Impact of the Beaufort lens on the Bowhead whales acoustic communication space and density estimates
Abstract
The long-term scientific goal of this proposal is to provide the basis to calculate the dynamic distribution of marine mammal popula,tion density and to map its spatial heterogeneity by exploiting all available acoustic information, especially the soundscape inform,ation describing the baseline statistics, as well as the variability, of the acoustic environment. The Arctic Ocean has been undergo,ing massive climate warming induced changes over recent decades. The most prominent one is the decrease in sea ice coverage, thickne,ss, and duration. Sea ice-free summers could appear as early as mid-century. In the Canada Basin, the ice-free area has increased by, as much as 70% compared to the climatological mean, making it one of the most impacted regions in the Arctic considering sea ice re,duction and ocean stratification. Aside from reduced sea ice, the Beaufort Duct, a recurring Pacific warm water intrusion first obse,rved in the early 1970s, has increased its geographic spread. Due to the significant impacts of the Beaufort Duct on the acoustic pr,opagation, it has recently received increased attention in the literature. In this proposal we aim to study the impact of the Beaufo,rt lens on Bowhead whale acoustic communication space and subsequently Bowhead whale density estimates. To this end we propose to st,udy if bowhead whales change their source level depending on the prevalent propagation conditions, as well as perform a density esti,mate for the 2016 ? 2017, on data collected during the CANAPE ONR Ocean Acoustics experiment, which is now available for analysis. T,he US Navy utilizes worldwide marine mammal density estimates to model the acoustic effects from naval exercises and training. Impro,vements to current static density estimates are a high priority need, and the proposed work on dynamic marine mammal distribution es,timation paves the way for this ultimate goal. With a growing interest in the arctic, and the fast pace with which the environmental, conditions are changing, understanding the impact on the use of the acoustic space by marine mammals and associated impacts of nava,l exercises due to changed acoustic propagation conditions, we think is a topic that is timely and of high relevance.Approved for pu,blic release
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Oct 06, 2022
- Source ID
- N000142212832
Entities
People
- Daniel Paranhos Zitterbart
Organizations
- Office of Naval Research
- United States Navy
- Woods Hole Oceanographic Institution