San Jose State University From the SelectedWorks of Scott A. Shaffer April 4, 2018 Fisheries exploitation by albatross quantified with lipid analysis Melinda G. Conners, Chicago Zoological Society Chandra Goetsch, University of California, Santa Cruz Suzanne M. Budge, Dalhousie University William A. Walker, NOAA Fisheries, Alaska Fisheries Science Center Yoko Mitani, Hokkaido University, et al. This work is licensed under a Creative Commons CC_BY International License. Available at: https://works.bepress.com/scott_shaffer/75/ ORIGINAL RESEARCH published: 04 April 2018 doi: 10.3389/fmars.2018.00113 Fisheries Exploitation by Albatross Quantified With Lipid Analysis Melinda G. Conners 1,2*, Chandra Goetsch 3, Suzanne M. Budge 4, William A. Walker 5, Yoko Mitani 6, Daniel P. Costa 3 and Scott A. Shaffer 2,7 1 Center for the Science of Animal Care and Welfare, Chicago Zoological Society, Brookfield, IL, United States, 2 Department of Ocean Sciences, University of California, Santa Cruz, Santa Cruz, CA, United States, 3 Department of Ecology & Evolutionary Biology, University of California, Santa Cruz, Santa Cruz, CA, United States, 4 Department of Process Engineering and Applied Science, Dalhousie University, Halifax, NS, Canada, 5 Marine Mammal Laboratory, Alaska Fisheries Science Center, National Marine Fisheries Service, National Oceanic Atmospheric Administration, Seattle, WA, United States, 6 Field Science Center for Northern Biosphere, Hokkaido University, Hakodate, Japan, 7 Department of Biological Sciences, San Jose State University, San Jose, CA, United States Mortality from incidental bycatch in longline fishery operations is a global threat to seabird populations, and especially so for the albatross family (Diomedeidae) in which 15 out of 22 species are threatened with extinction. Despite the risks, fisheries remain attractive to many species of seabird by providing access to high-energy foods in the form of discarded fish and offal, target fish, and baited hooks. Current policy regarding fisheries management is increasingly aimed at discard reform, exemplified Edited by: by a discard ban initiated in the European Union Common Fisheries Policy in 2014. Romuald Lipcius, While there is global agreement on the importance of minimizing the waste inherent in Virginia Institute of Marine Science, United States bycatch and discards, there is also growing concern that there is a need to understand Reviewed by: the extent to which marine animals rely on fisheries-associated resources, especially Andrew M. Fischer, at the colony and individual levels. We used a novel adaptation of quantitative fatty University of Tasmania, Australia acid signature analysis (QFASA) to quantify fisheries-associated prey in the diet of Leslie Cornick, Eastern Washington University, two threatened North Pacific albatross species. Diet was estimated with QFASA using United States multiple lipid classes from stomach oil collected from incubating and chick-brooding *Correspondence: Laysan and black-footed albatrosses across three breeding seasons. Prey-specific error Melinda G. Conners [email protected] was estimated by comparing QFASA estimated diets from known “simulated” diets, which informed the level of precaution appropriate when interpreting model results. Specialty section: Fisheries-associated diet occurred in both albatross species across both the incubation This article was submitted to Marine Conservation and and chick-brood stages; however, neither species relied on fisheries food as the dominant Sustainability, food source (consisting of <10% of the total pooled proportional diet in each species). a section of the journal While total diet proportion was low, the incidence of fisheries-associated resources Frontiers in Marine Science in albatross diets was highest in the 2009–2010 breeding season when there was Received: 16 November 2017 Accepted: 15 March 2018 a strong central Pacific El Niño. Additionally, the diets of a few individuals consisted Published: 04 April 2018 almost entirely of fisheries-associated food, indicating that some birds might specialize Citation: on this foraging tactic. QFASA proved a tractable method for estimating the importance Conners MG, Goetsch C, Budge SM, of fisheries-associated resources in albatross diet, and, as a tool, has the potential to Walker WA, Mitani Y, Costa DP and Shaffer SA (2018) Fisheries enable long-term monitoring of diet and fisheries reliance of breeding colonies in the Exploitation by Albatross Quantified northwestern Hawaiian Islands. With Lipid Analysis. Front. Mar. Sci. 5:113. Keywords: biochemical diet analysis, QFASA, fisheries resource management, Phoebastria, Procelleriformes, doi: 10.3389/fmars.2018.00113 seabird-fishery interaction, seabirds, bycatch Frontiers in Marine Science | www.frontiersin.org 