Linking deep-water prey fields with odontocete population structure and behavior
Abstract
Linking deep-water prey fields with odontocete population structure and behavior Beaked whales, specifically Blainville s (Mesoplodon densirostris) and Cuvier s (Ziphius cavirostris), are known to feed in the Tongue of the Ocean (TOTO), Bahamas. These species appear to be particularly sensitive to mid-frequency sonar based on observations and experimental investigation, and a number of mass strandings have occurred coincident with naval exercises. This has spurred considerable, primarily DOD-funded efforts to describe the biology and behavior of these previously intransigent species, with particular effort in TOTO. As a result, we now know that beaked whales use echolocation to forage primarily on squid at depths of 1000 m or more and show consistent habitat preferences. The foraging strategy of beaked whales presents major challenges for describing their ecology and the potential energetic effects of disturbance as 1) the rapid speed and relatively large size of these prey make traditional sampling tools ineffective and 2) beaked whale foraging depths are outside the effective (~600m) range of conventional ship-based acoustic measurements for assessing squid behavior and distribution. We propose to use a new, deep-water, scientific echosounder equipped Autonomous Underwater Vehicle (AUV) funded by DoD to: 1) Measure the distribution, abundance, organization, and size of squid, fish, and other potential deep-water prey in strategically-selected areas of TOTO and nearby areas, an area with rich information on the population biology and behavior, of beaked whales, 2) Synoptically sample the upper (0-600m) and lower (600-1200m) water column to examine the coherence between surface and deep-water prey characteristics, 3) Examine the relationship between historical beaked whale habitat use and current prey characteristics, 4) Apply both bottommounted and mobile passive acoustic systems to examine coherence between beaked whales and prey characteristics at fine spatial scales, 5) Quantify how prey resources may mitigate beaked whale responses to environmental disturbance, and 6) Identify key prey metrics for future analyses and incorporation into PCoD models. Together, we will describe prey fields and link these descriptions with existing odontocete population structure and behavior data in order to provide a critical, mechanistic link for understanding beaked whale ecology. The work we propose will provide a mechanistic link to interpret the passive acoustic, photo identification, genetic, behavioral, and population structure data invested in previously by DoD. Our goal is to provide a comparative framework for placing beaked whales within an ecological context. The work will convert our SERDP project from a demonstration of concept to an operational application, transitioning a variety of technologies invested in by DOD.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Aug 12, 2016
- Source ID
- N000141512204
Entities
People
- Kelly Benoit-Bird
Organizations
- Office of Naval Research
- Oregon State University
- United States Navy