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title: "Audubon's Shearwater associates with drifting Sargassum in the Atlantic Ocean"
---

# Audubon's Shearwater associates with drifting Sargassum in the Atlantic Ocean

Mary Moser ([Zoology Department, North Carolina State University](http://harvest.cals.ncsu.edu/biology/), Raleigh, USA) and David Lee, writing this year in the *[Wilson Journal of Ornithology](http://www.bioone.org/loi/wils)*, report on seabirds associating with *Sargassum* in the Western Atlantic, concluding that among procellariiforms, the Audubon's Shearwater*Puffinus lherminieri*specializes on prey associated with drifting reefs of the seaweed.

 The paper's abstract follows:

 "Drifting reefs of *Sargassum* (a brown alga) are used by a variety of pelagic seabirds in the western Atlantic Ocean. We examined gut contents from 964 individuals of 39 seabird species collected 5 to 60 km off the coast of North Carolina for evidence of *Sargassum* use. *Sargassum* pieces or *Sargassum*-associated prey were found in nine of 10 Procellariiformes species and less frequently among Charadriiformes (12 of 25 species). No *Sargassum*-associated prey was found in Pelecaniformes examined, but observational data indicated that Atlantic tropicbirds (*Phaethon lepturus and P. aethereus*) and Masked Boobies (*Sula dactylatra*) commonly foraged over *Sargassum*. Four species were considered *Sargassum* specialists, having frequencies of occurrence >25% and high volumes of *Sargassum*-associated prey: Audubon's Shearwater (*Puffinus lherminieri*), Royal Tern (*Thalasseus maximus*), Bridled Tern (*Onychoprion anaethetus*), and Red-necked Phalarope (*Phalaropus lobatus*). Seven species fed in *Sargassum* to a lesser extent, and nine species had ingested *Sargassum* pieces, but contained no *Sargassum*-associated prey. It is likely that other seabird species forage regularly over *Sargassum*, as our conclusions are based on relatively small sample sizes taken during random sampling in the open ocean. Our conservative analysis and extensive observational data indicate the *Sargassum* community is critical for feeding for some western North Atlantic seabirds. Degradation of *Sargassum* habitats by oil development, harvest, and/or ocean acidification would undoubtedly have negative effects on fitness of these birds."

 **Reference:**

 Mary L. Moser, M.L. &[http://www.bioone.org/doi/abs/10.1676/11-067.1#aff1](http://www.bioone.org/doi/abs/10.1676/11-067.1#aff1) Lee, D.S. 2012.  Foraging over *Sargassum* by Western North Atlantic Seabirds.  [*Wilson Journal of Ornithology* 124: 62-72](http://www.bioone.org/doi/abs/10.1676/11-067.1).

 John Cooper, ACAP Information Officer, 19 April 2012