Featured projects (1)

Project
Nutrients and energy are carried by seabirds from sea feeding grounds to breeding areas on land. In islands, marine matter fertilize soil and provide energy for several trophic levels, which may result in dependency between marine and terrestrial trophic webs. Oceanic islands in Brazil, are important breeding grounds for seabirds, but hold invasive exotic vertebrates that prey eggs and chicks of threatened seabirds. The goal of this project is to evaluate pathways of marine nutrient dissipation mediated by seabirds and the effects on terrestrial trophic webs. In addition, we investigate the influence of invasive species on seabirds in oceanic islands.

Featured research (15)

Highly mobile organisms can transport nutrients and energy among distinct ecosystems, such as between oceanic foraging areas and terrestrial breeding sites. Seabirds are great nutrient carriers and potentially play a key role in the maintenance of trophic webs on islands. In this study, we assessed three dimensions of marine nutrient dissipation—horizontal, temporal and vertical—on the tropical Meio Island of Fernando de Nor- onha Archipelago, Brazil. For this, C3 and C4 plants, ants and spiders found in a 100 m long transect between colonies of masked (Sula dactylatra) and red-footed boobies (Sula sula) were sampled during the rainy (the masked booby breeding period) and dry seasons (the red-footed booby breeding period). The marine contribu- tion to the terrestrial trophic web was analysed using Bayesian mixing models from a carbon and nitrogen stable isotope data set. The main findings indicate that marine nutrients in the terrestrial trophic web dissipated hori- zontally as the distance from the colony increased, which was more marked during the rainy season. On the ver- tical axis, the relative contribution of marine nutrients in terrestrial consumers was strongly related to food habits but not necessarily to the trophic level, dissipating rather than increasing, due to variable omnivory and the use of terrestrial food sources. The breeding strategy of the masked booby (i.e. incubating eggs on the ground), in addition to a larger body size and larger colony, could produce a more concentrated pulse of nutri- ents in comparison to seabirds nesting sparsely on trees, contributing more efficiently to the enrichment of mar- ine nutrients on land. The importance of seabirds for the maintenance of interconnected ecosystems has been demonstrated, and the role of marine-derived nutrients in the enrichment of nutrient-poor tropical islands.
Moult is an energetically demanding period, during which flight may be impaired and foraging ranges may become constrained. During the non‐breeding period, Great Ardenna gravis and Sooty A. grisea Shearwaters migrate from South Atlantic breeding colonies to aggregate at North Atlantic feeding grounds. We investigated whether both shearwater species used coastal Newfoundland, Canada, as a moulting area and used stable isotope ratios (δ15N, δ13C) of recently moulted primary feathers (P1, P5, P10) to infer moult location/diet for both species. Moult scores indicated that both species finished their moult (i.e. P6‐10) in coastal Newfoundland, which was further corroborated with similar stable isotope ratios for Great (δ15N = 15.17 ±1.13 ‰; δ13C = ‐18.66 ± 0.54 ‰) and Sooty Shearwaters (15.54 ±0.74 ‰; ‐18.43 ± 0.78 ‰); however, Sooty Shearwater moult was more advanced relative to Great Shearwater. In contrast, isotopic ratios of P1 and P5, which were grown before arriving in coastal Newfoundland, differed between and within species, suggesting divergent locations/diet during early moult. For Great Shearwaters, P1/P5 isotopic ratios were more variable (broader niche breadth) than P10, suggesting that some individuals started moulting in the South Atlantic prior to trans‐equatorial migration, while others start moulting in the North Atlantic Ocean. Sooty Shearwaters had two distinct groupings of either higher or lower δ15N in P1/P5, suggesting that individuals began moulting either on the Newfoundland Shelf or further offshore based on comparisons to reference shearwater feathers grown in known locations. These findings illustrate distinct locations and/or diets at the start of primary feather moult, both within and between species, but diets converged when aggregated together at the end of moult in coastal North America, where growing feathers of both species were sampled. More importantly, we identified an important area for both Sooty and Great Shearwaters to complete their moult in coastal Newfoundland. Protecting this moulting area would minimize disturbance and the impacts of threats (e.g., by‐catch) to both species during this energetically demanding period. The area has been suggested previously to be an important candidate area for protection due to annually persistent prey aggregations that can be spatiotemporally delimited based on specific prey habitat requirements.
