EcoPhysiology of Diving Air-breathing Predators – EcoDAP

EcoPhysiology of Diving Air-breathing Predators – EcoDAP

Research

Why focus on marine top predators?

Our goal at EcoDAP is to conduct multidisciplinary and rigorous research focused on 1) determining patterns of habitat utilisation and at-sea behaviour of marine predators; 2) investigating the trophic behaviour of individuals, populations, and species of marine predators and gaining insights about the status of the trophic webs and ecosystems from marine predators; and 3) understanding the interplay between physiological, behavioural and ecological factors that ultimately determine the resilience (and vulnerability) of marine top predators.

Today, we are witnessing the recovery of some populations of air-breathing marine predators (some of them reaching pre-exploitation levels) whilst others remain at critically low levels or continue to decline. This disparity poses a two-fold challenge to the scientific community. On the one hand, because of their high metabolic demands, biomass, and consumption rates, these species have the potential to control the trophodynamics of entire marine ecosystems and can serve as sentinels of their status. On the other hand, in order for us to implement effective conservation measures to protect these species, we need to understand how they operate at the individual and population levels, and the mechanisms they rely on to cope with fluctuations in their environment.  

Current Projects

This project is a collaboration with the Cornish Seal Sanctuary, in Cornwall. We are currently deploying tags on rehabilitated grey seal pups to track their at-sea movement patterns and diving behaviour during their first foraging trip. The Cornish Seal Sanctuary, located in Gweek, Cornwall, rescues and provides care for stranded, sick, injured or distressed seals found along the South West coast of England. We are partnering with the Sanctuary to instrument grey seal pups that have been nursed back to health and have gained weight to be deemed releasable.

Interested in observing seals in the wild? Make sure you follow the Defra guidelines and recommendations to avoid disturbing animals. You can learn more here.

Want to learn more about how to avoid disturbing seals? Check out this leaflet by the Seal Alliance!


 

LeadĀ PI: Dr. Luis A. Huckstadt

co-PIs:

Dr. Dan Costa – Department of Ecology and Evolutionary Biology, University of California Santa Cruz

Dr. Michael Tift – Department of Biology and Marine Biology, University of North Carolina – Wilmington

Dr. Peter Fretwell – British Antarctic Survey

Dr. Jaume Forcada – British Antarctic Survey

PhD Students: Alyssa Scott and Anna Pearson

Crabeater seals (Lobodon carcinophaga) are considered an excellent sentinel species through which to examine the effects of a changing climate on the extended Antarctic krill-dependent predator community and the structure of the entire ecosystem of the western Antarctic Peninsula. Over the last forty years, there have been significant changes in the temporal and spatial patterns of primary productivity, and shifts in the population dynamics of Antarctic krill, the dominant mid-trophic level species. The impact of such changes on year-round resident species of crabeater seals (the most important predator of Antarctic krill) is more difficult to understand as they are not associated with breeding colonies where their population fluctuations could be more readily observed. The proposed research is conceived under the premise that environmental change has accentuated the differences between the northern and southern western Antarctic Peninsula crabeater seal populations due to differential reductions in sea-ice and its possible effect on prey availability.

To address this question, this research will combine measurements on animal movement, stable isotope analyses, whole-animal physiology, and novel survey technologies (small Unmanned Aircraft Systems, satellite imagery) to build models. The project is a collaboration between an international and interdisciplinary team from the United States and United Kingdom. These studies will be essential to detect past, and project future, changes in the ecology of this species in response to changes in sea ice when comparing present-day measurements with those collected by the British Antarctic Survey in the mid-1900s. We will train at least 2 graduate students and several undergraduates across two US institutions, as well as one UK-based post-doctoral researcher. Students involved with this project will gain invaluable research experience in the lab and will have a unique opportunity to participate in Antarctic fieldwork.

Funding:

Check out the movement of the crabeater seals that we tagged in 2022 and 2023. These two years marked the two lowest Antarctic sea ice extent on record

PI: Luis Huckstadt

PhD Student: Kate Chadwick

Marine top predators have long been proposed to have the potential to serve as ā€˜sentinel speciesā€™ yet most of our efforts to gather ecosystem-level information from marine top predators remain limited to linking variability in individual success and mortality rates to shifts in the ecosystem productivity regime. This is likely due to the limited understanding that we have of the role of marine top predators in marine biogeochemical cycles, transfer of biomass, patterns of biological productivity, and nutrient fluxes.

We will develop an ecological monitoring system of the coastal marine ecosystem in South West England by combining approaches: bottom-up (remote sensing) and top-down (biogeochemical markers in marine top predators). By combining these two perspectives of ecosystem monitoring, we will gain a better understanding of how changes at the base of the ecosystem are dispersed through the trophic web until they reach top predators. We will be able to determine the sources and pathways of carbon that support the populations of pelagic fish and marine predators (trophic fluxes), allowing us to empirically link a particular perturbation in the area with the components of the ecosystem that might be affected (e.g.: the effects of temperature anomalies or Harmful Algal Blooms (HABs) on fish stocks and marine predators).

Because we are aiming at obtaining a better ecological understanding of mid-trophic species by using this combined monitoring approach, this project will have a direct effect on ecosystem and fisheries management, improving our ability to make better decisions about fishing stocks and other human economic activities in the area that depend on the marine ecosystem.

This research project aims to:
1) To develop a complementary ecological monitoring system that incorporates information at the base and top of the trophic web
2) To evaluate the use of top predatorā€™s tissue samples to document variation at the base of the trophic web
3) To contrast and validate the changes detected in marine predators with information on the base of trophic web obtained from remote sensing

This project is led by Dr. Andrea PiƱones of the Universidad Austral de Chile, Centro IDEAL, and COPAS-SurAustral, and funded by the Agencia Nacional de Investigacion y Desarrollo (Chile)

We will deploy instruments on Weddell seals (Leptonychotes weddellii) in the South Shetland Islands, Antarctica, to measure the temperature and salinity of the water column between 2022 and 2025. These measurements will allow the thermohaline properties of the upper water column to be described for fall and winter in regions where is difficult to access with conventional sampling methods. Thus, the hydrographic measurements will allow validation of fall-winter processes of a high-resolution model developed for the northern Antarctic Peninsula. Additionally, the track of seals will allow understanding of the foraging and movement behavior of Weddell seals, also poorly understood in the northern Western Antarctic Peninsula.

 

Funding:

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