Reef Fish Management Is Tough: Can Fisheries Acoustics Help?

Reef fish management is tough: Can fisheries acoustics help?

Kevin M. Boswell Marine Ecology & Acoustics Lab Primary Drivers

Understand factors that act to structure ecosystems, primary focus on habitat function and use by nekton - Distributional dynamics - Habitat associations and linkages - Behavior and trophic interactions

Requires continued development of novel approaches - Developing advanced approaches and platforms - Assimilating data at various resolutions and scales Difficulties lie in capacity for ‘observation’

High suspended load Diel variation- Day Diel variation- Day

Night

Pursue avenue other than transmitted light for ‘observing’ objects Active Acoustics • Acoustics are widely accepted tool for quantifying fish abundance and distribution across multiple environmental conditions • Benefits: reduced sampling effort, non-invasive, high resolution spatio- temporal data, reduced gear bias • Challenges: Require independent data to validate backscatter

Barracuda vs. Menhaden Echosounder Imaging Sonar Plankton and 10 m small scatterers Fish

20 m Natural reef Acoustics to inform fishery independent surveys

Aggregation studies: Goliath grouper- East Coast of FL. Permit- FL Keys Nassau grouper- Cayman Islands Pink snapper- Western Australia

West Florida Shelf: J.C. Taylor, NOAA Courtesy of Chris Dowling/Dani Waltrick Artificial vs Natural reefs Natural vs. Artificial Reef Communities West Florida Shelf- Acoustic/Optical Fisheries Independent Survey

Fishery-independent method to examine structure and biomass of reef communities at natural and artificial reef habitats

Approach: Geographic and depth stratified sampling program, across 48 stations per year.

Concurrent application of ROV, fisheries echosounders, and multibeam sonar - Rapid non-invasive/extractive methods - Accommodates study at multiple spatial scales - Quantitative metrics to examine reef-associated fauna West Florida Shelf- Acoustic/Optical Fisheries Independent Survey

Ultimate aim- develop cost effective strategy to efficiently quantify reef fish resources and provide critical fishery independent data to fill data gaps within assessment process West Florida Shelf- Acoustic/Optical Fisheries Independent Survey

Garner et al. 2019; White et al. In review Considerations for improving acoustic-based FI Surveys

Survey Design Ground truthing Acoustic modeling

Parallel 100m

Flower 100m Survey design

Parallel 100m

Flower 100m

Measure of means and variance will depend on: - Underlying structure of habitat - Spatial distribution of organisms - Transect design/patterns and autocorrelation

White et al. In review Stereo Camera ROV Ground truthing BAD!!!!

Acoustic data interpretation aided by validation of species, sizes, and orientation • ROVs/autonomous platforms • Baited/unbaited camera arrays • Stereo video systems J.C. Taylor, NOAA W.F. Patterson, UF • Lowcost options hand lowered through areas of high backscatter BETTER!!! Data needs: • Species ID, fish length estimates • Approximate altitude of fish off seafloor • Understanding effects of the acoustic dead zone Eurofishmagazine.com

Lasers Gastauer et al. 2016

Target Strength Measurements: In situ/Ex situ estimates

Acoustic properties of dominant fishes in GOM are largely unknown

Currently require broad assumptions on taxa and TS-L relationships

Opportunities for developing this baseline!! Considerations for improving FI Surveys

Traditional Sampling points

Benoit-Bird and Lawson 2016 Considerations for improving FI Surveys

Traditional Sampling points Statistical approach to interpreting length and TS distributions

Gastauer et al. 2017

Benoit-Bird and Lawson 2016 Probability Distribution Matching

+ offset = 𝑥𝑥𝑖𝑖−𝑥𝑥 𝜎𝜎𝑥𝑥 𝑥𝑥𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠

( + dist)/2 =

𝑇𝑇𝑆𝑆𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑 𝑆𝑆𝑆𝑆 𝑀𝑀𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑

Estimates of error can be derived around TS-L relationship

Binder et al. In prep. Opportunities to characterize acoustic properties of GOM fish

Imaged 149 individuals Balistidae (26) Haemulidae (78) Labridae (1) Lutjanidae (41) Serranidae (1) Sparidae (2)

Boswell et al. Accepted Opportunities to characterize acoustic properties of GOM fish

Imaged 149 individuals Balistidae (26) Haemulidae (78) Labridae (1) Lutjanidae (41) Serranidae (1) Sparidae (2)

Boswell et al. Accepted Opportunities to characterize acoustic properties of GOM fish

Boswell et al. Accepted Current and future efforts

• Use orientation (angle) as a variable • Extraction of multiple features for classifiers • Examine classification success w.r.t. variation in orientation • Examining alternative analyses • Unsupervised clustering • Neural network classification

Horst and Lane © When properties of dominant organisms are known… it can work.