Food availability and oceanographic conditions drive the distribution and movement of marine vertebrates. Tracking efforts towards seabirds usually focus on their breeding period, tagging adults in colonies. In this study, we tracked four juvenile and one adult Magellanic penguin (Spheniscus magellanicus) with satellite transmitters. These individuals were caught incidentally in gillnets and were tagged at sea, with the exception of the adult that was rehabilitated and released on the beach. The penguins were tracked in their wintering grounds, where behavior and oceanographic characteristics of the area used were determined. All five birds remained along the coast of southern Brazil and Uruguay in neritic waters up to 10 km offshore and 50 m in depth. The four juveniles used a mean area of 1,426 km 2 , travelling on average at 7.4 km/h. The high turning angles observed and mean sinuosity of 2.46 indicated that the penguins were foraging. The adult penguin covered an area of 1,033 km 2 , at a mean speed of 4.6 km/h, and with low sinuosity (0.43), which is suggestive of either travelling movements or an experienced hunter who needs a few turning angles to forage. The adult travelled 538 km in total, reaching a maximal distance of 465 km. Locations were obtained over a period of 7-10 days, and all five penguins remained in waters of the coastal branch of the Malvinas Current, an area characterized by cold sea surface temperatures (SST, mean = 13.4 • C) and high primary productivity. Salinity values (34.06 PSU) were also typical of the Malvinas Current and were influenced by the La Plata River plume, whose waters are low in salinity and nutrient rich. All five penguins remained near the coast probably because these waters are rich in nutrients, and carry the penguins' main prey, the Argentine anchovy (Engraulis anchoita). Regarding conservation concerns involving these penguins, we highlight the current management of the anchovy fisheries and the development of offshore windfarms that could potentially cause major disturbances to the penguins' foraging habitat. The establishment of the Albardão National Park in the nearshore area used by the penguins is highly desirable for the protection of the species and their feeding resources.
Human-induced rapid environmental changes can disrupt habitat quality in the short term. A decrease in quality of habitats associated with preference for these over other available higher quality is referred as ecological trap. In 2015, the Fundão dam containing iron mining tailings, eastern Brazil, collapsed and released about 50 million cubic meters of metal-rich mud composed by Fe, As, Cd, Hg, Pb in three rivers and the adjacent continental shelf. The area is a foraging site for dozens of seabird and shorebird species. In this study, we used a dataset from before and after Fundão dam collapse containing information on at-sea distribution during foraging activities (biologging), dietary aspects (stable isotopes), and trace elements concentration in feathers and blood from three seabird species known to use the area as foraging site: Phaethon aethereus, Sula leucogaster, and Pterodroma arminjoniana. In general, a substantial change in foraging strategies was not detected, as seabirds remain using areas and food resources similar to those used before the dam collapse. However, concentration of non-essential elements increased (e.g., Cd and As) while essential elements decreased (e.g., Mn and Zn), suggesting that the prey are contaminated by trace elements from tailings. This scenario represents evidence of an ecological trap as seabirds did not change habitat use, even though it had its quality reduced by contamination. The sinking-resuspension dynamics of tailings deposited on the continental shelf can temporally increase seabird exposure to contaminants, which can promote deleterious effects on populations using the region as foraging sites in medium and long terms.
Limited work to date has examined plastic ingestion in highly migratory seabirds like Great Shearwaters ( Ardenna gravis ) across their entire migratory range. We examined 217 Great Shearwaters obtained from 2008–2019 at multiple locations spanning their yearly migration cycle across the Northwest and South Atlantic to assess accumulation of ingested plastic as well as trends over time and between locations. A total of 2328 plastic fragments were documented in the ventriculus portion of the gastrointestinal tract, with an average of 9 plastic fragments per bird. The mass, count, and frequency of plastic occurrence (FO) varied by location, with higher plastic burdens but lower FO in South Atlantic adults and chicks from the breeding colonies. No fragments of the same size or morphology were found in the primary forage fish prey, the Sand Lance ( Ammodytes spp., n = 202) that supports Great Shearwaters in Massachusetts Bay, United States, suggesting the birds directly ingest the bulk of their plastic loads rather than accumulating via trophic transfer. Fourier-transform infrared spectroscopy indicated that low- and high-density polyethylene were the most common polymers ingested, within all years and locations. Individuals from the South Atlantic contained a higher proportion of larger plastic items and fragments compared to analogous life stages in the NW Atlantic, possibly due to increased use of remote, pelagic areas subject to reduced inputs of smaller, more diverse, and potentially less buoyant plastics found adjacent to coastal margins. Different signatures of polymer type, size, and category between similar life stages at different locations suggests rapid turnover of ingested plastics commensurate with migratory stage and location, though more empirical evidence is needed to ground-truth this hypothesis. This work is the first to comprehensively measure the accumulation of ingested plastics by Great Shearwaters over the last decade and across multiple locations spanning their yearly trans-equatorial migration cycle and underscores their utility as sentinels of plastic pollution in Atlantic ecosystems.

Lab head

Leandro Bugoni
Department
  • Institute of Biological Sciences - ICB

Members (14)

Guilherme Tavares Nunes
  • Universidade Federal do Rio Grande do Sul - Campus Litoral Norte
Fernanda Valls
  • Universidade Federal do Rio Grande (FURG)
Fernando Azevedo Faria
  • Universidade Federal do Rio Grande (FURG)
Aline B. Silva
  • Universidade Federal do Rio Grande (FURG)
Gustavo da Rosa Leal
  • Universidade Federal do Rio Grande (FURG)
Paloma Lumi Costa
  • Universidade Federal do Rio Grande (FURG)
Danielle Awabdi
  • Universidade Federal do Rio Grande (FURG)
Maite Arangüena-Proaño
  • Universidade Federal do Rio Grande (FURG)