Using an extension approach to address an emerging industry concern: A case study of winter fish losses in Arkansas

Luke A. Roy1, Anita M. Kelly2, Nathan Stone3, Carole R. Engle3, Jeonghwan Park4, Matthew A. Smith5, Herbert E. Quintero2

1School of Fisheries, Aquaculture & Aquatic Sciences, Auburn University2Aquaculture/Fisheries Center, University of Arkansas at Pine Bluff

3Engle-Stone Aquatic$, LLC4Pukyong National University

5College of Food, Agricultural, & Environmental Sciences, The Ohio State University

Introduction• Arkansas is the leading

producer of baitfish (16,000 acres) in the U.S. and a leading producer of sportfish

• Fish farmers in Arkansas reported large losses of fish in the Spring of 2013 when they began to harvest ponds

• The largest losses were observed by farmers raising fathead minnows, golden shiners, and centrarchids

What fish disappeared?

• fathead minnows• redear sunfish• coppernose bluegill• hybrid bluegill• bluegill• shiners• grass carp• hybrid striped bass• goldfish• largemouth bass

Questionnaire

• Farmers requested the help of Cooperative Extension to investigate the issue

• Determine the extent of the 2012/2013 winter fish losses on commercial farms in the state of Arkansas

• Explore different theories regarding winter fish losses

34 different Arkansas farmers were interviewed in June/July of 2013 by UAPB extension personnel

Questionnaire Results

• 79% of farmers interviewed reported unusual winter fish losses

• Losses were catastrophic on some farms (> 50% loss of the entire crop)

• Large numbers of lesser scaup (Aythya affinis) were observed on the farm (100%)

www.allposters.com

Arkansas Winter Fish Losses 2012/2013

*note: Combined losses of fathead minnows and golden shiners accounted for 36% of baitfish production in terms of water acres in AR

Fish Species # Water Acres Fathead minnows 3,242Golden shiners 2,543Bream 1,168Goldfish 135Largemouth bass 66Grass carp 50Hybrid striped bass 20Total 7,224

Potential causes suggested by farmers

• Extreme temperature fluctuations• Reduced winter feeding• Drought conditions in the Fall• Ducks• Chemicals derived from row crop production• Hydrogen sulfide

www.birdingdude.blogspot.com

First month on the job!

“Solve this problem and they will build a statue of you in Lonoke”

Dr. Nathan Stone

Approach

A plan was devised by UAPB extension and research personnel, USDA APHIS Wildlife Services, and USDA SNARC

1. Lesser scaup study2. Winter feeding studies

Arkansas baitfish and sportfish farms are located on the migratory route of many species of ducks which migrate

south in the winter along the Mississippi Flyway!

Ineffective counter measures

- The USFWS was not allowing any ducks on depredation permits- When scaup was requested to be added USFWS denied the

request, claiming that there was no evidence in the scientific literature that scaup ate more than 10% fish in their diet

Fish Eating Birds

• Double-crested cormorant (1lb fish/day)• Great blue heron (0.6 – 0.75 lb fish/day)• Great egret (0.3 lb fish/day)• White pelican (1-3 lbs fish/day)• Lesser scaup (??????)

Bird predation on fish farms

– Objective: Obtain preliminary data to use as evidence to add lesser scaup to depredation permits

– Scaup were examined for the presence of whole fish and the weight of fish consumed was quantified

– The presence of fish parts (bones, otoliths) in the gizzard was assessed

Lesser scaup study

Duck Collections

220 scaup were collected on baitfish (2014) and sportfish (2015) farms in Arkansas

Duck Dissections

As many as 26 bluegill found were in one duck!

Presence of whole fish and fish parts in the gizzards of lesser scaup on baitfish farms (2014)

0

5

10

15

20

25

30

35

40

45

Whole Fish Gizzard (fish parts)

Perc

ent

Pres

ence

(%)

Presence of whole fish and fish parts in the gizzards of lesser scaup on sportfish farms (2015)

404550556065707580859095

100

Whole Fish Gizzard (fish parts)

Perc

ent

Pres

ence

(%)

Duck Study• Lesser scaup are consuming fish on commercial baitfish

and sportfish farms in Arkansas• Fish losses to ducks represent a significant loss of

production and income to baitfish and sportfish farmers• Preliminary data from this study was utilized by USDA

APHIS Wildlife Services to convince the USFWS to add lesser scaup (25/yr) to existing bird depredation permits

• Preliminary data was utilized to secure a USDA SRAC grant ($299,992) to further investigate this issue (2016 – 2018)

Winter Feeding Trials:What does the literature say?