Kloser et al. 2002 90-170 kHz Broadband acoustics has potential

45-90 kHz to improve taxonomic resolution Broadband 35-45 kHz

120 kHz

70 kHz Narrowband 38 kHz

Boswell et al. In prep Other types of sonars- Multibeam imaging sonar (Kongsberg M3)

Shark depredation study on Permit a) b)

c) d)

e) f)

Depredation mortality associated with catch-and-release angling on offshore Permit (Trachinotus falcatus) spawning aggregations in the Florida Keys, USA. Binder et al. In revision ARIS Imaging Sonar Pelagic interactions

Marlin - Velocity (Δ distance) - Initiation distance - Turning angle/radius - Marlin size

Sardines/Mackerel - Δ School Area - Expansion/Contraction rate Θt1 - Δ velocity New tools for enhanced insights

Bait fish school

Individuals Take home message Use of acoustics offers additional non-invasive data element - Develop long-term, repeatable and non-invasive data series - Complementary to other collection methodologies - Quantify biological patterns across broad (or fine) temporal and spatial scales - Behavior, habitat association, physical/ecological processes - Requires dedicated effort to provide ground truthing datasets - Special care should be taken when developing survey designs Where did all the snapper go?

Part of stock ~limit level (B20)

~50-60% total allowable catch Pink snapper (not a snapper!) Assess acoustic methods -19 1- Target strength Latitude ( Latitude - Ex situ WA - Modelling ° )

2- Biomass surveys -39 http://www.fish.gov.au/report/60-Snapper-2016 Scoulding et al. Acoustic optical survey in July 2020

Closed area

WA Shark Bay

Workshop on the Survey Design and Assessment Considerations for Aggregating Fish Species in Reef Environments

Scoulding et al. Acknowledgements

Collaborators: Sven Gastauer (SIO) Support: Jim Locascio (Mote) Will Patterson (UFL) Geir Pedersen (IMR) Ben Scoulding (CSIRO) Patrick Sullivan (Cornell) Chris Taylor (NCCOS) Graduate Students: Ben Binder Savannah Labua Ivan Rodriguez-Pinto Allison White MISC Passive Acoustics

103 -20

102 -40 J.Modigliani Frequency (Hz) 101 -60 Relative PSD (dB) • Passively listen to environment, 4 efficient method for long-term 10 0 -20 monitoring 103 -40 102 -60 Frequency (Hz) • Characterize dominant sound 101 Relative PSD (dB) sources in ecosystems, examine change over time 0 -20 103 • Presence and behavior of predators -40 102 -60 Frequency (Hz) and prey Relative PSD (dB) 101 Time Habitat Types

MultibeamArtifical Reef- Oriskany Natural Reef- GC003

70kHz 70kHz Probability Distribution Matching

+ offset = 𝑥𝑥𝑖𝑖−𝑥𝑥 𝜎𝜎𝑥𝑥 𝑥𝑥𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠

( + dist)/2 =

𝑇𝑇𝑆𝑆𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑 𝑆𝑆𝑆𝑆 𝑀𝑀𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑 ( + dist)/2 = Matched Pairs 𝑇𝑇𝑆𝑆𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑 𝑆𝑆𝑆𝑆 𝑀𝑀𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑 Target Length Strength

120 -40.1 147 -39.1 162.5 -38.0 174 -37.0 194.3 -36.1

(Gasteur et al., 2017) Working Target Strength – Length Models

TS = 10.00 * Log10(SL) – 50.03 Modal Intervals (Maclennan & Menz, 1996)

TS = 20.00 * Log10(SL) – 72.17

Slope 20 (Simmonds and MacLennan, 2005)

TS = 39.31 * Log10(SL) – 115.2

Least Squares Estimate (Cordue et al., 2001)

TS = 23.90 * Log10(SL) – 90.74

Curve Fitting (Gasteur et al., 2017) Published TS-L relationships Other research pursuits Examining quantitative relationship between passive and active acoustic methodologies Night Study case: Goliath Grouper

Night 100 95 90 85 80

SPL (dB) 75 Day 70 65 60 0 1 2 3 4 5 6 Days

Boswell, Locascio, Binder Boswell, Locascio , Binder Also important tocharacterize ecosystem changes

Before September 12 th

During September 26 th

After November 4 th Low tide

High tide

Boswell et al. 2019 Functional groups respond to water level Prey Predator

Fine-scale asynchrony between predators and prey

Densities are linked to water level Patterns preserved irrespective of TOD Lowest densities associated with slack high-tide

Greatest densities associated with low water levels

BoswellBoswell et et al. al. 2019 2019 E&C D’Elia et al. In review