Caring about the future

ALBATROZ - Learning from the flight of the albatross: causes and consequences of individual foraging strategies, with links to demography, oceanography and fisheries
Coordinator - Paulo Catry (ISPA Instituto Universitário)
CESAM Responsible researcher - José Pedro Granadeiro
Programme - PTDC/MAR/099366/2008
Execution dates - 2009-11-01 - 2012-10-31 (36 Months)
Funding Entity - FCT
Funding for CESAM - 64770 €
Total Funding - 146340 €
Proponent Institution - ISPA Instituto Universitário
Participating Institutions
Universidade de Lisboa
Museu Nacional de História Natural

Project Description

Seabirds are major marine predators, with an annual food consumption approaching the global catch by all marine fisheries. Seabirds are relatively easy to study and thus they are increasingly being used for environmental monitoring, including the assessment of the effects of climate change. Human fisheries interact with seabirds in important ways, e.g. by providing discards, competing for prey, changing ecosystem structure and causing significant seabird mortality in fishing gear. For these and other reasons, many seabirds are globally threatened, and they are increasingly being taken into account in the ecosystem-based management of fisheries and in the design of marine protected areas.

However, for seabirds to be effectively used in spatially and temporally explicit ocean monitoring and seascape management there is a need for a better understanding of their responses (demographic, ecological, physiological and behavioural) to environmental variation at several relevant scales.

Our objectives are to achieve a very detailed understanding of 1) the factor determining the individual foraging strategies of Blackbrowed albatrosses (BBA) Thalassarche melanophris, 2) the mechanisms through which these factors operate and 3) the implications of individual decisions on fitness and on population demography.
A major capital for this project is a study population of BBA in the Falkland Islands with 6 years of detailed behavioural and
demographic data already collected. We will take advantage of recent developments in tracking technology and of analytical tools to further our knowledge of albatrosses and the Southern Patagonian Shelf.

We will develop new methods to study the interaction of BBA and fisheries at a level of detail never attempted before. We will use accurate GPS and immersion loggers (Mk7, also recording SST) for the fine details of bird movement and activity. We will use the Falklands Fisheries Department VMS (vessel monitoring system) data and electronic logbooks to get similarly detailed information (resolution <10 m, each 10 min) on all fishing activity in Falkland waters. The Falklands provide a particularly suited system to this end, as all fishing vessels are monitored with VMS. Using analytical tools such as first-passage time analysis, we will characterise consistent differences in area restricted search (ARS) patterns of birds associated with fisheries and birds feeding from other sources. If successful, this will allow the study of bird and fisheries interactions even in areas with limited or no VMS data. We will concurrently obtain stable isotope signatures of fishery discard products and of "natural" albatross prey. By using conventional dietary studies, isotope measurements and mixing models, we will develop further tools to measure the degree of interactions of birds and fisheries, both at the population and individual level.

We will then proceed with the study of the causes and consequences of albatross foraging behaviour. We will look at individual
variation caused by sex, age, morphology and individual specialisation. Individual specialisation has seldom been studied in seabirds, and never in relation to the association with fisheries. We will also look at at-sea segregation of individuals from neighbouring nesting colonies with varying overlaps in potential foraging range. Again, this is a little studied topic, but relevant for the understanding of the role of intraspecific competition in the distribution of colonies and individuals. It is also highly relevant to assess how representative are studies based on tracking a limited sample of birds from a number of pre-selected colonies.

GPS and activity recorder data from will be used to create a spatial and temporally explicit understanding of BBA foraging in the Southern Patagonian Shelf, with relevance to seascape management and the creation of marine protected areas. Bird distribution will be modelled using GIS and advanced statistical tools in relation to remotely sensed derived data (SST, wind, chlorophyll-a concentration), bathymetry, fisheries and distance to colony. Finally, we will evaluate the consequences of the foraging choices of albatrosses and their interactions with environmental variability. Questions to be addressed include: a) does foraging specialisation affect fitness correlates (eg. egg size, chick growth and survival, adult body condition)? b) does the degree of foraging specialisation vary in years of contrasting environmental conditions (SST, availability of discards, etc)? c) Which parameters are better correlated with environmental variables and short-term climate fluctuations and, hence, are more likely to convey interesting information for environmental monitoring? Parameters will include demographic (adult survival, breeding success), ecological (diet composition), physiological (egg size, chick growth, adult condition) and behavioural (foraging trip and brood-guard duration) variables.


Project webpage

CESAM members on this project
José Pedro Granadeiro
Team member, CESAM Principal Investigator

CESAM Funding: UIDP/50017/2020 + UIDB/50017/2020 + LA/P/0094/2020