Alewife: Assessment and Impacts on Lake Champlain

(Brooks and Dodson, 1965)

Marty Frye, Lecia Babeu, Will Matukonis, Zack Clark

Goal/Purpose Statement

We seek to understand the impacts of alewives on:

• Trophic interactions • Species populations • Aquatic ecosystem balance

In Lake Champlain

OBJECTIVES

• Select specific endpoints for assessing alewife impacts on natural systems in Lake Champlain.

• Examine the effects of alewife on: o Other fish specie’s eggs and larvaeo Salmonid populations  (Early Mortality Syndrome)o Zooplankton and Phytoplankton

Who's da Fish with da Funny Name?

   -Alosa pseudoharengus      -Anadramous fish of the herring family native to the Atlantic coast north from the Carolinas      -Planktivorous, focusing on larger zooplankton.  Also eat the larvae of other fish      -Preyed upon by most larger piscivorous fish      -A "brittle" species                -doesn't do well with dramatic temperature changes                -not easily transported by humans       

(Bean 2002)  (USGS 2010)  

Ecology and Life History (in Land locked Lakes)

    - Generalists.  Highly invasive.      - Out-compete other fish and over-feed on macro-                       zooplankton.      - Can become a huge part of the diet of larger fish.    - Don't like the super-cold.              - Retreat to deeper water during winter.            - Move towards shallow waters in April.            - Spawning peaks in July

Disclaimer: Alewife is a native and culturally valued fish along the Atlantic coast and connected river-ways and there are efforts to restore impaired populations in these areas. (Bean 2002) (Madenjian et al 2008)   

Introduction and Invasion in Other Lakes

    - First detected in Lake Ontario in 1873.  Established in all  Great Lakes by 1954.    - Modes of Introduction:          - Natural movement between water bodies           - Human stocking          - Movement through human-built waterways    - Recorded in Lake St. Catherine in 1997

(Bean 2002) (Good and Cargnelli 2004)

(USGS 2010)

Good and Cargnelli 2004

Alewife in Lake Champlain

  - First observed in 2003  - Exhibited a population boom and a winter mass die-off in 2007-2008.  - Monitoring and assessment underway              - No conclusive alewife impacts on the lake yet             - No management plan established  

(Vermont Agency of Natural Resources 2008)

Findings

Case Study - Otsego Lake, NY• Introduced in 1986, established population• Shallower than Lake Champlain, biologically similar 

                                                                               (Harman, 2006)

 In 1990s Otsego Lake exhibited increases in:• Oxygen depletion rates• Chlorophyll a• Phosphorus• Decrease in transparency

 Introduced fish species studied since 1930s, lots of pre-alewife data                                                                                                                                               (Albright et al., 2002)

http://www.maine.gov/dmr/searunfish/alewife/index.htm

Following Introduction

Water turned green with algaeo Lack of large algal grazing zooplanktono Large zooplankton population reduced by alewife 

                                                              Increased algal blooms increased turbidity

o Reduced Secchi depth measurements                                                                      (Harman, 2006)

co.carver.mn.us

lakechamplaincommittee.org

Secchi disk transparency in Otsego Lake prior to alewife introduction, and post alewife introduction (Harman, 2006).

Zooplankton Size Distribution

Introduction changes size distribution o Alewife prey selectively on large zooplanktono Zooplankton size distribution useful indicator of ecological

impacts of alewife                                                                          (Kraft, 2006)

 In Otsego Lake ciscoes dominated from 1970-1988

o Large bodied zooplankton dominated o Grazing on algae, low algal biomass o Alewife become more abundanto High transparency, deeper Secchi depth

                                                                                                                                 (Albright et al., 2002) 

hamiltonnature.org

Size Distribution Cont. Post introduction shift in zooplankton community        Alewife selectively prey on large zooplankton 

Daphnia and Leptodora        Since 1990s  

Bosmina coregoni        smaller zooplankton species has dominated Otsego Lake                                                                     (Albright et al, 2002)

