title: Interactions of marine mammals and birds with offshore membrane enclosures for growing algae (OMEGA).
abstract: BACKGROUND
  OMEGA is an integrated aquatic system to produce biofuels, treat and recycle wastewater, capture CO2, and expand aquaculture production. This system includes floating photobioreactors (PBRs) that will cover hundreds of hectares in marine bays. To assess the interactions of marine mammals and birds with PBRs, 9 × 1.3 m flat panel and 9.5 × 0.2 m tubular PBRs were deployed in a harbor and monitored day and night from October 10, 2011 to Janurary 22, 2012 using infrared video. To observe interactions with pinnipeds, two trained sea lions (Zalophus californianus) and one trained harbor seal (Phoca vitulina richardii) were observed and directed to interact with PBRs in tanks. To determine the forces required to puncture PBR plastic and the effects of weathering, Instron measurements were made with a sea otter (Enhydra lutris) tooth and bird beaks.
  
  
  RESULTS
  A total of 1,445 interactions of marine mammals and birds with PBRs were observed in the 2,424 hours of video recorded. The 95 marine mammal interactions, 94 by sea otters and one by a sea lion had average durations of three minutes (max 44 min) and represented about 1% of total recording time. The 1,350 bird interactions, primarily coots (Fulica americana) and gulls (Larus occidentalis and L. californicus) had average durations of six minutes (max. 170) and represented 5% of recording time. Interactive behaviors were characterized as passive (feeding, walking, resting, grooming, and social activity) or proactive (biting, pecking, investigating, and unspecified manipulating). Mammal interactions were predominantly proactive, whereas birds were passive. All interactions occurred primarily during the day. Ninety-six percent of otter interactions occurred in winter, whereas 73% of bird interactions in fall, correlating to their abundance in the harbor. Trained pinnipeds followed most commands to bite, drag, and haul-out onto PBRs, made no overt undirected interactions with the PBRs, but showed avoidance behavior to PBR tethers. Instron measurements indicated that sea-otter teeth and gull beaks can penetrate weathered plastic more easily than new plastic.
  
  
  CONCLUSIONS
  Otter and bird interactions with experimental PBRs were benign. Large-scale OMEGA systems are predicted to have both positive and negative environmental consequences.
authors: Moss Landing Marine Laboratories, Moss Landing, CA, USA ; CSS-Dynamac Inc., NASA Ames Research Center, Moffett Field, CA 94035, USA.
authors: Stephanie N
authors: SN
authors: Hughes
authors: University of California Santa Cruz, Santa Cruz, CA, USA.
authors: Sasha
authors: S
authors: Tozzi
authors: University Space Research Association, Moffett Field, CA, USA.
authors: Linden
authors: L
authors: Harris
authors: University Space Research Association, Moffett Field, CA, USA.
authors: Shawn
authors: S
authors: Harmsen
authors: California Department of Fish and Wildlife, Santa Cruz, CA, USA.
authors: Colleen
authors: C
authors: Young
authors: CSS-Dynamac Inc., NASA Ames Research Center, Moffett Field, CA 94035, USA.
authors: Jon
authors: J
authors: Rask
authors: California Department of Fish and Wildlife, Santa Cruz, CA, USA.
authors: Sharon
authors: S
authors: Toy-Choutka
authors: Search for Extraterrestrial Intelligence Institute, Mountain View, CA, USA.
authors: Kit
authors: K
authors: Clark
authors: Moss Landing Marine Laboratories, Moss Landing, CA, USA.
authors: Marilyn
authors: M
authors: Cruickshank
authors: Moss Landing Marine Laboratories, Moss Landing, CA, USA.
authors: Hamilton
authors: H
authors: Fennie
authors: Moss Landing Marine Laboratories, Moss Landing, CA, USA.
authors: Julie
authors: J
authors: Kuo
authors: University of California Santa Cruz, Santa Cruz, CA, USA ; NASA Ames Research Center, Moffett Field, CA, USA.
authors: Jonathan D
authors: JD
authors: Trent
keywords: Biofuels; Birds; Gulls; Marine mammals; Monterey Bay; Photobioreactors; Renewable energy; Sea otter; Wastewater treatment