Autonomous vehicle monitoring of movement and habitat use by mobile

nearshore species

Patrick LaneUniversity of Alaska Fairbanks

School of Fisheries and Ocean Sciences

IntroductionGoals

Study Site and Test SpeciesCompleted Work

Habitat SurveysTest Species Abundance Surveys

Preliminary Movement InformationConclusions

Future DirectionsAcknowledgements

Introduction• Sampling the distribution of nearshore, subtidal species can be

difficult.• Movement patterns complicate the study of distribution and have

important ecological and conservation implications.• Mobile organisms: energy transfer, spatial scale, conservation strategy• Value of measuring animal movement

(Pittman and McAlpine 2001, Holsman et al. 2006).

Julie Nielson

NOAA AFSC NOAA AFSC

Introduction• Movement, habitat use and spatial management strategies • Nearshore movement assessment techniques• Nearshore habitat use assessment techniques• Ultrasonic telemetry

NOAA AFSC

VEMCO Inc.

Julie Nielson

Goals1) Design and test an autonomous surface vehicle (ASV) telemetry

monitoring scheme (SCU RSL).

2) Compare movement rates to manual telemetry monitoring.

3) Use side-scan sonar habitat maps and ASV telemetry data to monitor habitat use (NOAA Hydropalooza).

– Compare to diver visual observations of tagged individuals

4) Assess seasonal changes in habitat structure.– Seasonal variability in habitat structure and integrity of one-time remote

mapping

Paul Mahacek SCU RSL

NOAA

Kasitsna Bay• Adjacent to NOAA/UAF Kasitsna Bay Laboratory• Variable habitat structure• Depth less than 40 m• Abundance of test organism: the helmet crab (Telmessus cheiragonus)

Kasitsna

Bay

Kachemak Bay

UAF Kasitsna Bay Laboratory

Kachemak BayHomer

Seldovia

Test Species: Telmessus cheiragonus

• Reaches a size of up to 10 cm carapace length• Intertidal to 110 m but not common below 30 to 40 m• Bristled carapace allows for easy attachment of tags• Found in a variety of habitats ranging from silt to rock seafloor

NOAA/ Jan Haaga

Completed Work• Habitat Availability

– Quantify habitat structure– Assess habitat variability

• Test Species Abundance– Quantify availability– Placement of future collections

• Preliminary Movement Information– Area to monitor vs. area used for tagging

Methods: Habitat Availability• July and August 2008• 12 30 m transects across 4 randomly placed sites 5 , 10 , 15 m • 6 randomly placed 1 x 1 m quadrats

– % cover understory algal canopy – % cover substrate(silt, sand, gravel, cobble, boulder, bedrock, shell debris)

• Rugosity measured at 6 random points

Kasitsna

Bay

UAF Kasitsna Bay Laboratory

Results: Habitat Availability

SiltSan

d

Gravel

Cobble

Boulde

r

Bedroc

k

She

ll

Unders

tory

102

SiltSan

d

Gravel

Cobble

Boulde

r

Bedroc

k

She

ll

Unders

tory

SiltSan

d

Gravel

Cobble

Boulde

r

Bedroc

k

She

ll

Unders

tory

20

40

60

80

100

N = 4N = 4N = 4

15 m 10 m 5 m

Rugosity: 100.7 – 109.0 cm/m

No significant difference based on depth (Tukey’s HSD p > 0.05)

Perc

ent C

over

(Ave

rage

+ 1

SD)

Methods: Test Species Abundance

• July and August 2008• Same sites surveyed as for habitat availability surveys• 12 30 x 4 m (120 m2) transects across 4 sites at 5, 10, 15 m• All test species counted, measured, and sexed• Size threshold: 11 individuals collected, measured, and weighed

Results: Test Species Abundance• Carapace length of 40 mm is the minimum size to tag• Only 4 females in all 12 transects• Abundance for males is shown:

Size (carapace length in mm)

Num

ber o

f Ind

ivid

uals

per

120

m2

(Ave

rage

+ 1

SD)

LS01234567

10

LS01234567

15

LS01234567

5 10 m 15 m5 m

<40 mm >40 mm <40 mm >40 mm <40 mm >40 mm

N = 4N = 4N = 4

Methods: Preliminary Movement Information

• November 2008: 4 male test organisms tagged with VEMCO V9 ultrasonic transmitters using epoxy and fiberglass

• February 2009: Study site monitored using manual telemetry and locations of three tagged individuals recorded using GPS

• Point-to-point minimal movement estimates calculated using UTM coordinates (84-85 days between release and monitoring)

(Taggert et al. 2007)

Results: Movement

100 m

281 m 84 m

31 m

Not Located

Kasitsna Bay

Kachemak Bay

• Minimal movement estimates (84-85 days)

• Future monitoring planned

Conclusions• Habitat Availability:

– Substrate type and algal cover– Variable across site

• Test Species Abundance:– Male individuals will be used for future tagging

• Preliminary Movement Information: – Within study area so far– Range of distances moved

NOAA/ Jan Haaga

John Thedinga

USGS

Future Directions• Habitat mapping (NOAA Hydropalooza).

• Scuba habitat availability surveys (summer, fall, winter, spring)

• Manual tracking, diver observations and autonomous surface vehicle ASV tracking (summer 2009 to summer 2010)

• Comparison of ASV tracking and sonar mapping approach to manual telemetry and scuba habitat observations– Movement rates and habitat use data

Mike Kenner UCSC

Paul Mahacek SCU RSL

AcknowledgementsAdvisory Committee

Brenda Konar, Ginny Eckert, Stephen JewettFunding

-Rasmuson Fisheries Research Center -NOAA West Coast and Polar Regions Undersea Research Center

-Vemco Inc.NOAA/UAF Kasitsna bay Laboratory

Dave Christie, Kris Holderied, Hans PedersonField Volunteers

Melissa Deiman, Terry Efird, Heloise Chenalot, Toben Spurkland, Nathan Stewart, Martin Shuster, Renato Boras