 Alewife have top down effect on food web

o Establishment -- fewer large cladoceran, especially daphnia

o Increased populations of small cladocerans and copepods

o Increased algal biomass, lack of large cladocerans consuming large algal particles

                                                                             (Kraft, 2006)

cf.adfg.state.ak.us

(Brooks and Dodson, 1965)

Landlocked vs. Anadromous Alewife

• Both prey on zooplanktono Landlocked, continuous interaction with zooplankton

• Keystone species in some E. North American lakeso Dominant in determining structure of zooplankton

communities

• Lakes with landlocked alewifeo Smaller bodied zooplankton o After introduction, rapid decline in zooplankton body sizeo Constant predation pressure on zooplankton o Zooplankton size remains small throughout growing seasono Changes in zooplankton community drive natural selection

of next generationo Eco-evolutionary feedbacks strong

(Palkovacs and Post, 2008)

Eco-evolutionary Feedbacks

Strong in landlocked populations• Landlocked alewives become morphologically adapted

to foraging on smaller prey• Consume smaller prey/zooplankton • Shift in body size of zooplankton present after

introduction • More pronounced for cladocerans than copepods

(Palkovacs and Post, 2008)fmel.ifas.ufl.edu

(Palkovacs and Post, 2008)

(Marsden 2010)

• Condition prevalent in species that prey upon alewife. (Lake Trout, Atlantic Salmon)

Lake Champlain: The extent to which alewife contribute to thiamine deficiency in fish species in unknown, however thiamine deficiencies have been recorded in Lake Trout, this is probably true for other species as well.

An enzyme present in certain plant/fish species that splits Thiamine molecules in two.

Thiamine http://arginine.chem.cornell.edu/Structures/Thi-I.html

http://www.answers.com/topic/thiaminase

A vitamin of the B-complex, essential to animals.

Family Cyprinidae (Minnows or carps):

Common bream (Abramis brama)Central stoneroller (Campostoma anomalum)Goldfish (Carassius auratus)Common carp (Cyprinus carpio)Emerald shiner (Notropis atherinoides)Spottail shiner (Notropis hudsonius)Rosy red, Fathead minnow (Pimephales promelas)Olive barb (Puntius sarana)

Family Salmonidae (Salmonids):

Lake whitefish (Coregonus clupeaformis)Round whitefish (Prosopium cylindraceum)

Family Catostomidae (Suckers):

White sucker (Catostomus commersonii)Bigmouth buffalo (Ictiobus cyprinellus)  Family Ictaluridae (North American freshwater catfishes):

Brown bullhead catfish (Ameiurus nebulosus)Channel catfish (Ictalurus punctatus)  Other families:Bowfin (Amia calva) - family Amiidae (Bowfins)Burbot (Lota lota) - family Lotidae (Hakes and burbots)White bass (Morone chrysops) - family Moronidae (Temperate basses)Rainbow smelt (Osmerus mordax) - family Osmeridae (Smelts)Loach, Weatherfish (Misgurnus sp.) - family Cobitidae (Loaches)

http://www.wetwebmedia.com/ca/volume_6/volume_6_1/thiaminase.htm

Characterized by:

-Loss of Equilibrium-Lethargy-Hemorrhaging-Hyperexcitability-Ultimately, death.

-Effects of EMS found in Atlantic Salmon, Steelhead Trout, and Lake Trout in the Great Lakes. (Mandenjian, 2008)

“The proliferation of alewives in the late 1870’s appears to have been the keystone change in the great lakes ecosystem that pushed the Atlantic Salmon population to extirpation via EMS reducing fry survival and perhaps also via anorexia, induced by thiamine deficiency, causing

starvation of adults.” (Ketola et al., 2000)