• Survival of young of the year (Age-0) fish over the winter depends on the interactions of:– Fish size– Water temperature– Abundance of food– Winter feeding practices– Predation– Disease/Parasites

• Survival rates of small fish during the winter are generally lower than for larger fish

• Fish that are 1-2 inches in size must feed over the winter in order to survive

• Small unfed fish suffer more during “Warm winters” (water temperatures > 4°C)

• One study has suggested that the temperature window between 4 – 10 °C is the worst for fish as food intake is not enough to cover resting metabolism (Lemons & Crawshaw, 1985, Physiological Zoology 58:175-180)

What does the literature say?

Winter Feeding Trials

2014– Hybrid bluegill (Lepomis macrochirus x

Lepomis cyanellus)– Native bluegill (Lepomis macrochirus),– Hybrid crappie (Pomoxis nigromaculatus x

Pomoxis annularis) – Redear sunfish (Lepomis microlophus)– Fathead minnow (Pimephales promelas)

2015– Coppernose bluegill (Lepomis macrochirus

subspecies)– Golden shiner (Notemigonus crysoleucas)

Methods• Evaluated 3 different feeding

regimes for 13 weeks (1x/week, 2x/week, and 1x/month) at a constant low temperature (7°C) for 7 different species of Arkansas-farm raised fish

• Determined effects on growth, survival, weight gain,fatty acid composition

• Canonical correlation analysis of fatty acid profiles

Fathead Minnows

Fish / Feeding Regime

Initial Weight

(g)

Final Weight

(g)

Survival (%)

WeightGain (%)

Condition Factor

2x/week 0.84 ± 0.02 0.87 ± 0.03 86.7 ± 7.6 2.95 ± 1.39a 0.74 ± 0.01a

1x/week 0.90 ± 0.06 0.88 ± 0.05 88.3 ± 7.6 - 2.30 ± 2.35b 0.70 ± 0.01b

1x/month 0.89 ± 0.05 0.80 ± 0.05 81.7 ± 12.6 -10.08 ± 2.05c 0.66 ± 0.02c

Golden ShinersFish / Feeding Regime

Initial Weight

(g)

Final Weight

(g)

Survival (%)

WeightGain (%)

Condition Factor

2x/week 0.88 ± 0.03 0.82 ± 0.09 88.3 ± 5.8 -6.84 ± 7.32 0.59 ± 0.02a

1x/week 0.87 ± 0.03 0.79 ± 0.01 80.0 ± 0.0 -9.50 ± 2.93 0.55 ± 0.02b

1x/month 0.88 ± 0.01 0.80 ± 0.04 65.0 ± 17.3 -8.27 ± 6.00 0.53 ± 0.01b

Weight loss by species -Centrarchids

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15

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25

30

35

Hybridbluegill

Coppernosebluegill

Nativebluegill

Hybridcrappie

Redearsunfish

Wei

ght L

oss

(%)

Winter Feeding study

• At the temperature examined in this study, all Centrarchids lost a large percentage of their body weight regardless of feeding regime

• Due to the large amount of weight lost by Centrarchids, fish should be fattened in the fall months before the temperature drops

• Winter feeding (1-2 per week depending on temperature) may be beneficial for baitfish

Conclusions• Farmer problems are diverse and often demand a multi-

disciplinary approach to come up with answers• In Extension, we are often forced to work in areas out of

our comfort zone (like working with ducks!) but must adapt to serve our stakeholders

• Money doesn’t grow on trees! – Extension should work closely with researchers to

aggressively pursue extramural funding for pressing stakeholder issues

– It took 3 years and multiple submissions of grants to several agencies before funding was secured

Acknowledgments

• Arkansas Fish Farmers• J.M. Malone, I.F. Anderson, and Treadway Fisheries for providing

fish for the studies• Arkansas Department of Agriculture ($3000)• Remington Arms (donated shotgun shells for the study)• Steve Rawles / Carl Webster (USDA – SNARC)• Alf Haukenes, Rebecca Lochmann• Micheal Kearby/Michael Hoy (USDA Wildlife Services)• Jimmy Avery, USDA Southern Regional Aquaculture Center• Brian Dorr, USDA APHIS Wildlife Research Center • Brian Davis, Mississippi State

Contact Information Luke A. Roy, Ph.D.

Extension Aquaculture SpecialistAuburn University

Alabama Fish Farming Centerroyluke@auburn.edu

http://sfaas.auburn.edu/luke-roy/