1 April 2018 | Volume 5 | Article 113 Conners et al. QFASA Estimates Fisheries Exploitation INTRODUCTION or how fisheries exploitation of a breeding colony relates to variability in oceanographic conditions. Additional limitations in An ecosystem approach to fisheries (EAF) aims to maintain vessel-based research are necessary to consider: for one, bycaught the health and sustainability of fishery industries and the birds may be a distinct subset of the populations, introducing ecosystems in which they function (Jennings et al., 2014). This a sampling bias, (Edwards et al., 2015). Also, encounters with recently adopted approach prompted the initiation of large- fishing vessels cannot be used as a proxy for direct interactions scale reform to fisheries management and policies, such as the with fisheries (Bodey et al., 2014; Sugishita et al., 2015; Collet proposed discard ban advocated by the European Commission et al., 2017). Therefore, there is a need to quantify seabird-fishery (Borges, 2015). Wide support of such policy reflects the dynamics independent from vessel-collected data. Quantifying scientific consensus that modern industrial fishery practices have the degree to which populations rely on fisheries subsidies substantially diminished biodiversity and ecosystem integrity remains an important, yet, in some cases, intractable problem. on a global scale (Pauly, 2002; Ormerod, 2003; Worm and This is especially true for albatrosses, which rapidly digest prey Myers, 2003; Pauly et al., 2005; Ainley and Blight, 2009). into a homogenous stomach oil (Warham, 1977; Tickell, 2000), When taking an ecosystem approach in fisheries management, thereby reducing, if not sometimes eliminating, the ability to however, it is important to evaluate both positive and negative visually identify fisheries-associated diet in stomach contents. impacts of fishing practices across taxa. While many studies and Biochemical dietary analyses, such as stable isotope, fatty acid, management efforts focus on the negative impacts of fishery and DNA barcoding, can circumvent some of the biases that bycatch, with obvious conservation benefits, it is also important occur in traditional stomach content diet estimations and are to consider potentially adverse impacts on species that have becoming increasingly important when describing the diet of learned to exploit fisheries subsidies. Particularly for species that free-ranging animals that are difficult to observe and/or sample, scavenge bait, catch, or fishery discards, policies that reduce such as albatross (Inger and Bearhop, 2008; McInnes et al., 2016, access to fisheries-associated resources may simultaneously 2017; Cherel et al., 2017). Lipids, and specifically fatty acids, have decrease or eliminate access to what was once a predictable long been used in the characterization of trophic webs both in food source. Thus, when projecting demographic consequences terrestrial and marine ecosystems (Ackman and Eaton, 1966; of fisheries management for scavenging marine consumers, it Connan et al., 2005). They are effective trophic biomarkers due is important to consider fishery resource exploitation as well as to their great diversity of structures and because they are often bycatch mortality rates. only synthesized de novo in certain organisms (Budge et al., Incidental mortality from fisheries bycatch is a principle threat 2006). Quantitative fatty acid signature analysis (QFASA) uses a to seabird biodiversity, particularly for the Procelleriformes robust statistical model to quantify predator diet by identifying (albatrosses and petrels) (Croxall and Gales, 1998; Tuck et al., the combination of prey fatty acid signatures most similar to 2001; Cherel et al., 2017; Pardo et al., 2017). Fifteen out of that of the predator while accounting for predator metabolism. 22 recognized species of albatrosses are currently threatened or QFASA is widely applied in marine trophic web studies, and diets endangered, of which three are critically endangered (IUCN, have been accurately estimated from fatty acids in stomach oil 2017). Population declines of at least 10 albatross species are and adipose and blubber tissue in free-ranging fish (Magnone attributed, at least in part, to adult mortality from fisheries et al., 2015), seabirds (Iverson et al., 2007; Wang et al., 2009), bycatch, and, specifically, to demersal and pelagic longline and marine mammals (Beck et al., 2007; Thiemann et al., 2008; operations (Weimerskirch et al., 1997; Gales and Robertson, Meynier et al., 2010; Bromaghin et al., 2013; Jansen, 2013). 1998; Tuck et al., 2001; Lewison and Crowder, 2003; Véran In this study, we evaluated the effectiveness of QFASA to et al., 2007). Despite the risk of injury or death, fisheries remain better understand fisheries exploitation