Heavily Impacted Fish Species

pond.dnr.cornell.edu

*NOT AT ALL TO "SCALE"*

Atlantic Salmon

• Early life stages of atlantic salmon are not at risk of predation by alewife because they do not overlap spatially. o Atlantic salmon spawn in up-stream reaches where they spend up to

two years.  (Ketola,2000)• Threat to Atlantic Salmon is mainly Early Mortality Syndrome • Lag time in negative effects on salmon populations

o EMS chokes recruitment rates (Madenjian, 2008)• Lake Ontario Example

o Strong correlation between alewife invasion and atlantic salmon extirpation. (Madenjian, 2008)

Lake Trout• The early life history of lake trout allows larvae to

be vulnerable to predation by alewife.o Spatial Overlap!o Pelagic lake trout eggs typically hatch during April and May

          (Madenjian, 2008)

• Tank experiments have shown that the predator avoidance response shown by lake trout larvae is to flee upward in the water column o Creates spatial overlap and leaves lake trout larvae very

susceptible to predation by alewives                                                 (Strakosh and Krueger 2005)

sciencenews.org

Lake Trout• Several other compounding factors which

contribute to Lake Trout population declineso Overfishingo Predation by sea lampreyo EMS

• Important to differentiate between lake trout population declines inducedby different factors.o Which declines are more

heavily alewife related?

sportfishingamericas.files.wordpress.com

Lake Trout

• Lake trout stocks collapsed in all five Laurentian Great Lakes by 1960, primarily through overfishing and predation by sea lampreys. (Hansen, 1999)

• Regardless of lake trout stocking programs begun in the 1960s and 1970s, only lake trout populations in Lake Superior have recovered.

   **highly correlated with a very low abundance of alewife**                                             (Madenjian, 2008)

• Remember: Even with successful recruitment, lake trout face a double threat from alewife - EMS and predation

Emerald Shiner• Due to its physical and ecological similarity to alewife, it is

particularly at risk to alewife invasions. o OVERLAP!

• Alewife interfere with emerald shiner reproduction by feeding on pelagic eggs and fry o Peak hatching of emerald shiner eggs occurs in June and July o Eggs and larvae are pelagic, and newly hatched larvae have been

observed primarily in shallow water  (Madenjian, 2008)• This life cycle overlaps spatially

and chronologically with alewifereproductive cycles and puts theemerald shiner at high risk ofpredation.

Emerald Shiner in the Great Lakes• Studies in the great lakes have shown a high correlation

between alewife population increases and emerald shiner population crashes.

• Studies in Lakes Michigan and Huron have shown that Emerald Shiner populations were greatly reduced during the early 1960so Coincident with the increased abundance of alewives in both lakes

                                                                 (Madenjian, 2008)• The emerald shiner population collapse in Lake Michigan

spread from the northern part of the lake southward o Spatially coincident with the spread of alewives into the lake

                                                                    (Wells, 1977)• Emerald shiner populations in Lakes Michigan, Huron, and

Ontario have not recovered since 1960 o Largely due to a lack in alewife population declines (Wells, 1977)

These aren't the only impacted fish species....

• Slimy sculpin• Lake whitefish• Cisco• Bloater• Rainbow smelt

• Yellow perch

• Deepwater sculpin

• Atlantic salmon• Lake trout• Emerald shiner

Strongest Effect

Minimal Effect

Chart Recreated from Madenjian, 2008 image: csulb.edu

Social Implications

• Die-offs reek and are unsightly   • Lost cultural heritage attached to native

fish being displaced• Reduced recreation/use of lake with more

die-offs• May increase algal blooms

bobberbobsfishen.com

Economic Implications

• Reduced lake trout and salmon viability makes for bad fishing.

• Tourism hurts: mass die-offs, fishing, stigma of having a non-pristine lake dominated by invasives

• Algal blooms lead to decreased use of lake for many activities

bizbox.slate.com/blog/dollar-sign.jpg

Ecological Implications...a take home message

• Prey fish species are largely displaced o Shifting trophic interactions

• Larger zooplankton are selectively preyed upono Small zooplankton and phytoplankton proliferate.

