Biology subjects

Zitterbart, D. P.

Publications and source records attributed to Zitterbart, D. P..

3 recordsLinked to original sources

bioRxiv2021

Effectiveness of surface-based North Atlantic right whale detection methods for vessel strike mitigation

Increasing commercial and recreational use of the worlds ocean leads to growing concerns on vessel and marine mammal encounters. For endangered species, like the North Atlantic right whale (NARW), vessel strikes can be responsible for the majority of the recorded deaths. Reducing the number of vessel strikes is key to improve North Atlantic right whale protection and a number of mitigation methods have been proposed and implemented. In this manuscript, we developed an agent-based model to assess the effectiveness of surface-based whale detection methods for vessel strike mitigation. We find that the effectiveness of such systems varies highly depending on the vessels speed and maneuverability. We also find that if vessel-based whale detection systems are used in conjunction with other mitigation measures such as general speed restrictions, they can be very effective and could lead to a significant decrease in vessel strikes when deployed at a large-scale.

scientific communication and education↗

bioRxiv2021

Biologging of emperor penguins - attachment techniques and associated deployment performance

An increasing number of marine animals are equipped with biologgers, to study their physiology, behaviour and ecology, often for conservation purposes. To minimise the impacts of biologgers on the animals welfare, the Refinement principle from the Three Rs framework (Replacement, Reduction, Refinement) urges to continuously test and evaluate new and updated biologging protocols. Here, we propose alternative and promising techniques for emperor penguin (Aptenodytes forsteri) capture and on-site logger deployment that aim to mitigate the potential negative impacts of logger deployment on these birds. We equipped adult emperor penguins for short-term (GPS, Time-Depth Recorder (TDR)) and long-term (i.e. planned for one year) deployments (ARGOS platforms, TDR), as well as juvenile emperor penguins for long-term deployments (ARGOS platforms) in the Weddell Sea area where they had not yet been studied. We describe and qualitatively evaluate our protocols for the attachment of biologgers on-site at the colony, the capture of the animals and the recovery of the devices after deployment. We report unprecedented recaptures of long-term equipped adult emperor penguins (50% of equipped individuals recaptured after 290 days). Our data demonstrate that the traditional technique of long-term attachment by gluing the biologgers directly to the back feathers is detrimental to the birds. It causes excessive feather breakage and the loss of the devices at an early stage. We therefore propose an alternative method of attachment for back-mounted devices. This technique led to successful year-round deployments on 37.5% of the equipped juveniles. Finally, we also disclose the first deployments of leg-bracelet mounted TDRs on emperor penguins. Our findings highlight the importance of monitoring potential impacts of biologger deployments on the animals and the need to remain critical towards established and new protocols.

ecology↗

bioRxiv2021

Juvenile emperor penguin range calls for extended conservation measures in the Southern Ocean

To protect the unique Southern Ocean biodiversity, conservation measures like marine protected areas (MPAs) are implemented based on the known habitat distribution of ecologically important species. However, distribution models focus on adults, neglecting that immatures animals can inhabit vastly different areas. Here, we show that current conservation efforts in the Southern Ocean are insufficient for ensuring the protection of the highly mobile Emperor penguin. We find that juveniles spend [~]90% of their time outside the boundaries of proposed and existing MPAs, and that their distribution extends far beyond (> 1500 km) the species extent of occurrence as defined by the International Union for Conservation of Nature. We argue that strategic conservation plans for Emperor penguin and long-lived ecologically important species must consider the dynamic habitat range of all age classes.

ecology↗