Guano deposition and nutrient enrichment in the vicinity of planktivorous and piscivorous seabird colonies in Spitsbergen

Abstract

The crucial role of seabirds in the enrichment of nutrient-poor polar terrestrial ecosystem is well-known. However, no studies have examined the potentially different impacts associated with piscivorous and planktivorous bird colonies on the surrounding tundra soils. Therefore, we compared guano deposition and physical and chemical parameters of soil near two large seabird colonies, one of planktivorous little auks (Alle alle) and the other comprising piscivorous Brunnich's guillemots (Uria lomvia) and kittiwakes (Rissa tridactyla). The two colonies generated similar levels of guano deposition, with the intensity of deposition decreasing away from the colony. Guano deposition adjacent to both colonies was considerably higher than that in control areas. The increased guano supply around colonies significantly enhanced soil conductivity, nitrogen (NO 3 -, NH 4 ? ), potassium (K ? ), and phosphate (PO 4 3-) ion concentrations and led to reduced pH values. Guano deposition explained 84 % (piscivorous colony) and 67 % (planktivorous colony) of the total variation in the tested soil parameters. Planktivore and piscivore colonies affected adjacent tundra in different ways. The phosphate content and pH value of soil influenced by piscivores were significantly higher than values measured in planktivore-influenced soil. The gradient of guano deposition and associated ion content in the soil decreased more rapidly with distance from the piscivore colony. Climate-induced changes in populations of planktivorous and piscivorous seabirds are expected in the study region and may therefore have substantial consequential effects on Arctic terrestrial ecosystems.

The influence of a seabird colony on abundance and species composition of water bears (Tardigrada) in Hornsund (Spitsbergen, Arctic)

“…This suggests that additional factors, besides plant communities' alteration, accounted for species composition of the tardigrades around the seabird colony. One of these factors could be soil pH, which was recognised to be lowered near little auk guano (Wait et al 2005;Mulder et al 2011;Zwolicki et al 2013). Dastych (1985Dastych ( , 1988 divided tardigrade species into five categories with respect to their preferences for pH values: eucalciphil, polycalciphil, mesocalciphil, oligocalciphil and acalciphil.…”

“…Such habitats are, for example, formed in the vicinity of seabird colonies. The supply of ornithogenic nutrients around these colonies, originating mainly from guano, significantly enhances soil conductivity, nitrogen, potassium and phosphate ion concentrations and decreases soil pH values, all of which dramatically change the environmental conditions (Mulder et al 2011;Zmudczyńska et al 2012;Zwolicki et al 2013;Klimaszyk et al 2015a, b). In polar regions, such fertilisation results in the development of exceptionally lush, compact and diverse plant and microbiota communities (Eurola and Hakala 1977;Odasz 1994;Ellis 2005;Zmudczyńska et al 2008Zmudczyńska et al , 2009Zmudczyńska-Skarbek et al 2013), which in turn attracts populations of herbivores, predators, scavengers and decomposers (Croll et al 2005;Jakubas et al 2008;Zmudczyńska et al 2012).…”

“…With an estimated number of 37 million breeding pairs, these are the most abundant seabirds in the Atlantic Ocean (including Svalbard), and probably one of the most numerous seabirds in the world (Wojczulanis-Jakubas et al 2011). Little auks are important consumers of sea resources, and due to the deposition of guano, feathers, egg shells and carcasses, while on land they are responsible for significant soil fertilisation, tundra productivity and diversity enhancement around their breeding colonies (Eurola and Hakala 1977;Jakubas et al 2008;Zwolicki et al 2013). This, in turn, is expected to be of an advantage to numerous invertebrates, including tardigrades.…”

Variability of polar scurvygrass Cochlearia groenlandica individual traits along a seabird influenced gradient across Spitsbergen tundra

“…Wainright et al 1998;Wait et al 2005;Zmudczyńska et al 2009;Mulder et al 2011;Smith et al 2011;Zwolicki et al 2013). Nonetheless, current knowledge and understanding of seabird impact on tundra productivity remains incomplete.…”

The Influence of Seabirds on the Concentration of Selected Heavy Metals in Organic Soil on the Bellsund Coast, Western Spitsbergen

“…In polar regions, the amount of nutrients delivered with avian excrement is much higher than from alternate sources and on a local scale it enriches the ecosystem significantly (Bildstein et al, 1992;Bokhorst et al, 2007). Introducing nutrients to the land food chain influences the chemical properties of soil and directly influences the flora in the proximity of avian colonies (Breuning-Madsen et al, 2008;Zwolicki et al, 2013Zwolicki et al, , 2015Ziółek and Melke, 2014).…”