• Large fish subject to EMS      are less viable

• Die-offs don't seem to have major ecological impacts.

www.studentforce.org.uk/toolkit

Assessment Endpoints

• Secchi depth measuring turbidity • Zooplankton species populations• Phytoplankton species populations/abundance• Population of at-risk fish species• Salmonid egg hatching success (EMS effects)• Direct testing for thiamine deficiency in salmonids

seagrant.wisc.eduhttp://www.paranormal-encyclopedia.com/c/champ/

Recommendations

Preventative Measures-• Strict measures restricting

transportation of alewife in-state are already in place.

Action-• Increase stocking of lake trout

and atlantic salmon following die-offs 

• Increase monitoringo zooplankton size distribution

and populations• More research on diet of

alewife and ecological niche in Lake Champlain

• Assess effectiveness of monitoring

... or dead ones.

Literature Cited

Albright., M.F., Harman, W.N, & Warner, D.M. (2002). Trophic changes in Otsego Lake, NY following the introduction of the alewife (Alosa psuedoharengus). Lake and Reservoir Management, 18(3), 215-226.  Bean, Tim. (2002) “Introduced Species Summary Project: Alewife: /Alosa pseudoherengus/.” Retrieved from http://www.columbia.edu/itc/cerc/danoff-burg/invasion_bio/inv_spp_summ/alewife.html.  Brooks, J. L. & Dodson, S. I. (1965). Predation, body size, and composition of plankton. Science, 150, 28-35.  Flittner, G. A. (1964). Morphometry and life history of the emerald shiner, Notropis atherinoides Rafinesque. Doctoral dissertation.University of Michigan, Ann Arbor.Hansen, M. J. (1999). Lake trout in the Great Lakes: basin wide stock collapse and binational restoration. Michigan State University Press. 417-453. Good, S and Cargnelli, L. (2004) "Alternative Strategies for the Management of Non-Indigenous Alewives in Lake St. Catherine, Vermont." Retrieved from _http://www.vtfishandwildlife.com/library/ Reports_and_Documents/Fish_and_Wildlife/Alewife_Final_Report_-_April_2004.pdf_.  Ketola, G. H., Bowser, P.R., Wooster, G.A., Wedge, L.R., & Hurst, S.S. (2000). Effects of thiamine on reproduction of Atlantic salmon and a new hypothesis for their extirpation in Lake Ontario.  Transactions of the American Fisheries Society, 129:607–612. Lake Champlain Alewife Impacts – February 2006 Workshop Summary (3 Speakers)  Harman, W. N. (2006, February). Trophic Changes Following the Introduction of the Alewife in Otsego Lake, NY. Lecture presented at Burlington, VT.   Kraft, C. E. (2006, February). Food Web Effects and Population Dynamics of Alewives, Lecture presented at Burlington, VT. Madenjian, C.P. (2008). Adverses Effects of Alewives on Laurentian Great Lakes Fish Communities. North American Journal of Fisheries Management, 28(1):263-282.  Palkovacs, E.P., and Post, D.M. (2008). Eco-evolutionary interactions between predators and prey: can predator-induced changes to prey communities feed back to shape predtor foraging traits? Evolutionary Ecology Research, 10:699-720.  

Post, D.M., Palkovacs, E.G., Schielke, E.G., & Dodson, S.I. (2008). Intraspecific phenotypic variation in a predator affects zooplankton community structure and cascading trophic interactions. Ecology, 89:2019-2032. Strakosh, T. R., and Krueger, C.C. (2005). Behavior of postemergent lake trout fry in the presence of the alewife, a nonnative predator. Journal of Great Lakes Research, 31:296–305. USGS. (2010). “Non-Indigenous Aquatic Species.” Retrieved from http://nas.er.usgs.gov/queries/ speciesmap.aspx?SpeciesID=490. Vermont Agency of Natural Resources. (2008). "Lake Champlain Sees Its First Alewife Die-Off." Retrieved from _http://www.vermont.gov/portal/government/article.php?news=201_. Wells, L. (1977). Changes in yellow perch (Perca flavescens) populations of Lake Michigan, 1954–75.Journal of the Fisheries Research Board of Canada, 34:1821-1829.