Treat root causes
- Target local resotration potential
- Explicit outcomes
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