Biotransport of metallic trace elements from marine to terrestrial ecosystems by seabirds

Abstract

Physical systems, such as currents and winds, have traditionally been considered responsible for transporting contaminants. Although evidence is mounting that animals play a role in this process through their movements, we still know little about how such contaminant biotransport occurs and the extent of effects at deposition sites. In the present study, we address this question by studying how rhinoceros auklets (Cerorhinca monocerata), a seabird that occurs in immense colonies (∼300 000 pairs at our study site, Teuri Island), affect contaminant levels at their colony and at nearby sites. More specifically, we hypothesize that contaminants are transported and deposited by seabirds at their colony and that these contaminants are passed on locally to the terrestrial ecosystem. To test this hypothesis, we analyzed the concentration of 9 heavy metal and metalloids, as well as δ13C and δ15N stable isotopes, in bird tissues, plants, and soil, both within and outside of the colony. The results show that rhinoceros auklets transport marine‐derived mercury (Hg), possibly from their wintering location, and deposit Hg via their feces at their breeding site, thereby contaminating plants and soils within the breeding colony. The present study confirms not only that animals can transport contaminants from marine to terrestrial ecosystems, potentially over unexpectedly long distances, but also that bird tissues contribute locally to plant contamination. Environ Toxicol Chem 2019;38:106–114. © 2018 SETAC

The influence of seabirds on their breeding, roosting and nesting grounds: A systematic review and meta‐analysis

“…These metals are often the focus of other environmental pollutant studies as they are well known for their toxicity, ability to bioaccumulate in organisms and their persistence and longevity in the environment (Šerić Jelaska et al, 2014). Many studies demonstrated the impact of pollutant laden guano on recipient environments by measuring metal concentrations in soils, vegetation and invertebrates, with results showing higher contaminant levels in samples from colonies compared to samples from control sites (Headley, 1996; Santamans et al, 2017; Shoji et al, 2019). Furthermore, of the few papers that did explore POP transport by seabirds, the majority of papers established a similar pattern, with higher concentrations of POPs in soils and organisms within colonies in comparison to areas without seabirds (Choy et al, 2010; Evenset et al, 2004; Foster et al, 2011; Roosens et al, 2007).…”

“…This ‘guanotrophication’, or seabird‐induced eutrophication, occurs when the level of nutrients added to a system exceeds what is required (Signa et al, 2015). As apex predators, many seabirds also exhibit high contaminant loads due to biomagnification and bioaccumulation along the marine food chain (Shoji et al, 2019). Chemicals, including persistent organic pollutants (POPs) and trace elements, can pass through individuals via feathers, eggs and guano (Furness & Camphuysen, 1997; Otero et al, 2018).…”

Transport of Cobalt and Silver From the Ocean to a Reef Island by Seabirds in the South China Sea

“…They reported high concentrations of Ag and Co in two ponds that were affected by Arctic terns and common eiders, respectively. A recent study by Shoji et al (2018) documented that Co was enriched in auklet-affected sites as well. All these studies suggest that seabirds could exert impacts on the distribution of Ag and Co within their colonies.…”

“…A number of studies have elucidated that birds could transfer various nutrient and metal elements. For example, a group of metals and metalloids in sediments have been identified as seabird-related elements Shoji et al, 2018;Sun et al, 2000). P in soil or sediments is a marker for seabird influence (Adame et al, 2015;.…”

Geolocator tagging links distributions in the non-breeding season to population genetic structure in a sentinel North Pacific seabird

“…Geolocator tagging revealed that the rhinoceros auklet is very widely distributed throughout the year in continental shelf waters of the temperate North Pacific Ocean. Within this realm, rhinoceros auklets are vulnerable to a wide variety of anthropogenic stressors including oiling at sea [125,126], bycatch in fishing gear [127][128][129], and chemical contamination of food webs [130][131][132][133]. They are also affected by oceanographic change [100,134].…”