ALBERT

Beschreibung: Sei whales (Balaenoptera borealis) is the least known whale species. Information on sei whale´s vocalizations in the south-eastern Pacific Ocean and its regional variability are even more scarce than that from other ocean areas. This research presents the first characterization of sei whale sounds recorded in Chile during austral autumn of 2016 and 2017. A total of 41 calls have been attributed to sei whale’s downsweeps. In 2016, calls ranged from an average maximum frequency of 105.3Hz down to an average minimum 35.6Hz over 1.6s with a peak frequency of 65.4Hz. During 2017, calls ranged from an average maximum frequency of 93.3Hz down to 42.2Hz (over 1.6s) with a peak frequency of 68.3Hz. The absolute minimum frequency recorded was 30Hz and the absolute maximum frequency was 129.4Hz. Calls generally occurred in pairs, but triplets or singles were also registered. These low frequency sounds share characteristics with recordings of sei whales near the Hawaii Islands, but with differences in the maximum frequencies and duration. These calls distinctly differ from sounds previously described for sei whales in the Southern Ocean and are the first documented sei whale calls in the South-eastern Pacific.

Beschreibung: The sei whale (Balaenoptera borealis) is one of the least known whale species. Information on sei whale distributions and its regional variability in the south-eastern Pacific Ocean are even more scarce than that from other areas. Vocalizations of sei whales from this region are not described yet. This research presents the first characterization of sei whale sounds recorded in Chile during the austral autumn of 2016 and 2017. Recordings were done opportunistically. A total of 41 calls were identified to be sei whale downsweeps. In 2016, calls ranged from an average maximum frequency of 105.3 Hz down to an average minimum of 35.6 Hz over 1.6 s with a peak frequency of 65.4 Hz. During 2017, calls ranged from an average maximum frequency of 93.3 down to 42.2 Hz (over 1.6 s) with a peak frequency of 68.3 Hz. The absolute minimum frequency recorded was 30 Hz and the absolute maximum frequency was 129.4 Hz. Calls generally occurred in pairs, but triplets or singles were also registered. These low-frequency sounds share characteristics with recordings of sei whales near the Hawai'ian Islands but with differences in the maximum frequencies and duration. These calls distinctly differ from sounds previously described for sei whales in the Southern Ocean and are the first documented sei whale calls in the south-eastern Pacific.

Beschreibung: Cold-water corals (CWC) can be found throughout a wide range of latitudes (79°N–78°S). Since they lack the photosymbiosis known for most of their tropical counterparts, they may thrive below the euphotic zone. Consequently, their growth predominantly depends on the prevalent environmental conditions, such as general food availability, seawater chemistry, currents, and temperature. Most CWC communities live in regions that will face CaCO3 undersaturation by the end of the century and are thus predicted to be threatened by ocean acidification (OA). This scenario is especially true for species inhabiting the Chilean fjord system, where present-day carbonate water chemistry already reaches values predicted for the end of the century. To understand the effect of the prevailing environmental conditions on the biomineralization of the CWC Tethocyathus endesa, a solitary scleractinian widely distributed in the Chilean Comau Fjord, a 12-month in situ experiment was conducted. The in situ skeletal growth of the test corals was assessed at two sites using the buoyant weight method. Sites were chosen to cover the naturally present carbonate chemistry gradient, with pH levels ranging between 7.90 ± 0.01 (mean ± SD) and 7.70 ± 0.02, and an aragonite saturation (Ωarag) between 1.47 ± 0.03 and 0.98 ± 0.05. The findings of this study provide one of the first in situ growth assessments of a solitary CWC species, with a skeletal mass increase of 46 ± 28 mg per year and individual, at a rate of 0.03 ± 0.02% day. They also indicate that, although the local seawater chemistry can be assumed to be unfavorable for calcification, growth rates of T. endesa are comparable to other cold-water scleractinians in less corrosive waters (e.g., Lophelia pertusa in the Mediterranean Sea).