Year-round passive acoustic data reveal spatio-temporal patterns in marine mammal community composition in the Weddell Sea, Antarctica

Abstract

To date, the majority of studies investigating marine mammal distribution and behavior take a single-species perspective, which is often driven by the logistic difficulties of collecting appropriate data at sea. Passive acoustic monitoring, provided recording tools exhibit sufficient bandwidth, has the potential to provide insights into community structure as devices operate autonomously simultaneously collecting data on baleen, pinniped and toothed whale acoustic presence. Data can provide information on local species diversity, residency times and co-occurrence. Here, we used multi-year passive acoustic data from 6 sites in the Weddell Sea, Southern Ocean, to explore how local marine mammal community compositions develop over time and in relation to sea-ice. Diversity peaked in austral late spring and early summer, shortly before seasonal sea-ice break-up. The effective number of species exhibited little variation over time, reflecting that species remain in Antarctic waters throughout austral winter. Community composition showed almost complete seasonal overturn, indicating that species replace each other throughout the year. For all 6 sites, community dissimilarity increased with increasing temporal distance, reflecting temporal trends in community composition beyond seasonality. Several species exhibited significant positive or negative co-occurrence patterns over time. These seasonal associations were consistent across all 5 oceanic sites, but partly inversed at the Western Antarctic Peninsula recording site. This study shows that the application of biodiversity metrics to passive acoustic monitoring data can foster insights into the timing of behaviors and community composition, which can boost the interpretation of responses in the light of ongoing environmental changes.

Static species distribution models in the marine realm: The case of baleen whales in the Southern Ocean

“…This evident temporal bias towards summer months seems inevitable when using only visual observation data. Passive Acoustic Monitoring (PAM), however, has provided ample evidence for the (near‐) year‐round presence of several species in this area (Filun et al., 2020; Schall et al., 2020; Thomisch et al., 2016; Van Opzeeland & Hillebrand, 2020; Van Opzeeland et al., 2013). Although we attempted to correct for spatial sampling bias using rarefaction, the absence of visual observations from the Weddell Sea has affected model predictability in this area (Figure 1).…”

Hurricane impacts on a coral reef soundscape

“…A recent study on juvenile bull shark ( Carcharchinus leucas ) movements before and after hurricane Irma also described predatory behavioral responses related to shifting prey densities [ 38 ]. Although active acoustic studies provide information on individual animal movements, passive acoustic monitoring provides information on soniferous species assemblages that use sounds to communicate, and thereby can be sampled to reflect potential deviations in behavior in response to disturbances such as hurricanes [ 39 – 41 ].…”

Marine soundscape variation reveals insights into baleen whales and their environment: a case study in central New Zealand

“…Globally, baleen whales are major biophonic contributors to marine soundscapes due to their loud, stereotyped communication calls, which are often emitted repeatedly as song [2][3][4]. The detection of baleen whales in acoustic data can provide insights into their distributions and movements, and locations of critical habitat [5][6][7][8][9][10]. Passive acoustic monitoring (PAM) using moored autonomous instruments is a useful method to study baleen whales, and other vocal species, consistently over time and space in areas that are challenging to access, such as polar regions and open ocean [6,[10][11][12][13]].…”

“…The detection of baleen whales in acoustic data can provide insights into their distributions and movements, and locations of critical habitat [5–10]. Passive acoustic monitoring (PAM) using moored autonomous instruments is a useful method to study baleen whales, and other vocal species, consistently over time and space in areas that are challenging to access, such as polar regions and open ocean [6,10–13]. An acoustic approach can collect multi-species data and rapidly increase understanding of free-ranging vocal species (e.g.…”

“…An acoustic approach can collect multi-species data and rapidly increase understanding of free-ranging vocal species (e.g. [10]).…”