Seabird Sessions 25 - a pile more guano

grant-humphriesGrant RW Humphries
  • 22 Nov

Hello everyone!

Seabird Sessions 25 will be going ahead this week at 1800 GMT on Wednesday November 25th.
We're talking a pile more cr@p this week with two poop-focused papers that are sure to bring you back to the aromatic wonders of seabird colonies.

De La Peña-Lastra, S., 2020. Seabird droppings: Effects on a global and local level. Science of The Total Environment, p.142148.

Abstract: Seabirds, with approximately 1 billion specimens, are the main exchangers of nutrients between Terrestial and Marine Systems and they have become an emerging interest group because of their effects on the planet's ecosystem. This review paper aims to highlight the impact of seabird droppings at different trophic levels, their occurrence, ecological risks and effects on soil, water, atmosphere and biota at global and local level to try to understand the ecological and climatic changes associated with the activities of these birds. Seabirds they have a very marked influence on the ecosystems where they form their colonies since, in addition to their function as predators, alongside with their depositions, they condition the primary producers and, consequently, the rest of the food chain. Their excrements contain large amounts of N, P and trace elements, most of which are bioavailable. In this study, besides bringing together the different works on nutrients and trace elements in excrements and differentiating some terms referring to these excrements, a brief historical overview of their importance for agriculture is made. In addition, the impacts produced by these birds on the ecosystem are also analysed according to two levels, at a global and local level. At each of these levels, a current state of the effects on the different compartments of the ecosystems is made, from the biota to the soils, the water or the atmosphere. This review supports the idea that more studies are needed both at the atmospheric level and in the terrestrial or marine environment for a better understanding of the changes these birds generate.

Groff, D.V., Hamley, K.M., Lessard, T.J., Greenawalt, K.E., Yasuhara, M., Brickle, P. and Gill, J.L., 2020. Seabird establishment during regional cooling drove a terrestrial ecosystem shift 5000 years ago. Science advances, 6(43), p.eabb2788.

Abstract: The coastal tussac (Poa flabellata) grasslands of the Falkland Islands are a critical seabird breeding habitat but have been drastically reduced by grazing and erosion. Meanwhile, the sensitivity of seabirds and tussac to climate change is unknown because of a lack of long-term records in the South Atlantic. Our 14,000-year multiproxy record reveals an ecosystem state shift following seabird establishment 5000 years ago, as marine-derived nutrients from guano facilitated tussac establishment, peat productivity, and increased fire. Seabird arrival coincided with regional cooling, suggesting that the Falkland Islands are a cold-climate refugium. Conservation efforts focusing on tussac restoration should include this terrestrial-marine linkage, although a warming Southern Ocean calls into question the long-term viability of the Falkland Islands as habitat for low-latitude seabirds.

The ZOOM link will be available online at 1700 GMT on November 25th! Looking forward to seeing you there.

Grant, Marianna and David